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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /third_party/rust/serde_yaml/src/de.rs
parentInitial commit. (diff)
downloadfirefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz
firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/serde_yaml/src/de.rs')
-rw-r--r--third_party/rust/serde_yaml/src/de.rs1525
1 files changed, 1525 insertions, 0 deletions
diff --git a/third_party/rust/serde_yaml/src/de.rs b/third_party/rust/serde_yaml/src/de.rs
new file mode 100644
index 0000000000..8ccf271093
--- /dev/null
+++ b/third_party/rust/serde_yaml/src/de.rs
@@ -0,0 +1,1525 @@
+use crate::error::{self, Error, ErrorImpl, Result};
+use crate::path::Path;
+use serde::de::{
+ self, Deserialize, DeserializeOwned, DeserializeSeed, Expected, IgnoredAny as Ignore,
+ IntoDeserializer, Unexpected, Visitor,
+};
+use std::collections::BTreeMap;
+use std::f64;
+use std::fmt;
+use std::io;
+use std::marker::PhantomData;
+use std::mem;
+use std::str;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use yaml_rust::parser::{Event as YamlEvent, MarkedEventReceiver, Parser};
+use yaml_rust::scanner::{Marker, TScalarStyle, TokenType};
+
+/// A structure that deserializes YAML into Rust values.
+///
+/// # Examples
+///
+/// Deserializing a single document:
+///
+/// ```
+/// use anyhow::Result;
+/// use serde::Deserialize;
+/// use serde_yaml::Value;
+///
+/// fn main() -> Result<()> {
+/// let input = "---\nk: 107\n";
+/// let de = serde_yaml::Deserializer::from_str(input);
+/// let value = Value::deserialize(de)?;
+/// println!("{:?}", value);
+/// Ok(())
+/// }
+/// ```
+///
+/// Deserializing multi-doc YAML:
+///
+/// ```
+/// use anyhow::Result;
+/// use serde::Deserialize;
+/// use serde_yaml::Value;
+///
+/// fn main() -> Result<()> {
+/// let input = "---\nk: 107\n...\n---\nj: 106\n";
+///
+/// for document in serde_yaml::Deserializer::from_str(input) {
+/// let value = Value::deserialize(document)?;
+/// println!("{:?}", value);
+/// }
+///
+/// Ok(())
+/// }
+/// ```
+pub struct Deserializer<'a> {
+ input: Input<'a>,
+}
+
+enum Input<'a> {
+ Str(&'a str),
+ Slice(&'a [u8]),
+ Read(Box<dyn io::Read + 'a>),
+ Multidoc(Arc<Multidoc>),
+ Fail(Arc<ErrorImpl>),
+}
+
+impl<'a> Deserializer<'a> {
+ /// Creates a YAML deserializer from a `&str`.
+ pub fn from_str(s: &'a str) -> Self {
+ let input = Input::Str(s);
+ Deserializer { input }
+ }
+
+ /// Creates a YAML deserializer from a `&[u8]`.
+ pub fn from_slice(v: &'a [u8]) -> Self {
+ let input = Input::Slice(v);
+ Deserializer { input }
+ }
+
+ /// Creates a YAML deserializer from an `io::Read`.
+ ///
+ /// Reader-based deserializers do not support deserializing borrowed types
+ /// like `&str`, since the `std::io::Read` trait has no non-copying methods
+ /// -- everything it does involves copying bytes out of the data source.
