Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 1841 insertions, 0 deletions

diff --git a/third_party/rust/ron/src/de/id.rs b/third_party/rust/ron/src/de/id.rs
new file mode 100644
index 0000000000..b8d7d59f87
--- /dev/null
+++ b/third_party/rust/ron/src/de/id.rs
@@ -0,0 +1,244 @@
+use serde::de::{self, Visitor};
+
+use super::{Deserializer, Error, Result};
+
+pub struct IdDeserializer<'a, 'b: 'a> {
+    d: &'a mut Deserializer<'b>,
+}
+
+impl<'a, 'b: 'a> IdDeserializer<'a, 'b> {
+    pub fn new(d: &'a mut Deserializer<'b>) -> Self {
+        IdDeserializer { d }
+    }
+}
+
+impl<'a, 'b: 'a, 'c> de::Deserializer<'b> for &'c mut IdDeserializer<'a, 'b> {
+    type Error = Error;
+
+    fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_identifier(visitor)
+    }
+
+    fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.deserialize_identifier(visitor)
+    }
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.deserialize_identifier(visitor)
+    }
+
+    fn deserialize_bool<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_i8<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_i16<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_i32<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_i64<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_i128<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_u8<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_u16<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_u32<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_u64<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_u128<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_f32<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_f64<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_char<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_string<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_bytes<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_byte_buf<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_option<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_unit<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_unit_struct<V>(self, _: &'static str, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_newtype_struct<V>(self, _: &'static str, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_seq<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_tuple<V>(self, _: usize, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_tuple_struct<V>(self, _: &'static str, _: usize, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_map<V>(self, _: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_struct<V>(
+        self,
+        _: &'static str,
+        _: &'static [&'static str],
+        _: V,
+    ) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_enum<V>(
+        self,
+        _: &'static str,
+        _: &'static [&'static str],
+        _: V,
+    ) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        unimplemented!("IdDeserializer may only be used for identifiers")
+    }
+
+    fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.deserialize_any(visitor)
+    }
+}
diff --git a/third_party/rust/ron/src/de/mod.rs b/third_party/rust/ron/src/de/mod.rs
new file mode 100644
index 0000000000..8c01d42a98
--- /dev/null
+++ b/third_party/rust/ron/src/de/mod.rs
@@ -0,0 +1,685 @@
+/// Deserialization module.
+pub use crate::error::{Error, ErrorCode, Result};
+pub use crate::parse::Position;
+
+use serde::de::{self, DeserializeSeed, Deserializer as SerdeError, Visitor};
+use std::{borrow::Cow, io, str};
+
+use self::{id::IdDeserializer, tag::TagDeserializer};
+use crate::{
+    extensions::Extensions,
+    parse::{AnyNum, Bytes, ParsedStr},
+};
+
+mod id;
+mod tag;
+#[cfg(test)]
+mod tests;
+mod value;
+
+/// The RON deserializer.
+///
+/// If you just want to simply deserialize a value,
+/// you can use the `from_str` convenience function.
+pub struct Deserializer<'de> {
+    bytes: Bytes<'de>,
+}
+
+impl<'de> Deserializer<'de> {
+    // Cannot implement trait here since output is tied to input lifetime 'de.
+    #[allow(clippy::should_implement_trait)]
+    pub fn from_str(input: &'de str) -> Result<Self> {
+        Deserializer::from_bytes(input.as_bytes())
+    }
+
+    pub fn from_bytes(input: &'de [u8]) -> Result<Self> {
+        Ok(Deserializer {
+            bytes: Bytes::new(input)?,
+        })
+    }
+
+    pub fn remainder(&self) -> Cow<'_, str> {
+        String::from_utf8_lossy(&self.bytes.bytes())
+    }
+}
+
+/// A convenience function for reading data from a reader
+/// and feeding into a deserializer.
+pub fn from_reader<R, T>(mut rdr: R) -> Result<T>
+where
+    R: io::Read,
+    T: de::DeserializeOwned,
+{
+    let mut bytes = Vec::new();
+    rdr.read_to_end(&mut bytes)?;
+
+    from_bytes(&bytes)
+}
+
+/// A convenience function for building a deserializer
+/// and deserializing a value of type `T` from a string.
+pub fn from_str<'a, T>(s: &'a str) -> Result<T>
+where
+    T: de::Deserialize<'a>,
+{
+    from_bytes(s.as_bytes())
+}
+
+/// A convenience function for building a deserializer
+/// and deserializing a value of type `T` from bytes.
+pub fn from_bytes<'a, T>(s: &'a [u8]) -> Result<T>
+where
+    T: de::Deserialize<'a>,
+{
+    let mut deserializer = Deserializer::from_bytes(s)?;
+    let t = T::deserialize(&mut deserializer)?;
+
+    deserializer.end()?;
+
+    Ok(t)
+}
+
+impl<'de> Deserializer<'de> {
+    /// Check if the remaining bytes are whitespace only,
+    /// otherwise return an error.
