Restructure directories to prep for syntex

serde/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "serde"
+version = "0.3.3"
+authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
+license = "MIT/Apache-2.0"
+description = "A generic serialization/deserialization framework"
+repository = "https://github.com/serde-rs/serde"
+documentation = "http://serde-rs.github.io/serde/serde"
+readme = "README.md"
+keywords = ["serialization"]
+
+[dependencies]
+num = "*"

serde/examples/json.rs

@@ -0,0 +1,64 @@
+#![feature(custom_derive, plugin)]
+#![plugin(serde_macros)]
+
+extern crate serde;
+
+use std::collections::BTreeMap;
+use serde::json;
+
+// Creating serializable types with serde is quite simple with `serde_macros`. It implements a
+// syntax extension that automatically generates the necessary serde trait implementations.
+#[derive(Debug, Serialize, Deserialize)]
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+fn main() {
+    let point = Point { x: 5, y: 6 };
+
+    // Serializing to JSON is pretty simple by using the `to_string` method:
+    let serialized_point = json::to_string(&point).unwrap();
+
+    println!("{}", serialized_point);
+    // prints:
+    //
+    // {"x":5,"y":6}
+
+    // There is also support for pretty printing using `to_string_pretty`:
+    let serialized_point = json::to_string_pretty(&point).unwrap();
+
+    println!("{}", serialized_point);
+    // prints:
+    //
+    // {
+    //   "x":5,
+    //   "y":6
+    // }
+
+    // Values can also be deserialized with the same style using `from_str`:
+    let deserialized_point: Point = json::from_str(&serialized_point).unwrap();
+
+    println!("{:?}", deserialized_point);
+    // prints:
+    //
+    // Point { x: 5, y: 6 }
+
+    // `Point`s aren't the only type that can be serialized to. Because `Point` members have the
+    // same type, they can be also serialized into a map. Also, 
+    let deserialized_map: BTreeMap<String, i64> = json::from_str(&serialized_point).unwrap();
+
+    println!("{:?}", deserialized_map);
+    // prints:
+    //
+    // {"x": 5, "y": 6}
+
+    // If you need to accept arbitrary data, you can also deserialize into `json::Value`, which
+    // can represent all JSON values.
+    let deserialized_value: json::Value = json::from_str(&serialized_point).unwrap();
+
+    println!("{:?}", deserialized_value);
+    // prints:
+    //
+    // {"x":5,"y":6}
+}

serde/src/buf.rs

@@ -0,0 +1,94 @@
+use std::cmp;
+use std::io;
+use std::slice;
+
+trait IntoBufRead {
+    type IntoBuf: io::BufRead + BufReadExt;
+
+    fn into_buf_read(self) -> Self::IntoBuf;
+}
+
+trait BufReadExt {
+    fn get_buf(&self) -> &[u8];
+    fn read_u8(&mut self) -> io::Result<Option<u8>>;
+}
+
+struct SliceReader<'a> {
+    buf: &'a [u8],
+}
+
+impl<'a> io::Read for SliceReader<'a> {
+    #[inline]
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let amt = cmp::min(buf.len(), self.buf.len());
+        let (a, b) = self.buf.split_at(amt);
+        slice::bytes::copy_memory(buf, a);
+        *self.buf = b;
+        Ok(amt)
+    }
+}
+
+impl<'a> io::BufRead for SliceReader<'a> {
+    fn fill_buf(&mut self) -> io::Result<&[u8]> { Ok(*self) }
+    fn consume(&mut self, amt: usize) { *self.buf = &self.buf[amt..]; }
+}
+
+impl<'a> BufReadExt for SliceReader<'a> {
+    fn get_buf(&self) -> &[u8] { self.buf }
+    fn read_u8(&mut self) -> io::Result<Option<u8>> {
+        let byte = self.buf.get(0);
+        *self.buf = &self.buf[1..];
+        byte
+    }
+}
+
+struct BufReader<R> {
+    inner: R,
+    buf: io::Cursor<Vec<u8>>,
+}
+
+impl<R> BufReader<R> where R: io::Read {
+    fn new(inner: R) -> Self {
+        BufferedReader::with_capacity(io::DEFAULT_BUF_SIZE, inner)
+    }
+
+    fn new(cap: usize, inner: R) -> Self {
+        BufferedReader {
+            inner: inner,
+            buf: io::Cursor::new(Vec::with_capacity(cap)),
+        }
+    }
+
+    fn into_inner(self) -> R {
+        self.inner
+    }
+}
+
+impl<R> Read for BufReader<R> where R: io::Read {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        // If we don't have any buffered data and we're doing a massive read
+        // (larger than our internal buffer), bypass our internal buffer
+        // entirely.
+        if self.buf.get_ref().len() == self.buf.position() as usize &&
+            buf.len() >= self.buf.get_ref().capacity() {
+            return self.inner.read(buf);
+        }
+        try!(self.fill_buf());
+        self.buf.read(buf)
+    }
+}
+
+impl<R> BufReadExt for BufReader<R> {
+    fn get_buf(&self) -> &[u8] {
+        self.buf.get_ref()
+    }
+
+    fn read_u8(&mut self) -> io::Result<Option<u8>> {
+        if self.buf.get_ref().len() == self.buf.position() as usize {
+
+        }
+        let byte = self.buf.get(0);
+        *self.buf = &self.buf[1..];
+        byte
+    }
+}