+ pub fn from_reader<R>(rdr: R) -> Self
+ where
+ R: io::Read + 'a,
+ {
+ let input = Input::Read(Box::new(rdr));
+ Deserializer { input }
+ }
+
+ fn de<T>(self, f: impl FnOnce(&mut DeserializerFromEvents) -> Result<T>) -> Result<T> {
+ if let Input::Multidoc(multidoc) = &self.input {
+ let mut pos = multidoc.pos.load(Ordering::Relaxed);
+ let t = f(&mut DeserializerFromEvents {
+ events: &multidoc.loader.events,
+ aliases: &multidoc.loader.aliases,
+ pos: &mut pos,
+ path: Path::Root,
+ remaining_depth: 128,
+ })?;
+ multidoc.pos.store(pos, Ordering::Relaxed);
+ return Ok(t);
+ }
+
+ let loader = loader(self.input)?;
+ if loader.events.is_empty() {
+ return Err(error::end_of_stream());
+ }
+ let mut pos = 0;
+ let t = f(&mut DeserializerFromEvents {
+ events: &loader.events,
+ aliases: &loader.aliases,
+ pos: &mut pos,
+ path: Path::Root,
+ remaining_depth: 128,
+ })?;
+ if pos == loader.events.len() {
+ Ok(t)
+ } else {
+ Err(error::more_than_one_document())
+ }
+ }
+}
+
+fn loader(input: Input) -> Result<Loader> {
+ enum Input2<'a> {
+ Str(&'a str),
+ Slice(&'a [u8]),
+ }
+
+ let mut buffer;
+ let input = match input {
+ Input::Str(s) => Input2::Str(s),
+ Input::Slice(bytes) => Input2::Slice(bytes),
+ Input::Read(mut rdr) => {
+ buffer = Vec::new();
+ rdr.read_to_end(&mut buffer).map_err(error::io)?;
+ Input2::Slice(&buffer)
+ }
+ Input::Multidoc(_) => unreachable!(),
+ Input::Fail(err) => return Err(error::shared(err)),
+ };
+
+ let input = match input {
+ Input2::Str(s) => s,
+ Input2::Slice(bytes) => str::from_utf8(bytes).map_err(error::str_utf8)?,
+ };
+
+ let mut parser = Parser::new(input.chars());
+ let mut loader = Loader {
+ events: Vec::new(),
+ aliases: BTreeMap::new(),
+ };
+ parser.load(&mut loader, true).map_err(error::scanner)?;
+ Ok(loader)
+}
+
+struct Multidoc {
+ loader: Loader,
+ pos: AtomicUsize,
+}
+
+impl<'de> Iterator for Deserializer<'de> {
+ type Item = Self;
+
+ fn next(&mut self) -> Option<Self> {
+ match &self.input {
+ Input::Multidoc(multidoc) => {
+ let pos = multidoc.pos.load(Ordering::Relaxed);
+ return if pos < multidoc.loader.events.len() {
+ Some(Deserializer {
+ input: Input::Multidoc(Arc::clone(multidoc)),
+ })
+ } else {
+ None
+ };
+ }
+ Input::Fail(err) => {
+ return Some(Deserializer {
+ input: Input::Fail(Arc::clone(err)),
+ });
+ }
+ _ => {}
+ }
+
+ let dummy = Input::Str("");
+ let input = mem::replace(&mut self.input, dummy);
+ match loader(input) {
+ Ok(loader) => {
+ let multidoc = Arc::new(Multidoc {
+ loader,
+ pos: AtomicUsize::new(0),
+ });
+ self.input = Input::Multidoc(Arc::clone(&multidoc));
+ if multidoc.loader.events.is_empty() {
+ None
+ } else {
+ Some(Deserializer {
+ input: Input::Multidoc(multidoc),
+ })
+ }
+ }
+ Err(err) => {
+ let fail = err.shared();
+ self.input = Input::Fail(Arc::clone(&fail));
+ Some(Deserializer {
+ input: Input::Fail(fail),
+ })
+ }
+ }
+ }
+}
+
+impl<'de> de::Deserializer<'de> for Deserializer<'de> {
+ type Error = Error;
+
+ fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_any(visitor))
+ }
+
+ fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_bool(visitor))
+ }
+
+ fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_i8(visitor))
+ }
+
+ fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_i16(visitor))
+ }
+
+ fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_i32(visitor))
+ }
+
+ fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_i64(visitor))
+ }
+
+ fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_i128(visitor))
+ }
+
+ fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_u8(visitor))
+ }
+
+ fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_u16(visitor))
+ }
+
+ fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_u32(visitor))
+ }
+
+ fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_u64(visitor))
+ }
+
+ fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_u128(visitor))
+ }
+
+ fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_f32(visitor))
+ }
+
+ fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_f64(visitor))
+ }
+
+ fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_char(visitor))
+ }
+
+ fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_str(visitor))
+ }
+
+ fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_string(visitor))
+ }
+
+ fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_bytes(visitor))
+ }
+
+ fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_byte_buf(visitor))
+ }
+
+ fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_option(visitor))
+ }
+
+ fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_unit(visitor))
+ }
+
+ fn deserialize_unit_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_unit_struct(name, visitor))
+ }
+
+ fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_newtype_struct(name, visitor))
+ }
+
+ fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_seq(visitor))
+ }
+
+ fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_tuple(len, visitor))
+ }
+
+ fn deserialize_tuple_struct<V>(
+ self,
+ name: &'static str,
+ len: usize,
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_tuple_struct(name, len, visitor))
+ }
+
+ fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_map(visitor))
+ }
+
+ fn deserialize_struct<V>(
+ self,
+ name: &'static str,
+ fields: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_struct(name, fields, visitor))
+ }
+
+ fn deserialize_enum<V>(
+ self,
+ name: &'static str,
+ variants: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_enum(name, variants, visitor))
+ }
+
+ fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_identifier(visitor))
+ }
+
+ fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.de(|state| state.deserialize_ignored_any(visitor))
+ }
+}
+
+pub struct Loader {
+ events: Vec<(Event, Marker)>,
+ /// Map from alias id to index in events.
