diff options
Diffstat (limited to 'third_party/rust/serde/src/de')
| -rw-r--r-- | third_party/rust/serde/src/de/format.rs | 30 | ||||
| -rw-r--r-- | third_party/rust/serde/src/de/ignored_any.rs | 243 | ||||
| -rw-r--r-- | third_party/rust/serde/src/de/impls.rs | 2733 | ||||
| -rw-r--r-- | third_party/rust/serde/src/de/mod.rs | 2299 | ||||
| -rw-r--r-- | third_party/rust/serde/src/de/seed.rs | 19 | ||||
| -rw-r--r-- | third_party/rust/serde/src/de/utf8.rs | 46 | ||||
| -rw-r--r-- | third_party/rust/serde/src/de/value.rs | 1714 |
7 files changed, 7084 insertions, 0 deletions
diff --git a/third_party/rust/serde/src/de/format.rs b/third_party/rust/serde/src/de/format.rs new file mode 100644 index 0000000000..f14580b8d1 --- /dev/null +++ b/third_party/rust/serde/src/de/format.rs @@ -0,0 +1,30 @@ +use lib::fmt::{self, Write}; +use lib::str; + +pub(super) struct Buf<'a> { + bytes: &'a mut [u8], + offset: usize, +} + +impl<'a> Buf<'a> { + pub fn new(bytes: &'a mut [u8]) -> Self { + Buf { bytes, offset: 0 } + } + + pub fn as_str(&self) -> &str { + let slice = &self.bytes[..self.offset]; + unsafe { str::from_utf8_unchecked(slice) } + } +} + +impl<'a> Write for Buf<'a> { + fn write_str(&mut self, s: &str) -> fmt::Result { + if self.offset + s.len() > self.bytes.len() { + Err(fmt::Error) + } else { + self.bytes[self.offset..self.offset + s.len()].copy_from_slice(s.as_bytes()); + self.offset += s.len(); + Ok(()) + } + } +} diff --git a/third_party/rust/serde/src/de/ignored_any.rs b/third_party/rust/serde/src/de/ignored_any.rs new file mode 100644 index 0000000000..9ed438e797 --- /dev/null +++ b/third_party/rust/serde/src/de/ignored_any.rs @@ -0,0 +1,243 @@ +use lib::*; + +use de::{ + Deserialize, Deserializer, EnumAccess, Error, MapAccess, SeqAccess, VariantAccess, Visitor, +}; + +/// An efficient way of discarding data from a deserializer. +/// +/// Think of this like `serde_json::Value` in that it can be deserialized from +/// any type, except that it does not store any information about the data that +/// gets deserialized. +/// +/// ```edition2018 +/// use std::fmt; +/// use std::marker::PhantomData; +/// +/// use serde::de::{ +/// self, Deserialize, DeserializeSeed, Deserializer, IgnoredAny, SeqAccess, Visitor, +/// }; +/// +/// /// A seed that can be used to deserialize only the `n`th element of a sequence +/// /// while efficiently discarding elements of any type before or after index `n`. +/// /// +/// /// For example to deserialize only the element at index 3: +/// /// +/// /// ``` +/// /// NthElement::new(3).deserialize(deserializer) +/// /// ``` +/// pub struct NthElement<T> { +/// n: usize, +/// marker: PhantomData<T>, +/// } +/// +/// impl<T> NthElement<T> { +/// pub fn new(n: usize) -> Self { +/// NthElement { +/// n: n, +/// marker: PhantomData, +/// } +/// } +/// } +/// +/// impl<'de, T> Visitor<'de> for NthElement<T> +/// where +/// T: Deserialize<'de>, +/// { +/// type Value = T; +/// +/// fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { +/// write!( +/// formatter, +/// "a sequence in which we care about element {}", +/// self.n +/// ) +/// } +/// +/// fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> +/// where +/// A: SeqAccess<'de>, +/// { +/// // Skip over the first `n` elements. +/// for i in 0..self.n { +/// // It is an error if the sequence ends before we get to element `n`. +/// if seq.next_element::<IgnoredAny>()?.is_none() { +/// return Err(de::Error::invalid_length(i, &self)); +/// } +/// } +/// +/// // Deserialize the one we care about. +/// let nth = match seq.next_element()? { +/// Some(nth) => nth, +/// None => { +/// return Err(de::Error::invalid_length(self.n, &self)); +/// } +/// }; +/// +/// // Skip over any remaining elements in the sequence after `n`. +/// while let Some(IgnoredAny) = seq.next_element()? { +/// // ignore +/// } +/// +/// Ok(nth) +/// } +/// } +/// +/// impl<'de, T> DeserializeSeed<'de> for NthElement<T> +/// where +/// T: Deserialize<'de>, +/// { +/// type Value = T; +/// +/// fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> +/// where +/// D: Deserializer<'de>, +/// { +/// deserializer.deserialize_seq(self) +/// } +/// } +/// +/// # fn example<'de, D>(deserializer: D) -> Result<(), D::Error> +/// # where +/// # D: Deserializer<'de>, +/// # { +/// // Deserialize only the sequence element at index 3 from this deserializer. +/// // The element at index 3 is required to be a string. Elements before and +/// // after index 3 are allowed to be of any type. +/// let s: String = NthElement::new(3).deserialize(deserializer)?; +/// # Ok(()) +/// # } +/// ``` +#[derive(Copy, Clone, Debug, Default)] +pub struct IgnoredAny; + +impl<'de> Visitor<'de> for IgnoredAny { + type Value = IgnoredAny; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("anything at all") + } + + #[inline] + fn visit_bool<E>(self, x: bool) -> Result<Self::Value, E> { + let _ = x; + Ok(IgnoredAny) + } + + #[inline] + fn visit_i64<E>(self, x: i64) -> Result<Self::Value, E> { + let _ = x; + Ok(IgnoredAny) + } + + serde_if_integer128! { + #[inline] + fn visit_i128<E>(self, x: i128) -> Result<Self::Value, E> { + let _ = x; + Ok(IgnoredAny) + } + } + + #[inline] + fn visit_u64<E>(self, x: u64) -> Result<Self::Value, E> { + let _ = x; + Ok(IgnoredAny) + } + + serde_if_integer128! { + #[inline] + fn visit_u128<E>(self, x: u128) -> Result<Self::Value, E> { + let _ = x; + Ok(IgnoredAny) + } + } + + #[inline] + fn visit_f64<E>(self, x: f64) -> Result<Self::Value, E> { + let _ = x; + Ok(IgnoredAny) + } + + #[inline] + fn visit_str<E>(self, s: &str) -> Result<Self::Value, E> + where + E: Error, + { + let _ = s; + Ok(IgnoredAny) + } + + #[inline] + fn visit_none<E>(self) -> Result<Self::Value, E> { + Ok(IgnoredAny) + } + + #[inline] + fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + IgnoredAny::deserialize(deserializer) + } + + #[inline] + fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + IgnoredAny::deserialize(deserializer) + } + + #[inline] + fn visit_unit<E>(self) -> Result<Self::Value, E> { + Ok(IgnoredAny) + } + + #[inline] + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + while let Some(IgnoredAny) = try!(seq.next_element()) { + // Gobble + } + Ok(IgnoredAny) + } + + #[inline] + fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error> + where + A: MapAccess<'de>, + { + while let Some((IgnoredAny, IgnoredAny)) = try!(map.next_entry()) { + // Gobble + } + Ok(IgnoredAny) + } + + #[inline] + fn visit_bytes<E>(self, bytes: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + let _ = bytes; + Ok(IgnoredAny) + } + + fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> + where + A: EnumAccess<'de>, + { + try!(data.variant::<IgnoredAny>()).1.newtype_variant() + } +} + +impl<'de> Deserialize<'de> for IgnoredAny { + #[inline] + fn deserialize<D>(deserializer: D) -> Result<IgnoredAny, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_ignored_any(IgnoredAny) + } +} diff --git a/third_party/rust/serde/src/de/impls.rs b/third_party/rust/serde/src/de/impls.rs new file mode 100644 index 0000000000..a257d9e2f4 --- /dev/null +++ b/third_party/rust/serde/src/de/impls.rs @@ -0,0 +1,2733 @@ +use lib::*; + +use de::{ + Deserialize, Deserializer, EnumAccess, Error, SeqAccess, Unexpected, VariantAccess, Visitor, +}; + +#[cfg(any(feature = "std", feature = "alloc", not(no_core_duration)))] +use de::MapAccess; + +use seed::InPlaceSeed; + +#[cfg(any(feature = "std", feature = "alloc"))] +use __private::size_hint; + +//////////////////////////////////////////////////////////////////////////////// + +struct UnitVisitor; + +impl<'de> Visitor<'de> for UnitVisitor { + type Value = (); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("unit") + } + + fn visit_unit<E>(self) -> Result<Self::Value, E> + where + E: Error, + { + Ok(()) + } +} + +impl<'de> Deserialize<'de> for () { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_unit(UnitVisitor) + } +} + +#[cfg(feature = "unstable")] +impl<'de> Deserialize<'de> for ! { + fn deserialize<D>(_deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + Err(Error::custom("cannot deserialize `!`")) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +struct BoolVisitor; + +impl<'de> Visitor<'de> for BoolVisitor { + type Value = bool; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a boolean") + } + + fn visit_bool<E>(self, v: bool) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v) + } +} + +impl<'de> Deserialize<'de> for bool { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_bool(BoolVisitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! impl_deserialize_num { + ($primitive:ident, $nonzero:ident $(cfg($($cfg:tt)*))*, $deserialize:ident $($method:ident!($($val:ident : $visit:ident)*);)*) => { + impl_deserialize_num!($primitive, $deserialize $($method!($($val : $visit)*);)*); + + #[cfg(all(not(no_num_nonzero), $($($cfg)*)*))] + impl<'de> Deserialize<'de> for num::$nonzero { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct NonZeroVisitor; + + impl<'de> Visitor<'de> for NonZeroVisitor { + type Value = num::$nonzero; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(concat!("a nonzero ", stringify!($primitive))) + } + + $($($method!(nonzero $primitive $val : $visit);)*)* + } + + deserializer.$deserialize(NonZeroVisitor) + } + } + }; + + ($primitive:ident, $deserialize:ident $($method:ident!($($val:ident : $visit:ident)*);)*) => { + impl<'de> Deserialize<'de> for $primitive { + #[inline] + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct PrimitiveVisitor; + + impl<'de> Visitor<'de> for PrimitiveVisitor { + type Value = $primitive; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(stringify!($primitive)) + } + + $($($method!($val : $visit);)*)* + } + + deserializer.$deserialize(PrimitiveVisitor) + } + } + }; +} + +macro_rules! num_self { + ($ty:ident : $visit:ident) => { + #[inline] + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v) + } + }; + + (nonzero $primitive:ident $ty:ident : $visit:ident) => { + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if let Some(nonzero) = Self::Value::new(v) { + Ok(nonzero) + } else { + Err(Error::invalid_value(Unexpected::Unsigned(0), &self)) + } + } + }; +} + +macro_rules! num_as_self { + ($ty:ident : $visit:ident) => { + #[inline] + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v as Self::Value) + } + }; + + (nonzero $primitive:ident $ty:ident : $visit:ident) => { + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if let Some(nonzero) = Self::Value::new(v as $primitive) { + Ok(nonzero) + } else { + Err(Error::invalid_value(Unexpected::Unsigned(0), &self)) + } + } + }; +} + +macro_rules! int_to_int { + ($ty:ident : $visit:ident) => { + #[inline] + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if Self::Value::min_value() as i64 <= v as i64 + && v as i64 <= Self::Value::max_value() as i64 + { + Ok(v as Self::Value) + } else { + Err(Error::invalid_value(Unexpected::Signed(v as i64), &self)) + } + } + }; + + (nonzero $primitive:ident $ty:ident : $visit:ident) => { + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if $primitive::min_value() as i64 <= v as i64 + && v as i64 <= $primitive::max_value() as i64 + { + if let Some(nonzero) = Self::Value::new(v as $primitive) { + return Ok(nonzero); + } + } + Err(Error::invalid_value(Unexpected::Signed(v as i64), &self)) + } + }; +} + +macro_rules! int_to_uint { + ($ty:ident : $visit:ident) => { + #[inline] + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if 0 <= v && v as u64 <= Self::Value::max_value() as u64 { + Ok(v as Self::Value) + } else { + Err(Error::invalid_value(Unexpected::Signed(v as i64), &self)) + } + } + }; + + (nonzero $primitive:ident $ty:ident : $visit:ident) => { + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if 0 < v && v as u64 <= $primitive::max_value() as u64 { + if let Some(nonzero) = Self::Value::new(v as $primitive) { + return Ok(nonzero); + } + } + Err(Error::invalid_value(Unexpected::Signed(v as i64), &self)) + } + }; +} + +macro_rules! uint_to_self { + ($ty:ident : $visit:ident) => { + #[inline] + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if v as u64 <= Self::Value::max_value() as u64 { + Ok(v as Self::Value) + } else { + Err(Error::invalid_value(Unexpected::Unsigned(v as u64), &self)) + } + } + }; + + (nonzero $primitive:ident $ty:ident : $visit:ident) => { + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if v as u64 <= $primitive::max_value() as u64 { + if let Some(nonzero) = Self::Value::new(v as $primitive) { + return Ok(nonzero); + } + } + Err(Error::invalid_value(Unexpected::Unsigned(v as u64), &self)) + } + }; +} + +impl_deserialize_num! { + i8, NonZeroI8 cfg(not(no_num_nonzero_signed)), deserialize_i8 + num_self!(i8:visit_i8); + int_to_int!(i16:visit_i16 i32:visit_i32 i64:visit_i64); + uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + i16, NonZeroI16 cfg(not(no_num_nonzero_signed)), deserialize_i16 + num_self!(i16:visit_i16); + num_as_self!(i8:visit_i8); + int_to_int!(i32:visit_i32 i64:visit_i64); + uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + i32, NonZeroI32 cfg(not(no_num_nonzero_signed)), deserialize_i32 + num_self!(i32:visit_i32); + num_as_self!(i8:visit_i8 i16:visit_i16); + int_to_int!(i64:visit_i64); + uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + i64, NonZeroI64 cfg(not(no_num_nonzero_signed)), deserialize_i64 + num_self!(i64:visit_i64); + num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32); + uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + isize, NonZeroIsize cfg(not(no_num_nonzero_signed)), deserialize_i64 + num_as_self!(i8:visit_i8 i16:visit_i16); + int_to_int!(i32:visit_i32 i64:visit_i64); + uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + u8, NonZeroU8, deserialize_u8 + num_self!(u8:visit_u8); + int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + uint_to_self!(u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + u16, NonZeroU16, deserialize_u16 + num_self!(u16:visit_u16); + num_as_self!(u8:visit_u8); + int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + uint_to_self!(u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + u32, NonZeroU32, deserialize_u32 + num_self!(u32:visit_u32); + num_as_self!(u8:visit_u8 u16:visit_u16); + int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + uint_to_self!(u64:visit_u64); +} + +impl_deserialize_num! { + u64, NonZeroU64, deserialize_u64 + num_self!(u64:visit_u64); + num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32); + int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); +} + +impl_deserialize_num! { + usize, NonZeroUsize, deserialize_u64 + num_as_self!(u8:visit_u8 u16:visit_u16); + int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + uint_to_self!(u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + f32, deserialize_f32 + num_self!(f32:visit_f32); + num_as_self!(f64:visit_f64); + num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +impl_deserialize_num! { + f64, deserialize_f64 + num_self!(f64:visit_f64); + num_as_self!(f32:visit_f32); + num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); +} + +serde_if_integer128! { + macro_rules! num_128 { + ($ty:ident : $visit:ident) => { + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if v as i128 >= Self::Value::min_value() as i128 + && v as u128 <= Self::Value::max_value() as u128 + { + Ok(v as Self::Value) + } else { + Err(Error::invalid_value( + Unexpected::Other(stringify!($ty)), + &self, + )) + } + } + }; + + (nonzero $primitive:ident $ty:ident : $visit:ident) => { + fn $visit<E>(self, v: $ty) -> Result<Self::Value, E> + where + E: Error, + { + if v as i128 >= $primitive::min_value() as i128 + && v as u128 <= $primitive::max_value() as u128 + { + if let Some(nonzero) = Self::Value::new(v as $primitive) { + Ok(nonzero) + } else { + Err(Error::invalid_value(Unexpected::Unsigned(0), &self)) + } + } else { + Err(Error::invalid_value( + Unexpected::Other(stringify!($ty)), + &self, + )) + } + } + }; + } + + impl_deserialize_num! { + i128, NonZeroI128 cfg(not(no_num_nonzero_signed)), deserialize_i128 + num_self!(i128:visit_i128); + num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); + num_128!(u128:visit_u128); + } + + impl_deserialize_num! { + u128, NonZeroU128, deserialize_u128 + num_self!(u128:visit_u128); + num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64); + int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64); + num_128!(i128:visit_i128); + } +} + +//////////////////////////////////////////////////////////////////////////////// + +struct CharVisitor; + +impl<'de> Visitor<'de> for CharVisitor { + type Value = char; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a character") + } + + #[inline] + fn visit_char<E>(self, v: char) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v) + } + + #[inline] + fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> + where + E: Error, + { + let mut iter = v.chars(); + match (iter.next(), iter.next()) { + (Some(c), None) => Ok(c), + _ => Err(Error::invalid_value(Unexpected::Str(v), &self)), + } + } +} + +impl<'de> Deserialize<'de> for char { + #[inline] + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_char(CharVisitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +struct StringVisitor; +#[cfg(any(feature = "std", feature = "alloc"))] +struct StringInPlaceVisitor<'a>(&'a mut String); + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de> Visitor<'de> for StringVisitor { + type Value = String; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a string") + } + + fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v.to_owned()) + } + + fn visit_string<E>(self, v: String) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v) + } + + fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match str::from_utf8(v) { + Ok(s) => Ok(s.to_owned()), + Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)), + } + } + + fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E> + where + E: Error, + { + match String::from_utf8(v) { + Ok(s) => Ok(s), + Err(e) => Err(Error::invalid_value( + Unexpected::Bytes(&e.into_bytes()), + &self, + )), + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'a, 'de> Visitor<'de> for StringInPlaceVisitor<'a> { + type Value = (); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a string") + } + + fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> + where + E: Error, + { + self.0.clear(); + self.0.push_str(v); + Ok(()) + } + + fn visit_string<E>(self, v: String) -> Result<Self::Value, E> + where + E: Error, + { + *self.0 = v; + Ok(()) + } + + fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match str::from_utf8(v) { + Ok(s) => { + self.0.clear(); + self.0.push_str(s); + Ok(()) + } + Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)), + } + } + + fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E> + where + E: Error, + { + match String::from_utf8(v) { + Ok(s) => { + *self.0 = s; + Ok(()) + } + Err(e) => Err(Error::invalid_value( + Unexpected::Bytes(&e.into_bytes()), + &self, + )), + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de> Deserialize<'de> for String { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_string(StringVisitor) + } + + fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_string(StringInPlaceVisitor(place)) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +struct StrVisitor; + +impl<'a> Visitor<'a> for StrVisitor { + type Value = &'a str; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a borrowed string") + } + + fn visit_borrowed_str<E>(self, v: &'a str) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v) // so easy + } + + fn visit_borrowed_bytes<E>(self, v: &'a [u8]) -> Result<Self::Value, E> + where + E: Error, + { + str::from_utf8(v).map_err(|_| Error::invalid_value(Unexpected::Bytes(v), &self)) + } +} + +impl<'de: 'a, 'a> Deserialize<'de> for &'a str { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_str(StrVisitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +struct BytesVisitor; + +impl<'a> Visitor<'a> for BytesVisitor { + type Value = &'a [u8]; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a borrowed byte array") + } + + fn visit_borrowed_bytes<E>(self, v: &'a [u8]) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v) + } + + fn visit_borrowed_str<E>(self, v: &'a str) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v.as_bytes()) + } +} + +impl<'de: 'a, 'a> Deserialize<'de> for &'a [u8] { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_bytes(BytesVisitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(feature = "std")] +struct CStringVisitor; + +#[cfg(feature = "std")] +impl<'de> Visitor<'de> for CStringVisitor { + type Value = CString; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("byte array") + } + + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let len = size_hint::cautious(seq.size_hint()); + let mut values = Vec::with_capacity(len); + + while let Some(value) = try!