serde/src/bytes.rs

@@ -0,0 +1,213 @@
+//! Helper module to enable serializing bytes more efficiently
+
+use std::ops;
+use std::fmt;
+use std::ascii;
+
+use ser;
+use de;
+
+///////////////////////////////////////////////////////////////////////////////
+
+/// `Bytes` wraps a `&[u8]` in order to serialize into a byte array.
+#[derive(Clone, Copy, Eq, Hash, PartialEq, PartialOrd, Ord)]
+pub struct Bytes<'a> {
+    bytes: &'a [u8],
+}
+
+impl<'a> fmt::Debug for Bytes<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "b\"{}\"", escape_bytestring(self.bytes))
+    }
+}
+
+impl<'a> From<&'a [u8]> for Bytes<'a> {
+    fn from(bytes: &'a [u8]) -> Self {
+        Bytes {
+            bytes: bytes,
+        }
+    }
+}
+
+impl<'a> From<&'a Vec<u8>> for Bytes<'a> {
+    fn from(bytes: &'a Vec<u8>) -> Self {
+        Bytes {
+            bytes: &bytes,
+        }
+    }
+}
+
+impl<'a> Into<&'a [u8]> for Bytes<'a> {
+    fn into(self) -> &'a [u8] {
+        self.bytes
+    }
+}
+
+impl<'a> ops::Deref for Bytes<'a> {
+    type Target = [u8];
+
+    fn deref(&self) -> &[u8] { self.bytes }
+}
+
+impl<'a> ser::Serialize for Bytes<'a> {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: ser::Serializer
+    {
+        serializer.visit_bytes(self.bytes)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+/// `ByteBuf` wraps a `Vec<u8>` in order to hook into serialize and from deserialize a byte array.
+#[derive(Clone, Eq, Hash, PartialEq, PartialOrd, Ord)]
+pub struct ByteBuf {
+    bytes: Vec<u8>,
+}
+
+impl ByteBuf {
+    pub fn new() -> Self {
+        ByteBuf {
+            bytes: Vec::new(),
+        }
+    }
+
+    pub fn with_capacity(cap: usize) -> Self {
+        ByteBuf {
+            bytes: Vec::with_capacity(cap)
+        }
+    }
+}
+
+impl fmt::Debug for ByteBuf {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "b\"{}\"", escape_bytestring(self.bytes.as_ref()))
+    }
+}
+
+impl Into<Vec<u8>> for ByteBuf {
+    fn into(self) -> Vec<u8> {
+        self.bytes
+    }
+}
+
+impl From<Vec<u8>> for ByteBuf {
+    fn from(bytes: Vec<u8>) -> Self {
+        ByteBuf {
+            bytes: bytes,
+        }
+    }
+}
+
+impl AsRef<Vec<u8>> for ByteBuf {
+    fn as_ref(&self) -> &Vec<u8> {
+        &self.bytes
+    }
+}
+
+impl AsRef<[u8]> for ByteBuf {
+    fn as_ref(&self) -> &[u8] {
+        &self.bytes
+    }
+}
+
+impl AsMut<Vec<u8>> for ByteBuf {
+    fn as_mut(&mut self) -> &mut Vec<u8> {
+        &mut self.bytes
+    }
+}
+
+impl AsMut<[u8]> for ByteBuf {
+    fn as_mut(&mut self) -> &mut [u8] {
+        &mut self.bytes
+    }
+}
+
+impl ops::Deref for ByteBuf {
+    type Target = [u8];
+
+    fn deref(&self) -> &[u8] { &self.bytes[..] }
+}
+
+impl ops::DerefMut for ByteBuf {
+    fn deref_mut(&mut self) -> &mut [u8] { &mut self.bytes[..] }
+}
+
+impl ser::Serialize for ByteBuf {
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: ser::Serializer
+    {
+        serializer.visit_bytes(&self)
+    }
+}
+
+pub struct ByteBufVisitor;
+
+impl de::Visitor for ByteBufVisitor {
+    type Value = ByteBuf;
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<ByteBuf, E>
+        where E: de::Error,
+    {
+        Ok(ByteBuf {
+            bytes: Vec::new(),
+        })
+    }
+
+    #[inline]
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<ByteBuf, V::Error>
+        where V: de::SeqVisitor,
+    {
+        let (len, _) = visitor.size_hint();
+        let mut values = Vec::with_capacity(len);
+
+        while let Some(value) = try!(visitor.visit()) {
+            values.push(value);
+        }
+
+        try!(visitor.end());
+
+        Ok(ByteBuf {
+            bytes: values,
+        })
+    }
+
+    #[inline]
+    fn visit_bytes<E>(&mut self, v: &[u8]) -> Result<ByteBuf, E>
+        where E: de::Error,
+    {
+        self.visit_byte_buf(v.to_vec())
+    }
+
+    #[inline]
+    fn visit_byte_buf<E>(&mut self, v: Vec<u8>) -> Result<ByteBuf, E>
+        where E: de::Error,
+    {
+        Ok(ByteBuf {
+            bytes: v,
+        })
+    }
+}
+
+impl de::Deserialize for ByteBuf {
+    #[inline]
+    fn deserialize<D>(deserializer: &mut D) -> Result<ByteBuf, D::Error>
+        where D: de::Deserializer
+    {
+        deserializer.visit_bytes(ByteBufVisitor)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+fn escape_bytestring(bytes: &[u8]) -> String {
+    let mut result = String::new();
+    for &b in bytes {
+        for esc in ascii::escape_default(b) {
+            result.push(esc as char);
+        }
+    }
+    result
+}