+ aliases: BTreeMap<usize, usize>,
+}
+
+impl MarkedEventReceiver for Loader {
+ fn on_event(&mut self, event: YamlEvent, marker: Marker) {
+ let event = match event {
+ YamlEvent::Nothing
+ | YamlEvent::StreamStart
+ | YamlEvent::StreamEnd
+ | YamlEvent::DocumentStart
+ | YamlEvent::DocumentEnd => return,
+
+ YamlEvent::Alias(id) => Event::Alias(id),
+ YamlEvent::Scalar(value, style, id, tag) => {
+ self.aliases.insert(id, self.events.len());
+ Event::Scalar(value, style, tag)
+ }
+ YamlEvent::SequenceStart(id) => {
+ self.aliases.insert(id, self.events.len());
+ Event::SequenceStart
+ }
+ YamlEvent::SequenceEnd => Event::SequenceEnd,
+ YamlEvent::MappingStart(id) => {
+ self.aliases.insert(id, self.events.len());
+ Event::MappingStart
+ }
+ YamlEvent::MappingEnd => Event::MappingEnd,
+ };
+ self.events.push((event, marker));
+ }
+}
+
+#[derive(Debug, PartialEq)]
+enum Event {
+ Alias(usize),
+ Scalar(String, TScalarStyle, Option<TokenType>),
+ SequenceStart,
+ SequenceEnd,
+ MappingStart,
+ MappingEnd,
+}
+
+struct DeserializerFromEvents<'a> {
+ events: &'a [(Event, Marker)],
+ /// Map from alias id to index in events.
+ aliases: &'a BTreeMap<usize, usize>,
+ pos: &'a mut usize,
+ path: Path<'a>,
+ remaining_depth: u8,
+}
+
+impl<'a> DeserializerFromEvents<'a> {
+ fn peek(&self) -> Result<(&'a Event, Marker)> {
+ match self.events.get(*self.pos) {
+ Some(event) => Ok((&event.0, event.1)),
+ None => Err(error::end_of_stream()),
+ }
+ }
+
+ fn next(&mut self) -> Result<(&'a Event, Marker)> {
+ self.opt_next().ok_or_else(error::end_of_stream)
+ }
+
+ fn opt_next(&mut self) -> Option<(&'a Event, Marker)> {
+ self.events.get(*self.pos).map(|event| {
+ *self.pos += 1;
+ (&event.0, event.1)
+ })
+ }
+
+ fn jump(&'a self, pos: &'a mut usize) -> Result<DeserializerFromEvents<'a>> {
+ match self.aliases.get(pos) {
+ Some(&found) => {
+ *pos = found;
+ Ok(DeserializerFromEvents {
+ events: self.events,
+ aliases: self.aliases,
+ pos,
+ path: Path::Alias { parent: &self.path },
+ remaining_depth: self.remaining_depth,
+ })
+ }
+ None => panic!("unresolved alias: {}", *pos),
+ }
+ }
+
+ fn ignore_any(&mut self) {
+ enum Nest {
+ Sequence,
+ Mapping,
+ }
+
+ let mut stack = Vec::new();
+
+ while let Some((event, _)) = self.opt_next() {
+ match event {
+ Event::Alias(_) | Event::Scalar(_, _, _) => {}
+ Event::SequenceStart => {
+ stack.push(Nest::Sequence);
+ }
+ Event::MappingStart => {
+ stack.push(Nest::Mapping);
+ }
+ Event::SequenceEnd => match stack.pop() {
+ Some(Nest::Sequence) => {}
+ None | Some(Nest::Mapping) => {
+ panic!("unexpected end of sequence");
+ }
+ },
+ Event::MappingEnd => match stack.pop() {
+ Some(Nest::Mapping) => {}
+ None | Some(Nest::Sequence) => {
+ panic!("unexpected end of mapping");
+ }
+ },
+ }
+ if stack.is_empty() {
+ return;
+ }
+ }
+
+ if !stack.is_empty() {
+ panic!("missing end event");
+ }
+ }
+
+ fn visit_sequence<'de, V>(&mut self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (value, len) = self.recursion_check(|de| {
+ let mut seq = SeqAccess { de, len: 0 };
+ let value = visitor.visit_seq(&mut seq)?;
+ Ok((value, seq.len))
+ })?;
+ self.end_sequence(len)?;
+ Ok(value)
+ }
+
+ fn visit_mapping<'de, V>(&mut self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (value, len) = self.recursion_check(|de| {
+ let mut map = MapAccess {
+ de,
+ len: 0,
+ key: None,
+ };
+ let value = visitor.visit_map(&mut map)?;
+ Ok((value, map.len))
+ })?;
+ self.end_mapping(len)?;
+ Ok(value)
+ }
+
+ fn end_sequence(&mut self, len: usize) -> Result<()> {
+ let total = {
+ let mut seq = SeqAccess { de: self, len };
+ while de::SeqAccess::next_element::<Ignore>(&mut seq)?.is_some() {}
+ seq.len
+ };
+ assert_eq!(Event::SequenceEnd, *self.next()?.0);
+ if total == len {
+ Ok(())
+ } else {
+ struct ExpectedSeq(usize);
