Adding upstream version 86.0.1.upstream/86.0.1upstream

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

2 files changed, 1112 insertions, 0 deletions

diff --git a/third_party/rust/ron/src/ser/mod.rs b/third_party/rust/ron/src/ser/mod.rs
new file mode 100644
index 0000000000..ca1cea3dad
--- /dev/null
+++ b/third_party/rust/ron/src/ser/mod.rs
@@ -0,0 +1,1089 @@
+use serde::{ser, Deserialize, Serialize};
+use std::io;
+
+use crate::error::{Error, Result};
+use crate::extensions::Extensions;
+
+mod value;
+
+/// Serializes `value` into `writer`
+pub fn to_writer<W, T>(writer: W, value: &T) -> Result<()>
+where
+    W: io::Write,
+    T: Serialize,
+{
+    let mut s = Serializer::new(writer, None, false)?;
+    value.serialize(&mut s)
+}
+
+/// Serializes `value` into `writer` in a pretty way.
+pub fn to_writer_pretty<W, T>(writer: W, value: &T, config: PrettyConfig) -> Result<()>
+where
+    W: io::Write,
+    T: Serialize,
+{
+    let mut s = Serializer::new(writer, Some(config), false)?;
+    value.serialize(&mut s)
+}
+
+/// Serializes `value` and returns it as string.
+///
+/// This function does not generate any newlines or nice formatting;
+/// if you want that, you can use `to_string_pretty` instead.
+pub fn to_string<T>(value: &T) -> Result<String>
+where
+    T: Serialize,
+{
+    let buf = Vec::new();
+    let mut s = Serializer::new(buf, None, false)?;
+    value.serialize(&mut s)?;
+    Ok(String::from_utf8(s.output).expect("Ron should be utf-8"))
+}
+
+/// Serializes `value` in the recommended RON layout in a pretty way.
+pub fn to_string_pretty<T>(value: &T, config: PrettyConfig) -> Result<String>
+where
+    T: Serialize,
+{
+    let buf = Vec::new();
+    let mut s = Serializer::new(buf, Some(config), false)?;
+    value.serialize(&mut s)?;
+    Ok(String::from_utf8(s.output).expect("Ron should be utf-8"))
+}
+
+/// Pretty serializer state
+struct Pretty {
+    indent: usize,
+    sequence_index: Vec<usize>,
+}
+
+/// Pretty serializer configuration.
+///
+/// # Examples
+///
+/// ```
+/// use ron::ser::PrettyConfig;
+///
+/// let my_config = PrettyConfig::new()
+///     .with_depth_limit(4)
+///     // definitely superior (okay, just joking)
+///     .with_indentor("\t".to_owned());
+/// ```
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct PrettyConfig {
+    /// Limit the pretty-ness up to the given depth.
+    #[serde(default = "default_depth_limit")]
+    pub depth_limit: usize,
+    /// New line string
+    #[serde(default = "default_new_line")]
+    pub new_line: String,
+    /// Indentation string
+    #[serde(default = "default_indentor")]
+    pub indentor: String,
+    /// Separate tuple members with indentation
+    #[serde(default = "default_separate_tuple_members")]
+    pub separate_tuple_members: bool,
+    /// Enumerate array items in comments
+    #[serde(default = "default_enumerate_arrays")]
+    pub enumerate_arrays: bool,
+    /// Always include the decimal in floats
+    #[serde(default = "default_decimal_floats")]
+    pub decimal_floats: bool,
+    /// Enable extensions. Only configures 'implicit_some' for now.
+    pub extensions: Extensions,
+    /// Private field to ensure adding a field is non-breaking.
+    #[serde(skip)]
+    _future_proof: (),
+}
+
+impl PrettyConfig {
+    /// Creates a default `PrettyConfig`.
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    /// Limits the pretty-formatting based on the number of indentations.
+    /// I.e., with a depth limit of 5, starting with an element of depth
+    /// (indentation level) 6, everything will be put into the same line,
+    /// without pretty formatting.