(seq.next_element()) { + values.push(value); + } + + CString::new(values).map_err(Error::custom) + } + + fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + CString::new(v).map_err(Error::custom) + } + + fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E> + where + E: Error, + { + CString::new(v).map_err(Error::custom) + } + + fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> + where + E: Error, + { + CString::new(v).map_err(Error::custom) + } + + fn visit_string<E>(self, v: String) -> Result<Self::Value, E> + where + E: Error, + { + CString::new(v).map_err(Error::custom) + } +} + +#[cfg(feature = "std")] +impl<'de> Deserialize<'de> for CString { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_byte_buf(CStringVisitor) + } +} + +macro_rules! forwarded_impl { + ( + $(#[doc = $doc:tt])* + ($($id:ident),*), $ty:ty, $func:expr + ) => { + $(#[doc = $doc])* + impl<'de $(, $id : Deserialize<'de>,)*> Deserialize<'de> for $ty { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + Deserialize::deserialize(deserializer).map($func) + } + } + } +} + +#[cfg(all(feature = "std", not(no_de_boxed_c_str)))] +forwarded_impl!((), Box<CStr>, CString::into_boxed_c_str); + +#[cfg(not(no_core_reverse))] +forwarded_impl!((T), Reverse<T>, Reverse); + +//////////////////////////////////////////////////////////////////////////////// + +struct OptionVisitor<T> { + marker: PhantomData<T>, +} + +impl<'de, T> Visitor<'de> for OptionVisitor<T> +where + T: Deserialize<'de>, +{ + type Value = Option<T>; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("option") + } + + #[inline] + fn visit_unit<E>(self) -> Result<Self::Value, E> + where + E: Error, + { + Ok(None) + } + + #[inline] + fn visit_none<E>(self) -> Result<Self::Value, E> + where + E: Error, + { + Ok(None) + } + + #[inline] + fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + T::deserialize(deserializer).map(Some) + } + + fn __private_visit_untagged_option<D>(self, deserializer: D) -> Result<Self::Value, ()> + where + D: Deserializer<'de>, + { + Ok(T::deserialize(deserializer).ok()) + } +} + +impl<'de, T> Deserialize<'de> for Option<T> +where + T: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_option(OptionVisitor { + marker: PhantomData, + }) + } + + // The Some variant's repr is opaque, so we can't play cute tricks with its + // tag to have deserialize_in_place build the content in place unconditionally. + // + // FIXME: investigate whether branching on the old value being Some to + // deserialize_in_place the value is profitable (probably data-dependent?) +} + +//////////////////////////////////////////////////////////////////////////////// + +struct PhantomDataVisitor<T: ?Sized> { + marker: PhantomData<T>, +} + +impl<'de, T: ?Sized> Visitor<'de> for PhantomDataVisitor<T> { + type Value = PhantomData<T>; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("unit") + } + + #[inline] + fn visit_unit<E>(self) -> Result<Self::Value, E> + where + E: Error, + { + Ok(PhantomData) + } +} + +impl<'de, T: ?Sized> Deserialize<'de> for PhantomData<T> { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + let visitor = PhantomDataVisitor { + marker: PhantomData, + }; + deserializer.deserialize_unit_struct("PhantomData", visitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +macro_rules! seq_impl { + ( + $ty:ident <T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound1:ident $(+ $bound2:ident)*)*>, + $access:ident, + $clear:expr, + $with_capacity:expr, + $reserve:expr, + $insert:expr + ) => { + impl<'de, T $(, $typaram)*> Deserialize<'de> for $ty<T $(, $typaram)*> + where + T: Deserialize<'de> $(+ $tbound1 $(+ $tbound2)*)*, + $($typaram: $bound1 $(+ $bound2)*,)* + { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct SeqVisitor<T $(, $typaram)*> { + marker: PhantomData<$ty<T $(, $typaram)*>>, + } + + impl<'de, T $(, $typaram)*> Visitor<'de> for SeqVisitor<T $(, $typaram)*> + where + T: Deserialize<'de> $(+ $tbound1 $(+ $tbound2)*)*, + $($typaram: $bound1 $(+ $bound2)*,)* + { + type Value = $ty<T $(, $typaram)*>; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a sequence") + } + + #[inline] + fn visit_seq<A>(self, mut $access: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let mut values = $with_capacity; + + while let Some(value) = try!($access.next_element()) { + $insert(&mut values, value); + } + + Ok(values) + } + } + + let visitor = SeqVisitor { marker: PhantomData }; + deserializer.deserialize_seq(visitor) + } + + fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error> + where + D: Deserializer<'de>, + { + struct SeqInPlaceVisitor<'a, T: 'a $(, $typaram: 'a)*>(&'a mut $ty<T $(, $typaram)*>); + + impl<'a, 'de, T $(, $typaram)*> Visitor<'de> for SeqInPlaceVisitor<'a, T $(, $typaram)*> + where + T: Deserialize<'de> $(+ $tbound1 $(+ $tbound2)*)*, + $($typaram: $bound1 $(+ $bound2)*,)* + { + type Value = (); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a sequence") + } + + #[inline] + fn visit_seq<A>(mut self, mut $access: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + $clear(&mut self.0); + $reserve(&mut self.0, size_hint::cautious($access.size_hint())); + + // FIXME: try to overwrite old values here? (Vec, VecDeque, LinkedList) + while let Some(value) = try!($access.next_element()) { + $insert(&mut self.0, value); + } + + Ok(()) + } + } + + deserializer.deserialize_seq(SeqInPlaceVisitor(place)) + } + } + } +} + +// Dummy impl of reserve +#[cfg(any(feature = "std", feature = "alloc"))] +fn nop_reserve<T>(_seq: T, _n: usize) {} + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!( + BinaryHeap<T: Ord>, + seq, + BinaryHeap::clear, + BinaryHeap::with_capacity(size_hint::cautious(seq.size_hint())), + BinaryHeap::reserve, + BinaryHeap::push +); + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!( + BTreeSet<T: Eq + Ord>, + seq, + BTreeSet::clear, + BTreeSet::new(), + nop_reserve, + BTreeSet::insert +); + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!( + LinkedList<T>, + seq, + LinkedList::clear, + LinkedList::new(), + nop_reserve, + LinkedList::push_back +); + +#[cfg(feature = "std")] +seq_impl!( + HashSet<T: Eq + Hash, S: BuildHasher + Default>, + seq, + HashSet::clear, + HashSet::with_capacity_and_hasher(size_hint::cautious(seq.size_hint()), S::default()), + HashSet::reserve, + HashSet::insert); + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!( + VecDeque<T>, + seq, + VecDeque::clear, + VecDeque::with_capacity(size_hint::cautious(seq.size_hint())), + VecDeque::reserve, + VecDeque::push_back +); + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, T> Deserialize<'de> for Vec<T> +where + T: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct VecVisitor<T> { + marker: PhantomData<T>, + } + + impl<'de, T> Visitor<'de> for VecVisitor<T> + where + T: Deserialize<'de>, + { + type Value = Vec<T>; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a sequence") + } + + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let mut values = Vec::with_capacity(size_hint::cautious(seq.size_hint())); + + while let Some(value) = try!(seq.next_element()) { + values.push(value); + } + + Ok(values) + } + } + + let visitor = VecVisitor { + marker: PhantomData, + }; + deserializer.deserialize_seq(visitor) + } + + fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error> + where + D: Deserializer<'de>, + { + struct VecInPlaceVisitor<'a, T: 'a>(&'a mut Vec<T>); + + impl<'a, 'de, T> Visitor<'de> for VecInPlaceVisitor<'a, T> + where + T: Deserialize<'de>, + { + type Value = (); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a sequence") + } + + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let hint = size_hint::cautious(seq.size_hint()); + if let Some(additional) = hint.checked_sub(self.0.len()) { + self.0.reserve(additional); + } + + for i in 0..self.0.len() { + let next = { + let next_place = InPlaceSeed(&mut self.0[i]); + try!(seq.next_element_seed(next_place)) + }; + if next.is_none() { + self.0.truncate(i); + return Ok(()); + } + } + + while let Some(value) = try!(seq.next_element()) { + self.0.push(value); + } + + Ok(()) + } + } + + deserializer.deserialize_seq(VecInPlaceVisitor(place)) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +struct ArrayVisitor<A> { + marker: PhantomData<A>, +} +struct ArrayInPlaceVisitor<'a, A: 'a>(&'a mut A); + +impl<A> ArrayVisitor<A> { + fn new() -> Self { + ArrayVisitor { + marker: PhantomData, + } + } +} + +impl<'de, T> Visitor<'de> for ArrayVisitor<[T; 0]> { + type Value = [T; 0]; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("an empty array") + } + + #[inline] + fn visit_seq<A>(self, _: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + Ok([]) + } +} + +// Does not require T: Deserialize<'de>. +impl<'de, T> Deserialize<'de> for [T; 0] { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_tuple(0, ArrayVisitor::<[T; 0]>::new()) + } +} + +macro_rules! array_impls { + ($($len:expr => ($($n:tt)+))+) => { + $( + impl<'de, T> Visitor<'de> for ArrayVisitor<[T; $len]> + where + T: Deserialize<'de>, + { + type Value = [T; $len]; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(concat!("an array of length ", $len)) + } + + #[inline] + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + Ok([$( + match try!(seq.next_element()) { + Some(val) => val, + None => return Err(Error::invalid_length($n, &self)), + } + ),+]) + } + } + + impl<'a, 'de, T> Visitor<'de> for ArrayInPlaceVisitor<'a, [T; $len]> + where + T: Deserialize<'de>, + { + type Value = (); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(concat!("an array of length ", $len)) + } + + #[inline] + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let mut fail_idx = None; + for (idx, dest) in self.0[..].iter_mut().enumerate() { + if try!(seq.next_element_seed(InPlaceSeed(dest))).is_none() { + fail_idx = Some(idx); + break; + } + } + if let Some(idx) = fail_idx { + return Err(Error::invalid_length(idx, &self)); + } + Ok(()) + } + } + + impl<'de, T> Deserialize<'de> for [T; $len] + where + T: Deserialize<'de>, + { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_tuple($len, ArrayVisitor::<[T; $len]>::new()) + } + + fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_tuple($len, ArrayInPlaceVisitor(place)) + } + } + )+ + } +} + +array_impls! { + 1 => (0) + 2 => (0 1) + 3 => (0 1 2) + 4 => (0 1 2 3) + 5 => (0 1 2 3 4) + 6 => (0 1 2 3 4 5) + 7 => (0 1 2 3 4 5 6) + 8 => (0 1 2 3 4 5 6 7) + 9 => (0 1 2 3 4 5 6 7 8) + 10 => (0 1 2 3 4 5 6 7 8 9) + 11 => (0 1 2 3 4 5 6 7 8 9 10) + 12 => (0 1 2 3 4 5 6 7 8 9 10 11) + 13 => (0 1 2 3 4 5 6 7 8 9 10 11 12) + 14 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13) + 15 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14) + 16 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15) + 17 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16) + 18 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17) + 19 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18) + 20 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19) + 21 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20) + 22 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21) + 23 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22) + 24 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23) + 25 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24) + 26 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25) + 27 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26) + 28 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27) + 29 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28) + 30 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29) + 31 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30) + 32 => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31) +} + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! tuple_impls { + ($($len:tt => ($($n:tt $name:ident)+))+) => { + $( + impl<'de, $($name: Deserialize<'de>),+> Deserialize<'de> for ($($name,)+) { + #[inline] + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct TupleVisitor<$($name,)+> { + marker: PhantomData<($($name,)+)>, + } + + impl<'de, $($name: Deserialize<'de>),+> Visitor<'de> for TupleVisitor<$($name,)+> { + type Value = ($($name,)+); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(concat!("a tuple of size ", $len)) + } + + #[inline] + #[allow(non_snake_case)] + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + $( + let $name = match try!(seq.next_element()) { + Some(value) => value, + None => return Err(Error::invalid_length($n, &self)), + }; + )+ + + Ok(($($name,)+)) + } + } + + deserializer.deserialize_tuple($len, TupleVisitor { marker: PhantomData }) + } + + #[inline] + fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error> + where + D: Deserializer<'de>, + { + struct TupleInPlaceVisitor<'a, $($name: 'a,)+>(&'a mut ($($name,)+)); + + impl<'a, 'de, $($name: Deserialize<'de>),+> Visitor<'de> for TupleInPlaceVisitor<'a, $($name,)+> { + type Value = (); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(concat!("a tuple of size ", $len)) + } + + #[inline] + #[allow(non_snake_case)] + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + $( + if try!(seq.next_element_seed(InPlaceSeed(&mut (self.0).$n))).is_none() { + return Err(Error::invalid_length($n, &self)); + } + )+ + + Ok(()) + } + } + + deserializer.deserialize_tuple($len, TupleInPlaceVisitor(place)) + } + } + )+ + } +} + +tuple_impls! { + 1 => (0 T0) + 2 => (0 T0 1 T1) + 3 => (0 T0 1 T1 2 T2) + 4 => (0 T0 1 T1 2 T2 3 T3) + 5 => (0 T0 1 T1 2 T2 3 T3 4 T4) + 6 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5) + 7 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6) + 8 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7) + 9 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8) + 10 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9) + 11 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10) + 12 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11) + 13 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12) + 14 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13) + 15 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14) + 16 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14 15 T15) +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +macro_rules! map_impl { + ( + $ty:ident <K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound1:ident $(+ $bound2:ident)*)*>, + $access:ident, + $with_capacity:expr + ) => { + impl<'de, K, V $(, $typaram)*> Deserialize<'de> for $ty<K, V $(, $typaram)*> + where + K: Deserialize<'de> $(+ $kbound1 $(+ $kbound2)*)*, + V: Deserialize<'de>, + $($typaram: $bound1 $(+ $bound2)*),* + { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct MapVisitor<K, V $(, $typaram)*> { + marker: PhantomData<$ty<K, V $(, $typaram)*>>, + } + + impl<'de, K, V $(, $typaram)*> Visitor<'de> for MapVisitor<K, V $(, $typaram)*> + where + K: Deserialize<'de> $(+ $kbound1 $(+ $kbound2)*)*, + V: Deserialize<'de>, + $($typaram: $bound1 $(+ $bound2)*),* + { + type Value = $ty<K, V $(, $typaram)*>; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a map") + } + + #[inline] + fn visit_map<A>(self, mut $access: A) -> Result<Self::Value, A::Error> + where + A: MapAccess<'de>, + { + let mut values = $with_capacity; + + while let Some((key, value)) = try!($access.next_entry()) { + values.insert(key, value); + } + + Ok(values) + } + } + + let visitor = MapVisitor { marker: PhantomData }; + deserializer.deserialize_map(visitor) + } + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +map_impl!( + BTreeMap<K: Ord, V>, + map, + BTreeMap::new()); + +#[cfg(feature = "std")] +map_impl!( + HashMap<K: Eq + Hash, V, S: BuildHasher + Default>, + map, + HashMap::with_capacity_and_hasher(size_hint::cautious(map.size_hint()), S::default())); + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(feature = "std")] +macro_rules! parse_ip_impl { + ($expecting:tt $ty:ty; $size:tt) => { + impl<'de> Deserialize<'de> for $ty { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + if deserializer.is_human_readable() { + deserializer.deserialize_str(FromStrVisitor::new($expecting)) + } else { + <[u8; $size]>::deserialize(deserializer).map(<$ty>::from) + } + } + } + }; +} + +#[cfg(feature = "std")] +macro_rules! variant_identifier { + ( + $name_kind:ident ($($variant:ident; $bytes:expr; $index:expr),*) + $expecting_message:expr, + $variants_name:ident + ) => { + enum $name_kind { + $($variant),* + } + + static $variants_name: &'static [&'static str] = &[$(stringify!($variant)),*]; + + impl<'de> Deserialize<'de> for $name_kind { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct KindVisitor; + + impl<'de> Visitor<'de> for KindVisitor { + type Value = $name_kind; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str($expecting_message) + } + + fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E> + where + E: Error, + { + match value { + $( + $index => Ok($name_kind :: $variant), + )* + _ => Err(Error::invalid_value(Unexpected::Unsigned(value), &self),), + } + } + + fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> + where + E: Error, + { + match value { + $( + stringify!($variant) => Ok($name_kind :: $variant), + )* + _ => Err(Error::unknown_variant(value, $variants_name)), + } + } + + fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match value { + $( + $bytes => Ok($name_kind :: $variant), + )* + _ => { + match str::from_utf8(value) { + Ok(value) => Err(Error::unknown_variant(value, $variants_name)), + Err(_) => Err(Error::invalid_value(Unexpected::Bytes(value), &self)), + } + } + } + } + } + + deserializer.deserialize_identifier(KindVisitor) + } + } + } +} + +#[cfg(feature = "std")] +macro_rules! deserialize_enum { + ( + $name:ident $name_kind:ident ($($variant:ident; $bytes:expr; $index:expr),*) + $expecting_message:expr, + $deserializer:expr + ) => { + variant_identifier! { + $name_kind ($($variant; $bytes; $index),*) + $expecting_message, + VARIANTS + } + + struct EnumVisitor; + impl<'de> Visitor<'de> for EnumVisitor { + type Value = $name; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(concat!("a ", stringify!($name))) + } + + + fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> + where + A: EnumAccess<'de>, + { + match try!(data.variant()) { + $( + ($name_kind :: $variant, v) => v.newtype_variant().map($name :: $variant), + )* + } + } + } + $deserializer.deserialize_enum(stringify!($name), VARIANTS, EnumVisitor) + } +} + +#[cfg(feature = "std")] +impl<'de> Deserialize<'de> for net::IpAddr { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + if deserializer.is_human_readable() { + deserializer.deserialize_str(FromStrVisitor::new("IP address")) + } else { + use lib::net::IpAddr; + deserialize_enum! { + IpAddr IpAddrKind (V4; b"V4"; 0, V6; b"V6"; 1) + "`V4` or `V6`", + deserializer + } + } + } +} + +#[cfg(feature = "std")] +parse_ip_impl!("IPv4 address" net::Ipv4Addr; 4); + +#[cfg(feature = "std")] +parse_ip_impl!("IPv6 address" net::Ipv6Addr; 16); + +#[cfg(feature = "std")] +macro_rules! parse_socket_impl { + ($expecting:tt $ty:ty, $new:expr) => { + impl<'de> Deserialize<'de> for $ty { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + if deserializer.is_human_readable() { + deserializer.deserialize_str(FromStrVisitor::new($expecting)) + } else { + <(_, u16)>::deserialize(deserializer).map(|(ip, port)| $new(ip, port)) + } + } + } + }; +} + +#[cfg(feature = "std")] +impl<'de> Deserialize<'de> for net::SocketAddr { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + if deserializer.is_human_readable() { + deserializer.deserialize_str(FromStrVisitor::new("socket address")) + } else { + use lib::net::SocketAddr; + deserialize_enum! { + SocketAddr SocketAddrKind (V4; b"V4"; 0, V6; b"V6"; 1) + "`V4` or `V6`", + deserializer + } + } + } +} + +#[cfg(feature = "std")] +parse_socket_impl!("IPv4 socket address" net::SocketAddrV4, net::SocketAddrV4::new); + +#[cfg(feature = "std")] +parse_socket_impl!("IPv6 socket address" net::SocketAddrV6, |ip, port| net::SocketAddrV6::new( + ip, port, 0, 0 +)); + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(feature = "std")] +struct PathVisitor; + +#[cfg(feature = "std")] +impl<'a> Visitor<'a> for PathVisitor { + type Value = &'a Path; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("a borrowed path") + } + + fn visit_borrowed_str<E>(self, v: &'a str) -> Result<Self::Value, E> + where + E: Error, + { + Ok(v.as_ref()) + } + + fn visit_borrowed_bytes<E>(self, v: &'a [u8]) -> Result<Self::Value, E> + where + E: Error, + { + str::from_utf8(v) + .map(AsRef::as_ref) + .map_err(|_| Error::invalid_value(Unexpected::Bytes(v), &self)) + } +} + +#[cfg(feature = "std")] +impl<'de: 'a, 'a> Deserialize<'de> for &'a Path { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_str(PathVisitor) + } +} + +#[cfg(feature = "std")] +struct PathBufVisitor; + +#[cfg(feature = "std")] +impl<'de> Visitor<'de> for PathBufVisitor { + type Value = PathBuf; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("path string") + } + + fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> + where + E: Error, + { + Ok(From::from(v)) + } + + fn visit_string<E>(self, v: String) -> Result<Self::Value, E> + where + E: Error, + { + Ok(From::from(v)) + } + + fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + str::from_utf8(v) + .map(From::from) + .map_err(|_| Error::invalid_value(Unexpected::Bytes(v), &self)) + } + + fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E> + where + E: Error, + { + String::from_utf8(v) + .map(From::from) + .map_err(|e| Error::invalid_value(Unexpected::Bytes(&e.into_bytes()), &self)) + } +} + +#[cfg(feature = "std")] +impl<'de> Deserialize<'de> for PathBuf { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_string(PathBufVisitor) + } +} + +#[cfg(all(feature = "std", not(no_de_boxed_path)))] +forwarded_impl!