+ impl Expected for ExpectedSeq {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ if self.0 == 1 {
+ write!(formatter, "sequence of 1 element")
+ } else {
+ write!(formatter, "sequence of {} elements", self.0)
+ }
+ }
+ }
+ Err(de::Error::invalid_length(total, &ExpectedSeq(len)))
+ }
+ }
+
+ fn end_mapping(&mut self, len: usize) -> Result<()> {
+ let total = {
+ let mut map = MapAccess {
+ de: self,
+ len,
+ key: None,
+ };
+ while de::MapAccess::next_entry::<Ignore, Ignore>(&mut map)?.is_some() {}
+ map.len
+ };
+ assert_eq!(Event::MappingEnd, *self.next()?.0);
+ if total == len {
+ Ok(())
+ } else {
+ struct ExpectedMap(usize);
+ impl Expected for ExpectedMap {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ if self.0 == 1 {
+ write!(formatter, "map containing 1 entry")
+ } else {
+ write!(formatter, "map containing {} entries", self.0)
+ }
+ }
+ }
+ Err(de::Error::invalid_length(total, &ExpectedMap(len)))
+ }
+ }
+
+ fn recursion_check<F: FnOnce(&mut Self) -> Result<T>, T>(&mut self, f: F) -> Result<T> {
+ let previous_depth = self.remaining_depth;
+ self.remaining_depth = previous_depth
+ .checked_sub(1)
+ .ok_or_else(error::recursion_limit_exceeded)?;
+ let result = f(self);
+ self.remaining_depth = previous_depth;
+ result
+ }
+}
+
+fn visit_scalar<'de, V>(
+ v: &str,
+ style: TScalarStyle,
+ tag: &Option<TokenType>,
+ visitor: V,
+) -> Result<V::Value>
+where
+ V: Visitor<'de>,
+{
+ if let Some(TokenType::Tag(handle, suffix)) = tag {
+ if handle == "!!" {
+ match suffix.as_ref() {
+ "bool" => match v.parse::<bool>() {
+ Ok(v) => visitor.visit_bool(v),
+ Err(_) => Err(de::Error::invalid_value(Unexpected::Str(v), &"a boolean")),
+ },
+ "int" => match v.parse::<i64>() {
+ Ok(v) => visitor.visit_i64(v),
+ Err(_) => Err(de::Error::invalid_value(Unexpected::Str(v), &"an integer")),
+ },
+ "float" => match v.parse::<f64>() {
+ Ok(v) => visitor.visit_f64(v),
+ Err(_) => Err(de::Error::invalid_value(Unexpected::Str(v), &"a float")),
+ },
+ "null" => match v {
+ "~" | "null" => visitor.visit_unit(),
+ _ => Err(de::Error::invalid_value(Unexpected::Str(v), &"null")),
+ },
+ _ => visitor.visit_str(v),
+ }
+ } else {
+ visitor.visit_str(v)
+ }
+ } else if style == TScalarStyle::Plain {
+ visit_untagged_str(visitor, v)
+ } else {
+ visitor.visit_str(v)
+ }
+}
+
+struct SeqAccess<'a: 'r, 'r> {
+ de: &'r mut DeserializerFromEvents<'a>,
+ len: usize,
+}
+
+impl<'de, 'a, 'r> de::SeqAccess<'de> for SeqAccess<'a, 'r> {
+ type Error = Error;
+
+ fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+ where
+ T: DeserializeSeed<'de>,
+ {
+ match self.de.peek()?.0 {
+ Event::SequenceEnd => Ok(None),
+ _ => {
+ let mut element_de = DeserializerFromEvents {
+ events: self.de.events,
+ aliases: self.de.aliases,
+ pos: self.de.pos,
+ path: Path::Seq {
+ parent: &self.de.path,
+ index: self.len,
+ },
+ remaining_depth: self.de.remaining_depth,
+ };
+ self.len += 1;
+ seed.deserialize(&mut element_de).map(Some)
+ }
+ }
+ }
+}
+
+struct MapAccess<'a: 'r, 'r> {
+ de: &'r mut DeserializerFromEvents<'a>,
+ len: usize,
+ key: Option<&'a str>,
+}
+
+impl<'de, 'a, 'r> de::MapAccess<'de> for MapAccess<'a, 'r> {
+ type Error = Error;
+
+ fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
+ where
+ K: DeserializeSeed<'de>,
+ {
+ match self.de.peek()?.0 {
+ Event::MappingEnd => Ok(None),
+ Event::Scalar(key, _, _) => {
+ self.len += 1;
+ self.key = Some(key);
+ seed.deserialize(&mut *self.de).map(Some)
+ }
+ _ => {
+ self.len += 1;
+ self.key = None;
+ seed.deserialize(&mut *self.de).map(Some)
+ }
+ }
+ }
+
+ fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value>
+ where
+ V: DeserializeSeed<'de>,
+ {
+ let mut value_de = DeserializerFromEvents {
+ events: self.de.events,
+ aliases: self.de.aliases,
+ pos: self.de.pos,
+ path: if let Some(key) = self.key {