+    ///
+    /// Default: [std::usize::MAX]
+    pub fn with_depth_limit(mut self, depth_limit: usize) -> Self {
+        self.depth_limit = depth_limit;
+
+        self
+    }
+
+    /// Configures the newlines used for serialization.
+    ///
+    /// Default: `\r\n` on Windows, `\n` otherwise
+    pub fn with_new_line(mut self, new_line: String) -> Self {
+        self.new_line = new_line;
+
+        self
+    }
+
+    /// Configures the string sequence used for indentation.
+    ///
+    /// Default: 4 spaces
+    pub fn with_indentor(mut self, indentor: String) -> Self {
+        self.indentor = indentor;
+
+        self
+    }
+
+    /// Configures whether tuples are single- or multi-line.
+    /// If set to `true`, tuples will have their fields indented and in new
+    /// lines. If set to `false`, tuples will be serialized without any
+    /// newlines or indentations.
+    ///
+    /// Default: `false`
+    pub fn with_separate_tuple_members(mut self, separate_tuple_members: bool) -> Self {
+        self.separate_tuple_members = separate_tuple_members;
+
+        self
+    }
+
+    /// Configures whether a comment shall be added to every array element,
+    /// indicating the index.
+    ///
+    /// Default: `false`
+    pub fn with_enumerate_arrays(mut self, enumerate_arrays: bool) -> Self {
+        self.enumerate_arrays = enumerate_arrays;
+
+        self
+    }
+
+    /// Configures whether floats should always include a decimal.
+    /// When false `1.0` will serialize as `1`
+    /// When true `1.0` will serialize as `1.0`
+    ///
+    /// Default: `false`
+    pub fn with_decimal_floats(mut self, decimal_floats: bool) -> Self {
+        self.decimal_floats = decimal_floats;
+
+        self
+    }
+
+    /// Configures extensions
+    ///
+    /// Default: Extensions::empty()
+    pub fn with_extensions(mut self, extensions: Extensions) -> Self {
+        self.extensions = extensions;
+
+        self
+    }
+}
+
+fn default_depth_limit() -> usize {
+    !0
+}
+
+fn default_new_line() -> String {
+    #[cfg(not(target_os = "windows"))]
+    let new_line = "\n".to_string();
+    #[cfg(target_os = "windows")]
+    let new_line = "\r\n".to_string();
+
+    new_line
+}
+
+fn default_decimal_floats() -> bool {
+    false
+}
+
+fn default_indentor() -> String {
+    "    ".to_string()
+}
+
+fn default_separate_tuple_members() -> bool {
+    false
+}
+
+fn default_enumerate_arrays() -> bool {
+    false
+}
+
+impl Default for PrettyConfig {
+    fn default() -> Self {
+        PrettyConfig {
+            depth_limit: default_depth_limit(),
+            new_line: default_new_line(),
+            indentor: default_indentor(),
+            separate_tuple_members: default_separate_tuple_members(),
+            enumerate_arrays: default_enumerate_arrays(),
+            extensions: Extensions::default(),
+            decimal_floats: default_decimal_floats(),
+            _future_proof: (),
+        }
+    }
+}
+
+/// The RON serializer.
+///
+/// You can just use `to_string` for deserializing a value.
+/// If you want it pretty-printed, take a look at the `pretty` module.
+pub struct Serializer<W: io::Write> {
+    output: W,
+    pretty: Option<(PrettyConfig, Pretty)>,
+    struct_names: bool,
+    is_empty: Option<bool>,
+}
+
+impl<W: io::Write> Serializer<W> {
+    /// Creates a new `Serializer`.
+    ///
+    /// Most of the time you can just use `to_string` or `to_string_pretty`.