((), Box<Path>, PathBuf::into_boxed_path); + +//////////////////////////////////////////////////////////////////////////////// + +// If this were outside of the serde crate, it would just use: +// +// #[derive(Deserialize)] +// #[serde(variant_identifier)] +#[cfg(all(feature = "std", any(unix, windows)))] +variant_identifier! { + OsStringKind (Unix; b"Unix"; 0, Windows; b"Windows"; 1) + "`Unix` or `Windows`", + OSSTR_VARIANTS +} + +#[cfg(all(feature = "std", any(unix, windows)))] +struct OsStringVisitor; + +#[cfg(all(feature = "std", any(unix, windows)))] +impl<'de> Visitor<'de> for OsStringVisitor { + type Value = OsString; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("os string") + } + + #[cfg(unix)] + fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> + where + A: EnumAccess<'de>, + { + use std::os::unix::ffi::OsStringExt; + + match try!(data.variant()) { + (OsStringKind::Unix, v) => v.newtype_variant().map(OsString::from_vec), + (OsStringKind::Windows, _) => Err(Error::custom( + "cannot deserialize Windows OS string on Unix", + )), + } + } + + #[cfg(windows)] + fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> + where + A: EnumAccess<'de>, + { + use std::os::windows::ffi::OsStringExt; + + match try!(data.variant()) { + (OsStringKind::Windows, v) => v + .newtype_variant::<Vec<u16>>() + .map(|vec| OsString::from_wide(&vec)), + (OsStringKind::Unix, _) => Err(Error::custom( + "cannot deserialize Unix OS string on Windows", + )), + } + } +} + +#[cfg(all(feature = "std", any(unix, windows)))] +impl<'de> Deserialize<'de> for OsString { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_enum("OsString", OSSTR_VARIANTS, OsStringVisitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +forwarded_impl!((T), Box<T>, Box::new); + +#[cfg(any(feature = "std", feature = "alloc"))] +forwarded_impl!((T), Box<[T]>, Vec::into_boxed_slice); + +#[cfg(any(feature = "std", feature = "alloc"))] +forwarded_impl!((), Box<str>, String::into_boxed_str); + +#[cfg(all(no_de_rc_dst, feature = "rc", any(feature = "std", feature = "alloc")))] +forwarded_impl! { + /// This impl requires the [`"rc"`] Cargo feature of Serde. + /// + /// Deserializing a data structure containing `Arc` will not attempt to + /// deduplicate `Arc` references to the same data. Every deserialized `Arc` + /// will end up with a strong count of 1. + /// + /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc + (T), Arc<T>, Arc::new +} + +#[cfg(all(no_de_rc_dst, feature = "rc", any(feature = "std", feature = "alloc")))] +forwarded_impl! { + /// This impl requires the [`"rc"`] Cargo feature of Serde. + /// + /// Deserializing a data structure containing `Rc` will not attempt to + /// deduplicate `Rc` references to the same data. Every deserialized `Rc` + /// will end up with a strong count of 1. + /// + /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc + (T), Rc<T>, Rc::new +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, 'a, T: ?Sized> Deserialize<'de> for Cow<'a, T> +where + T: ToOwned, + T::Owned: Deserialize<'de>, +{ + #[inline] + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + T::Owned::deserialize(deserializer).map(Cow::Owned) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// This impl requires the [`"rc"`] Cargo feature of Serde. The resulting +/// `Weak<T>` has a reference count of 0 and cannot be upgraded. +/// +/// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc +#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))] +impl<'de, T: ?Sized> Deserialize<'de> for RcWeak<T> +where + T: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + try!(Option::<T>::deserialize(deserializer)); + Ok(RcWeak::new()) + } +} + +/// This impl requires the [`"rc"`] Cargo feature of Serde. The resulting +/// `Weak<T>` has a reference count of 0 and cannot be upgraded. +/// +/// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc +#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))] +impl<'de, T: ?Sized> Deserialize<'de> for ArcWeak<T> +where + T: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + try!(Option::<T>::deserialize(deserializer)); + Ok(ArcWeak::new()) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(all( + not(no_de_rc_dst), + feature = "rc", + any(feature = "std", feature = "alloc") +))] +macro_rules! box_forwarded_impl { + ( + $(#[doc = $doc:tt])* + $t:ident + ) => { + $(#[doc = $doc])* + impl<'de, T: ?Sized> Deserialize<'de> for $t<T> + where + Box<T>: Deserialize<'de>, + { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + Box::deserialize(deserializer).map(Into::into) + } + } + }; +} + +#[cfg(all( + not(no_de_rc_dst), + feature = "rc", + any(feature = "std", feature = "alloc") +))] +box_forwarded_impl! { + /// This impl requires the [`"rc"`] Cargo feature of Serde. + /// + /// Deserializing a data structure containing `Rc` will not attempt to + /// deduplicate `Rc` references to the same data. Every deserialized `Rc` + /// will end up with a strong count of 1. + /// + /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc + Rc +} + +#[cfg(all( + not(no_de_rc_dst), + feature = "rc", + any(feature = "std", feature = "alloc") +))] +box_forwarded_impl! { + /// This impl requires the [`"rc"`] Cargo feature of Serde. + /// + /// Deserializing a data structure containing `Arc` will not attempt to + /// deduplicate `Arc` references to the same data. Every deserialized `Arc` + /// will end up with a strong count of 1. + /// + /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc + Arc +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<'de, T> Deserialize<'de> for Cell<T> +where + T: Deserialize<'de> + Copy, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + T::deserialize(deserializer).map(Cell::new) + } +} + +forwarded_impl!((T), RefCell<T>, RefCell::new); + +#[cfg(feature = "std")] +forwarded_impl!((T), Mutex<T>, Mutex::new); + +#[cfg(feature = "std")] +forwarded_impl!((T), RwLock<T>, RwLock::new); + +//////////////////////////////////////////////////////////////////////////////// + +// This is a cleaned-up version of the impl generated by: +// +// #[derive(Deserialize)] +// #[serde(deny_unknown_fields)] +// struct Duration { +// secs: u64, +// nanos: u32, +// } +#[cfg(any(feature = "std", not(no_core_duration)))] +impl<'de> Deserialize<'de> for Duration { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + // If this were outside of the serde crate, it would just use: + // + // #[derive(Deserialize)] + // #[serde(field_identifier, rename_all = "lowercase")] + enum Field { + Secs, + Nanos, + } + + impl<'de> Deserialize<'de> for Field { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct FieldVisitor; + + impl<'de> Visitor<'de> for FieldVisitor { + type Value = Field; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("`secs` or `nanos`") + } + + fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> + where + E: Error, + { + match value { + "secs" => Ok(Field::Secs), + "nanos" => Ok(Field::Nanos), + _ => Err(Error::unknown_field(value, FIELDS)), + } + } + + fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match value { + b"secs" => Ok(Field::Secs), + b"nanos" => Ok(Field::Nanos), + _ => { + let value = ::__private::from_utf8_lossy(value); + Err(Error::unknown_field(&*value, FIELDS)) + } + } + } + } + + deserializer.deserialize_identifier(FieldVisitor) + } + } + + fn check_overflow<E>(secs: u64, nanos: u32) -> Result<(), E> + where + E: Error, + { + static NANOS_PER_SEC: u32 = 1_000_000_000; + match secs.checked_add((nanos / NANOS_PER_SEC) as u64) { + Some(_) => Ok(()), + None => Err(E::custom("overflow deserializing Duration")), + } + } + + struct DurationVisitor; + + impl<'de> Visitor<'de> for DurationVisitor { + type Value = Duration; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("struct Duration") + } + + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let secs: u64 = match try!(seq.next_element()) { + Some(value) => value, + None => { + return Err(Error::invalid_length(0, &self)); + } + }; + let nanos: u32 = match try!(seq.next_element()) { + Some(value) => value, + None => { + return Err(Error::invalid_length(1, &self)); + } + }; + try!(check_overflow(secs, nanos)); + Ok(Duration::new(secs, nanos)) + } + + fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error> + where + A: MapAccess<'de>, + { + let mut secs: Option<u64> = None; + let mut nanos: Option<u32> = None; + while let Some(key) = try!(map.next_key()) { + match key { + Field::Secs => { + if secs.is_some() { + return Err(<A::Error as Error>::duplicate_field("secs")); + } + secs = Some(try!(map.next_value())); + } + Field::Nanos => { + if nanos.is_some() { + return Err(<A::Error as Error>::duplicate_field("nanos")); + } + nanos = Some(try!(map.next_value())); + } + } + } + let secs = match secs { + Some(secs) => secs, + None => return Err(<A::Error as Error>::missing_field("secs")), + }; + let nanos = match nanos { + Some(nanos) => nanos, + None => return Err(<A::Error as Error>::missing_field("nanos")), + }; + try!(check_overflow(secs, nanos)); + Ok(Duration::new(secs, nanos)) + } + } + + const FIELDS: &'static [&'static str] = &["secs", "nanos"]; + deserializer.deserialize_struct("Duration", FIELDS, DurationVisitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(feature = "std")] +impl<'de> Deserialize<'de> for SystemTime { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + // Reuse duration + enum Field { + Secs, + Nanos, + } + + impl<'de> Deserialize<'de> for Field { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct FieldVisitor; + + impl<'de> Visitor<'de> for FieldVisitor { + type Value = Field; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("`secs_since_epoch` or `nanos_since_epoch`") + } + + fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> + where + E: Error, + { + match value { + "secs_since_epoch" => Ok(Field::Secs), + "nanos_since_epoch" => Ok(Field::Nanos), + _ => Err(Error::unknown_field(value, FIELDS)), + } + } + + fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match value { + b"secs_since_epoch" => Ok(Field::Secs), + b"nanos_since_epoch" => Ok(Field::Nanos), + _ => { + let value = String::from_utf8_lossy(value); + Err(Error::unknown_field(&value, FIELDS)) + } + } + } + } + + deserializer.deserialize_identifier(FieldVisitor) + } + } + + fn check_overflow<E>(secs: u64, nanos: u32) -> Result<(), E> + where + E: Error, + { + static NANOS_PER_SEC: u32 = 1_000_000_000; + match secs.checked_add((nanos / NANOS_PER_SEC) as u64) { + Some(_) => Ok(()), + None => Err(E::custom("overflow deserializing SystemTime epoch offset")), + } + } + + struct DurationVisitor; + + impl<'de> Visitor<'de> for DurationVisitor { + type Value = Duration; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("struct SystemTime") + } + + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let secs: u64 = match try!(seq.next_element()) { + Some(value) => value, + None => { + return Err(Error::invalid_length(0, &self)); + } + }; + let nanos: u32 = match try!(seq.next_element()) { + Some(value) => value, + None => { + return Err(Error::invalid_length(1, &self)); + } + }; + try!(check_overflow(secs, nanos)); + Ok(Duration::new(secs, nanos)) + } + + fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error> + where + A: MapAccess<'de>, + { + let mut secs: Option<u64> = None; + let mut nanos: Option<u32> = None; + while let Some(key) = try!(map.next_key()) { + match key { + Field::Secs => { + if secs.is_some() { + return Err(<A::Error as Error>::duplicate_field( + "secs_since_epoch", + )); + } + secs = Some(try!(map.next_value())); + } + Field::Nanos => { + if nanos.is_some() { + return Err(<A::Error as Error>::duplicate_field( + "nanos_since_epoch", + )); + } + nanos = Some(try!(map.next_value())); + } + } + } + let secs = match secs { + Some(secs) => secs, + None => return Err(<A::Error as Error>::missing_field("secs_since_epoch")), + }; + let nanos = match nanos { + Some(nanos) => nanos, + None => return Err(<A::Error as Error>::missing_field("nanos_since_epoch")), + }; + try!(check_overflow(secs, nanos)); + Ok(Duration::new(secs, nanos)) + } + } + + const FIELDS: &'static [&'static str] = &["secs_since_epoch", "nanos_since_epoch"]; + let duration = try!(deserializer.deserialize_struct("SystemTime", FIELDS, DurationVisitor)); + #[cfg(not(no_systemtime_checked_add))] + let ret = UNIX_EPOCH + .checked_add(duration) + .ok_or_else(|| D::Error::custom("overflow deserializing SystemTime")); + #[cfg(no_systemtime_checked_add)] + let ret = Ok(UNIX_EPOCH + duration); + ret + } +} + +//////////////////////////////////////////////////////////////////////////////// + +// Similar to: +// +// #[derive(Deserialize)] +// #[serde(deny_unknown_fields)] +// struct Range { +// start: u64, +// end: u32, +// } +impl<'de, Idx> Deserialize<'de> for Range<Idx> +where + Idx: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + let (start, end) = try!(deserializer.deserialize_struct( + "Range", + range::FIELDS, + range::RangeVisitor { + expecting: "struct Range", + phantom: PhantomData, + }, + )); + Ok(start..end) + } +} + +#[cfg(not(no_range_inclusive))] +impl<'de, Idx> Deserialize<'de> for RangeInclusive<Idx> +where + Idx: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + let (start, end) = try!(deserializer.deserialize_struct( + "RangeInclusive", + range::FIELDS, + range::RangeVisitor { + expecting: "struct RangeInclusive", + phantom: PhantomData, + }, + )); + Ok(RangeInclusive::new(start, end)) + } +} + +mod range { + use lib::*; + + use de::{Deserialize, Deserializer, Error, MapAccess, SeqAccess, Visitor}; + + pub const FIELDS: &'static [&'static str] = &["start", "end"]; + + // If this were outside of the serde crate, it would just use: + // + // #[derive(Deserialize)] + // #[serde(field_identifier, rename_all = "lowercase")] + enum Field { + Start, + End, + } + + impl<'de> Deserialize<'de> for Field { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct FieldVisitor; + + impl<'de> Visitor<'de> for FieldVisitor { + type Value = Field; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("`start` or `end`") + } + + fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> + where + E: Error, + { + match value { + "start" => Ok(Field::Start), + "end" => Ok(Field::End), + _ => Err(Error::unknown_field(value, FIELDS)), + } + } + + fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match value { + b"start" => Ok(Field::Start), + b"end" => Ok(Field::End), + _ => { + let value = ::__private::from_utf8_lossy(value); + Err(Error::unknown_field(&*value, FIELDS)) + } + } + } + } + + deserializer.deserialize_identifier(FieldVisitor) + } + } + + pub struct RangeVisitor<Idx> { + pub expecting: &'static str, + pub phantom: PhantomData<Idx>, + } + + impl<'de, Idx> Visitor<'de> for RangeVisitor<Idx> + where + Idx: Deserialize<'de>, + { + type Value = (Idx, Idx); + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(self.expecting) + } + + fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let start: Idx = match try!(seq.next_element()) { + Some(value) => value, + None => { + return Err(Error::invalid_length(0, &self)); + } + }; + let end: Idx = match try!(seq.next_element()) { + Some(value) => value, + None => { + return Err(Error::invalid_length(1, &self)); + } + }; + Ok((start, end)) + } + + fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error> + where + A: MapAccess<'de>, + { + let mut start: Option<Idx> = None; + let mut end: Option<Idx> = None; + while let Some(key) = try!(map.next_key()) { + match key { + Field::Start => { + if start.is_some() { + return Err(<A::Error as Error>::duplicate_field("start")); + } + start = Some(try!(map.next_value())); + } + Field::End => { + if end.is_some() { + return Err(<A::Error as Error>::duplicate_field("end")); + } + end = Some(try!(map.next_value())); + } + } + } + let start = match start { + Some(start) => start, + None => return Err(<A::Error as Error>::missing_field("start")), + }; + let end = match end { + Some(end) => end, + None => return Err(<A::Error as Error>::missing_field("end")), + }; + Ok((start, end)) + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(not(no_ops_bound), all(feature = "std", not(no_collections_bound))))] +impl<'de, T> Deserialize<'de> for Bound<T> +where + T: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + enum Field { + Unbounded, + Included, + Excluded, + } + + impl<'de> Deserialize<'de> for Field { + #[inline] + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct FieldVisitor; + + impl<'de> Visitor<'de> for FieldVisitor { + type Value = Field; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("`Unbounded`, `Included` or `Excluded`") + } + + fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E> + where + E: Error, + { + match value { + 0 => Ok(Field::Unbounded), + 1 => Ok(Field::Included), + 2 => Ok(Field::Excluded), + _ => Err(Error::invalid_value(Unexpected::Unsigned(value), &self)), + } + } + + fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> + where + E: Error, + { + match value { + "Unbounded" => Ok(Field::Unbounded), + "Included" => Ok(Field::Included), + "Excluded" => Ok(Field::Excluded), + _ => Err(Error::unknown_variant(value, VARIANTS)), + } + } + + fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match value { + b"Unbounded" => Ok(Field::Unbounded), + b"Included" => Ok(Field::Included), + b"Excluded" => Ok(Field::Excluded), + _ => match str::from_utf8(value) { + Ok(value) => Err(Error::unknown_variant(value, VARIANTS)), + Err(_) => { + Err(Error::invalid_value(Unexpected::Bytes(value), &self)) + } + }, + } + } + } + + deserializer.deserialize_identifier(FieldVisitor) + } + } + + struct BoundVisitor<T>(PhantomData<Bound<T>>); + + impl<'de, T> Visitor<'de> for BoundVisitor<T> + where + T: Deserialize<'de>, + { + type Value = Bound<T>; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("enum Bound") + } + + fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> + where + A: EnumAccess<'de>, + { + match try!(data.variant()) { + (Field::Unbounded, v) => v.unit_variant().map(|()| Bound::Unbounded), + (Field::Included, v) => v.newtype_variant().map(Bound::Included), + (Field::Excluded, v) => v.newtype_variant().map(Bound::Excluded), + } + } + } + + const VARIANTS: &'static [&'static str] = &["Unbounded", "Included", "Excluded"]; + + deserializer.deserialize_enum("Bound", VARIANTS, BoundVisitor(PhantomData)) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<'de, T, E> Deserialize<'de> for Result<T, E> +where + T: Deserialize<'de>, + E: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + // If this were outside of the serde crate, it would just use: + // + // #[derive(Deserialize)] + // #[serde(variant_identifier)] + enum Field { + Ok, + Err, + } + + impl<'de> Deserialize<'de> for Field { + #[inline] + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + struct FieldVisitor; + + impl<'de> Visitor<'de> for FieldVisitor { + type Value = Field; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("`Ok` or `Err`") + } + + fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E> + where + E: Error, + { + match value { + 0 => Ok(Field::Ok), + 1 => Ok(Field::Err), + _ => Err(Error::invalid_value(Unexpected::Unsigned(value), &self)), + } + } + + fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> + where + E: Error, + { + match value { + "Ok" => Ok(Field::Ok), + "Err" => Ok(Field::Err), + _ => Err(Error::unknown_variant(value, VARIANTS)), + } + } + + fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + match value { + b"Ok" => Ok(Field::Ok), + b"Err" => Ok(Field::Err), + _ => match str::from_utf8(value) { + Ok(value) => Err(Error::unknown_variant(value, VARIANTS)), + Err(_) => { + Err(Error::invalid_value(Unexpected::Bytes(value), &self)) + } + }, + } + } + } + + deserializer.deserialize_identifier(FieldVisitor) + } + } + + struct ResultVisitor<T, E>(PhantomData<Result<T, E>>); + + impl<'de, T, E> Visitor<'de> for ResultVisitor<T, E> + where + T: Deserialize<'de>, + E: Deserialize<'de>, + { + type Value = Result<T, E>; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("enum Result") + } + + fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> + where + A: EnumAccess<'de>, + { + match try!