+ Path::Map {
+ parent: &self.de.path,
+ key,
+ }
+ } else {
+ Path::Unknown {
+ parent: &self.de.path,
+ }
+ },
+ remaining_depth: self.de.remaining_depth,
+ };
+ seed.deserialize(&mut value_de)
+ }
+}
+
+struct EnumAccess<'a: 'r, 'r> {
+ de: &'r mut DeserializerFromEvents<'a>,
+ name: &'static str,
+ tag: Option<&'static str>,
+}
+
+impl<'de, 'a, 'r> de::EnumAccess<'de> for EnumAccess<'a, 'r> {
+ type Error = Error;
+ type Variant = DeserializerFromEvents<'r>;
+
+ fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant)>
+ where
+ V: DeserializeSeed<'de>,
+ {
+ #[derive(Debug)]
+ enum Nope {}
+
+ struct BadKey {
+ name: &'static str,
+ }
+
+ impl<'de> Visitor<'de> for BadKey {
+ type Value = Nope;
+
+ fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ write!(formatter, "variant of enum `{}`", self.name)
+ }
+ }
+
+ let variant = if let Some(tag) = self.tag {
+ tag
+ } else {
+ match self.de.next()?.0 {
+ Event::Scalar(s, _, _) => &**s,
+ _ => {
+ *self.de.pos -= 1;
+ let bad = BadKey { name: self.name };
+ return Err(de::Deserializer::deserialize_any(&mut *self.de, bad).unwrap_err());
+ }
+ }
+ };
+
+ let str_de = IntoDeserializer::<Error>::into_deserializer(variant);
+ let ret = seed.deserialize(str_de)?;
+ let variant_visitor = DeserializerFromEvents {
+ events: self.de.events,
+ aliases: self.de.aliases,
+ pos: self.de.pos,
+ path: Path::Map {
+ parent: &self.de.path,
+ key: variant,
+ },
+ remaining_depth: self.de.remaining_depth,
+ };
+ Ok((ret, variant_visitor))
+ }
+}
+
+impl<'de, 'a> de::VariantAccess<'de> for DeserializerFromEvents<'a> {
+ type Error = Error;
+
+ fn unit_variant(mut self) -> Result<()> {
+ Deserialize::deserialize(&mut self)
+ }
+
+ fn newtype_variant_seed<T>(mut self, seed: T) -> Result<T::Value>
+ where
+ T: DeserializeSeed<'de>,
+ {
+ seed.deserialize(&mut self)
+ }
+
+ fn tuple_variant<V>(mut self, _len: usize, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ de::Deserializer::deserialize_seq(&mut self, visitor)
+ }
+
+ fn struct_variant<V>(mut self, fields: &'static [&'static str], visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ de::Deserializer::deserialize_struct(&mut self, "", fields, visitor)
+ }
+}
+
+struct UnitVariantAccess<'a: 'r, 'r> {
+ de: &'r mut DeserializerFromEvents<'a>,
+}
+
+impl<'de, 'a, 'r> de::EnumAccess<'de> for UnitVariantAccess<'a, 'r> {
+ type Error = Error;
+ type Variant = Self;
+
+ fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant)>
+ where
+ V: DeserializeSeed<'de>,
+ {
+ Ok((seed.deserialize(&mut *self.de)?, self))
+ }
+}
+
+impl<'de, 'a, 'r> de::VariantAccess<'de> for UnitVariantAccess<'a, 'r> {
+ type Error = Error;
+
+ fn unit_variant(self) -> Result<()> {
+ Ok(())
+ }
+
+ fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value>
+ where
+ T: DeserializeSeed<'de>,
+ {
+ Err(de::Error::invalid_type(
+ Unexpected::UnitVariant,
+ &"newtype variant",
+ ))
+ }
+
+ fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value>
+ where
+ V: 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>
+ where
+ V: Visitor<'de>,
+ {
+ Err(de::Error::invalid_type(
+ Unexpected::UnitVariant,
+ &"struct variant",
+ ))
+ }
+}
+
+fn visit_untagged_str<'de, V>(visitor: V, v: &str) -> Result<V::Value>
+where
+ V: Visitor<'de>,
+{
+ if v == "~" || v == "null" {
+ return visitor.visit_unit();
+ }
+ if v == "true" {
+ return visitor.visit_bool(true);
+ }
+ if v == "false" {
+ return visitor.visit_bool(false);
+ }
+ if let Some(rest) = Option::or(v.strip_prefix("0x"), v.strip_prefix("+0x")) {
+ if let Ok(n) = u64::from_str_radix(rest, 16) {
+ return visitor.visit_u64(n);
+ }
+ }
+ if let Some(rest) = v.strip_prefix("-0x") {
+ let negative = format!("-{}", rest);
+ if let Ok(n) = i64::from_str_radix(&negative, 16) {
+ return visitor.visit_i64(n);
+ }
+ }