+    pub fn new(mut writer: W, config: Option<PrettyConfig>, struct_names: bool) -> Result<Self> {
+        if let Some(conf) = &config {
+            if conf.extensions.contains(Extensions::IMPLICIT_SOME) {
+                writer.write_all(b"#![enable(implicit_some)]")?;
+                writer.write_all(conf.new_line.as_bytes())?;
+            };
+        };
+        Ok(Serializer {
+            output: writer,
+            pretty: config.map(|conf| {
+                (
+                    conf,
+                    Pretty {
+                        indent: 0,
+                        sequence_index: Vec::new(),
+                    },
+                )
+            }),
+            struct_names,
+            is_empty: None,
+        })
+    }
+
+    fn is_pretty(&self) -> bool {
+        match self.pretty {
+            Some((ref config, ref pretty)) => pretty.indent <= config.depth_limit,
+            None => false,
+        }
+    }
+
+    fn separate_tuple_members(&self) -> bool {
+        self.pretty
+            .as_ref()
+            .map_or(false, |&(ref config, _)| config.separate_tuple_members)
+    }
+
+    fn decimal_floats(&self) -> bool {
+        self.pretty
+            .as_ref()
+            .map_or(false, |&(ref config, _)| config.decimal_floats)
+    }
+
+    fn extensions(&self) -> Extensions {
+        self.pretty
+            .as_ref()
+            .map_or(Extensions::empty(), |&(ref config, _)| config.extensions)
+    }
+
+    fn start_indent(&mut self) -> Result<()> {
+        if let Some((ref config, ref mut pretty)) = self.pretty {
+            pretty.indent += 1;
+            if pretty.indent <= config.depth_limit {
+                let is_empty = self.is_empty.unwrap_or(false);
+
+                if !is_empty {
+                    self.output.write_all(config.new_line.as_bytes())?;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn indent(&mut self) -> io::Result<()> {
+        if let Some((ref config, ref pretty)) = self.pretty {
+            if pretty.indent <= config.depth_limit {
+                for _ in 0..pretty.indent {
+                    self.output.write_all(config.indentor.as_bytes())?;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn end_indent(&mut self) -> io::Result<()> {
+        if let Some((ref config, ref mut pretty)) = self.pretty {
+            if pretty.indent <= config.depth_limit {
+                let is_empty = self.is_empty.unwrap_or(false);
+
+                if !is_empty {
+                    for _ in 1..pretty.indent {
+                        self.output.write_all(config.indentor.as_bytes())?;
+                    }
+                }
+            }
+            pretty.indent -= 1;
+
+            self.is_empty = None;
+        }
+        Ok(())
+    }
+
+    fn serialize_escaped_str(&mut self, value: &str) -> io::Result<()> {
+        self.output.write_all(b"\"")?;
+        let mut scalar = [0u8; 4];
+        for c in value.chars().flat_map(|c| c.escape_debug()) {
+            self.output
+                .write_all(c.encode_utf8(&mut scalar).as_bytes())?;
+        }
+        self.output.write_all(b"\"")?;
+        Ok(())
+    }
+}
+
+impl<'a, W: io::Write> ser::Serializer for &'a mut Serializer<W> {
+    type Error = Error;
+    type Ok = ();
+    type SerializeMap = Compound<'a, W>;
+    type SerializeSeq = Compound<'a, W>;
+    type SerializeStruct = Compound<'a, W>;
+    type SerializeStructVariant = Compound<'a, W>;
+    type SerializeTuple = Compound<'a, W>;
+    type SerializeTupleStruct = Compound<'a, W>;
+    type SerializeTupleVariant = Compound<'a, W>;
+
+    fn serialize_bool(self, v: bool) -> Result<()> {
+        self.output.write_all(if v { b"true" } else { b"false" })?;
+        Ok(())
+    }
+
+    fn serialize_i8(self, v: i8) -> Result<()> {
+        self.serialize_i128(v as i128)
+    }
+
+    fn serialize_i16(self, v: i16) -> Result<()> {