(data.variant()) { + (Field::Ok, v) => v.newtype_variant().map(Ok), + (Field::Err, v) => v.newtype_variant().map(Err), + } + } + } + + const VARIANTS: &'static [&'static str] = &["Ok", "Err"]; + + deserializer.deserialize_enum("Result", VARIANTS, ResultVisitor(PhantomData)) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<'de, T> Deserialize<'de> for Wrapping<T> +where + T: Deserialize<'de>, +{ + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + Deserialize::deserialize(deserializer).map(Wrapping) + } +} + +#[cfg(all(feature = "std", not(no_std_atomic)))] +macro_rules! atomic_impl { + ($($ty:ident $size:expr)*) => { + $( + #[cfg(any(no_target_has_atomic, target_has_atomic = $size))] + impl<'de> Deserialize<'de> for $ty { + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>, + { + Deserialize::deserialize(deserializer).map(Self::new) + } + } + )* + }; +} + +#[cfg(all(feature = "std", not(no_std_atomic)))] +atomic_impl! { + AtomicBool "8" + AtomicI8 "8" + AtomicI16 "16" + AtomicI32 "32" + AtomicIsize "ptr" + AtomicU8 "8" + AtomicU16 "16" + AtomicU32 "32" + AtomicUsize "ptr" +} + +#[cfg(all(feature = "std", not(no_std_atomic64)))] +atomic_impl! { + AtomicI64 "64" + AtomicU64 "64" +} + +#[cfg(feature = "std")] +struct FromStrVisitor<T> { + expecting: &'static str, + ty: PhantomData<T>, +} + +#[cfg(feature = "std")] +impl<T> FromStrVisitor<T> { + fn new(expecting: &'static str) -> Self { + FromStrVisitor { + expecting: expecting, + ty: PhantomData, + } + } +} + +#[cfg(feature = "std")] +impl<'de, T> Visitor<'de> for FromStrVisitor<T> +where + T: str::FromStr, + T::Err: fmt::Display, +{ + type Value = T; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(self.expecting) + } + + fn visit_str<E>(self, s: &str) -> Result<Self::Value, E> + where + E: Error, + { + s.parse().map_err(Error::custom) + } +} diff --git a/third_party/rust/serde/src/de/mod.rs b/third_party/rust/serde/src/de/mod.rs new file mode 100644 index 0000000000..ca29ec610b --- /dev/null +++ b/third_party/rust/serde/src/de/mod.rs @@ -0,0 +1,2299 @@ +//! Generic data structure deserialization framework. +//! +//! The two most important traits in this module are [`Deserialize`] and +//! [`Deserializer`]. +//! +//! - **A type that implements `Deserialize` is a data structure** that can be +//! deserialized from any data format supported by Serde, and conversely +//! - **A type that implements `Deserializer` is a data format** that can +//! deserialize any data structure supported by Serde. +//! +//! # The Deserialize trait +//! +//! Serde provides [`Deserialize`] implementations for many Rust primitive and +//! standard library types. The complete list is below. All of these can be +//! deserialized using Serde out of the box. +//! +//! Additionally, Serde provides a procedural macro called [`serde_derive`] to +//! automatically generate [`Deserialize`] implementations for structs and enums +//! in your program. See the [derive section of the manual] for how to use this. +//! +//! In rare cases it may be necessary to implement [`Deserialize`] manually for +//! some type in your program. See the [Implementing `Deserialize`] section of +//! the manual for more about this. +//! +//! Third-party crates may provide [`Deserialize`] implementations for types +//! that they expose. For example the [`linked-hash-map`] crate provides a +//! [`LinkedHashMap<K, V>`] type that is deserializable by Serde because the +//! crate provides an implementation of [`Deserialize`] for it. +//! +//! # The Deserializer trait +//! +//! [`Deserializer`] implementations are provided by third-party crates, for +//! example [`serde_json`], [`serde_yaml`] and [`postcard`]. +//! +//! A partial list of well-maintained formats is given on the [Serde +//! website][data formats]. +//! +//! # Implementations of Deserialize provided by Serde +//! +//! This is a slightly different set of types than what is supported for +//! serialization. Some types can be serialized by Serde but not deserialized. +//! One example is `OsStr`. +//! +//! - **Primitive types**: +//! - bool +//! - i8, i16, i32, i64, i128, isize +//! - u8, u16, u32, u64, u128, usize +//! - f32, f64 +//! - char +//! - **Compound types**: +//! - \[T; 0\] through \[T; 32\] +//! - tuples up to size 16 +//! - **Common standard library types**: +//! - String +//! - Option\<T\> +//! - Result\<T, E\> +//! - PhantomData\<T\> +//! - **Wrapper types**: +//! - Box\<T\> +//! - Box\<\[T\]\> +//! - Box\<str\> +//! - Cow\<'a, T\> +//! - Cell\<T\> +//! - RefCell\<T\> +//! - Mutex\<T\> +//! - RwLock\<T\> +//! - Rc\<T\> *(if* features = ["rc"] *is enabled)* +//! - Arc\<T\> *(if* features = ["rc"] *is enabled)* +//! - **Collection types**: +//! - BTreeMap\<K, V\> +//! - BTreeSet\<T\> +//! - BinaryHeap\<T\> +//! - HashMap\<K, V, H\> +//! - HashSet\<T, H\> +//! - LinkedList\<T\> +//! - VecDeque\<T\> +//! - Vec\<T\> +//! - **Zero-copy types**: +//! - &str +//! - &\[u8\] +//! - **FFI types**: +//! - CString +//! - Box\<CStr\> +//! - OsString +//! - **Miscellaneous standard library types**: +//! - Duration +//! - SystemTime +//! - Path +//! - PathBuf +//! - Range\<T\> +//! - RangeInclusive\<T\> +//! - Bound\<T\> +//! - num::NonZero* +//! - `!` *(unstable)* +//! - **Net types**: +//! - IpAddr +//! - Ipv4Addr +//! - Ipv6Addr +//! - SocketAddr +//! - SocketAddrV4 +//! - SocketAddrV6 +//! +//! [Implementing `Deserialize`]: https://serde.rs/impl-deserialize.html +//! [`Deserialize`]: ../trait.Deserialize.html +//! [`Deserializer`]: ../trait.Deserializer.html +//! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html +//! [`postcard`]: https://github.com/jamesmunns/postcard +//! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map +//! [`serde_derive`]: https://crates.io/crates/serde_derive +//! [`serde_json`]: https://github.com/serde-rs/json +//! [`serde_yaml`]: https://github.com/dtolnay/serde-yaml +//! [derive section of the manual]: https://serde.rs/derive.html +//! [data formats]: https://serde.rs/#data-formats + +use lib::*; + +//////////////////////////////////////////////////////////////////////////////// + +pub mod value; + +#[cfg(not(no_integer128))] +mod format; +mod ignored_any; +mod impls; +mod utf8; + +pub use self::ignored_any::IgnoredAny; + +#[cfg(feature = "std")] +#[doc(no_inline)] +pub use std::error::Error as StdError; +#[cfg(not(feature = "std"))] +#[doc(no_inline)] +pub use std_error::Error as StdError; + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! declare_error_trait { + (Error: Sized $(+ $($supertrait:ident)::+)*) => { + /// The `Error` trait allows `Deserialize` implementations to create descriptive + /// error messages belonging to the `Deserializer` against which they are + /// currently running. + /// + /// Every `Deserializer` declares an `Error` type that encompasses both + /// general-purpose deserialization errors as well as errors specific to the + /// particular deserialization format. For example the `Error` type of + /// `serde_json` can represent errors like an invalid JSON escape sequence or an + /// unterminated string literal, in addition to the error cases that are part of + /// this trait. + /// + /// Most deserializers should only need to provide the `Error::custom` method + /// and inherit the default behavior for the other methods. + /// + /// # Example implementation + /// + /// The [example data format] presented on the website shows an error + /// type appropriate for a basic JSON data format. + /// + /// [example data format]: https://serde.rs/data-format.html + pub trait Error: Sized $(+ $($supertrait)::+)* { + /// Raised when there is general error when deserializing a type. + /// + /// The message should not be capitalized and should not end with a period. + /// + /// ```edition2018 + /// # use std::str::FromStr; + /// # + /// # struct IpAddr; + /// # + /// # impl FromStr for IpAddr { + /// # type Err = String; + /// # + /// # fn from_str(_: &str) -> Result<Self, String> { + /// # unimplemented!() + /// # } + /// # } + /// # + /// use serde::de::{self, Deserialize, Deserializer}; + /// + /// impl<'de> Deserialize<'de> for IpAddr { + /// fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + /// where + /// D: Deserializer<'de>, + /// { + /// let s = String::deserialize(deserializer)?; + /// s.parse().map_err(de::Error::custom) + /// } + /// } + /// ``` + fn custom<T>(msg: T) -> Self + where + T: Display; + + /// Raised when a `Deserialize` receives a type different from what it was + /// expecting. + /// + /// The `unexp` argument provides information about what type was received. + /// This is the type that was present in the input file or other source data + /// of the Deserializer. + /// + /// The `exp` argument provides information about what type was being + /// expected. This is the type that is written in the program. + /// + /// For example if we try to deserialize a String out of a JSON file + /// containing an integer, the unexpected type is the integer and the + /// expected type is the string. + #[cold] + fn invalid_type(unexp: Unexpected, exp: &Expected) -> Self { + Error::custom(format_args!("invalid type: {}, expected {}", unexp, exp)) + } + + /// Raised when a `Deserialize` receives a value of the right type but that + /// is wrong for some other reason. + /// + /// The `unexp` argument provides information about what value was received. + /// This is the value that was present in the input file or other source + /// data of the Deserializer. + /// + /// The `exp` argument provides information about what value was being + /// expected. This is the type that is written in the program. + /// + /// For example if we try to deserialize a String out of some binary data + /// that is not valid UTF-8, the unexpected value is the bytes and the + /// expected value is a string. + #[cold] + fn invalid_value(unexp: Unexpected, exp: &Expected) -> Self { + Error::custom(format_args!("invalid value: {}, expected {}", unexp, exp)) + } + + /// Raised when deserializing a sequence or map and the input data contains + /// too many or too few elements. + /// + /// The `len` argument is the number of elements encountered. The sequence + /// or map may have expected more arguments or fewer arguments. + /// + /// The `exp` argument provides information about what data was being + /// expected. For example `exp` might say that a tuple of size 6 was + /// expected. + #[cold] + fn invalid_length(len: usize, exp: &Expected) -> Self { + Error::custom(format_args!("invalid length {}, expected {}", len, exp)) + } + + /// Raised when a `Deserialize` enum type received a variant with an + /// unrecognized name. + #[cold] + fn unknown_variant(variant: &str, expected: &'static [&'static str]) -> Self { + if expected.is_empty() { + Error::custom(format_args!( + "unknown variant `{}`, there are no variants", + variant + )) + } else { + Error::custom(format_args!( + "unknown variant `{}`, expected {}", + variant, + OneOf { names: expected } + )) + } + } + + /// Raised when a `Deserialize` struct type received a field with an + /// unrecognized name. + #[cold] + fn unknown_field(field: &str, expected: &'static [&'static str]) -> Self { + if expected.is_empty() { + Error::custom(format_args!( + "unknown field `{}`, there are no fields", + field + )) + } else { + Error::custom(format_args!( + "unknown field `{}`, expected {}", + field, + OneOf { names: expected } + )) + } + } + + /// Raised when a `Deserialize` struct type expected to receive a required + /// field with a particular name but that field was not present in the + /// input. + #[cold] + fn missing_field(field: &'static str) -> Self { + Error::custom(format_args!("missing field `{}`", field)) + } + + /// Raised when a `Deserialize` struct type received more than one of the + /// same field. + #[cold] + fn duplicate_field(field: &'static str) -> Self { + Error::custom(format_args!("duplicate field `{}`", field)) + } + } + } +} + +#[cfg(feature = "std")] +declare_error_trait!(Error: Sized + StdError); + +#[cfg(not(feature = "std"))] +declare_error_trait!(Error: Sized + Debug + Display); + +/// `Unexpected` represents an unexpected invocation of any one of the `Visitor` +/// trait methods. +/// +/// This is used as an argument to the `invalid_type`, `invalid_value`, and +/// `invalid_length` methods of the `Error` trait to build error messages. +/// +/// ```edition2018 +/// # use std::fmt; +/// # +/// # use serde::de::{self, Unexpected, Visitor}; +/// # +/// # struct Example; +/// # +/// # impl<'de> Visitor<'de> for Example { +/// # type Value = (); +/// # +/// # fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { +/// # write!(formatter, "definitely not a boolean") +/// # } +/// # +/// fn visit_bool<E>(self, v: bool) -> Result<Self::Value, E> +/// where +/// E: de::Error, +/// { +/// Err(de::Error::invalid_type(Unexpected::Bool(v), &self)) +/// } +/// # } +/// ``` +#[derive(Copy, Clone, PartialEq, Debug)] +pub enum Unexpected<'a> { + /// The input contained a boolean value that was not expected. + Bool(bool), + + /// The input contained an unsigned integer `u8`, `u16`, `u32` or `u64` that + /// was not expected. + Unsigned(u64), + + /// The input contained a signed integer `i8`, `i16`, `i32` or `i64` that + /// was not expected. + Signed(i64), + + /// The input contained a floating point `f32` or `f64` that was not + /// expected. + Float(f64), + + /// The input contained a `char` that was not expected. + Char(char), + + /// The input contained a `&str` or `String` that was not expected. + Str(&'a str), + + /// The input contained a `&[u8]` or `Vec<u8>` that was not expected. + Bytes(&'a [u8]), + + /// The input contained a unit `()` that was not expected. + Unit, + + /// The input contained an `Option<T>` that was not expected. + Option, + + /// The input contained a newtype struct that was not expected. + NewtypeStruct, + + /// The input contained a sequence that was not expected. + Seq, + + /// The input contained a map that was not expected. + Map, + + /// The input contained an enum that was not expected. + Enum, + + /// The input contained a unit variant that was not expected. + UnitVariant, + + /// The input contained a newtype variant that was not expected. + NewtypeVariant, + + /// The input contained a tuple variant that was not expected. + TupleVariant, + + /// The input contained a struct variant that was not expected. + StructVariant, + + /// A message stating what uncategorized thing the input contained that was + /// not expected. + /// + /// The message should be a noun or noun phrase, not capitalized and without + /// a period. An example message is "unoriginal superhero". + Other(&'a str), +} + +impl<'a> fmt::Display for Unexpected<'a> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + use self::Unexpected::*; + match *self { + Bool(b) => write!(formatter, "boolean `{}`", b), + Unsigned(i) => write!(formatter, "integer `{}`", i), + Signed(i) => write!(formatter, "integer `{}`", i), + Float(f) => write!(formatter, "floating point `{}`", f), + Char(c) => write!(formatter, "character `{}`", c), + Str(s) => write!(formatter, "string {:?}", s), + Bytes(_) => write!(formatter, "byte array"), + Unit => write!(formatter, "unit value"), + Option => write!(formatter, "Option value"), + NewtypeStruct => write!(formatter, "newtype struct"), + Seq => write!(formatter, "sequence"), + Map => write!(formatter, "map"), + Enum => write!(formatter, "enum"), + UnitVariant => write!(formatter, "unit variant"), + NewtypeVariant => write!(formatter, "newtype variant"), + TupleVariant => write!(formatter, "tuple variant"), + StructVariant => write!(formatter, "struct variant"), + Other(other) => formatter.write_str(other), + } + } +} + +/// `Expected` represents an explanation of what data a `Visitor` was expecting +/// to receive. +/// +/// This is used as an argument to the `invalid_type`, `invalid_value`, and +/// `invalid_length` methods of the `Error` trait to build error messages. The +/// message should be a noun or noun phrase that completes the sentence "This +/// Visitor expects to receive ...", for example the message could be "an +/// integer between 0 and 64". The message should not be capitalized and should +/// not end with a period. +/// +/// Within the context of a `Visitor` implementation, the `Visitor` itself +/// (`&self`) is an implementation of this trait. +/// +/// ```edition2018 +/// # use std::fmt; +/// # +/// # use serde::de::{self, Unexpected, Visitor}; +/// # +/// # struct Example; +/// # +/// # impl<'de> Visitor<'de> for Example { +/// # type Value = (); +/// # +/// # fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { +/// # write!(formatter, "definitely not a boolean") +/// # } +/// # +/// fn visit_bool<E>(self, v: bool) -> Result<Self::Value, E> +/// where +/// E: de::Error, +/// { +/// Err(de::Error::invalid_type(Unexpected::Bool(v), &self)) +/// } +/// # } +/// ``` +/// +/// Outside of a `Visitor`, `&"..."` can be used. +/// +/// ```edition2018 +/// # use serde::de::{self, Unexpected}; +/// # +/// # fn example<E>() -> Result<(), E> +/// # where +/// # E: de::Error, +/// # { +/// # let v = true; +/// return Err(de::Error::invalid_type(Unexpected::Bool(v), &"a negative integer")); +/// # } +/// ``` +pub trait Expected { + /// Format an explanation of what data was being expected. Same signature as + /// the `Display` and `Debug` traits. + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result; +} + +impl<'de, T> Expected for T +where + T: Visitor<'de>, +{ + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + self.expecting(formatter) + } +} + +impl<'a> Expected for &'a str { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(self) + } +} + +impl<'a> Display for Expected + 'a { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + Expected::fmt(self, formatter) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A **data structure** that can be deserialized from any data format supported +/// by Serde. +/// +/// Serde provides `Deserialize` implementations for many Rust primitive and +/// standard library types. The complete list is [here][crate::de]. All of these +/// can be deserialized using Serde out of the box. +/// +/// Additionally, Serde provides a procedural macro called `serde_derive` to +/// automatically generate `Deserialize` implementations for structs and enums +/// in your program. See the [derive section of the manual][derive] for how to +/// use this. +/// +/// In rare cases it may be necessary to implement `Deserialize` manually for +/// some type in your program. See the [Implementing +/// `Deserialize`][impl-deserialize] section of the manual for more about this. +/// +/// Third-party crates may provide `Deserialize` implementations for types that +/// they expose. For example the `linked-hash-map` crate provides a +/// `LinkedHashMap<K, V>` type that is deserializable by Serde because the crate +/// provides an implementation of `Deserialize` for it. +/// +/// [derive]: https://serde.rs/derive.html +/// [impl-deserialize]: https://serde.rs/impl-deserialize.html +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed by `Self` when deserialized. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +pub trait Deserialize<'de>: Sized { + /// Deserialize this value from the given Serde deserializer. + /// + /// See the [Implementing `Deserialize`][impl-deserialize] section of the + /// manual for more information about how to implement this method. + /// + /// [impl-deserialize]: https://serde.rs/impl-deserialize.html + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + where + D: Deserializer<'de>; + + /// Deserializes a value into `self` from the given Deserializer. + /// + /// The purpose of this method is to allow the deserializer to reuse + /// resources and avoid copies. As such, if this method returns an error, + /// `self` will be in an indeterminate state where some parts of the struct + /// have been overwritten. Although whatever state that is will be + /// memory-safe. + /// + /// This is generally useful when repeatedly deserializing values that + /// are processed one at a time, where the value of `self` doesn't matter + /// when the next deserialization occurs. + /// + /// If you manually implement this, your recursive deserializations should + /// use `deserialize_in_place`. + /// + /// This method is stable and an official public API, but hidden from the + /// documentation because it is almost never what newbies are looking for. + /// Showing it in rustdoc would cause it to be featured more prominently + /// than it deserves. + #[doc(hidden)] + fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error> + where + D: Deserializer<'de>, + { + // Default implementation just delegates to `deserialize` impl. + *place = try!(Deserialize::deserialize(deserializer)); + Ok(()) + } +} + +/// A data structure that can be deserialized without borrowing any data from +/// the deserializer. +/// +/// This is primarily useful for trait bounds on functions. For example a +/// `from_str` function may be able to deserialize a data structure that borrows +/// from the input string, but a `from_reader` function may only deserialize +/// owned data. +/// +/// ```edition2018 +/// # use serde::de::{Deserialize, DeserializeOwned}; +/// # use std::io::{Read, Result}; +/// # +/// # trait Ignore { +/// fn from_str<'a, T>(s: &'a str) -> Result<T> +/// where +/// T: Deserialize<'a>; +/// +/// fn from_reader<R, T>(rdr: R) -> Result<T> +/// where +/// R: Read, +/// T: DeserializeOwned; +/// # } +/// ``` +/// +/// # Lifetime +/// +/// The relationship between `Deserialize` and `DeserializeOwned` in trait +/// bounds is explained in more detail on the page [Understanding deserializer +/// lifetimes]. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +pub trait DeserializeOwned: for<'de> Deserialize<'de> {} +impl<T> DeserializeOwned for T where T: for<'de> Deserialize<'de> {} + +/// `DeserializeSeed` is the stateful form of the `Deserialize` trait. If you +/// ever find yourself looking for a way to pass data into a `Deserialize` impl, +/// this trait is the way to do it. +/// +/// As one example of stateful deserialization consider deserializing a JSON +/// array into an existing buffer. Using the `Deserialize` trait we could +/// deserialize a JSON array into a `Vec<T>` but it would be a freshly allocated +/// `Vec<T>`; there is no way for `Deserialize` to reuse a previously allocated +/// buffer. Using `DeserializeSeed` instead makes this possible as in the +/// example code below. +/// +/// The canonical API for stateless deserialization looks like this: +/// +/// ```edition2018 +/// # use serde::Deserialize; +/// # +/// # enum Error {} +/// # +/// fn func<'de, T: Deserialize<'de>>() -> Result<T, Error> +/// # { +/// # unimplemented!() +/// # } +/// ``` +/// +/// Adjusting an API like this to support stateful deserialization is a matter +/// of accepting a seed as input: +/// +/// ```edition2018 +/// # use serde::de::DeserializeSeed; +/// # +/// # enum Error {} +/// # +/// fn func_seed<'de, T: DeserializeSeed<'de>>(seed: T) -> Result<T::Value, Error> +/// # { +/// # let _ = seed; +/// # unimplemented!() +/// # } +/// ``` +/// +/// In practice the majority of deserialization is stateless. An API expecting a +/// seed can be appeased by passing `std::marker::PhantomData` as a seed in the +/// case of stateless deserialization. +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed by `Self::Value` when deserialized. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example +/// +/// Suppose we have JSON that looks like `[[1, 2], [3, 4, 5], [6]]` and we need +/// to deserialize it into a flat representation like `vec![1, 2, 3, 4, 5, 6]`. +/// Allocating a brand new `Vec<T>` for each subarray would be slow. Instead we +/// would like to allocate a single `Vec<T>` and then deserialize each subarray +/// into it. This requires stateful deserialization using the `DeserializeSeed` +/// trait. +/// +/// ```edition2018 +/// use std::fmt; +/// use std::marker::PhantomData; +/// +/// use serde::de::{Deserialize, DeserializeSeed, Deserializer, SeqAccess, Visitor}; +/// +/// // A DeserializeSeed implementation that uses stateful deserialization to +/// // append array elements onto the end of an existing vector. The preexisting +/// // state ("seed") in this case is the Vec<T>. The `deserialize` method of +/// // `ExtendVec` will be traversing the inner arrays of the JSON input and +/// // appending each integer into the existing Vec. +/// struct ExtendVec<'a, T: 'a>(&'a mut Vec<T>); +/// +/// impl<'de, 'a, T> DeserializeSeed<'de> for ExtendVec<'a, T> +/// where +/// T: Deserialize<'de>, +/// { +/// // The return type of the `deserialize` method. This implementation +/// // appends onto an existing vector but does not create any new data +/// // structure, so the return type is (). +/// type Value = (); +/// +/// fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> +/// where +/// D: Deserializer<'de>, +/// { +/// // Visitor implementation that will walk an inner array of the JSON +/// // input. +/// struct ExtendVecVisitor<'a, T: 'a>(&'a mut Vec<T>); +/// +/// impl<'de, 'a, T> Visitor<'de> for ExtendVecVisitor<'a, T> +/// where +/// T: Deserialize<'de>, +/// { +/// type Value = (); +/// +/// fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { +/// write!(formatter, "an array of integers") +/// } +/// +/// fn visit_seq<A>(self, mut seq: A) -> Result<(), A::Error> +/// where +/// A: SeqAccess<'de>, +/// { +/// // Decrease the number of reallocations if there are many elements +/// if let Some(size_hint) = seq.size_hint() { +/// self.0.reserve(size_hint); +/// } +/// +/// // Visit each element in the inner array and push it onto +/// // the existing vector. +/// while let Some(elem) = seq.next_element()? { +/// self.0.push(elem); +/// } +/// Ok(()) +/// } +/// } +/// +/// deserializer.deserialize_seq(ExtendVecVisitor(self.0)) +/// } +/// } +/// +/// // Visitor implementation that will walk the outer array of the JSON input. +/// struct FlattenedVecVisitor<T>(PhantomData<T>); +/// +/// impl<'de, T> Visitor<'de> for FlattenedVecVisitor<T> +/// where +/// T: Deserialize<'de>, +/// { +/// // This Visitor constructs a single Vec<T> to hold the flattened +/// // contents of the inner arrays. +/// type Value = Vec<T>; +/// +/// fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { +/// write!(formatter, "an array of arrays") +/// } +/// +/// fn visit_seq<A>(self, mut seq: A) -> Result<Vec<T>, A::Error> +/// where +/// A: SeqAccess<'de>, +/// { +/// // Create a single Vec to hold the flattened contents. +/// let mut vec = Vec::new(); +/// +/// // Each iteration through this loop is one inner array. +/// while let Some(()) = seq.next_element_seed(ExtendVec(&mut vec))? { +/// // Nothing to do; inner array has been appended into `vec`. +/// } +/// +/// // Return the finished vec. +/// Ok(vec) +/// } +/// } +/// +/// # fn example<'de, D>(deserializer: D) -> Result<(), D::Error> +/// # where +/// # D: Deserializer<'de>, +/// # { +/// let visitor = FlattenedVecVisitor(PhantomData); +/// let flattened: Vec<u64> = deserializer.deserialize_seq(visitor)?; +/// # Ok(()) +/// # } +/// ``` +pub trait DeserializeSeed<'de>: Sized { + /// The type produced by using this seed. + type Value; + + /// Equivalent to the more common `Deserialize::deserialize` method, except + /// with some initial piece of data (the seed) passed in. + fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>; +} + +impl<'de, T> DeserializeSeed<'de> for PhantomData<T> +where + T: Deserialize<'de>, +{ + type Value = T; + + #[inline] + fn deserialize<D>(self, deserializer: D) -> Result<T, D::Error> + where + D: Deserializer<'de>, + { + T::deserialize(deserializer) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A **data format** that can deserialize any data structure supported by +/// Serde. +/// +/// The role of this trait is to define the deserialization half of the [Serde +/// data model], which is a way to categorize every Rust data type into one of +/// 29 possible types. Each method of the `Deserializer` trait corresponds to one +/// of the types of the data model. +/// +/// Implementations of `Deserialize` map themselves into this data model by +/// passing to the `Deserializer` a `Visitor` implementation that can receive +/// these various types. +/// +/// The types that make up the Serde data model are: +/// +/// - **14 primitive types** +/// - bool +/// - i8, i16, i32, i64, i128 +/// - u8, u16, u32, u64, u128 +/// - f32, f64 +/// - char +/// - **string** +/// - UTF-8 bytes with a length and no null terminator. +/// - When serializing, all strings are handled equally. When deserializing, +/// there are three flavors of strings: transient, owned, and borrowed. +/// - **byte array** - \[u8\] +/// - Similar to strings, during deserialization byte arrays can be +/// transient, owned, or borrowed. +/// - **option** +/// - Either none or some value. +/// - **unit** +/// - The type of `()` in Rust. It represents an anonymous value containing +/// no data. +/// - **unit_struct** +/// - For example `struct Unit` or `PhantomData<T>`. It represents a named +/// value containing no data. +/// - **unit_variant** +/// - For example the `E::A` and `E::B` in `enum E { A, B }`. +/// - **newtype_struct** +/// - For example `struct Millimeters(u8)`. +/// - **newtype_variant** +/// - For example the `E::N` in `enum E { N(u8) }`. +/// - **seq** +/// - A variably sized heterogeneous sequence of values, for example `Vec<T>` +/// or `HashSet<T>`. When serializing, the length may or may not be known +/// before iterating through all the data. When deserializing, the length +/// is determined by looking at the serialized data. +/// - **tuple** +/// - A statically sized heterogeneous sequence of values for which the +/// length will be known at deserialization time without looking at the +/// serialized data, for example `(u8,)` or `(String, u64, Vec<T>)` or +/// `[u64; 10]`. +/// - **tuple_struct** +/// - A named tuple, for example `struct Rgb(u8, u8, u8)`. +/// - **tuple_variant** +/// - For example the `E::T` in `enum E { T(u8, u8) }`. +/// - **map** +/// - A heterogeneous key-value pairing, for example `BTreeMap<K, V>`. +/// - **struct** +/// - A heterogeneous key-value pairing in which the keys are strings and +/// will be known at deserialization time without looking at the serialized +/// data, for example `struct S { r: u8, g: u8, b: u8 }`. +/// - **struct_variant** +/// - For example the `E::S` in `enum E { S { r: u8, g: u8, b: u8 } }`. +/// +/// The `Deserializer` trait supports two entry point styles which enables +/// different kinds of deserialization. +/// +/// 1. The `deserialize_any` method. Self-describing data formats like JSON are +/// able to look at the serialized data and tell what it represents. For +/// example the JSON deserializer may see an opening curly brace (`{`) and +/// know that it is seeing a map. If the data format supports +/// `Deserializer::deserialize_any`, it will drive the Visitor using whatever +/// type it sees in the input. JSON uses this approach when deserializing +/// `serde_json::Value` which is an enum that can represent any JSON +/// document. Without knowing what is in a JSON document, we can deserialize +/// it to `serde_json::Value` by going through +/// `Deserializer::deserialize_any`. +/// +/// 2. The various `deserialize_*` methods. Non-self-describing formats like +/// Postcard need to be told what is in the input in order to deserialize it. +/// The `deserialize_*` methods are hints to the deserializer for how to +/// interpret the next piece of input. Non-self-describing formats are not +/// able to deserialize something like `serde_json::Value` which relies on +/// `Deserializer::deserialize_any`. +/// +/// When implementing `Deserialize`, you should avoid relying on +/// `Deserializer::deserialize_any` unless you need to be told by the +/// Deserializer what type is in the input. Know that relying on +/// `Deserializer::deserialize_any` means your data type will be able to +/// deserialize from self-describing formats only, ruling out Postcard and many +/// others. +/// +/// [Serde data model]: https://serde.rs/data-model.html +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed from the input when deserializing. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example implementation +/// +/// The [example data format] presented on the website contains example code for +/// a basic JSON `Deserializer`. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait Deserializer<'de>: Sized { + /// The error type that can be returned if some error occurs during + /// deserialization. + type Error: Error; + + /// Require the `Deserializer` to figure out how to drive the visitor based + /// on what data type is in the input. + /// + /// When implementing `Deserialize`, you should avoid relying on + /// `Deserializer::deserialize_any` unless you need to be told by the + /// Deserializer what type is in the input. Know that relying on + /// `Deserializer::deserialize_any` means your data type will be able to + /// deserialize from self-describing formats only, ruling out Postcard and + /// many others. + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a `bool` value. + fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting an `i8` value. + fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting an `i16` value. + fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting an `i32` value. + fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting an `i64` value. + fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + serde_if_integer128! { + /// Hint that the `Deserialize` type is expecting an `i128` value. + /// + /// This method is available only on Rust compiler versions >=1.26. The + /// default behavior unconditionally returns an error. + fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de> + { + let _ = visitor; + Err(Error::custom("i128 is not supported")) + } + } + + /// Hint that the `Deserialize` type is expecting a `u8` value. + fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a `u16` value. + fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a `u32` value. + fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a `u64` value. + fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + serde_if_integer128! { + /// Hint that the `Deserialize` type is expecting an `u128` value. + /// + /// This method is available only on Rust compiler versions >=1.26. The + /// default behavior unconditionally returns an error. + fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de> + { + let _ = visitor; + Err(Error::custom("u128 is not supported")) + } + } + + /// Hint that the `Deserialize` type is expecting a `f32` value. + fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a `f64` value. + fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a `char` value. + fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a string value and does + /// not benefit from taking ownership of buffered data owned by the + /// `Deserializer`. + /// + /// If the `Visitor` would benefit from taking ownership of `String` data, + /// indicate this to the `Deserializer` by using `deserialize_string` + /// instead. + fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a string value and would + /// benefit from taking ownership of buffered data owned by the + /// `Deserializer`. + /// + /// If the `Visitor` would not benefit from taking ownership of `String` + /// data, indicate that to the `Deserializer` by using `deserialize_str` + /// instead. + fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a byte array and does not + /// benefit from taking ownership of buffered data owned by the + /// `Deserializer`. + /// + /// If the `Visitor` would benefit from taking ownership of `Vec<u8>` data, + /// indicate this to the `Deserializer` by using `deserialize_byte_buf` + /// instead. + fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a byte array and would + /// benefit from taking ownership of buffered data owned by the + /// `Deserializer`. + /// + /// If the `Visitor` would not benefit from taking ownership of `Vec<u8>` + /// data, indicate that to the `Deserializer` by using `deserialize_bytes` + /// instead. + fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting an optional value. + /// + /// This allows deserializers that encode an optional value as a nullable + /// value to convert the null value into `None` and a regular value into + /// `Some(value)`. + fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a unit value. + fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a unit struct with a + /// particular name. + fn deserialize_unit_struct<V>( + self, + name: &'static str, + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a newtype struct with a + /// particular name. + fn deserialize_newtype_struct<V>( + self, + name: &'static str, + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a sequence of values. + fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a sequence of values and + /// knows how many values there are without looking at the serialized data. + fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a tuple struct with a + /// particular name and number of fields. + fn deserialize_tuple_struct<V>( + self, + name: &'static str, + len: usize, + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a map of key-value pairs. + fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting a struct with a particular + /// name and fields. + fn deserialize_struct<V>( + self, + name: &'static str, + fields: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting an enum value with a + /// particular name and possible variants. + fn deserialize_enum<V>( + self, + name: &'static str, + variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type is expecting the name of a struct + /// field or the discriminant of an enum variant. + fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Hint that the `Deserialize` type needs to deserialize a value whose type + /// doesn't matter because it is ignored. + /// + /// Deserializers for non-self-describing formats may not support this mode. + fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Determine whether `Deserialize` implementations should expect to + /// deserialize their human-readable form. + /// + /// Some types have a human-readable form that may be somewhat expensive to + /// construct, as well as a binary form that is compact and efficient. + /// Generally text-based formats like JSON and YAML will prefer to use the + /// human-readable one and binary formats like Postcard will prefer the + /// compact one. + /// + /// ```edition2018 + /// # use std::ops::Add; + /// # use std::str::FromStr; + /// # + /// # struct Timestamp; + /// # + /// # impl Timestamp { + /// # const EPOCH: Timestamp = Timestamp; + /// # } + /// # + /// # impl FromStr for Timestamp { + /// # type Err = String; + /// # fn from_str(_: &str) -> Result<Self, Self::Err> { + /// # unimplemented!() + /// # } + /// # } + /// # + /// # struct Duration; + /// # + /// # impl Duration { + /// # fn seconds(_: u64) -> Self { unimplemented!() } + /// # } + /// # + /// # impl Add<Duration> for Timestamp { + /// # type Output = Timestamp; + /// # fn add(self, _: Duration) -> Self::Output { + /// # unimplemented!() + /// # } + /// # } + /// # + /// use serde::de::{self, Deserialize, Deserializer}; + /// + /// impl<'de> Deserialize<'de> for Timestamp { + /// fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> + /// where + /// D: Deserializer<'de>, + /// { + /// if deserializer.is_human_readable() { + /// // Deserialize from a human-readable string like "2015-05-15T17:01:00Z". + /// let s = String::deserialize(deserializer)?; + /// Timestamp::from_str(&s).map_err(de::Error::custom) + /// } else { + /// // Deserialize from a compact binary representation, seconds since + /// // the Unix epoch. + /// let n = u64::deserialize(deserializer)?; + /// Ok(Timestamp::EPOCH + Duration::seconds(n)) + /// } + /// } + /// } + /// ``` + /// + /// The default implementation of this method returns `true`. Data formats + /// may override this to `false` to request a compact form for types that + /// support one. Note that modifying this method to change a format from + /// human-readable to compact or vice versa should be regarded as a breaking + /// change, as a value serialized in human-readable mode is not required to + /// deserialize from the same data in compact mode. + #[inline] + fn is_human_readable(&self) -> bool { + true + } + + // Not public API. + #[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))] + #[doc(hidden)] + fn __deserialize_content<V>( + self, + _: ::actually_private::T, + visitor: V, + ) -> Result<::private::de::Content<'de>, Self::Error> + where + V: Visitor<'de, Value = ::private::de::Content<'de>>, + { + self.deserialize_any(visitor) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// This trait represents a visitor that walks through a deserializer. +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the requirement for lifetime of data +/// that may be borrowed by `Self::Value`. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example +/// +/// ```edition2018 +/// # use std::fmt; +/// # +/// # use serde::de::{self, Unexpected, Visitor}; +/// # +/// /// A visitor that deserializes a long string - a string containing at least +/// /// some minimum number of bytes. +/// struct LongString { +/// min: usize, +/// } +/// +/// impl<'de> Visitor<'de> for LongString { +/// type Value = String; +/// +/// fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { +/// write!(formatter, "a string containing at least {} bytes", self.min) +/// } +/// +/// fn visit_str<E>(self, s: &str) -> Result<Self::Value, E> +/// where +/// E: de::Error, +/// { +/// if s.len() >= self.min { +/// Ok(s.to_owned()) +/// } else { +/// Err(de::Error::invalid_value(Unexpected::Str(s), &self)) +/// } +/// } +/// } +/// ``` +pub trait Visitor<'de>: Sized { + /// The value produced by this visitor. + type Value; + + /// Format a message stating what data this Visitor expects to receive. + /// + /// This is used in error messages. The message should complete the sentence + /// "This Visitor expects to receive ...", for example the message could be + /// "an integer between 0 and 64". The message should not be capitalized and + /// should not end with a period. + /// + /// ```edition2018 + /// # use std::fmt; + /// # + /// # struct S { + /// # max: usize, + /// # } + /// # + /// # impl<'de> serde::de::Visitor<'de> for S { + /// # type Value = (); + /// # + /// fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + /// write!