+    pub fn end(&mut self) -> Result<()> {
+        self.bytes.skip_ws()?;
+
+        if self.bytes.bytes().is_empty() {
+            Ok(())
+        } else {
+            self.bytes.err(ErrorCode::TrailingCharacters)
+        }
+    }
+
+    /// Called from `deserialize_any` when a struct was detected. Decides if
+    /// there is a unit, tuple or usual struct and deserializes it
+    /// accordingly.
+    ///
+    /// This method assumes there is no identifier left.
+    fn handle_any_struct<V>(&mut self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        // Create a working copy
+        let mut bytes = self.bytes;
+
+        if bytes.consume("(") {
+            bytes.skip_ws()?;
+
+            if bytes.check_tuple_struct()? {
+                // first argument is technically incorrect, but ignored anyway
+                self.deserialize_tuple(0, visitor)
+            } else {
+                // first two arguments are technically incorrect, but ignored anyway
+                self.deserialize_struct("", &[], visitor)
+            }
+        } else {
+            visitor.visit_unit()
+        }
+    }
+}
+
+impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.consume_ident("true") {
+            return visitor.visit_bool(true);
+        } else if self.bytes.consume_ident("false") {
+            return visitor.visit_bool(false);
+        } else if self.bytes.check_ident("Some") {
+            return self.deserialize_option(visitor);
+        } else if self.bytes.consume_ident("None") {
+            return visitor.visit_none();
+        } else if self.bytes.consume("()") {
+            return visitor.visit_unit();
+        } else if self.bytes.consume_ident("inf") {
+            return visitor.visit_f64(std::f64::INFINITY);
+        } else if self.bytes.consume_ident("-inf") {
+            return visitor.visit_f64(std::f64::NEG_INFINITY);
+        } else if self.bytes.consume_ident("NaN") {
+            return visitor.visit_f64(std::f64::NAN);
+        }
+
+        // `identifier` does not change state if it fails
+        let ident = self.bytes.identifier().ok();
+
+        if ident.is_some() {
+            self.bytes.skip_ws()?;
+
+            return self.handle_any_struct(visitor);
+        }
+
+        match self.bytes.peek_or_eof()? {
+            b'(' => self.handle_any_struct(visitor),
+            b'[' => self.deserialize_seq(visitor),
+            b'{' => self.deserialize_map(visitor),
+            b'0'..=b'9' | b'+' | b'-' => {
+                let any_num: AnyNum = self.bytes.any_num()?;
+
+                match any_num {
+                    AnyNum::F32(x) => visitor.visit_f32(x),
+                    AnyNum::F64(x) => visitor.visit_f64(x),
+                    AnyNum::I8(x) => visitor.visit_i8(x),
+                    AnyNum::U8(x) => visitor.visit_u8(x),
+                    AnyNum::I16(x) => visitor.visit_i16(x),
+                    AnyNum::U16(x) => visitor.visit_u16(x),
+                    AnyNum::I32(x) => visitor.visit_i32(x),
+                    AnyNum::U32(x) => visitor.visit_u32(x),
+                    AnyNum::I64(x) => visitor.visit_i64(x),
+                    AnyNum::U64(x) => visitor.visit_u64(x),
+                    AnyNum::I128(x) => visitor.visit_i128(x),
+                    AnyNum::U128(x) => visitor.visit_u128(x),
+                }
+            }
+            b'.' => self.deserialize_f64(visitor),
+            b'"' | b'r' => self.deserialize_string(visitor),
+            b'\'' => self.deserialize_char(visitor),
+            other => self.bytes.err(ErrorCode::UnexpectedByte(other as char)),
+        }
+    }
+
+    fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_bool(self.bytes.bool()?)
+    }
+
+    fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_i8(self.bytes.signed_integer()?)
+    }
+
+    fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_i16(self.bytes.signed_integer()?)
+    }
+
+    fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_i32(self.bytes.signed_integer()?)
+    }
+
+    fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_i64(self.bytes.signed_integer()?)
+    }
+
+    fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_i128(self.bytes.signed_integer()?)
+    }
+
+    fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_u8(self.bytes.unsigned_integer()?)
+    }
+
+    fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_u16(self.bytes.unsigned_integer()?)
+    }
+
+    fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_u32(self.bytes.unsigned_integer()?)
+    }
+
+    fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_u64(self.bytes.unsigned_integer()?)
+    }
+
+    fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_u128(self.bytes.unsigned_integer()?)
+    }
+
+    fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_f32(self.bytes.float()?)
+    }
+
+    fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_f64(self.bytes.float()?)
+    }
+
+    fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_char(self.bytes.char()?)