+ if let Some(rest) = Option::or(v.strip_prefix("0o"), v.strip_prefix("+0o")) {
+ if let Ok(n) = u64::from_str_radix(rest, 8) {
+ return visitor.visit_u64(n);
+ }
+ }
+ if let Some(rest) = v.strip_prefix("-0o") {
+ let negative = format!("-{}", rest);
+ if let Ok(n) = i64::from_str_radix(&negative, 8) {
+ return visitor.visit_i64(n);
+ }
+ }
+ if let Some(rest) = Option::or(v.strip_prefix("0b"), v.strip_prefix("+0b")) {
+ if let Ok(n) = u64::from_str_radix(rest, 2) {
+ return visitor.visit_u64(n);
+ }
+ }
+ if let Some(rest) = v.strip_prefix("-0b") {
+ let negative = format!("-{}", rest);
+ if let Ok(n) = i64::from_str_radix(&negative, 2) {
+ return visitor.visit_i64(n);
+ }
+ }
+ if {
+ let v = v.trim_start_matches(&['-', '+'][..]);
+ v.len() > 1 && v.starts_with('0') && v[1..].bytes().all(|b| b.is_ascii_digit())
+ } {
+ // After handling the different number encodings above if we are left
+ // with leading zero(s) followed by numeric characters this is in fact a
+ // string according to the YAML 1.2 spec.
+ // https://yaml.org/spec/1.2/spec.html#id2761292
+ return visitor.visit_str(v);
+ }
+ if let Ok(n) = v.parse() {
+ return visitor.visit_u64(n);
+ }
+ if let Ok(n) = v.parse() {
+ return visitor.visit_u128(n);
+ }
+ if let Ok(n) = v.parse() {
+ return visitor.visit_i64(n);
+ }
+ if let Ok(n) = v.parse() {
+ return visitor.visit_i128(n);
+ }
+ match v.trim_start_matches('+') {
+ ".inf" | ".Inf" | ".INF" => return visitor.visit_f64(f64::INFINITY),
+ _ => (),
+ }
+ if v == "-.inf" || v == "-.Inf" || v == "-.INF" {
+ return visitor.visit_f64(f64::NEG_INFINITY);
+ }
+ if v == ".nan" || v == ".NaN" || v == ".NAN" {
+ return visitor.visit_f64(f64::NAN);
+ }
+ if let Ok(n) = v.parse::<f64>() {
+ if n.is_finite() {
+ return visitor.visit_f64(n);
+ }
+ }
+ visitor.visit_str(v)
+}
+
+fn invalid_type(event: &Event, exp: &dyn Expected) -> Error {
+ enum Void {}
+
+ struct InvalidType<'a> {
+ exp: &'a dyn Expected,
+ }
+
+ impl<'de, 'a> Visitor<'de> for InvalidType<'a> {
+ type Value = Void;
+
+ fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ self.exp.fmt(formatter)
+ }
+ }
+
+ match event {
+ Event::Alias(_) => unreachable!(),
+ Event::Scalar(v, style, tag) => {
+ let get_type = InvalidType { exp };
+ match visit_scalar(v, *style, tag, get_type) {
+ Ok(void) => match void {},
+ Err(invalid_type) => invalid_type,
+ }
+ }
+ Event::SequenceStart => de::Error::invalid_type(Unexpected::Seq, exp),
+ Event::MappingStart => de::Error::invalid_type(Unexpected::Map, exp),
+ Event::SequenceEnd => panic!("unexpected end of sequence"),
+ Event::MappingEnd => panic!("unexpected end of mapping"),
+ }
+}
+
+impl<'a> DeserializerFromEvents<'a> {
+ fn deserialize_scalar<'de, V>(&mut self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (next, marker) = self.next()?;
+ match next {
+ Event::Alias(mut pos) => self.jump(&mut pos)?.deserialize_scalar(visitor),
+ Event::Scalar(v, style, tag) => visit_scalar(v, *style, tag, visitor),
+ other => Err(invalid_type(other, &visitor)),
+ }
+ .map_err(|err| error::fix_marker(err, marker, self.path))
+ }
+}
+
+impl<'de, 'a, 'r> de::Deserializer<'de> for &'r mut DeserializerFromEvents<'a> {
+ type Error = Error;
+
+ fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (next, marker) = self.next()?;
+ match next {
+ Event::Alias(mut pos) => self.jump(&mut pos)?.deserialize_any(visitor),
+ Event::Scalar(v, style, tag) => visit_scalar(v, *style, tag, visitor),
+ Event::SequenceStart => self.visit_sequence(visitor),
+ Event::MappingStart => self.visit_mapping(visitor),
+ Event::SequenceEnd => panic!("unexpected end of sequence"),
+ Event::MappingEnd => panic!("unexpected end of mapping"),
+ }
+ // The de::Error impl creates errors with unknown line and column. Fill
+ // in the position here by looking at the current index in the input.