(formatter, "an integer between 0 and {}", self.max) + /// } + /// # } + /// ``` + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result; + + /// The input contains a boolean. + /// + /// The default implementation fails with a type error. + fn visit_bool<E>(self, v: bool) -> Result<Self::Value, E> + where + E: Error, + { + Err(Error::invalid_type(Unexpected::Bool(v), &self)) + } + + /// The input contains an `i8`. + /// + /// The default implementation forwards to [`visit_i64`]. + /// + /// [`visit_i64`]: #method.visit_i64 + fn visit_i8<E>(self, v: i8) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_i64(v as i64) + } + + /// The input contains an `i16`. + /// + /// The default implementation forwards to [`visit_i64`]. + /// + /// [`visit_i64`]: #method.visit_i64 + fn visit_i16<E>(self, v: i16) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_i64(v as i64) + } + + /// The input contains an `i32`. + /// + /// The default implementation forwards to [`visit_i64`]. + /// + /// [`visit_i64`]: #method.visit_i64 + fn visit_i32<E>(self, v: i32) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_i64(v as i64) + } + + /// The input contains an `i64`. + /// + /// The default implementation fails with a type error. + fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E> + where + E: Error, + { + Err(Error::invalid_type(Unexpected::Signed(v), &self)) + } + + serde_if_integer128! { + /// The input contains a `i128`. + /// + /// This method is available only on Rust compiler versions >=1.26. The + /// default implementation fails with a type error. + fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E> + where + E: Error, + { + let mut buf = [0u8; 58]; + let mut writer = format::Buf::new(&mut buf); + fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as i128", v)).unwrap(); + Err(Error::invalid_type(Unexpected::Other(writer.as_str()), &self)) + } + } + + /// The input contains a `u8`. + /// + /// The default implementation forwards to [`visit_u64`]. + /// + /// [`visit_u64`]: #method.visit_u64 + fn visit_u8<E>(self, v: u8) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_u64(v as u64) + } + + /// The input contains a `u16`. + /// + /// The default implementation forwards to [`visit_u64`]. + /// + /// [`visit_u64`]: #method.visit_u64 + fn visit_u16<E>(self, v: u16) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_u64(v as u64) + } + + /// The input contains a `u32`. + /// + /// The default implementation forwards to [`visit_u64`]. + /// + /// [`visit_u64`]: #method.visit_u64 + fn visit_u32<E>(self, v: u32) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_u64(v as u64) + } + + /// The input contains a `u64`. + /// + /// The default implementation fails with a type error. + fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E> + where + E: Error, + { + Err(Error::invalid_type(Unexpected::Unsigned(v), &self)) + } + + serde_if_integer128! { + /// The input contains a `u128`. + /// + /// This method is available only on Rust compiler versions >=1.26. The + /// default implementation fails with a type error. + fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E> + where + E: Error, + { + let mut buf = [0u8; 57]; + let mut writer = format::Buf::new(&mut buf); + fmt::Write::write_fmt(&mut writer, format_args!("integer `{}` as u128", v)).unwrap(); + Err(Error::invalid_type(Unexpected::Other(writer.as_str()), &self)) + } + } + + /// The input contains an `f32`. + /// + /// The default implementation forwards to [`visit_f64`]. + /// + /// [`visit_f64`]: #method.visit_f64 + fn visit_f32<E>(self, v: f32) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_f64(v as f64) + } + + /// The input contains an `f64`. + /// + /// The default implementation fails with a type error. + fn visit_f64<E>(self, v: f64) -> Result<Self::Value, E> + where + E: Error, + { + Err(Error::invalid_type(Unexpected::Float(v), &self)) + } + + /// The input contains a `char`. + /// + /// The default implementation forwards to [`visit_str`] as a one-character + /// string. + /// + /// [`visit_str`]: #method.visit_str + #[inline] + fn visit_char<E>(self, v: char) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_str(utf8::encode(v).as_str()) + } + + /// The input contains a string. The lifetime of the string is ephemeral and + /// it may be destroyed after this method returns. + /// + /// This method allows the `Deserializer` to avoid a copy by retaining + /// ownership of any buffered data. `Deserialize` implementations that do + /// not benefit from taking ownership of `String` data should indicate that + /// to the deserializer by using `Deserializer::deserialize_str` rather than + /// `Deserializer::deserialize_string`. + /// + /// It is never correct to implement `visit_string` without implementing + /// `visit_str`. Implement neither, both, or just `visit_str`. + fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> + where + E: Error, + { + Err(Error::invalid_type(Unexpected::Str(v), &self)) + } + + /// The input contains a string that lives at least as long as the + /// `Deserializer`. + /// + /// This enables zero-copy deserialization of strings in some formats. For + /// example JSON input containing the JSON string `"borrowed"` can be + /// deserialized with zero copying into a `&'a str` as long as the input + /// data outlives `'a`. + /// + /// The default implementation forwards to `visit_str`. + #[inline] + fn visit_borrowed_str<E>(self, v: &'de str) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_str(v) + } + + /// The input contains a string and ownership of the string is being given + /// to the `Visitor`. + /// + /// This method allows the `Visitor` to avoid a copy by taking ownership of + /// a string created by the `Deserializer`. `Deserialize` implementations + /// that benefit from taking ownership of `String` data should indicate that + /// to the deserializer by using `Deserializer::deserialize_string` rather + /// than `Deserializer::deserialize_str`, although not every deserializer + /// will honor such a request. + /// + /// It is never correct to implement `visit_string` without implementing + /// `visit_str`. Implement neither, both, or just `visit_str`. + /// + /// The default implementation forwards to `visit_str` and then drops the + /// `String`. + #[inline] + #[cfg(any(feature = "std", feature = "alloc"))] + fn visit_string<E>(self, v: String) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_str(&v) + } + + /// The input contains a byte array. The lifetime of the byte array is + /// ephemeral and it may be destroyed after this method returns. + /// + /// This method allows the `Deserializer` to avoid a copy by retaining + /// ownership of any buffered data. `Deserialize` implementations that do + /// not benefit from taking ownership of `Vec<u8>` data should indicate that + /// to the deserializer by using `Deserializer::deserialize_bytes` rather + /// than `Deserializer::deserialize_byte_buf`. + /// + /// It is never correct to implement `visit_byte_buf` without implementing + /// `visit_bytes`. Implement neither, both, or just `visit_bytes`. + fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E> + where + E: Error, + { + let _ = v; + Err(Error::invalid_type(Unexpected::Bytes(v), &self)) + } + + /// The input contains a byte array that lives at least as long as the + /// `Deserializer`. + /// + /// This enables zero-copy deserialization of bytes in some formats. For + /// example Postcard data containing bytes can be deserialized with zero + /// copying into a `&'a [u8]` as long as the input data outlives `'a`. + /// + /// The default implementation forwards to `visit_bytes`. + #[inline] + fn visit_borrowed_bytes<E>(self, v: &'de [u8]) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_bytes(v) + } + + /// The input contains a byte array and ownership of the byte array is being + /// given to the `Visitor`. + /// + /// This method allows the `Visitor` to avoid a copy by taking ownership of + /// a byte buffer created by the `Deserializer`. `Deserialize` + /// implementations that benefit from taking ownership of `Vec<u8>` data + /// should indicate that to the deserializer by using + /// `Deserializer::deserialize_byte_buf` rather than + /// `Deserializer::deserialize_bytes`, although not every deserializer will + /// honor such a request. + /// + /// It is never correct to implement `visit_byte_buf` without implementing + /// `visit_bytes`. Implement neither, both, or just `visit_bytes`. + /// + /// The default implementation forwards to `visit_bytes` and then drops the + /// `Vec<u8>`. + #[cfg(any(feature = "std", feature = "alloc"))] + fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E> + where + E: Error, + { + self.visit_bytes(&v) + } + + /// The input contains an optional that is absent. + /// + /// The default implementation fails with a type error. + fn visit_none<E>(self) -> Result<Self::Value, E> + where + E: Error, + { + Err(Error::invalid_type(Unexpected::Option, &self)) + } + + /// The input contains an optional that is present. + /// + /// The default implementation fails with a type error. + fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + let _ = deserializer; + Err(Error::invalid_type(Unexpected::Option, &self)) + } + + /// The input contains a unit `()`. + /// + /// The default implementation fails with a type error. + fn visit_unit<E>(self) -> Result<Self::Value, E> + where + E: Error, + { + Err(Error::invalid_type(Unexpected::Unit, &self)) + } + + /// The input contains a newtype struct. + /// + /// The content of the newtype struct may be read from the given + /// `Deserializer`. + /// + /// The default implementation fails with a type error. + fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + let _ = deserializer; + Err(Error::invalid_type(Unexpected::NewtypeStruct, &self)) + } + + /// The input contains a sequence of elements. + /// + /// The default implementation fails with a type error. + fn visit_seq<A>(self, seq: A) -> Result<Self::Value, A::Error> + where + A: SeqAccess<'de>, + { + let _ = seq; + Err(Error::invalid_type(Unexpected::Seq, &self)) + } + + /// The input contains a key-value map. + /// + /// The default implementation fails with a type error. + fn visit_map<A>(self, map: A) -> Result<Self::Value, A::Error> + where + A: MapAccess<'de>, + { + let _ = map; + Err(Error::invalid_type(Unexpected::Map, &self)) + } + + /// The input contains an enum. + /// + /// The default implementation fails with a type error. + fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> + where + A: EnumAccess<'de>, + { + let _ = data; + Err(Error::invalid_type(Unexpected::Enum, &self)) + } + + // Used when deserializing a flattened Option field. Not public API. + #[doc(hidden)] + fn __private_visit_untagged_option<D>(self, _: D) -> Result<Self::Value, ()> + where + D: Deserializer<'de>, + { + Err(()) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// Provides a `Visitor` access to each element of a sequence in the input. +/// +/// This is a trait that a `Deserializer` passes to a `Visitor` implementation, +/// which deserializes each item in a sequence. +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed by deserialized sequence elements. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SeqAccess` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SeqAccess<'de> { + /// The error type that can be returned if some error occurs during + /// deserialization. + type Error: Error; + + /// This returns `Ok(Some(value))` for the next value in the sequence, or + /// `Ok(None)` if there are no more remaining items. + /// + /// `Deserialize` implementations should typically use + /// `SeqAccess::next_element` instead. + fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> + where + T: DeserializeSeed<'de>; + + /// This returns `Ok(Some(value))` for the next value in the sequence, or + /// `Ok(None)` if there are no more remaining items. + /// + /// This method exists as a convenience for `Deserialize` implementations. + /// `SeqAccess` implementations should not override the default behavior. + #[inline] + fn next_element<T>(&mut self) -> Result<Option<T>, Self::Error> + where + T: Deserialize<'de>, + { + self.next_element_seed(PhantomData) + } + + /// Returns the number of elements remaining in the sequence, if known. + #[inline] + fn size_hint(&self) -> Option<usize> { + None + } +} + +impl<'de, 'a, A: ?Sized> SeqAccess<'de> for &'a mut A +where + A: SeqAccess<'de>, +{ + type Error = A::Error; + + #[inline] + fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> + where + T: DeserializeSeed<'de>, + { + (**self).next_element_seed(seed) + } + + #[inline] + fn next_element<T>(&mut self) -> Result<Option<T>, Self::Error> + where + T: Deserialize<'de>, + { + (**self).next_element() + } + + #[inline] + fn size_hint(&self) -> Option<usize> { + (**self).size_hint() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// Provides a `Visitor` access to each entry of a map in the input. +/// +/// This is a trait that a `Deserializer` passes to a `Visitor` implementation. +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed by deserialized map entries. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `MapAccess` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait MapAccess<'de> { + /// The error type that can be returned if some error occurs during + /// deserialization. + type Error: Error; + + /// This returns `Ok(Some(key))` for the next key in the map, or `Ok(None)` + /// if there are no more remaining entries. + /// + /// `Deserialize` implementations should typically use + /// `MapAccess::next_key` or `MapAccess::next_entry` instead. + fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error> + where + K: DeserializeSeed<'de>; + + /// This returns a `Ok(value)` for the next value in the map. + /// + /// `Deserialize` implementations should typically use + /// `MapAccess::next_value` instead. + /// + /// # Panics + /// + /// Calling `next_value_seed` before `next_key_seed` is incorrect and is + /// allowed to panic or return bogus results. + fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error> + where + V: DeserializeSeed<'de>; + + /// This returns `Ok(Some((key, value)))` for the next (key-value) pair in + /// the map, or `Ok(None)` if there are no more remaining items. + /// + /// `MapAccess` implementations should override the default behavior if a + /// more efficient implementation is possible. + /// + /// `Deserialize` implementations should typically use + /// `MapAccess::next_entry` instead. + #[inline] + fn next_entry_seed<K, V>( + &mut self, + kseed: K, + vseed: V, + ) -> Result<Option<(K::Value, V::Value)>, Self::Error> + where + K: DeserializeSeed<'de>, + V: DeserializeSeed<'de>, + { + match try!(self.next_key_seed(kseed)) { + Some(key) => { + let value = try!(self.next_value_seed(vseed)); + Ok(Some((key, value))) + } + None => Ok(None), + } + } + + /// This returns `Ok(Some(key))` for the next key in the map, or `Ok(None)` + /// if there are no more remaining entries. + /// + /// This method exists as a convenience for `Deserialize` implementations. + /// `MapAccess` implementations should not override the default behavior. + #[inline] + fn next_key<K>(&mut self) -> Result<Option<K>, Self::Error> + where + K: Deserialize<'de>, + { + self.next_key_seed(PhantomData) + } + + /// This returns a `Ok(value)` for the next value in the map. + /// + /// This method exists as a convenience for `Deserialize` implementations. + /// `MapAccess` implementations should not override the default behavior. + /// + /// # Panics + /// + /// Calling `next_value` before `next_key` is incorrect and is allowed to + /// panic or return bogus results. + #[inline] + fn next_value<V>(&mut self) -> Result<V, Self::Error> + where + V: Deserialize<'de>, + { + self.next_value_seed(PhantomData) + } + + /// This returns `Ok(Some((key, value)))` for the next (key-value) pair in + /// the map, or `Ok(None)` if there are no more remaining items. + /// + /// This method exists as a convenience for `Deserialize` implementations. + /// `MapAccess` implementations should not override the default behavior. + #[inline] + fn next_entry<K, V>(&mut self) -> Result<Option<(K, V)>, Self::Error> + where + K: Deserialize<'de>, + V: Deserialize<'de>, + { + self.next_entry_seed(PhantomData, PhantomData) + } + + /// Returns the number of entries remaining in the map, if known. + #[inline] + fn size_hint(&self) -> Option<usize> { + None + } +} + +impl<'de, 'a, A: ?Sized> MapAccess<'de> for &'a mut A +where + A: MapAccess<'de>, +{ + type Error = A::Error; + + #[inline] + fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error> + where + K: DeserializeSeed<'de>, + { + (**self).next_key_seed(seed) + } + + #[inline] + fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error> + where + V: DeserializeSeed<'de>, + { + (**self).next_value_seed(seed) + } + + #[inline] + fn next_entry_seed<K, V>( + &mut self, + kseed: K, + vseed: V, + ) -> Result<Option<(K::Value, V::Value)>, Self::Error> + where + K: DeserializeSeed<'de>, + V: DeserializeSeed<'de>, + { + (**self).next_entry_seed(kseed, vseed) + } + + #[inline] + fn next_entry<K, V>(&mut self) -> Result<Option<(K, V)>, Self::Error> + where + K: Deserialize<'de>, + V: Deserialize<'de>, + { + (**self).next_entry() + } + + #[inline] + fn next_key<K>(&mut self) -> Result<Option<K>, Self::Error> + where + K: Deserialize<'de>, + { + (**self).next_key() + } + + #[inline] + fn next_value<V>(&mut self) -> Result<V, Self::Error> + where + V: Deserialize<'de>, + { + (**self).next_value() + } + + #[inline] + fn size_hint(&self) -> Option<usize> { + (**self).size_hint() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// Provides a `Visitor` access to the data of an enum in the input. +/// +/// `EnumAccess` is created by the `Deserializer` and passed to the +/// `Visitor` in order to identify which variant of an enum to deserialize. +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed by the deserialized enum variant. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `EnumAccess` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait EnumAccess<'de>: Sized { + /// The error type that can be returned if some error occurs during + /// deserialization. + type Error: Error; + /// The `Visitor` that will be used to deserialize the content of the enum + /// variant. + type Variant: VariantAccess<'de, Error = Self::Error>; + + /// `variant` is called to identify which variant to deserialize. + /// + /// `Deserialize` implementations should typically use `EnumAccess::variant` + /// instead. + fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Self::Error> + where + V: DeserializeSeed<'de>; + + /// `variant` is called to identify which variant to deserialize. + /// + /// This method exists as a convenience for `Deserialize` implementations. + /// `EnumAccess` implementations should not override the default behavior. + #[inline] + fn variant<V>(self) -> Result<(V, Self::Variant), Self::Error> + where + V: Deserialize<'de>, + { + self.variant_seed(PhantomData) + } +} + +/// `VariantAccess` is a visitor that is created by the `Deserializer` and +/// passed to the `Deserialize` to deserialize the content of a particular enum +/// variant. +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed by the deserialized enum variant. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `VariantAccess` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait VariantAccess<'de>: Sized { + /// The error type that can be returned if some error occurs during + /// deserialization. Must match the error type of our `EnumAccess`. + type Error: Error; + + /// Called when deserializing a variant with no values. + /// + /// If the data contains a different type of variant, the following + /// `invalid_type` error should be constructed: + /// + /// ```edition2018 + /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected}; + /// # + /// # struct X; + /// # + /// # impl<'de> VariantAccess<'de> for X { + /// # type Error = value::Error; + /// # + /// fn unit_variant(self) -> Result<(), Self::Error> { + /// // What the data actually contained; suppose it is a tuple variant. + /// let unexp = Unexpected::TupleVariant; + /// Err(de::Error::invalid_type(unexp, &"unit variant")) + /// } + /// # + /// # fn newtype_variant_seed<T>(self, _: T) -> Result<T::Value, Self::Error> + /// # where + /// # T: DeserializeSeed<'de>, + /// # { unimplemented!() } + /// # + /// # fn tuple_variant<V>(self, _: usize, _: V) -> Result<V::Value, Self::Error> + /// # where + /// # V: Visitor<'de>, + /// # { unimplemented!() } + /// # + /// # fn struct_variant<V>(self, _: &[&str], _: V) -> Result<V::Value, Self::Error> + /// # where + /// # V: Visitor<'de>, + /// # { unimplemented!() } + /// # } + /// ``` + fn unit_variant(self) -> Result<(), Self::Error>; + + /// Called when deserializing a variant with a single value. + /// + /// `Deserialize` implementations should typically use + /// `VariantAccess::newtype_variant` instead. + /// + /// If the data contains a different type of variant, the following + /// `invalid_type` error should be constructed: + /// + /// ```edition2018 + /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected}; + /// # + /// # struct X; + /// # + /// # impl<'de> VariantAccess<'de> for X { + /// # type Error = value::Error; + /// # + /// # fn unit_variant(self) -> Result<(), Self::Error> { + /// # unimplemented!