+        self.serialize_i128(v as i128)
+    }
+
+    fn serialize_i32(self, v: i32) -> Result<()> {
+        self.serialize_i128(v as i128)
+    }
+
+    fn serialize_i64(self, v: i64) -> Result<()> {
+        self.serialize_i128(v as i128)
+    }
+
+    fn serialize_i128(self, v: i128) -> Result<()> {
+        // TODO optimize
+        write!(self.output, "{}", v)?;
+        Ok(())
+    }
+
+    fn serialize_u8(self, v: u8) -> Result<()> {
+        self.serialize_u128(v as u128)
+    }
+
+    fn serialize_u16(self, v: u16) -> Result<()> {
+        self.serialize_u128(v as u128)
+    }
+
+    fn serialize_u32(self, v: u32) -> Result<()> {
+        self.serialize_u128(v as u128)
+    }
+
+    fn serialize_u64(self, v: u64) -> Result<()> {
+        self.serialize_u128(v as u128)
+    }
+
+    fn serialize_u128(self, v: u128) -> Result<()> {
+        write!(self.output, "{}", v)?;
+        Ok(())
+    }
+
+    fn serialize_f32(self, v: f32) -> Result<()> {
+        write!(self.output, "{}", v)?;
+        // TODO: use f32::EPSILON when minimum supported rust version is 1.43
+        pub const EPSILON: f32 = 1.19209290e-07_f32;
+        if self.decimal_floats() && (v - v.floor()).abs() < EPSILON {
+            write!(self.output, ".0")?;
+        }
+        Ok(())
+    }
+
+    fn serialize_f64(self, v: f64) -> Result<()> {
+        write!(self.output, "{}", v)?;
+        // TODO: use f64::EPSILON when minimum supported rust version is 1.43
+        pub const EPSILON: f64 = 2.2204460492503131e-16_f64;
+        if self.decimal_floats() && (v - v.floor()).abs() < EPSILON {
+            write!(self.output, ".0")?;
+        }
+        Ok(())
+    }
+
+    fn serialize_char(self, v: char) -> Result<()> {
+        self.output.write_all(b"'")?;
+        if v == '\\' || v == '\'' {
+            self.output.write_all(b"\\")?;
+        }
+        write!(self.output, "{}", v)?;
+        self.output.write_all(b"'")?;
+        Ok(())
+    }
+
+    fn serialize_str(self, v: &str) -> Result<()> {
+        self.serialize_escaped_str(v)?;
+
+        Ok(())
+    }
+
+    fn serialize_bytes(self, v: &[u8]) -> Result<()> {
+        self.serialize_str(base64::encode(v).as_str())
+    }
+
+    fn serialize_none(self) -> Result<()> {
+        self.output.write_all(b"None")?;
+
+        Ok(())
+    }
+
+    fn serialize_some<T>(self, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        let implicit_some = self.extensions().contains(Extensions::IMPLICIT_SOME);
+        if !implicit_some {
+            self.output.write_all(b"Some(")?;
+        }
+        value.serialize(&mut *self)?;
+        if !implicit_some {
+            self.output.write_all(b")")?;
+        }
+
+        Ok(())
+    }
+
+    fn serialize_unit(self) -> Result<()> {
+        self.output.write_all(b"()")?;
+
+        Ok(())
+    }
+
+    fn serialize_unit_struct(self, name: &'static str) -> Result<()> {
+        if self.struct_names {
+            self.output.write_all(name.as_bytes())?;
+
+            Ok(())
+        } else {
+            self.serialize_unit()
+        }
+    }
+
+    fn serialize_unit_variant(self, _: &'static str, _: u32, variant: &'static str) -> Result<()> {
+        self.output.write_all(variant.as_bytes())?;
+
+        Ok(())
+    }
+
+    fn serialize_newtype_struct<T>(self, name: &'static str, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        if self.struct_names {
+            self.output.write_all(name.as_bytes())?;
+        }
+
+        self.output.write_all(b"(")?;
+        value.serialize(&mut *self)?;
+        self.output.write_all(b")")?;
+        Ok(())
+    }
+
+    fn serialize_newtype_variant<T>(
+        self,
+        _: &'static str,
+        _: u32,
+        variant: &'static str,
+        value: &T,
+    ) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        self.output.write_all(variant.as_bytes())?;
+        self.output.write_all(b"(")?;