+ .map_err(|err| error::fix_marker(err, marker, self.path))
+ }
+
+ fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (next, marker) = self.next()?;
+ match next {
+ Event::Scalar(v, _, _) => visitor.visit_str(v),
+ Event::Alias(mut pos) => self.jump(&mut pos)?.deserialize_str(visitor),
+ other => Err(invalid_type(other, &visitor)),
+ }
+ .map_err(|err: Error| error::fix_marker(err, marker, self.path))
+ }
+
+ fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_any(visitor)
+ }
+
+ fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_bytes(visitor)
+ }
+
+ /// Parses `null` as None and any other values as `Some(...)`.
+ fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let is_some = match self.peek()?.0 {
+ Event::Alias(mut pos) => {
+ *self.pos += 1;
+ return self.jump(&mut pos)?.deserialize_option(visitor);
+ }
+ Event::Scalar(v, style, tag) => {
+ if *style != TScalarStyle::Plain {
+ true
+ } else if let Some(TokenType::Tag(handle, suffix)) = tag {
+ if handle == "!!" && suffix == "null" {
+ if v == "~" || v == "null" {
+ false
+ } else {
+ return Err(de::Error::invalid_value(Unexpected::Str(v), &"null"));
+ }
+ } else {
+ true
+ }
+ } else {
+ v != "~" && v != "null"
+ }
+ }
+ Event::SequenceStart | Event::MappingStart => true,
+ Event::SequenceEnd => panic!("unexpected end of sequence"),
+ Event::MappingEnd => panic!("unexpected end of mapping"),
+ };
+ if is_some {
+ visitor.visit_some(self)
+ } else {
+ *self.pos += 1;
+ visitor.visit_none()
+ }
+ }
+
+ fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_scalar(visitor)
+ }
+
+ fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_unit(visitor)
+ }
+
+ /// Parses a newtype struct as the underlying value.
+ fn deserialize_newtype_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ visitor.visit_newtype_struct(self)
+ }
+
+ fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (next, marker) = self.next()?;
+ match next {
+ Event::Alias(mut pos) => self.jump(&mut pos)?.deserialize_seq(visitor),
+ Event::SequenceStart => self.visit_sequence(visitor),
+ other => Err(invalid_type(other, &visitor)),
+ }
+ .map_err(|err| error::fix_marker(err, marker, self.path))
+ }
+
+ fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_seq(visitor)
+ }
+
+ fn deserialize_tuple_struct<V>(
+ self,
+ _name: &'static str,
+ _len: usize,
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_seq(visitor)
+ }
+
+ fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (next, marker) = self.next()?;
+ match next {
+ Event::Alias(mut pos) => self.jump(&mut pos)?.deserialize_map(visitor),
+ Event::MappingStart => self.visit_mapping(visitor),
+ other => Err(invalid_type(other, &visitor)),
+ }
+ .map_err(|err| error::fix_marker(err, marker, self.path))
+ }
+
+ fn deserialize_struct<V>(
+ self,
+ name: &'static str,
+ fields: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (next, marker) = self.next()?;
+ match next {
+ Event::Alias(mut pos) => self
+ .jump(&mut pos)?
+ .deserialize_struct(name, fields, visitor),
+ Event::SequenceStart => self.visit_sequence(visitor),
+ Event::MappingStart => self.visit_mapping(visitor),
+ other => Err(invalid_type(other, &visitor)),
+ }
+ .map_err(|err| error::fix_marker(err, marker, self.path))
+ }
+
+ /// Parses an enum as a single key:value pair where the key identifies the
+ /// variant and the value gives the content. A String will also parse correctly
+ /// to a unit enum value.
+ fn deserialize_enum<V>(
+ self,
+ name: &'static str,
+ variants: &'static [&'static str],
+ visitor: V,
+ ) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ let (next, marker) = self.peek()?;
+ match next {
+ Event::Alias(mut pos) => {
+ *self.pos += 1;
+ self.jump(&mut pos)?