+    }
+
+    fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        match self.bytes.string()? {
+            ParsedStr::Allocated(s) => visitor.visit_string(s),
+            ParsedStr::Slice(s) => visitor.visit_borrowed_str(s),
+        }
+    }
+
+    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_byte_buf(visitor)
+    }
+
+    fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        let res = {
+            let string = self.bytes.string()?;
+            let base64_str = match string {
+                ParsedStr::Allocated(ref s) => s.as_str(),
+                ParsedStr::Slice(ref s) => s,
+            };
+            base64::decode(base64_str)
+        };
+
+        match res {
+            Ok(byte_buf) => visitor.visit_byte_buf(byte_buf),
+            Err(err) => self.bytes.err(ErrorCode::Base64Error(err)),
+        }
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.consume("None") {
+            visitor.visit_none()
+        } else if self.bytes.exts.contains(Extensions::IMPLICIT_SOME) {
+            visitor.visit_some(&mut *self)
+        } else if self.bytes.consume("Some") && {
+            self.bytes.skip_ws()?;
+            self.bytes.consume("(")
+        } {
+            self.bytes.skip_ws()?;
+
+            let v = visitor.visit_some(&mut *self)?;
+
+            self.bytes.skip_ws()?;
+
+            if self.bytes.consume(")") {
+                Ok(v)
+            } else {
+                self.bytes.err(ErrorCode::ExpectedOptionEnd)
+            }
+        } else {
+            self.bytes.err(ErrorCode::ExpectedOption)
+        }
+    }
+
+    // In Serde, unit means an anonymous value containing no data.
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.consume("()") {
+            visitor.visit_unit()
+        } else {
+            self.bytes.err(ErrorCode::ExpectedUnit)
+        }
+    }
+
+    fn deserialize_unit_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.consume(name) {
+            visitor.visit_unit()
+        } else {
+            self.deserialize_unit(visitor)
+        }
+    }
+
+    fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.exts.contains(Extensions::UNWRAP_NEWTYPES) {
+            return visitor.visit_newtype_struct(&mut *self);
+        }
+
+        self.bytes.consume(name);
+
+        self.bytes.skip_ws()?;
+
+        if self.bytes.consume("(") {
+            self.bytes.skip_ws()?;
+            let value = visitor.visit_newtype_struct(&mut *self)?;
+            self.bytes.comma()?;
+
+            if self.bytes.consume(")") {
+                Ok(value)
+            } else {
+                self.bytes.err(ErrorCode::ExpectedStructEnd)
+            }
+        } else {
+            self.bytes.err(ErrorCode::ExpectedStruct)
+        }
+    }
+
+    fn deserialize_seq<V>(mut self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.consume("[") {
+            let value = visitor.visit_seq(CommaSeparated::new(b']', &mut self))?;
+            self.bytes.comma()?;
+
+            if self.bytes.consume("]") {
+                Ok(value)
+            } else {
+                self.bytes.err(ErrorCode::ExpectedArrayEnd)
+            }
+        } else {
+            self.bytes.err(ErrorCode::ExpectedArray)
+        }
+    }
+
+    fn deserialize_tuple<V>(mut self, _len: usize, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.consume("(") {
+            let value = visitor.visit_seq(CommaSeparated::new(b')', &mut self))?;
+            self.bytes.comma()?;
+
+            if self.bytes.consume(")") {
+                Ok(value)
+            } else {
+                self.bytes.err(ErrorCode::ExpectedArrayEnd)
+            }
+        } else {
+            self.bytes.err(ErrorCode::ExpectedArray)
+        }
+    }
+
+    fn deserialize_tuple_struct<V>(
+        self,
+        name: &'static str,
+        len: usize,
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        self.bytes.consume(name);
+        self.deserialize_tuple(len, visitor)
+    }
+
+    fn deserialize_map<V>(mut self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        if self.bytes.consume("{") {
+            let value = visitor.visit_map(CommaSeparated::new(b'}', &mut self))?;
+            self.bytes.comma()?;
+
+            if self.bytes.consume("}") {
+                Ok(value)
+            } else {
+                self.bytes.err(ErrorCode::ExpectedMapEnd)
+            }
+        } else {
+            self.bytes.err(ErrorCode::ExpectedMap)
+        }
+    }
+
+    fn deserialize_struct<V>(
+        mut self,
+        name: &'static str,
+        _fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        self.bytes.consume(name);
+
+        self.bytes.skip_ws()?;
+
+        if self.bytes.consume("(") {
+            let value = visitor.visit_map(CommaSeparated::new(b')', &mut self))?;
+            self.bytes.comma()?;
+
+            if self.bytes.consume(")") {
+                Ok(value)
+            } else {
+                self.bytes.err(ErrorCode::ExpectedStructEnd)
+            }
+        } else {
+            self.bytes.err(ErrorCode::ExpectedStruct)
+        }
+    }
+
+    fn deserialize_enum<V>(
+        self,
+        _name: &'static str,
+        _variants: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_enum(Enum::new(self))
+    }
+
+    fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_str(
+            str::from_utf8(self.bytes.identifier()?).map_err(|e| self.bytes.error(e.into()))?,
+        )
+    }
+
+    fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        self.deserialize_any(visitor)