() + /// # } + /// # + /// fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value, Self::Error> + /// where + /// T: DeserializeSeed<'de>, + /// { + /// // What the data actually contained; suppose it is a unit variant. + /// let unexp = Unexpected::UnitVariant; + /// Err(de::Error::invalid_type(unexp, &"newtype variant")) + /// } + /// # + /// # fn tuple_variant<V>(self, _: usize, _: V) -> Result<V::Value, Self::Error> + /// # where + /// # V: Visitor<'de>, + /// # { unimplemented!() } + /// # + /// # fn struct_variant<V>(self, _: &[&str], _: V) -> Result<V::Value, Self::Error> + /// # where + /// # V: Visitor<'de>, + /// # { unimplemented!() } + /// # } + /// ``` + fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Self::Error> + where + T: DeserializeSeed<'de>; + + /// Called when deserializing a variant with a single value. + /// + /// This method exists as a convenience for `Deserialize` implementations. + /// `VariantAccess` implementations should not override the default + /// behavior. + #[inline] + fn newtype_variant<T>(self) -> Result<T, Self::Error> + where + T: Deserialize<'de>, + { + self.newtype_variant_seed(PhantomData) + } + + /// Called when deserializing a tuple-like variant. + /// + /// The `len` is the number of fields expected in the tuple variant. + /// + /// If the data contains a different type of variant, the following + /// `invalid_type` error should be constructed: + /// + /// ```edition2018 + /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected}; + /// # + /// # struct X; + /// # + /// # impl<'de> VariantAccess<'de> for X { + /// # type Error = value::Error; + /// # + /// # fn unit_variant(self) -> Result<(), Self::Error> { + /// # unimplemented!() + /// # } + /// # + /// # fn newtype_variant_seed<T>(self, _: T) -> Result<T::Value, Self::Error> + /// # where + /// # T: DeserializeSeed<'de>, + /// # { unimplemented!() } + /// # + /// fn tuple_variant<V>( + /// self, + /// _len: usize, + /// _visitor: V, + /// ) -> Result<V::Value, Self::Error> + /// where + /// V: Visitor<'de>, + /// { + /// // What the data actually contained; suppose it is a unit variant. + /// let unexp = Unexpected::UnitVariant; + /// Err(de::Error::invalid_type(unexp, &"tuple variant")) + /// } + /// # + /// # fn struct_variant<V>(self, _: &[&str], _: V) -> Result<V::Value, Self::Error> + /// # where + /// # V: Visitor<'de>, + /// # { unimplemented!() } + /// # } + /// ``` + fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; + + /// Called when deserializing a struct-like variant. + /// + /// The `fields` are the names of the fields of the struct variant. + /// + /// If the data contains a different type of variant, the following + /// `invalid_type` error should be constructed: + /// + /// ```edition2018 + /// # use serde::de::{self, value, DeserializeSeed, Visitor, VariantAccess, Unexpected}; + /// # + /// # struct X; + /// # + /// # impl<'de> VariantAccess<'de> for X { + /// # type Error = value::Error; + /// # + /// # fn unit_variant(self) -> Result<(), Self::Error> { + /// # unimplemented!() + /// # } + /// # + /// # fn newtype_variant_seed<T>(self, _: T) -> Result<T::Value, Self::Error> + /// # where + /// # T: DeserializeSeed<'de>, + /// # { unimplemented!() } + /// # + /// # fn tuple_variant<V>(self, _: usize, _: V) -> Result<V::Value, Self::Error> + /// # where + /// # V: Visitor<'de>, + /// # { unimplemented!() } + /// # + /// fn struct_variant<V>( + /// self, + /// _fields: &'static [&'static str], + /// _visitor: V, + /// ) -> Result<V::Value, Self::Error> + /// where + /// V: Visitor<'de>, + /// { + /// // What the data actually contained; suppose it is a unit variant. + /// let unexp = Unexpected::UnitVariant; + /// Err(de::Error::invalid_type(unexp, &"struct variant")) + /// } + /// # } + /// ``` + fn struct_variant<V>( + self, + fields: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>; +} + +//////////////////////////////////////////////////////////////////////////////// + +/// Converts an existing value into a `Deserializer` from which other values can +/// be deserialized. +/// +/// # Lifetime +/// +/// The `'de` lifetime of this trait is the lifetime of data that may be +/// borrowed from the resulting `Deserializer`. See the page [Understanding +/// deserializer lifetimes] for a more detailed explanation of these lifetimes. +/// +/// [Understanding deserializer lifetimes]: https://serde.rs/lifetimes.html +/// +/// # Example +/// +/// ```edition2018 +/// use std::str::FromStr; +/// use serde::Deserialize; +/// use serde::de::{value, IntoDeserializer}; +/// +/// #[derive(Deserialize)] +/// enum Setting { +/// On, +/// Off, +/// } +/// +/// impl FromStr for Setting { +/// type Err = value::Error; +/// +/// fn from_str(s: &str) -> Result<Self, Self::Err> { +/// Self::deserialize(s.into_deserializer()) +/// } +/// } +/// ``` +pub trait IntoDeserializer<'de, E: Error = value::Error> { + /// The type of the deserializer being converted into. + type Deserializer: Deserializer<'de, Error = E>; + + /// Convert this value into a deserializer. + fn into_deserializer(self) -> Self::Deserializer; +} + +//////////////////////////////////////////////////////////////////////////////// + +/// Used in error messages. +/// +/// - expected `a` +/// - expected `a` or `b` +/// - expected one of `a`, `b`, `c` +/// +/// The slice of names must not be empty. +struct OneOf { + names: &'static [&'static str], +} + +impl Display for OneOf { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + match self.names.len() { + 0 => panic!(), // special case elsewhere + 1 => write!(formatter, "`{}`", self.names[0]), + 2 => write!(formatter, "`{}` or `{}`", self.names[0], self.names[1]), + _ => { + try!(write!(formatter, "one of ")); + for (i, alt) in self.names.iter().enumerate() { + if i > 0 { + try!(write!(formatter, ", ")); + } + try!(write!(formatter, "`{}`", alt)); + } + Ok(()) + } + } + } +} diff --git a/third_party/rust/serde/src/de/seed.rs b/third_party/rust/serde/src/de/seed.rs new file mode 100644 index 0000000000..13b7ea461b --- /dev/null +++ b/third_party/rust/serde/src/de/seed.rs @@ -0,0 +1,19 @@ +use de::{Deserialize, DeserializeSeed, Deserializer}; + +/// A DeserializeSeed helper for implementing deserialize_in_place Visitors. +/// +/// Wraps a mutable reference and calls deserialize_in_place on it. +pub struct InPlaceSeed<'a, T: 'a>(pub &'a mut T); + +impl<'a, 'de, T> DeserializeSeed<'de> for InPlaceSeed<'a, T> +where + T: Deserialize<'de>, +{ + type Value = (); + fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + T::deserialize_in_place(deserializer, self.0) + } +} diff --git a/third_party/rust/serde/src/de/utf8.rs b/third_party/rust/serde/src/de/utf8.rs new file mode 100644 index 0000000000..576fd03cfa --- /dev/null +++ b/third_party/rust/serde/src/de/utf8.rs @@ -0,0 +1,46 @@ +use lib::*; + +const TAG_CONT: u8 = 0b1000_0000; +const TAG_TWO_B: u8 = 0b1100_0000; +const TAG_THREE_B: u8 = 0b1110_0000; +const TAG_FOUR_B: u8 = 0b1111_0000; +const MAX_ONE_B: u32 = 0x80; +const MAX_TWO_B: u32 = 0x800; +const MAX_THREE_B: u32 = 0x10000; + +#[inline] +pub fn encode(c: char) -> Encode { + let code = c as u32; + let mut buf = [0; 4]; + let pos = if code < MAX_ONE_B { + buf[3] = code as u8; + 3 + } else if code < MAX_TWO_B { + buf[2] = (code >> 6 & 0x1F) as u8 | TAG_TWO_B; + buf[3] = (code & 0x3F) as u8 | TAG_CONT; + 2 + } else if code < MAX_THREE_B { + buf[1] = (code >> 12 & 0x0F) as u8 | TAG_THREE_B; + buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT; + buf[3] = (code & 0x3F) as u8 | TAG_CONT; + 1 + } else { + buf[0] = (code >> 18 & 0x07) as u8 | TAG_FOUR_B; + buf[1] = (code >> 12 & 0x3F) as u8 | TAG_CONT; + buf[2] = (code >> 6 & 0x3F) as u8 | TAG_CONT; + buf[3] = (code & 0x3F) as u8 | TAG_CONT; + 0 + }; + Encode { buf: buf, pos: pos } +} + +pub struct Encode { + buf: [u8; 4], + pos: usize, +} + +impl Encode { + pub fn as_str(&self) -> &str { + str::from_utf8(&self.buf[self.pos..]).unwrap() + } +} diff --git a/third_party/rust/serde/src/de/value.rs b/third_party/rust/serde/src/de/value.rs new file mode 100644 index 0000000000..5d88862159 --- /dev/null +++ b/third_party/rust/serde/src/de/value.rs @@ -0,0 +1,1714 @@ +//! Building blocks for deserializing basic values using the `IntoDeserializer` +//! trait. +//! +//! ```edition2018 +//! use std::str::FromStr; +//! use serde::Deserialize; +//! use serde::de::{value, IntoDeserializer}; +//! +//! #[derive(Deserialize)] +//! enum Setting { +//! On, +//! Off, +//! } +//! +//! impl FromStr for Setting { +//! type Err = value::Error; +//! +//! fn from_str(s: &str) -> Result<Self, Self::Err> { +//! Self::deserialize(s.into_deserializer()) +//! } +//! } +//! ``` + +use lib::*; + +use self::private::{First, Second}; +use __private::size_hint; +use de::{self, Deserializer, Expected, IntoDeserializer, SeqAccess, Visitor}; +use ser; + +//////////////////////////////////////////////////////////////////////////////// + +// For structs that contain a PhantomData. We do not want the trait +// bound `E: Clone` inferred by derive(Clone). +macro_rules! impl_copy_clone { + ($ty:ident $(<$lifetime:tt>)*) => { + impl<$($lifetime,)* E> Copy for $ty<$($lifetime,)* E> {} + + impl<$($lifetime,)* E> Clone for $ty<$($lifetime,)* E> { + fn clone(&self) -> Self { + *self + } + } + }; +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A minimal representation of all possible errors that can occur using the +/// `IntoDeserializer` trait. +#[derive(Clone, PartialEq)] +pub struct Error { + err: ErrorImpl, +} + +#[cfg(any(feature = "std", feature = "alloc"))] +type ErrorImpl = Box<str>; +#[cfg(not(any(feature = "std", feature = "alloc")))] +type ErrorImpl = (); + +impl de::Error for Error { + #[cfg(any(feature = "std", feature = "alloc"))] + #[cold] + fn custom<T>(msg: T) -> Self + where + T: Display, + { + Error { + err: msg.to_string().into_boxed_str(), + } + } + + #[cfg(not(any(feature = "std", feature = "alloc")))] + #[cold] + fn custom<T>(msg: T) -> Self + where + T: Display, + { + let _ = msg; + Error { err: () } + } +} + +impl ser::Error for Error { + #[cold] + fn custom<T>(msg: T) -> Self + where + T: Display, + { + de::Error::custom(msg) + } +} + +impl Display for Error { + #[cfg(any(feature = "std", feature = "alloc"))] + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str(&self.err) + } + + #[cfg(not(any(feature = "std", feature = "alloc")))] + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("Serde deserialization error") + } +} + +impl Debug for Error { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + let mut debug = formatter.debug_tuple("Error"); + #[cfg(any(feature = "std", feature = "alloc"))] + debug.field(&self.err); + debug.finish() + } +} + +#[cfg(feature = "std")] +impl error::Error for Error { + fn description(&self) -> &str { + &self.err + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<'de, E> IntoDeserializer<'de, E> for () +where + E: de::Error, +{ + type Deserializer = UnitDeserializer<E>; + + fn into_deserializer(self) -> UnitDeserializer<E> { + UnitDeserializer::new() + } +} + +/// A deserializer holding a `()`. +pub struct UnitDeserializer<E> { + marker: PhantomData<E>, +} + +impl_copy_clone!(UnitDeserializer); + +impl<E> UnitDeserializer<E> { + #[allow(missing_docs)] + pub fn new() -> Self { + UnitDeserializer { + marker: PhantomData, + } + } +} + +impl<'de, E> de::Deserializer<'de> for UnitDeserializer<E> +where + E: de::Error, +{ + type Error = E; + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf unit unit_struct newtype_struct seq tuple tuple_struct + map struct enum identifier ignored_any + } + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_unit() + } + + fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_none() + } +} + +impl<E> Debug for UnitDeserializer<E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.debug_struct("UnitDeserializer").finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer that cannot be instantiated. +#[cfg(feature = "unstable")] +pub struct NeverDeserializer<E> { + never: !, + marker: PhantomData<E>, +} + +#[cfg(feature = "unstable")] +impl<'de, E> IntoDeserializer<'de, E> for ! +where + E: de::Error, +{ + type Deserializer = NeverDeserializer<E>; + + fn into_deserializer(self) -> Self::Deserializer { + self + } +} + +#[cfg(feature = "unstable")] +impl<'de, E> de::Deserializer<'de> for NeverDeserializer<E> +where + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(self, _visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + self.never + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct enum identifier ignored_any + } +} + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! primitive_deserializer { + ($ty:ty, $doc:tt, $name:ident, $method:ident $($cast:tt)*) => { + #[doc = "A deserializer holding"] + #[doc = $doc] + pub struct $name<E> { + value: $ty, + marker: PhantomData<E> + } + + impl_copy_clone!($name); + + impl<'de, E> IntoDeserializer<'de, E> for $ty + where + E: de::Error, + { + type Deserializer = $name<E>; + + fn into_deserializer(self) -> $name<E> { + $name::new(self) + } + } + + impl<E> $name<E> { + #[allow(missing_docs)] + pub fn new(value: $ty) -> Self { + $name { + value: value, + marker: PhantomData, + } + } + } + + impl<'de, E> de::Deserializer<'de> for $name<E> + where + E: de::Error, + { + type Error = E; + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str + string bytes byte_buf option unit unit_struct newtype_struct seq + tuple tuple_struct map struct enum identifier ignored_any + } + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.$method(self.value $($cast)*) + } + } + + impl<E> Debug for $name<E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct(stringify!($name)) + .field("value", &self.value) + .finish() + } + } + } +} + +primitive_deserializer!(bool, "a `bool`.", BoolDeserializer, visit_bool); +primitive_deserializer!(i8, "an `i8`.", I8Deserializer, visit_i8); +primitive_deserializer!(i16, "an `i16`.", I16Deserializer, visit_i16); +primitive_deserializer!(i32, "an `i32`.", I32Deserializer, visit_i32); +primitive_deserializer!(i64, "an `i64`.", I64Deserializer, visit_i64); +primitive_deserializer!(isize, "an `isize`.", IsizeDeserializer, visit_i64 as i64); +primitive_deserializer!(u8, "a `u8`.", U8Deserializer, visit_u8); +primitive_deserializer!(u16, "a `u16`.", U16Deserializer, visit_u16); +primitive_deserializer!(u64, "a `u64`.", U64Deserializer, visit_u64); +primitive_deserializer!(usize, "a `usize`.", UsizeDeserializer, visit_u64 as u64); +primitive_deserializer!(f32, "an `f32`.", F32Deserializer, visit_f32); +primitive_deserializer!(f64, "an `f64`.", F64Deserializer, visit_f64); +primitive_deserializer!(char, "a `char`.", CharDeserializer, visit_char); + +serde_if_integer128! { + primitive_deserializer!(i128, "an `i128`.", I128Deserializer, visit_i128); + primitive_deserializer!(u128, "a `u128`.", U128Deserializer, visit_u128); +} + +/// A deserializer holding a `u32`. +pub struct U32Deserializer<E> { + value: u32, + marker: PhantomData<E>, +} + +impl_copy_clone!(U32Deserializer); + +impl<'de, E> IntoDeserializer<'de, E> for u32 +where + E: de::Error, +{ + type Deserializer = U32Deserializer<E>; + + fn into_deserializer(self) -> U32Deserializer<E> { + U32Deserializer::new(self) + } +} + +impl<E> U32Deserializer<E> { + #[allow(missing_docs)] + pub fn new(value: u32) -> Self { + U32Deserializer { + value: value, + marker: PhantomData, + } + } +} + +impl<'de, E> de::Deserializer<'de> for U32Deserializer<E> +where + E: de::Error, +{ + type Error = E; + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct identifier ignored_any + } + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_u32(self.value) + } + + fn deserialize_enum<V>( + self, + name: &str, + variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let _ = name; + let _ = variants; + visitor.visit_enum(self) + } +} + +impl<'de, E> de::EnumAccess<'de> for U32Deserializer<E> +where + E: de::Error, +{ + type Error = E; + type Variant = private::UnitOnly<E>; + + fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> + where + T: de::DeserializeSeed<'de>, + { + seed.deserialize(self).map(private::unit_only) + } +} + +impl<E> Debug for U32Deserializer<E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("U32Deserializer") + .field("value", &self.value) + .finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding a `&str`. +pub struct StrDeserializer<'a, E> { + value: &'a str, + marker: PhantomData<E>, +} + +impl_copy_clone!(StrDeserializer<'de>); + +impl<'de, 'a, E> IntoDeserializer<'de, E> for &'a str +where + E: de::Error, +{ + type Deserializer = StrDeserializer<'a, E>; + + fn into_deserializer(self) -> StrDeserializer<'a, E> { + StrDeserializer::new(self) + } +} + +impl<'a, E> StrDeserializer<'a, E> { + #[allow(missing_docs)] + pub fn new(value: &'a str) -> Self { + StrDeserializer { + value: value, + marker: PhantomData, + } + } +} + +impl<'de, 'a, E> de::Deserializer<'de> for StrDeserializer<'a, E> +where + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_str(self.value) + } + + fn deserialize_enum<V>( + self, + name: &str, + variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let _ = name; + let _ = variants; + visitor.visit_enum(self) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct identifier ignored_any + } +} + +impl<'de, 'a, E> de::EnumAccess<'de> for StrDeserializer<'a, E> +where + E: de::Error, +{ + type Error = E; + type Variant = private::UnitOnly<E>; + + fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> + where + T: de::DeserializeSeed<'de>, + { + seed.deserialize(self).map(private::unit_only) + } +} + +impl<'a, E> Debug for StrDeserializer<'a, E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("StrDeserializer") + .field("value", &self.value) + .finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding a `&str` with a lifetime tied to another +/// deserializer. +pub struct BorrowedStrDeserializer<'de, E> { + value: &'de str, + marker: PhantomData<E>, +} + +impl_copy_clone!(BorrowedStrDeserializer<'de>); + +impl<'de, E> BorrowedStrDeserializer<'de, E> { + /// Create a new borrowed deserializer from the given string. + pub fn new(value: &'de str) -> BorrowedStrDeserializer<'de, E> { + BorrowedStrDeserializer { + value: value, + marker: PhantomData, + } + } +} + +impl<'de, E> de::Deserializer<'de> for BorrowedStrDeserializer<'de, E> +where + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_borrowed_str(self.value) + } + + fn deserialize_enum<V>( + self, + name: &str, + variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let _ = name; + let _ = variants; + visitor.visit_enum(self) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct identifier ignored_any + } +} + +impl<'de, E> de::EnumAccess<'de> for BorrowedStrDeserializer<'de, E> +where + E: de::Error, +{ + type Error = E; + type Variant = private::UnitOnly<E>; + + fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> + where + T: de::DeserializeSeed<'de>, + { + seed.deserialize(self).map(private::unit_only) + } +} + +impl<'de, E> Debug for BorrowedStrDeserializer<'de, E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("BorrowedStrDeserializer") + .field("value", &self.value) + .finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding a `String`. +#[cfg(any(feature = "std", feature = "alloc"))] +pub struct StringDeserializer<E> { + value: String, + marker: PhantomData<E>, +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<E> Clone for StringDeserializer<E> { + fn clone(&self) -> Self { + StringDeserializer { + value: self.value.clone(), + marker: PhantomData, + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, E> IntoDeserializer<'de, E> for String +where + E: de::Error, +{ + type Deserializer = StringDeserializer<E>; + + fn into_deserializer(self) -> StringDeserializer<E> { + StringDeserializer::new(self) + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<E> StringDeserializer<E> { + #[allow(missing_docs)] + pub fn new(value: String) -> Self { + StringDeserializer { + value: value, + marker: PhantomData, + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, E> de::Deserializer<'de> for StringDeserializer<E> +where + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_string(self.value) + } + + fn deserialize_enum<V>( + self, + name: &str, + variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let _ = name; + let _ = variants; + visitor.visit_enum(self) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct identifier ignored_any + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, E> de::EnumAccess<'de> for StringDeserializer<E> +where + E: de::Error, +{ + type Error = E; + type Variant = private::UnitOnly<E>; + + fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> + where + T: de::DeserializeSeed<'de>, + { + seed.deserialize(self).map(private::unit_only) + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<E> Debug for StringDeserializer<E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("StringDeserializer") + .field("value", &self.value) + .finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding a `Cow<str>`. +#[cfg(any(feature = "std", feature = "alloc"))] +pub struct CowStrDeserializer<'a, E> { + value: Cow<'a, str>, + marker: PhantomData<E>, +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'a, E> Clone for CowStrDeserializer<'a, E> { + fn clone(&self) -> Self { + CowStrDeserializer { + value: self.value.clone(), + marker: PhantomData, + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, 'a, E> IntoDeserializer<'de, E> for Cow<'a, str> +where + E: de::Error, +{ + type Deserializer = CowStrDeserializer<'a, E>; + + fn into_deserializer(self) -> CowStrDeserializer<'a, E> { + CowStrDeserializer::new(self) + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'a, E> CowStrDeserializer<'a, E> { + #[allow(missing_docs)] + pub fn new(value: Cow<'a, str>) -> Self { + CowStrDeserializer { + value: value, + marker: PhantomData, + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, 'a, E> de::Deserializer<'de> for CowStrDeserializer<'a, E> +where + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + match self.value { + Cow::Borrowed(string) => visitor.visit_str(string), + Cow::Owned(string) => visitor.visit_string(string), + } + } + + fn deserialize_enum<V>( + self, + name: &str, + variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let _ = name; + let _ = variants; + visitor.visit_enum(self) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct identifier ignored_any + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, 'a, E> de::EnumAccess<'de> for CowStrDeserializer<'a, E> +where + E: de::Error, +{ + type Error = E; + type Variant = private::UnitOnly<E>; + + fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> + where + T: de::DeserializeSeed<'de>, + { + seed.deserialize(self).map(private::unit_only) + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'a, E> Debug for CowStrDeserializer<'a, E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("CowStrDeserializer") + .field("value", &self.value) + .finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding a `&[u8]`. Always calls [`Visitor::visit_bytes`]. +pub struct BytesDeserializer<'a, E> { + value: &'a [u8], + marker: PhantomData<E>, +} + +impl<'a, E> BytesDeserializer<'a, E> { + /// Create a new deserializer from the given bytes. + pub fn new(value: &'a [u8]) -> Self { + BytesDeserializer { + value: value, + marker: PhantomData, + } + } +} + +impl_copy_clone!