+
+        value.serialize(&mut *self)?;
+
+        self.output.write_all(b")")?;
+        Ok(())
+    }
+
+    fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
+        self.output.write_all(b"[")?;
+
+        if let Some(len) = len {
+            self.is_empty = Some(len == 0);
+        }
+
+        self.start_indent()?;
+
+        if let Some((_, ref mut pretty)) = self.pretty {
+            pretty.sequence_index.push(0);
+        }
+
+        Ok(Compound::Map {
+            ser: self,
+            state: State::First,
+        })
+    }
+
+    fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple> {
+        self.output.write_all(b"(")?;
+
+        if self.separate_tuple_members() {
+            self.is_empty = Some(len == 0);
+
+            self.start_indent()?;
+        }
+
+        Ok(Compound::Map {
+            ser: self,
+            state: State::First,
+        })
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        name: &'static str,
+        len: usize,
+    ) -> Result<Self::SerializeTupleStruct> {
+        if self.struct_names {
+            self.output.write_all(name.as_bytes())?;
+        }
+
+        self.serialize_tuple(len)
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        variant: &'static str,
+        len: usize,
+    ) -> Result<Self::SerializeTupleVariant> {
+        self.output.write_all(variant.as_bytes())?;
+        self.output.write_all(b"(")?;
+
+        if self.separate_tuple_members() {
+            self.is_empty = Some(len == 0);
+
+            self.start_indent()?;
+        }
+
+        Ok(Compound::Map {
+            ser: self,
+            state: State::First,
+        })
+    }
+
+    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap> {
+        self.output.write_all(b"{")?;
+
+        if let Some(len) = len {
+            self.is_empty = Some(len == 0);
+        }
+
+        self.start_indent()?;
+
+        Ok(Compound::Map {
+            ser: self,
+            state: State::First,
+        })
+    }
+
+    fn serialize_struct(self, name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
+        if self.struct_names {
+            self.output.write_all(name.as_bytes())?;
+        }
+        self.output.write_all(b"(")?;
+
+        self.is_empty = Some(len == 0);
+        self.start_indent()?;
+
+        Ok(Compound::Map {
+            ser: self,
+            state: State::First,
+        })
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        variant: &'static str,
+        len: usize,
+    ) -> Result<Self::SerializeStructVariant> {
+        self.output.write_all(variant.as_bytes())?;
+        self.output.write_all(b"(")?;
+
+        self.is_empty = Some(len == 0);
+        self.start_indent()?;
+
+        Ok(Compound::Map {
+            ser: self,
+            state: State::First,
+        })
+    }
+}
+
+impl<'a, W: io::Write> ser::SerializeSeq for Compound<'a, W> {
+    type Error = Error;
+    type Ok = ();
+
+    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        let ser = match self {
+            Compound::Map {
+                state: ref mut s @ State::First,
+                ser,
+            } => {
+                *s = State::Rest;
+                ser
+            }
+            Compound::Map {
+                state: State::Rest,
+                ser,
+            } => {
+                ser.output.write_all(b",")?;
+                if let Some((ref config, ref mut pretty)) = ser.pretty {
+                    if pretty.indent <= config.depth_limit {
+                        if config.enumerate_arrays {
+                            assert!(config.new_line.contains('\n'));
+                            let index = pretty.sequence_index.last_mut().unwrap();
+                            //TODO: when /**/ comments are supported, prepend the index
+                            // to an element instead of appending it.