+    }
+}
+
+struct CommaSeparated<'a, 'de: 'a> {
+    de: &'a mut Deserializer<'de>,
+    terminator: u8,
+    had_comma: bool,
+}
+
+impl<'a, 'de> CommaSeparated<'a, 'de> {
+    fn new(terminator: u8, de: &'a mut Deserializer<'de>) -> Self {
+        CommaSeparated {
+            de,
+            terminator,
+            had_comma: true,
+        }
+    }
+
+    fn err<T>(&self, kind: ErrorCode) -> Result<T> {
+        self.de.bytes.err(kind)
+    }
+
+    fn has_element(&mut self) -> Result<bool> {
+        self.de.bytes.skip_ws()?;
+
+        Ok(self.had_comma && self.de.bytes.peek_or_eof()? != self.terminator)
+    }
+}
+
+impl<'de, 'a> de::SeqAccess<'de> for CommaSeparated<'a, 'de> {
+    type Error = Error;
+
+    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+    where
+        T: DeserializeSeed<'de>,
+    {
+        if self.has_element()? {
+            let res = seed.deserialize(&mut *self.de)?;
+
+            self.had_comma = self.de.bytes.comma()?;
+
+            Ok(Some(res))
+        } else {
+            Ok(None)
+        }
+    }
+}
+
+impl<'de, 'a> de::MapAccess<'de> for CommaSeparated<'a, 'de> {
+    type Error = Error;
+
+    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
+    where
+        K: DeserializeSeed<'de>,
+    {
+        if self.has_element()? {
+            if self.terminator == b')' {
+                seed.deserialize(&mut IdDeserializer::new(&mut *self.de))
+                    .map(Some)
+            } else {
+                seed.deserialize(&mut *self.de).map(Some)
+            }
+        } else {
+            Ok(None)
+        }
+    }
+
+    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value>
+    where
+        V: DeserializeSeed<'de>,
+    {
+        self.de.bytes.skip_ws()?;
+
+        if self.de.bytes.consume(":") {
+            self.de.bytes.skip_ws()?;
+
+            let res = seed.deserialize(&mut TagDeserializer::new(&mut *self.de))?;
+
+            self.had_comma = self.de.bytes.comma()?;
+
+            Ok(res)
+        } else {
+            self.err(ErrorCode::ExpectedMapColon)
+        }
+    }
+}
+
+struct Enum<'a, 'de: 'a> {
+    de: &'a mut Deserializer<'de>,
+}
+
+impl<'a, 'de> Enum<'a, 'de> {
+    fn new(de: &'a mut Deserializer<'de>) -> Self {
+        Enum { de }
+    }
+}
+
+impl<'de, 'a> de::EnumAccess<'de> for Enum<'a, 'de> {
+    type Error = Error;
+    type Variant = Self;
+
+    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant)>
+    where
+        V: DeserializeSeed<'de>,
+    {
+        self.de.bytes.skip_ws()?;
+
+        let value = seed.deserialize(&mut *self.de)?;
+
+        Ok((value, self))
+    }
+}
+
+impl<'de, 'a> de::VariantAccess<'de> for Enum<'a, 'de> {
+    type Error = Error;
+
+    fn unit_variant(self) -> Result<()> {
+        Ok(())
+    }
+
+    fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value>
+    where
+        T: DeserializeSeed<'de>,
+    {
+        self.de.bytes.skip_ws()?;
+
+        if self.de.bytes.consume("(") {
+            self.de.bytes.skip_ws()?;
+
+            let val = seed.deserialize(&mut *self.de)?;
+
+            self.de.bytes.comma()?;
+
+            if self.de.bytes.consume(")") {
+                Ok(val)
+            } else {
+                self.de.bytes.err(ErrorCode::ExpectedStructEnd)
+            }
+        } else {
+            self.de.bytes.err(ErrorCode::ExpectedStruct)
+        }
+    }
+
+    fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        self.de.bytes.skip_ws()?;
+
+        self.de.deserialize_tuple(len, visitor)
+    }
+
+    fn struct_variant<V>(self, fields: &'static [&'static str], visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        self.de.bytes.skip_ws()?;
+
+        self.de.deserialize_struct("", fields, visitor)
+    }
+}
diff --git a/third_party/rust/ron/src/de/tag.rs b/third_party/rust/ron/src/de/tag.rs
new file mode 100644
index 0000000000..76a8bb7973
--- /dev/null
+++ b/third_party/rust/ron/src/de/tag.rs
@@ -0,0 +1,249 @@
+use serde::de::{self, Visitor};
+
+use super::{Deserializer, Error, Result};
+
+pub struct TagDeserializer<'a, 'b: 'a> {
+    d: &'a mut Deserializer<'b>,
+}
+
+impl<'a, 'b: 'a> TagDeserializer<'a, 'b> {
+    pub fn new(d: &'a mut Deserializer<'b>) -> Self {
+        TagDeserializer { d }
+    }
+}
+
+impl<'a, 'b: 'a, 'c> de::Deserializer<'b> for &'c mut TagDeserializer<'a, 'b> {
+    type Error = Error;
+
+    fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_str(visitor)
+    }
+
+    fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.deserialize_str(visitor)
+    }
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_any(visitor)
+    }
+
+    fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_bool(visitor)
+    }
+
+    fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_i8(visitor)
+    }
+
+    fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_i16(visitor)
+    }
+
+    fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_i32(visitor)
+    }
+
+    fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_i64(visitor)
+    }
+
+    fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_i128(visitor)
+    }
+
+    fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_u8(visitor)
+    }
+
+    fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_u16(visitor)
+    }
+
+    fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_u32(visitor)
+    }
+
+    fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_u64(visitor)
+    }
+