serde/src/de/impls.rs

@@ -0,0 +1,857 @@
+use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
+use std::hash::Hash;
+use std::marker::PhantomData;
+use std::path;
+use std::rc::Rc;
+use std::str;
+use std::sync::Arc;
+use std::str;
+
+use num::FromPrimitive;
+
+use de::{
+    Deserialize,
+    Deserializer,
+    Error,
+    MapVisitor,
+    SeqVisitor,
+    Visitor,
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct UnitVisitor;
+
+impl Visitor for UnitVisitor {
+    type Value = ();
+
+    fn visit_unit<E>(&mut self) -> Result<(), E>
+        where E: Error,
+    {
+        Ok(())
+    }
+
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<(), V::Error>
+        where V: SeqVisitor,
+    {
+        visitor.end()
+    }
+}
+
+impl Deserialize for () {
+    fn deserialize<D>(deserializer: &mut D) -> Result<(), D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(UnitVisitor)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct BoolVisitor;
+
+impl Visitor for BoolVisitor {
+    type Value = bool;
+
+    fn visit_bool<E>(&mut self, v: bool) -> Result<bool, E>
+        where E: Error,
+    {
+        Ok(v)
+    }
+
+    fn visit_str<E>(&mut self, s: &str) -> Result<bool, E>
+        where E: Error,
+    {
+        match s.trim() {
+            "true" => Ok(true),
+            "false" => Ok(false),
+            _ => Err(Error::syntax_error()),
+        }
+    }
+}
+
+impl Deserialize for bool {
+    fn deserialize<D>(deserializer: &mut D) -> Result<bool, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(BoolVisitor)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+macro_rules! impl_deserialize_num_method {
+    ($src_ty:ty, $method:ident, $from_method:ident) => {
+        #[inline]
+        fn $method<E>(&mut self, v: $src_ty) -> Result<T, E>
+            where E: Error,
+        {
+            match FromPrimitive::$from_method(v) {
+                Some(v) => Ok(v),
+                None => Err(Error::syntax_error()),
+            }
+        }
+    }
+}
+
+pub struct PrimitiveVisitor<T> {
+    marker: PhantomData<T>,
+}
+
+impl<T> PrimitiveVisitor<T> {
+    #[inline]
+    pub fn new() -> Self {
+        PrimitiveVisitor {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<
+    T: Deserialize + FromPrimitive + str::FromStr
+> Visitor for PrimitiveVisitor<T> {
+    type Value = T;
+
+    impl_deserialize_num_method!(isize, visit_isize, from_isize);
+    impl_deserialize_num_method!(i8, visit_i8, from_i8);
+    impl_deserialize_num_method!(i16, visit_i16, from_i16);
+    impl_deserialize_num_method!(i32, visit_i32, from_i32);
+    impl_deserialize_num_method!(i64, visit_i64, from_i64);
+    impl_deserialize_num_method!(usize, visit_usize, from_usize);
+    impl_deserialize_num_method!(u8, visit_u8, from_u8);
+    impl_deserialize_num_method!(u16, visit_u16, from_u16);
+    impl_deserialize_num_method!(u32, visit_u32, from_u32);
+    impl_deserialize_num_method!(u64, visit_u64, from_u64);
+    impl_deserialize_num_method!(f32, visit_f32, from_f32);
+    impl_deserialize_num_method!(f64, visit_f64, from_f64);
+
+    #[inline]
+    fn visit_str<E>(&mut self, v: &str) -> Result<T, E>
+        where E: Error,
+    {
+        str::FromStr::from_str(v.trim()).or(Err(Error::syntax_error()))
+    }
+}
+
+macro_rules! impl_deserialize_num {
+    ($ty:ty) => {
+        impl Deserialize for $ty {
+            #[inline]
+            fn deserialize<D>(deserializer: &mut D) -> Result<$ty, D::Error>
+                where D: Deserializer,
+            {
+                deserializer.visit(PrimitiveVisitor::new())
+            }
+        }
+    }
+}
+
+impl_deserialize_num!(isize);
+impl_deserialize_num!(i8);
+impl_deserialize_num!(i16);
+impl_deserialize_num!(i32);