+                            write!(ser.output, "// [{}]", index).unwrap();
+                            *index += 1;
+                        }
+                        ser.output.write_all(config.new_line.as_bytes())?;
+                    }
+                }
+                ser
+            }
+        };
+        ser.indent()?;
+
+        value.serialize(&mut **ser)?;
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<()> {
+        let ser = match self {
+            Compound::Map {
+                ser,
+                state: State::Rest,
+            } => {
+                if let Some((ref config, ref mut pretty)) = ser.pretty {
+                    if pretty.indent <= config.depth_limit {
+                        ser.output.write_all(b",")?;
+                        ser.output.write_all(config.new_line.as_bytes())?;
+                    }
+                }
+                ser
+            }
+            Compound::Map { ser, .. } => ser,
+        };
+        ser.end_indent()?;
+
+        if let Some((_, ref mut pretty)) = ser.pretty {
+            pretty.sequence_index.pop();
+        }
+
+        ser.output.write_all(b"]")?;
+        Ok(())
+    }
+}
+pub enum State {
+    First,
+    Rest,
+}
+pub enum Compound<'a, W: io::Write> {
+    Map {
+        ser: &'a mut Serializer<W>,
+        state: State,
+    },
+}
+impl<'a, W: io::Write> ser::SerializeTuple for Compound<'a, W> {
+    type Error = Error;
+    type Ok = ();
+
+    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        let ser = match self {
+            Compound::Map {
+                ser,
+                state: ref mut s @ State::First,
+            } => {
+                *s = State::Rest;
+                ser
+            }
+            Compound::Map { ser, .. } => {
+                ser.output.write_all(b",")?;
+                if let Some((ref config, ref pretty)) = ser.pretty {
+                    if pretty.indent <= config.depth_limit {
+                        ser.output.write_all(if ser.separate_tuple_members() {
+                            config.new_line.as_bytes()
+                        } else {
+                            b" "
+                        })?;
+                    }
+                }
+                ser
+            }
+        };
+
+        if ser.separate_tuple_members() {
+            ser.indent()?;
+        }
+
+        value.serialize(&mut **ser)?;
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<()> {
+        let ser = match self {
+            Compound::Map {
+                ser,
+                state: State::Rest,
+            } => {
+                if let Some((ref config, ref pretty)) = ser.pretty {
+                    if ser.separate_tuple_members() && pretty.indent <= config.depth_limit {
+                        ser.output.write_all(b",")?;
+                        ser.output.write_all(config.new_line.as_bytes())?;
+                    }
+                }
+                ser
+            }
+            Compound::Map { ser, .. } => ser,
+        };
+        if ser.separate_tuple_members() {
+            ser.end_indent()?;
+        }
+
+        ser.output.write_all(b")")?;
+
+        Ok(())
+    }
+}
+
+// Same thing but for tuple structs.
+impl<'a, W: io::Write> ser::SerializeTupleStruct for Compound<'a, W> {
+    type Error = Error;
+    type Ok = ();
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        ser::SerializeTuple::serialize_element(self, value)
+    }
+
+    fn end(self) -> Result<()> {
+        ser::SerializeTuple::end(self)
+    }
+}
+
+impl<'a, W: io::Write> ser::SerializeTupleVariant for Compound<'a, W> {
+    type Error = Error;
+    type Ok = ();
+
+    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        ser::SerializeTuple::serialize_element(self, value)
+    }
+
+    fn end(self) -> Result<()> {
+        ser::SerializeTuple::end(self)
+    }
+}
+
+impl<'a, W: io::Write> ser::SerializeMap for Compound<'a, W> {
+    type Error = Error;
+    type Ok = ();
+
+    fn serialize_key<T>(&mut self, key: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        let ser = match self {