+    fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_u128(visitor)
+    }
+
+    fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_f32(visitor)
+    }
+
+    fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_f64(visitor)
+    }
+
+    fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_char(visitor)
+    }
+
+    fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_string(visitor)
+    }
+
+    fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_bytes(visitor)
+    }
+
+    fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_byte_buf(visitor)
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_option(visitor)
+    }
+
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_unit(visitor)
+    }
+
+    fn deserialize_unit_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_unit_struct(name, visitor)
+    }
+
+    fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_newtype_struct(name, visitor)
+    }
+
+    fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_seq(visitor)
+    }
+
+    fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_tuple(len, visitor)
+    }
+
+    fn deserialize_tuple_struct<V>(
+        self,
+        name: &'static str,
+        len: usize,
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_tuple_struct(name, len, visitor)
+    }
+
+    fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_map(visitor)
+    }
+
+    fn deserialize_struct<V>(
+        self,
+        name: &'static str,
+        fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.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<'b>,
+    {
+        self.d.deserialize_enum(name, variants, visitor)
+    }
+
+    fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'b>,
+    {
+        self.d.deserialize_ignored_any(visitor)
+    }
+}
diff --git a/third_party/rust/ron/src/de/tests.rs b/third_party/rust/ron/src/de/tests.rs
new file mode 100644
index 0000000000..f74b87b658
--- /dev/null
+++ b/third_party/rust/ron/src/de/tests.rs
@@ -0,0 +1,328 @@
+use serde::Deserialize;
+use serde_bytes;
+
+use super::*;
+
+#[derive(Debug, PartialEq, Deserialize)]
+struct EmptyStruct1;
+
+#[derive(Debug, PartialEq, Deserialize)]
+struct EmptyStruct2 {}
+
+#[derive(Clone, Copy, Debug, PartialEq, Deserialize)]
+struct MyStruct {
+    x: f32,
+    y: f32,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Deserialize)]
+enum MyEnum {
+    A,
+    B(bool),
+    C(bool, f32),
+    D { a: i32, b: i32 },
+}
+
+#[derive(Debug, Deserialize, PartialEq)]
+struct BytesStruct {
+    small: Vec<u8>,
+    #[serde(with = "serde_bytes")]
+    large: Vec<u8>,
+}
+
+#[test]
+fn test_empty_struct() {
+    assert_eq!(Ok(EmptyStruct1), from_str("EmptyStruct1"));
+    assert_eq!(Ok(EmptyStruct2 {}), from_str("EmptyStruct2()"));
+}
+
+#[test]
+fn test_struct() {
+    let my_struct = MyStruct { x: 4.0, y: 7.0 };
+
+    assert_eq!(Ok(my_struct), from_str("MyStruct(x:4,y:7,)"));
+    assert_eq!(Ok(my_struct), from_str("(x:4,y:7)"));
+
+    #[derive(Debug, PartialEq, Deserialize)]
+    struct NewType(i32);
+
+    assert_eq!(Ok(NewType(42)), from_str("NewType(42)"));
+    assert_eq!(Ok(NewType(33)), from_str("(33)"));
+
+    #[derive(Debug, PartialEq, Deserialize)]
+    struct TupleStruct(f32, f32);
+
+    assert_eq!(Ok(TupleStruct(2.0, 5.0)), from_str("TupleStruct(2,5,)"));
+    assert_eq!(Ok(TupleStruct(3.0, 4.0)), from_str("(3,4)"));
+}
+
+#[test]
+fn test_option() {
+    assert_eq!(Ok(Some(1u8)), from_str("Some(1)"));
+    assert_eq!(Ok(None::<u8>), from_str("None"));
+}
+
+#[test]
+fn test_enum() {
+    assert_eq!(Ok(MyEnum::A), from_str("A"));
+    assert_eq!(Ok(MyEnum::B(true)), from_str("B(true,)"));
+    assert_eq!(Ok(MyEnum::C(true, 3.5)), from_str("C(true,3.5,)"));
+    assert_eq!(Ok(MyEnum::D { a: 2, b: 3 }), from_str("D(a:2,b:3,)"));
+}
+
+#[test]
+fn test_array() {
+    let empty: [i32; 0] = [];
+    assert_eq!(Ok(empty), from_str("()"));
+    let empty_array = empty.to_vec();
+    assert_eq!(Ok(empty_array), from_str("[]"));
+
+    assert_eq!(Ok([2, 3, 4i32]), from_str("(2,3,4,)"));
+    assert_eq!(Ok([2, 3, 4i32].to_vec()), from_str("[2,3,4,]"));
+}
+
+#[test]
+fn test_map() {
+    use std::collections::HashMap;
+
+    let mut map = HashMap::new();
+    map.insert((true, false), 4);
+    map.insert((false, false), 123);
+
+    assert_eq!(
+        Ok(map),
+        from_str(
+            "{
+        (true,false,):4,
+        (false,false,):123,
+    }"
+        )
+    );
+}
+
+#[test]
+fn test_string() {
+    let s: String = from_str("\"String\"").unwrap();
+    assert_eq!("String", s);
+
+    let raw: String = from_str("r\"String\"").unwrap();
+    assert_eq!("String", raw);
+
+    let raw_hashes: String = from_str("r#\"String\"#").unwrap();
+    assert_eq!("String", raw_hashes);
+
+    let raw_hashes_multiline: String = from_str("r#\"String with\nmultiple\nlines\n\"#").unwrap();
+    assert_eq!("String with\nmultiple\nlines\n", raw_hashes_multiline);
+
+    let raw_hashes_quote: String = from_str("r##\"String with \"#\"##").unwrap();
+    assert_eq!("String with \"#", raw_hashes_quote);
+}
+
+#[test]
+fn test_char() {
+    assert_eq!(Ok('c'), from_str("'c'"));
+}
+
+#[test]
+fn test_escape_char() {
+    assert_eq!('\'', from_str::<char>("'\\''").unwrap());
+}
+
+#[test]
+fn test_escape() {
+    assert_eq!("\"Quoted\"", from_str::<String>(r#""\"Quoted\"""#).unwrap());
+}
+
+#[test]
+fn test_comment() {
+    assert_eq!(
+        MyStruct { x: 1.0, y: 2.0 },
+        from_str(
+            "(
+x: 1.0, // x is just 1
+// There is another comment in the very next line..