+ .deserialize_enum(name, variants, visitor)
+ }
+ Event::Scalar(_, _, t) => {
+ if let Some(TokenType::Tag(handle, suffix)) = t {
+ if handle == "!" {
+ if let Some(tag) = variants.iter().find(|v| *v == suffix) {
+ return visitor.visit_enum(EnumAccess {
+ de: self,
+ name,
+ tag: Some(tag),
+ });
+ }
+ }
+ }
+ visitor.visit_enum(UnitVariantAccess { de: self })
+ }
+ Event::MappingStart => {
+ *self.pos += 1;
+ let value = visitor.visit_enum(EnumAccess {
+ de: self,
+ name,
+ tag: None,
+ })?;
+ self.end_mapping(1)?;
+ Ok(value)
+ }
+ Event::SequenceStart => {
+ let err = de::Error::invalid_type(Unexpected::Seq, &"string or singleton map");
+ Err(error::fix_marker(err, marker, self.path))
+ }
+ Event::SequenceEnd => panic!("unexpected end of sequence"),
+ Event::MappingEnd => panic!("unexpected end of mapping"),
+ }
+ }
+
+ fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.deserialize_str(visitor)
+ }
+
+ fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+ where
+ V: Visitor<'de>,
+ {
+ self.ignore_any();
+ visitor.visit_unit()
+ }
+}
+
+/// Deserialize an instance of type `T` from a string of YAML text.
+///
+/// This conversion can fail if the structure of the Value does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the Value
+/// contains something other than a YAML map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the YAML map or some number is too big to fit in the expected primitive
+/// type.
+///
+/// YAML currently does not support zero-copy deserialization.
+pub fn from_str<T>(s: &str) -> Result<T>
+where
+ T: DeserializeOwned,
+{
+ from_str_seed(s, PhantomData)
+}
+
+/// Deserialize an instance of type `T` from a string of YAML text with a seed.
+///
+/// This conversion can fail if the structure of the Value does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the Value
+/// contains something other than a YAML map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the YAML map or some number is too big to fit in the expected primitive
+/// type.
+///
+/// YAML currently does not support zero-copy deserialization.
+pub fn from_str_seed<T, S>(s: &str, seed: S) -> Result<T>
+where
+ S: for<'de> DeserializeSeed<'de, Value = T>,
+{
+ seed.deserialize(Deserializer::from_str(s))
+}
+
+/// Deserialize an instance of type `T` from an IO stream of YAML.
+///
+/// This conversion can fail if the structure of the Value does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the Value
+/// contains something other than a YAML map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the YAML map or some number is too big to fit in the expected primitive
+/// type.
+pub fn from_reader<R, T>(rdr: R) -> Result<T>
+where
+ R: io::Read,
+ T: DeserializeOwned,
+{
+ from_reader_seed(rdr, PhantomData)
+}
+
+/// Deserialize an instance of type `T` from an IO stream of YAML with a seed.
+///
+/// This conversion can fail if the structure of the Value does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the Value
+/// contains something other than a YAML map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the YAML map or some number is too big to fit in the expected primitive
+/// type.
+pub fn from_reader_seed<R, T, S>(rdr: R, seed: S) -> Result<T>
+where
+ R: io::Read,
+ S: for<'de> DeserializeSeed<'de, Value = T>,
+{
+ seed.deserialize(Deserializer::from_reader(rdr))
+}
+
+/// Deserialize an instance of type `T` from bytes of YAML text.
+///
+/// This conversion can fail if the structure of the Value does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the Value
+/// contains something other than a YAML map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the YAML map or some number is too big to fit in the expected primitive
+/// type.
+///
+/// YAML currently does not support zero-copy deserialization.
+pub fn from_slice<T>(v: &[u8]) -> Result<T>
+where
+ T: DeserializeOwned,
+{
+ from_slice_seed(v, PhantomData)
+}
+
+/// Deserialize an instance of type `T` from bytes of YAML text with a seed.
+///
+/// This conversion can fail if the structure of the Value does not match the
+/// structure expected by `T`, for example if `T` is a struct type but the Value
+/// contains something other than a YAML map. It can also fail if the structure
+/// is correct but `T`'s implementation of `Deserialize` decides that something
+/// is wrong with the data, for example required struct fields are missing from
+/// the YAML map or some number is too big to fit in the expected primitive
+/// type.
+///
+/// YAML currently does not support zero-copy deserialization.
+pub fn from_slice_seed<T, S>(v: &[u8], seed: S) -> Result<T>
+where
+ S: for<'de> DeserializeSeed<'de, Value = T>,
+{
+ seed.deserialize(Deserializer::from_slice(v))
+}