(BytesDeserializer<'a>); + +impl<'de, 'a, E> IntoDeserializer<'de, E> for &'a [u8] +where + E: de::Error, +{ + type Deserializer = BytesDeserializer<'a, E>; + + fn into_deserializer(self) -> BytesDeserializer<'a, E> { + BytesDeserializer::new(self) + } +} + +impl<'de, 'a, E> Deserializer<'de> for BytesDeserializer<'a, E> +where + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>, + { + visitor.visit_bytes(self.value) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct enum identifier ignored_any + } +} + +impl<'a, E> Debug for BytesDeserializer<'a, E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("BytesDeserializer") + .field("value", &self.value) + .finish() + } +} + +/// A deserializer holding a `&[u8]` with a lifetime tied to another +/// deserializer. Always calls [`Visitor::visit_borrowed_bytes`]. +pub struct BorrowedBytesDeserializer<'de, E> { + value: &'de [u8], + marker: PhantomData<E>, +} + +impl<'de, E> BorrowedBytesDeserializer<'de, E> { + /// Create a new borrowed deserializer from the given borrowed bytes. + pub fn new(value: &'de [u8]) -> Self { + BorrowedBytesDeserializer { + value: value, + marker: PhantomData, + } + } +} + +impl_copy_clone!(BorrowedBytesDeserializer<'de>); + +impl<'de, E> Deserializer<'de> for BorrowedBytesDeserializer<'de, E> +where + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>, + { + visitor.visit_borrowed_bytes(self.value) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct enum identifier ignored_any + } +} + +impl<'de, E> Debug for BorrowedBytesDeserializer<'de, E> { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("BorrowedBytesDeserializer") + .field("value", &self.value) + .finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer that iterates over a sequence. +#[derive(Clone)] +pub struct SeqDeserializer<I, E> { + iter: iter::Fuse<I>, + count: usize, + marker: PhantomData<E>, +} + +impl<I, E> SeqDeserializer<I, E> +where + I: Iterator, +{ + /// Construct a new `SeqDeserializer<I, E>`. + pub fn new(iter: I) -> Self { + SeqDeserializer { + iter: iter.fuse(), + count: 0, + marker: PhantomData, + } + } +} + +impl<I, E> SeqDeserializer<I, E> +where + I: Iterator, + E: de::Error, +{ + /// Check for remaining elements after passing a `SeqDeserializer` to + /// `Visitor::visit_seq`. + pub fn end(self) -> Result<(), E> { + let remaining = self.iter.count(); + if remaining == 0 { + Ok(()) + } else { + // First argument is the number of elements in the data, second + // argument is the number of elements expected by the Deserialize. + Err(de::Error::invalid_length( + self.count + remaining, + &ExpectedInSeq(self.count), + )) + } + } +} + +impl<'de, I, T, E> de::Deserializer<'de> for SeqDeserializer<I, E> +where + I: Iterator<Item = T>, + T: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(mut self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let v = try!(visitor.visit_seq(&mut self)); + try!(self.end()); + Ok(v) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct enum identifier ignored_any + } +} + +impl<'de, I, T, E> de::SeqAccess<'de> for SeqDeserializer<I, E> +where + I: Iterator<Item = T>, + T: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Error = E; + + fn next_element_seed<V>(&mut self, seed: V) -> Result<Option<V::Value>, Self::Error> + where + V: de::DeserializeSeed<'de>, + { + match self.iter.next() { + Some(value) => { + self.count += 1; + seed.deserialize(value.into_deserializer()).map(Some) + } + None => Ok(None), + } + } + + fn size_hint(&self) -> Option<usize> { + size_hint::from_bounds(&self.iter) + } +} + +struct ExpectedInSeq(usize); + +impl Expected for ExpectedInSeq { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + if self.0 == 1 { + write!(formatter, "1 element in sequence") + } else { + write!(formatter, "{} elements in sequence", self.0) + } + } +} + +impl<I, E> Debug for SeqDeserializer<I, E> +where + I: Debug, +{ + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("SeqDeserializer") + .field("iter", &self.iter) + .field("count", &self.count) + .finish() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, T, E> IntoDeserializer<'de, E> for Vec<T> +where + T: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Deserializer = SeqDeserializer<<Self as IntoIterator>::IntoIter, E>; + + fn into_deserializer(self) -> Self::Deserializer { + SeqDeserializer::new(self.into_iter()) + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, T, E> IntoDeserializer<'de, E> for BTreeSet<T> +where + T: IntoDeserializer<'de, E> + Eq + Ord, + E: de::Error, +{ + type Deserializer = SeqDeserializer<<Self as IntoIterator>::IntoIter, E>; + + fn into_deserializer(self) -> Self::Deserializer { + SeqDeserializer::new(self.into_iter()) + } +} + +#[cfg(feature = "std")] +impl<'de, T, S, E> IntoDeserializer<'de, E> for HashSet<T, S> +where + T: IntoDeserializer<'de, E> + Eq + Hash, + S: BuildHasher, + E: de::Error, +{ + type Deserializer = SeqDeserializer<<Self as IntoIterator>::IntoIter, E>; + + fn into_deserializer(self) -> Self::Deserializer { + SeqDeserializer::new(self.into_iter()) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding a `SeqAccess`. +#[derive(Clone, Debug)] +pub struct SeqAccessDeserializer<A> { + seq: A, +} + +impl<A> SeqAccessDeserializer<A> { + /// Construct a new `SeqAccessDeserializer<A>`. + pub fn new(seq: A) -> Self { + SeqAccessDeserializer { seq: seq } + } +} + +impl<'de, A> de::Deserializer<'de> for SeqAccessDeserializer<A> +where + A: de::SeqAccess<'de>, +{ + type Error = A::Error; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_seq(self.seq) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct enum identifier ignored_any + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer that iterates over a map. +pub struct MapDeserializer<'de, I, E> +where + I: Iterator, + I::Item: private::Pair, +{ + iter: iter::Fuse<I>, + value: Option<Second<I::Item>>, + count: usize, + lifetime: PhantomData<&'de ()>, + error: PhantomData<E>, +} + +impl<'de, I, E> MapDeserializer<'de, I, E> +where + I: Iterator, + I::Item: private::Pair, +{ + /// Construct a new `MapDeserializer<I, E>`. + pub fn new(iter: I) -> Self { + MapDeserializer { + iter: iter.fuse(), + value: None, + count: 0, + lifetime: PhantomData, + error: PhantomData, + } + } +} + +impl<'de, I, E> MapDeserializer<'de, I, E> +where + I: Iterator, + I::Item: private::Pair, + E: de::Error, +{ + /// Check for remaining elements after passing a `MapDeserializer` to + /// `Visitor::visit_map`. + pub fn end(self) -> Result<(), E> { + let remaining = self.iter.count(); + if remaining == 0 { + Ok(()) + } else { + // First argument is the number of elements in the data, second + // argument is the number of elements expected by the Deserialize. + Err(de::Error::invalid_length( + self.count + remaining, + &ExpectedInMap(self.count), + )) + } + } +} + +impl<'de, I, E> MapDeserializer<'de, I, E> +where + I: Iterator, + I::Item: private::Pair, +{ + fn next_pair(&mut self) -> Option<(First<I::Item>, Second<I::Item>)> { + match self.iter.next() { + Some(kv) => { + self.count += 1; + Some(private::Pair::split(kv)) + } + None => None, + } + } +} + +impl<'de, I, E> de::Deserializer<'de> for MapDeserializer<'de, I, E> +where + I: Iterator, + I::Item: private::Pair, + First<I::Item>: IntoDeserializer<'de, E>, + Second<I::Item>: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Error = E; + + fn deserialize_any<V>(mut self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let value = try!(visitor.visit_map(&mut self)); + try!(self.end()); + Ok(value) + } + + fn deserialize_seq<V>(mut self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let value = try!(visitor.visit_seq(&mut self)); + try!(self.end()); + Ok(value) + } + + fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let _ = len; + self.deserialize_seq(visitor) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct tuple_struct map + struct enum identifier ignored_any + } +} + +impl<'de, I, E> de::MapAccess<'de> for MapDeserializer<'de, I, E> +where + I: Iterator, + I::Item: private::Pair, + First<I::Item>: IntoDeserializer<'de, E>, + Second<I::Item>: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Error = E; + + fn next_key_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> + where + T: de::DeserializeSeed<'de>, + { + match self.next_pair() { + Some((key, value)) => { + self.value = Some(value); + seed.deserialize(key.into_deserializer()).map(Some) + } + None => Ok(None), + } + } + + fn next_value_seed<T>(&mut self, seed: T) -> Result<T::Value, Self::Error> + where + T: de::DeserializeSeed<'de>, + { + let value = self.value.take(); + // Panic because this indicates a bug in the program rather than an + // expected failure. + let value = value.expect("MapAccess::next_value called before next_key"); + seed.deserialize(value.into_deserializer()) + } + + fn next_entry_seed<TK, TV>( + &mut self, + kseed: TK, + vseed: TV, + ) -> Result<Option<(TK::Value, TV::Value)>, Self::Error> + where + TK: de::DeserializeSeed<'de>, + TV: de::DeserializeSeed<'de>, + { + match self.next_pair() { + Some((key, value)) => { + let key = try!(kseed.deserialize(key.into_deserializer())); + let value = try!(vseed.deserialize(value.into_deserializer())); + Ok(Some((key, value))) + } + None => Ok(None), + } + } + + fn size_hint(&self) -> Option<usize> { + size_hint::from_bounds(&self.iter) + } +} + +impl<'de, I, E> de::SeqAccess<'de> for MapDeserializer<'de, I, E> +where + I: Iterator, + I::Item: private::Pair, + First<I::Item>: IntoDeserializer<'de, E>, + Second<I::Item>: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Error = E; + + fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> + where + T: de::DeserializeSeed<'de>, + { + match self.next_pair() { + Some((k, v)) => { + let de = PairDeserializer(k, v, PhantomData); + seed.deserialize(de).map(Some) + } + None => Ok(None), + } + } + + fn size_hint(&self) -> Option<usize> { + size_hint::from_bounds(&self.iter) + } +} + +// Cannot #[derive(Clone)] because of the bound `Second<I::Item>: Clone`. +impl<'de, I, E> Clone for MapDeserializer<'de, I, E> +where + I: Iterator + Clone, + I::Item: private::Pair, + Second<I::Item>: Clone, +{ + fn clone(&self) -> Self { + MapDeserializer { + iter: self.iter.clone(), + value: self.value.clone(), + count: self.count, + lifetime: self.lifetime, + error: self.error, + } + } +} + +impl<'de, I, E> Debug for MapDeserializer<'de, I, E> +where + I: Iterator + Debug, + I::Item: private::Pair, + Second<I::Item>: Debug, +{ + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter + .debug_struct("MapDeserializer") + .field("iter", &self.iter) + .field("value", &self.value) + .field("count", &self.count) + .finish() + } +} + +// Used in the `impl SeqAccess for MapDeserializer` to visit the map as a +// sequence of pairs. +struct PairDeserializer<A, B, E>(A, B, PhantomData<E>); + +impl<'de, A, B, E> de::Deserializer<'de> for PairDeserializer<A, B, E> +where + A: IntoDeserializer<'de, E>, + B: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Error = E; + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct tuple_struct map + struct enum identifier ignored_any + } + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + self.deserialize_seq(visitor) + } + + fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + let mut pair_visitor = PairVisitor(Some(self.0), Some(self.1), PhantomData); + let pair = try!(visitor.visit_seq(&mut pair_visitor)); + if pair_visitor.1.is_none() { + Ok(pair) + } else { + let remaining = pair_visitor.size_hint().unwrap(); + // First argument is the number of elements in the data, second + // argument is the number of elements expected by the Deserialize. + Err(de::Error::invalid_length(2, &ExpectedInSeq(2 - remaining))) + } + } + + fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + if len == 2 { + self.deserialize_seq(visitor) + } else { + // First argument is the number of elements in the data, second + // argument is the number of elements expected by the Deserialize. + Err(de::Error::invalid_length(2, &ExpectedInSeq(len))) + } + } +} + +struct PairVisitor<A, B, E>(Option<A>, Option<B>, PhantomData<E>); + +impl<'de, A, B, E> de::SeqAccess<'de> for PairVisitor<A, B, E> +where + A: IntoDeserializer<'de, E>, + B: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Error = E; + + fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> + where + T: de::DeserializeSeed<'de>, + { + if let Some(k) = self.0.take() { + seed.deserialize(k.into_deserializer()).map(Some) + } else if let Some(v) = self.1.take() { + seed.deserialize(v.into_deserializer()).map(Some) + } else { + Ok(None) + } + } + + fn size_hint(&self) -> Option<usize> { + if self.0.is_some() { + Some(2) + } else if self.1.is_some() { + Some(1) + } else { + Some(0) + } + } +} + +struct ExpectedInMap(usize); + +impl Expected for ExpectedInMap { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + if self.0 == 1 { + write!(formatter, "1 element in map") + } else { + write!(formatter, "{} elements in map", self.0) + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +impl<'de, K, V, E> IntoDeserializer<'de, E> for BTreeMap<K, V> +where + K: IntoDeserializer<'de, E> + Eq + Ord, + V: IntoDeserializer<'de, E>, + E: de::Error, +{ + type Deserializer = MapDeserializer<'de, <Self as IntoIterator>::IntoIter, E>; + + fn into_deserializer(self) -> Self::Deserializer { + MapDeserializer::new(self.into_iter()) + } +} + +#[cfg(feature = "std")] +impl<'de, K, V, S, E> IntoDeserializer<'de, E> for HashMap<K, V, S> +where + K: IntoDeserializer<'de, E> + Eq + Hash, + V: IntoDeserializer<'de, E>, + S: BuildHasher, + E: de::Error, +{ + type Deserializer = MapDeserializer<'de, <Self as IntoIterator>::IntoIter, E>; + + fn into_deserializer(self) -> Self::Deserializer { + MapDeserializer::new(self.into_iter()) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding a `MapAccess`. +#[derive(Clone, Debug)] +pub struct MapAccessDeserializer<A> { + map: A, +} + +impl<A> MapAccessDeserializer<A> { + /// Construct a new `MapAccessDeserializer<A>`. + pub fn new(map: A) -> Self { + MapAccessDeserializer { map: map } + } +} + +impl<'de, A> de::Deserializer<'de> for MapAccessDeserializer<A> +where + A: de::MapAccess<'de>, +{ + type Error = A::Error; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_map(self.map) + } + + fn deserialize_enum<V>( + self, + _name: &str, + _variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_enum(self) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct identifier ignored_any + } +} + +impl<'de, A> de::EnumAccess<'de> for MapAccessDeserializer<A> +where + A: de::MapAccess<'de>, +{ + type Error = A::Error; + type Variant = private::MapAsEnum<A>; + + fn variant_seed<T>(mut self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> + where + T: de::DeserializeSeed<'de>, + { + match try!(self.map.next_key_seed(seed)) { + Some(key) => Ok((key, private::map_as_enum(self.map))), + None => Err(de::Error::invalid_type(de::Unexpected::Map, &"enum")), + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A deserializer holding an `EnumAccess`. +#[derive(Clone, Debug)] +pub struct EnumAccessDeserializer<A> { + access: A, +} + +impl<A> EnumAccessDeserializer<A> { + /// Construct a new `EnumAccessDeserializer<A>`. + pub fn new(access: A) -> Self { + EnumAccessDeserializer { access: access } + } +} + +impl<'de, A> de::Deserializer<'de> for EnumAccessDeserializer<A> +where + A: de::EnumAccess<'de>, +{ + type Error = A::Error; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + visitor.visit_enum(self.access) + } + + forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct enum identifier ignored_any + } +} + +//////////////////////////////////////////////////////////////////////////////// + +mod private { + use lib::*; + + use de::{self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor}; + + pub struct UnitOnly<E> { + marker: PhantomData<E>, + } + + pub fn unit_only<T, E>(t: T) -> (T, UnitOnly<E>) { + ( + t, + UnitOnly { + marker: PhantomData, + }, + ) + } + + impl<'de, E> de::VariantAccess<'de> for UnitOnly<E> + where + E: de::Error, + { + type Error = E; + + fn unit_variant(self) -> Result<(), Self::Error> { + Ok(()) + } + + fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value, Self::Error> + where + T: de::DeserializeSeed<'de>, + { + Err(de::Error::invalid_type( + Unexpected::UnitVariant, + &"newtype variant", + )) + } + + fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + Err(de::Error::invalid_type( + Unexpected::UnitVariant, + &"tuple variant", + )) + } + + fn struct_variant<V>( + self, + _fields: &'static [&'static str], + _visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: de::Visitor<'de>, + { + Err(de::Error::invalid_type( + Unexpected::UnitVariant, + &"struct variant", + )) + } + } + + pub struct MapAsEnum<A> { + map: A, + } + + pub fn map_as_enum<A>(map: A) -> MapAsEnum<A> { + MapAsEnum { map: map } + } + + impl<'de, A> VariantAccess<'de> for MapAsEnum<A> + where + A: MapAccess<'de>, + { + type Error = A::Error; + + fn unit_variant(mut self) -> Result<(), Self::Error> { + self.map.next_value() + } + + fn newtype_variant_seed<T>(mut self, seed: T) -> Result<T::Value, Self::Error> + where + T: DeserializeSeed<'de>, + { + self.map.next_value_seed(seed) + } + + fn tuple_variant<V>(mut self, len: usize, visitor: V) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>, + { + self.map.next_value_seed(SeedTupleVariant { + len: len, + visitor: visitor, + }) + } + + fn struct_variant<V>( + mut self, + _fields: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Self::Error> + where + V: Visitor<'de>, + { + self.map + .next_value_seed(SeedStructVariant { visitor: visitor }) + } + } + + struct SeedTupleVariant<V> { + len: usize, + visitor: V, + } + + impl<'de, V> DeserializeSeed<'de> for SeedTupleVariant<V> + where + V: Visitor<'de>, + { + type Value = V::Value; + + fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_tuple(self.len, self.visitor) + } + } + + struct SeedStructVariant<V> { + visitor: V, + } + + impl<'de, V> DeserializeSeed<'de> for SeedStructVariant<V> + where + V: Visitor<'de>, + { + type Value = V::Value; + + fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> + where + D: Deserializer<'de>, + { + deserializer.deserialize_map(self.visitor) + } + } + + /// Avoid having to restate the generic types on `MapDeserializer`. The + /// `Iterator::Item` contains enough information to figure out K and V. + pub trait Pair { + type First; + type Second; + fn split(self) -> (Self::First, Self::Second); + } + + impl<A, B> Pair for (A, B) { + type First = A; + type Second = B; + fn split(self) -> (A, B) { + self + } + } + + pub type First<T> = <T as Pair>::First; + pub type Second<T> = <T as Pair>::Second; +} |