+// And y is indeed
+y: 2.0 // 2!
+    )"
+        )
+        .unwrap()
+    );
+}
+
+fn err<T>(kind: ErrorCode, line: usize, col: usize) -> Result<T> {
+    Err(Error {
+        code: kind,
+        position: Position { line, col },
+    })
+}
+
+#[test]
+fn test_err_wrong_value() {
+    use self::ErrorCode::*;
+    use std::collections::HashMap;
+
+    assert_eq!(from_str::<f32>("'c'"), err(ExpectedFloat, 1, 1));
+    assert_eq!(from_str::<String>("'c'"), err(ExpectedString, 1, 1));
+    assert_eq!(from_str::<HashMap<u32, u32>>("'c'"), err(ExpectedMap, 1, 1));
+    assert_eq!(from_str::<[u8; 5]>("'c'"), err(ExpectedArray, 1, 1));
+    assert_eq!(from_str::<Vec<u32>>("'c'"), err(ExpectedArray, 1, 1));
+    assert_eq!(from_str::<MyEnum>("'c'"), err(ExpectedIdentifier, 1, 1));
+    assert_eq!(from_str::<MyStruct>("'c'"), err(ExpectedStruct, 1, 1));
+    assert_eq!(from_str::<(u8, bool)>("'c'"), err(ExpectedArray, 1, 1));
+    assert_eq!(from_str::<bool>("notabool"), err(ExpectedBoolean, 1, 1));
+
+    assert_eq!(
+        from_str::<MyStruct>("MyStruct(\n    x: true)"),
+        err(ExpectedFloat, 2, 8)
+    );
+    assert_eq!(
+        from_str::<MyStruct>("MyStruct(\n    x: 3.5, \n    y:)"),
+        err(ExpectedFloat, 3, 7)
+    );
+}
+
+#[test]
+fn test_perm_ws() {
+    assert_eq!(
+        from_str::<MyStruct>("\nMyStruct  \t ( \n x   : 3.5 , \t y\n: 4.5 \n ) \t\n"),
+        Ok(MyStruct { x: 3.5, y: 4.5 })
+    );
+}
+
+#[test]
+fn untagged() {
+    #[derive(Deserialize, Debug, PartialEq)]
+    #[serde(untagged)]
+    enum Untagged {
+        U8(u8),
+        Bool(bool),
+    }
+
+    assert_eq!(from_str::<Untagged>("true").unwrap(), Untagged::Bool(true));
+    assert_eq!(from_str::<Untagged>("8").unwrap(), Untagged::U8(8));
+}
+
+#[test]
+fn forgot_apostrophes() {
+    let de: Result<(i32, String)> = from_str("(4, \"Hello)");
+
+    assert!(match de {
+        Err(Error {
+            code: ErrorCode::ExpectedStringEnd,
+            position: _,
+        }) => true,
+        _ => false,
+    });
+}
+
+#[test]
+fn expected_attribute() {
+    let de: Result<String> = from_str("#\"Hello\"");
+
+    assert_eq!(de, err(ErrorCode::ExpectedAttribute, 1, 2));
+}
+
+#[test]
+fn expected_attribute_end() {
+    let de: Result<String> = from_str("#![enable(unwrap_newtypes) \"Hello\"");
+
+    assert_eq!(de, err(ErrorCode::ExpectedAttributeEnd, 1, 28));
+}
+
+#[test]
+fn invalid_attribute() {
+    let de: Result<String> = from_str("#![enable(invalid)] \"Hello\"");
+
+    assert_eq!(
+        de,
+        err(ErrorCode::NoSuchExtension("invalid".to_string()), 1, 18)
+    );
+}
+
+#[test]
+fn multiple_attributes() {
+    #[derive(Debug, Deserialize, PartialEq)]
+    struct New(String);
+    let de: Result<New> =
+        from_str("#![enable(unwrap_newtypes)] #![enable(unwrap_newtypes)] \"Hello\"");
+
+    assert_eq!(de, Ok(New("Hello".to_owned())));
+}
+
+#[test]
+fn uglified_attribute() {
+    let de: Result<()> = from_str(
+        "#   !\
+    // We definitely want to add a comment here
+    [\t\tenable( // best style ever
+            unwrap_newtypes  ) ] ()",
+    );
+
+    assert_eq!(de, Ok(()));
+}
+
+#[test]
+fn implicit_some() {
+    use serde::de::DeserializeOwned;
+
+    fn de<T: DeserializeOwned>(s: &str) -> Option<T> {
+        let enable = "#![enable(implicit_some)]\n".to_string();
+
+        from_str::<Option<T>>(&(enable + s)).unwrap()
+    }
+
+    assert_eq!(de("'c'"), Some('c'));
+    assert_eq!(de("5"), Some(5));
+    assert_eq!(de("\"Hello\""), Some("Hello".to_owned()));
+    assert_eq!(de("false"), Some(false));