+            Compound::Map {
+                ser,
+                state: ref mut s @ State::First,
+            } => {
+                *s = State::Rest;
+                ser
+            }
+            Compound::Map {
+                ser,
+                state: State::Rest,
+            } => {
+                ser.output.write_all(b",")?;
+
+                if let Some((ref config, ref pretty)) = ser.pretty {
+                    if pretty.indent <= config.depth_limit {
+                        ser.output.write_all(config.new_line.as_bytes())?;
+                    }
+                }
+                ser
+            }
+        };
+        ser.indent()?;
+        key.serialize(&mut **ser)
+    }
+
+    fn serialize_value<T>(&mut self, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        match self {
+            Compound::Map { ser, .. } => {
+                ser.output.write_all(b":")?;
+
+                if ser.is_pretty() {
+                    ser.output.write_all(b" ")?;
+                }
+
+                value.serialize(&mut **ser)?;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<()> {
+        let ser = match self {
+            Compound::Map {
+                ser,
+                state: State::Rest,
+            } => {
+                if let Some((ref config, ref pretty)) = ser.pretty {
+                    if pretty.indent <= config.depth_limit {
+                        ser.output.write_all(b",")?;
+                        ser.output.write_all(config.new_line.as_bytes())?;
+                    }
+                }
+
+                ser
+            }
+            Compound::Map { ser, .. } => ser,
+        };
+        ser.end_indent()?;
+        ser.output.write_all(b"}")?;
+        Ok(())
+    }
+}
+
+impl<'a, W: io::Write> ser::SerializeStruct for Compound<'a, W> {
+    type Error = Error;
+    type Ok = ();
+
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        let ser = match self {
+            Compound::Map {
+                ser,
+                state: ref mut s @ State::First,
+            } => {
+                *s = State::Rest;
+                ser
+            }
+            Compound::Map { ser, .. } => {
+                ser.output.write_all(b",")?;
+
+                if let Some((ref config, ref pretty)) = ser.pretty {
+                    if pretty.indent <= config.depth_limit {
+                        ser.output.write_all(config.new_line.as_bytes())?;
+                    }
+                }
+                ser
+            }
+        };
+        ser.indent()?;
+        ser.output.write_all(key.as_bytes())?;
+        ser.output.write_all(b":")?;
+
+        if ser.is_pretty() {
+            ser.output.write_all(b" ")?;
+        }
+
+        value.serialize(&mut **ser)?;
+
+        Ok(())
+    }
+
+    fn end(self) -> Result<()> {
+        let ser = match self {
+            Compound::Map {
+                ser,
+                state: State::Rest,
+            } => {
+                if let Some((ref config, ref pretty)) = ser.pretty {
+                    if pretty.indent <= config.depth_limit {
+                        ser.output.write_all(b",")?;
+                        ser.output.write_all(config.new_line.as_bytes())?;
+                    }
+                }
+                ser
+            }
+            Compound::Map { ser, .. } => ser,
+        };
+        ser.end_indent()?;
+        ser.output.write_all(b")")?;
+        Ok(())
+    }
+}
+
+impl<'a, W: io::Write> ser::SerializeStructVariant for Compound<'a, W> {
+    type Error = Error;
+    type Ok = ();
+
+    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+    where
+        T: ?Sized + Serialize,
+    {
+        ser::SerializeStruct::serialize_field(self, key, value)
+    }
+
+    fn end(self) -> Result<()> {
+        ser::SerializeStruct::end(self)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[derive(Serialize)]
+    struct EmptyStruct1;
+
+    #[derive(Serialize)]
+    struct EmptyStruct2 {}
+