+    assert_eq!(
+        de("MyStruct(x: .4, y: .5)"),
+        Some(MyStruct { x: 0.4, y: 0.5 })
+    );
+
+    assert_eq!(de::<char>("None"), None);
+
+    // Not concise
+    assert_eq!(de::<Option<Option<char>>>("None"), None);
+}
+
+#[test]
+fn ws_tuple_newtype_variant() {
+    assert_eq!(Ok(MyEnum::B(true)), from_str("B  ( \n true \n ) "));
+}
+
+#[test]
+fn test_byte_stream() {
+    assert_eq!(
+        Ok(BytesStruct {
+            small: vec![1, 2],
+            large: vec![1, 2, 3, 4]
+        }),
+        from_str("BytesStruct( small:[1, 2], large:\"AQIDBA==\" )"),
+    );
+}
+
+#[test]
+fn test_numbers() {
+    assert_eq!(
+        Ok(vec![1234, 12345, 123456, 1234567, 555_555]),
+        from_str("[1_234, 12_345, 1_2_3_4_5_6, 1_234_567, 5_55_55_5]"),
+    );
+}
+
+fn de_any_number(s: &str) -> AnyNum {
+    let mut bytes = Bytes::new(s.as_bytes()).unwrap();
+
+    bytes.any_num().unwrap()
+}
+
+#[test]
+fn test_any_number_precision() {
+    assert_eq!(de_any_number("1"), AnyNum::U8(1));
+    assert_eq!(de_any_number("+1"), AnyNum::I8(1));
+    assert_eq!(de_any_number("-1"), AnyNum::I8(-1));
+    assert_eq!(de_any_number("-1.0"), AnyNum::F32(-1.0));
+    assert_eq!(de_any_number("1."), AnyNum::F32(1.));
+    assert_eq!(de_any_number("-1."), AnyNum::F32(-1.));
+    assert_eq!(de_any_number("0.3"), AnyNum::F64(0.3));
+}
diff --git a/third_party/rust/ron/src/de/value.rs b/third_party/rust/ron/src/de/value.rs
new file mode 100644
index 0000000000..92acca2068
--- /dev/null
+++ b/third_party/rust/ron/src/de/value.rs
@@ -0,0 +1,335 @@
+use std::fmt;
+
+use serde::{
+    de::{Error, MapAccess, SeqAccess, Visitor},
+    Deserialize, Deserializer,
+};
+
+use crate::{
+    de,
+    value::{Map, Number, Value},
+};
+
+impl std::str::FromStr for Value {
+    type Err = de::Error;
+
+    /// Creates a value from a string reference.
+    fn from_str(s: &str) -> de::Result<Self> {
+        let mut de = super::Deserializer::from_str(s)?;
+
+        let val = Value::deserialize(&mut de)?;
+        de.end()?;
+
+        Ok(val)
+    }
+}
+
+impl<'de> Deserialize<'de> for Value {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_any(ValueVisitor)
+    }
+}
+
+struct ValueVisitor;
+
+impl<'de> Visitor<'de> for ValueVisitor {
+    type Value = Value;
+
+    fn expecting(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "a RON value")
+    }
+
+    fn visit_bool<E>(self, v: bool) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::Bool(v))
+    }
+
+    fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::Number(Number::new(v)))
+    }
+
+    fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        self.visit_f64(v as f64)
+    }
+
+    fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::Number(Number::new(v)))
+    }
+
+    fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        self.visit_f64(v as f64)
+    }
+
+    fn visit_f64<E>(self, v: f64) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::Number(Number::new(v)))
+    }
+
+    fn visit_char<E>(self, v: char) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::Char(v))
+    }
+
+    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        self.visit_string(v.to_owned())
+    }
+
+    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::String(v))
+    }
+
+    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        self.visit_byte_buf(v.to_vec())
+    }
+
+    fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        self.visit_string(String::from_utf8(v).map_err(|e| Error::custom(format!("{}", e)))?)
+    }
+
+    fn visit_none<E>(self) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::Option(None))
+    }
+
+    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        Ok(Value::Option(Some(Box::new(
+            deserializer.deserialize_any(ValueVisitor)?,
+        ))))
+    }
+
+    fn visit_unit<E>(self) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(Value::Unit)
+    }
+
+    fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_any(ValueVisitor)
+    }
+
+    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+    where
+        A: SeqAccess<'de>,
+    {
+        let mut vec = Vec::new();
+        if let Some(cap) = seq.size_hint() {
+            vec.reserve_exact(cap);
+        }
+
+        while let Some(x) = seq.next_element()? {
+            vec.push(x);
+        }
+
+        Ok(Value::Seq(vec))
+    }
+
+    fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+    where
+        A: MapAccess<'de>,
+    {
+        let mut res: Map = Map::new();
+
+        while let Some(entry) = map.next_entry()? {
+            res.insert(entry.0, entry.1);
+        }
+
+        Ok(Value::Map(res))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::str::FromStr;
+
+    fn eval(s: &str) -> Value {
+        s.parse().expect("Failed to parse")
+    }
+
+    #[test]
+    fn test_none() {
+        assert_eq!(eval("None"), Value::Option(None));
+    }
+
+    #[test]
+    fn test_some() {
+        assert_eq!(eval("Some(())"), Value::Option(Some(Box::new(Value::Unit))));
+        assert_eq!(
+            eval("Some  (  () )"),
+            Value::Option(Some(Box::new(Value::Unit)))
+        );
+    }
+
+    #[test]
+    fn test_tuples_basic() {
+        assert_eq!(
+            eval("(3, 4.0, 5.0)"),
+            Value::Seq(vec![
+                Value::Number(Number::new(3)),
+                Value::Number(Number::new(4.0)),
+                Value::Number(Number::new(5.0)),
+            ],),
+        );
+    }
+
+    #[test]
+    fn test_tuples_ident() {
+        assert_eq!(
+            eval("(true, 3, 4, 5.0)"),
+            Value::Seq(vec![
+                Value::Bool(true),
+                Value::Number(Number::new(3)),
+                Value::Number(Number::new(4)),
+                Value::Number(Number::new(5.0)),
+            ]),
+        );
+    }
+
+    #[test]
+    fn test_tuples_error() {
+        use crate::de::{Error, ErrorCode, Position};
+
+        assert_eq!(
+            Value::from_str("Foo:").unwrap_err(),
+            Error {
+                code: ErrorCode::TrailingCharacters,
+                position: Position { col: 4, line: 1 }
+            },
+        );
+    }
+
+    #[test]
+    fn test_floats() {
+        assert_eq!(
+            eval("(inf, -inf, NaN)"),
+            Value::Seq(vec![
+                Value::Number(Number::new(std::f64::INFINITY)),
+                Value::Number(Number::new(std::f64::NEG_INFINITY)),
+                Value::Number(Number::new(std::f64::NAN)),
+            ]),
+        );
+    }
+
+    #[test]
+    fn test_complex() {
+        assert_eq!(
+            eval(
+                "Some([
+    Room ( width: 20, height: 5, name: \"The Room\" ),
+
+    (
+        width: 10.0,
+        height: 10.0,
+        name: \"Another room\",
+        enemy_levels: {
+            \"Enemy1\": 3,
+            \"Enemy2\": 5,
+            \"Enemy3\": 7,
+        },
+    ),
+])"
+            ),
+            Value::Option(Some(Box::new(Value::Seq(vec![
+                Value::Map(
+                    vec![
+                        (
+                            Value::String("width".to_owned()),
+                            Value::Number(Number::new(20)),
+                        ),
+                        (
+                            Value::String("height".to_owned()),
+                            Value::Number(Number::new(5)),
+                        ),
+                        (
+                            Value::String("name".to_owned()),
+                            Value::String("The Room".to_owned()),
+                        ),
+                    ]
+                    .into_iter()
+                    .collect(),
+                ),
+                Value::Map(
+                    vec![
+                        (
+                            Value::String("width".to_owned()),
+                            Value::Number(Number::new(10.0)),
+                        ),
+                        (
+                            Value::String("height".to_owned()),
+                            Value::Number(Number::new(10.0)),
+                        ),
+                        (
+                            Value::String("name".to_owned()),
+                            Value::String("Another room".to_owned()),
+                        ),
+                        (
+                            Value::String("enemy_levels".to_owned()),
+                            Value::Map(
+                                vec![
+                                    (
+                                        Value::String("Enemy1".to_owned()),
+                                        Value::Number(Number::new(3)),
+                                    ),
+                                    (
+                                        Value::String("Enemy2".to_owned()),
+                                        Value::Number(Number::new(5)),
+                                    ),
+                                    (
+                                        Value::String("Enemy3".to_owned()),
+                                        Value::Number(Number::new(7)),
+                                    ),
+                                ]
+                                .into_iter()
+                                .collect(),
+                            ),
+                        ),
+                    ]
+                    .into_iter()
+                    .collect(),
+                ),
+            ]))))
+        );
+    }
+}