+    #[derive(Serialize)]
+    struct MyStruct {
+        x: f32,
+        y: f32,
+    }
+
+    #[derive(Serialize)]
+    enum MyEnum {
+        A,
+        B(bool),
+        C(bool, f32),
+        D { a: i32, b: i32 },
+    }
+
+    #[test]
+    fn test_empty_struct() {
+        assert_eq!(to_string(&EmptyStruct1).unwrap(), "()");
+        assert_eq!(to_string(&EmptyStruct2 {}).unwrap(), "()");
+    }
+
+    #[test]
+    fn test_struct() {
+        let my_struct = MyStruct { x: 4.0, y: 7.0 };
+
+        assert_eq!(to_string(&my_struct).unwrap(), "(x:4,y:7)");
+
+        #[derive(Serialize)]
+        struct NewType(i32);
+
+        assert_eq!(to_string(&NewType(42)).unwrap(), "(42)");
+
+        #[derive(Serialize)]
+        struct TupleStruct(f32, f32);
+
+        assert_eq!(to_string(&TupleStruct(2.0, 5.0)).unwrap(), "(2,5)");
+    }
+
+    #[test]
+    fn test_option() {
+        assert_eq!(to_string(&Some(1u8)).unwrap(), "Some(1)");
+        assert_eq!(to_string(&None::<u8>).unwrap(), "None");
+    }
+
+    #[test]
+    fn test_enum() {
+        assert_eq!(to_string(&MyEnum::A).unwrap(), "A");
+        assert_eq!(to_string(&MyEnum::B(true)).unwrap(), "B(true)");
+        assert_eq!(to_string(&MyEnum::C(true, 3.5)).unwrap(), "C(true,3.5)");
+        assert_eq!(to_string(&MyEnum::D { a: 2, b: 3 }).unwrap(), "D(a:2,b:3)");
+    }
+
+    #[test]
+    fn test_array() {
+        let empty: [i32; 0] = [];
+        assert_eq!(to_string(&empty).unwrap(), "()");
+        let empty_ref: &[i32] = &empty;
+        assert_eq!(to_string(&empty_ref).unwrap(), "[]");
+
+        assert_eq!(to_string(&[2, 3, 4i32]).unwrap(), "(2,3,4)");
+        assert_eq!(to_string(&(&[2, 3, 4i32] as &[i32])).unwrap(), "[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);
+
+        let s = to_string(&map).unwrap();
+        s.starts_with("{");
+        s.contains("(true,false):4");
+        s.contains("(false,false):123");
+        s.ends_with("}");
+    }
+
+    #[test]
+    fn test_string() {
+        assert_eq!(to_string(&"Some string").unwrap(), "\"Some string\"");
+    }
+
+    #[test]
+    fn test_char() {
+        assert_eq!(to_string(&'c').unwrap(), "'c'");
+    }
+
+    #[test]
+    fn test_escape() {
+        assert_eq!(to_string(&r#""Quoted""#).unwrap(), r#""\"Quoted\"""#);
+    }
+
+    #[test]
+    fn test_byte_stream() {
+        use serde_bytes;
+
+        let small: [u8; 16] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
+        assert_eq!(
+            to_string(&small).unwrap(),
+            "(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)"
+        );
+
+        let large = vec![255u8; 64];
+        let large = serde_bytes::Bytes::new(&large);
+        assert_eq!(
+            to_string(&large).unwrap(),
+            concat!(
+                "\"/////////////////////////////////////////",
+                "////////////////////////////////////////////w==\""
+            )
+        );
+    }
+}
diff --git a/third_party/rust/ron/src/ser/value.rs b/third_party/rust/ron/src/ser/value.rs
new file mode 100644
index 0000000000..1a47758986
--- /dev/null
+++ b/third_party/rust/ron/src/ser/value.rs
@@ -0,0 +1,23 @@
+use serde::ser::{Serialize, Serializer};
+
+use crate::value::{Number, Value};
+
+impl Serialize for Value {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        match *self {
+            Value::Bool(b) => serializer.serialize_bool(b),
+            Value::Char(c) => serializer.serialize_char(c),
+            Value::Map(ref m) => Serialize::serialize(m, serializer),
+            Value::Number(Number::Float(ref f)) => serializer.serialize_f64(f.get()),
+            Value::Number(Number::Integer(i)) => serializer.serialize_i64(i),
+            Value::Option(Some(ref o)) => serializer.serialize_some(o.as_ref()),
+            Value::Option(None) => serializer.serialize_none(),
+            Value::String(ref s) => serializer.serialize_str(s),
+            Value::Seq(ref s) => Serialize::serialize(s, serializer),
+            Value::Unit => serializer.serialize_unit(),
+        }
+    }
+}