+impl_deserialize_num!(i64);
+impl_deserialize_num!(usize);
+impl_deserialize_num!(u8);
+impl_deserialize_num!(u16);
+impl_deserialize_num!(u32);
+impl_deserialize_num!(u64);
+impl_deserialize_num!(f32);
+impl_deserialize_num!(f64);
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct CharVisitor;
+
+impl Visitor for CharVisitor {
+    type Value = char;
+
+    #[inline]
+    fn visit_char<E>(&mut self, v: char) -> Result<char, E>
+        where E: Error,
+    {
+        Ok(v)
+    }
+
+    #[inline]
+    fn visit_str<E>(&mut self, v: &str) -> Result<char, E>
+        where E: Error,
+    {
+        let mut iter = v.chars();
+        if let Some(v) = iter.next() {
+            if iter.next().is_some() {
+                Err(Error::syntax_error())
+            } else {
+                Ok(v)
+            }
+        } else {
+            Err(Error::end_of_stream_error())
+        }
+    }
+}
+
+impl Deserialize for char {
+    #[inline]
+    fn deserialize<D>(deserializer: &mut D) -> Result<char, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(CharVisitor)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct StringVisitor;
+
+impl Visitor for StringVisitor {
+    type Value = String;
+
+    fn visit_str<E>(&mut self, v: &str) -> Result<String, E>
+        where E: Error,
+    {
+        Ok(v.to_string())
+    }
+
+    fn visit_string<E>(&mut self, v: String) -> Result<String, E>
+        where E: Error,
+    {
+        Ok(v)
+    }
+
+    fn visit_bytes<E>(&mut self, v: &[u8]) -> Result<String, E>
+        where E: Error,
+    {
+        match str::from_utf8(v) {
+            Ok(s) => Ok(s.to_string()),
+            Err(_) => Err(Error::syntax_error()),
+        }
+    }
+
+    fn visit_byte_buf<'a, E>(&mut self, v: Vec<u8>) -> Result<String, E>
+        where E: Error,
+    {
+        match String::from_utf8(v) {
+            Ok(s) => Ok(s),
+            Err(_) => Err(Error::syntax_error()),
+        }
+    }
+}
+
+impl Deserialize for String {
+    fn deserialize<D>(deserializer: &mut D) -> Result<String, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(StringVisitor)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct OptionVisitor<T> {
+    marker: PhantomData<T>,
+}
+
+impl<
+    T: Deserialize,
+> Visitor for OptionVisitor<T> {
+    type Value = Option<T>;
+
+    #[inline]
+    fn visit_none<E>(&mut self) -> Result<Option<T>, E>
+        where E: Error,
+    {
+        Ok(None)
+    }
+
+    #[inline]
+    fn visit_some<D>(&mut self, deserializer: &mut D) -> Result<Option<T>, D::Error>
+        where D: Deserializer,
+    {
+        Ok(Some(try!(Deserialize::deserialize(deserializer))))
+    }
+}
+
+impl<T> Deserialize for Option<T> where T: Deserialize {
+    fn deserialize<D>(deserializer: &mut D) -> Result<Option<T>, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit_option(OptionVisitor { marker: PhantomData })
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct BTreeSetVisitor<T> {
+    marker: PhantomData<T>,
+}
+
+impl<T> BTreeSetVisitor<T> {
+    pub fn new() -> Self {
+        BTreeSetVisitor {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<T> Visitor for BTreeSetVisitor<T>
+    where T: Deserialize + Eq + Ord,
+{
+    type Value = BTreeSet<T>;
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<BTreeSet<T>, E>
+        where E: Error,
+    {
+        Ok(BTreeSet::new())
+    }
+
+    #[inline]
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<BTreeSet<T>, V::Error>
+        where V: SeqVisitor,
+    {
+        let mut values = BTreeSet::new();
+
+        while let Some(value) = try!(visitor.visit()) {
+            values.insert(value);
+        }
+
+        try!(visitor.end());
+
+        Ok(values)
+    }
+}
+
+impl<T> Deserialize for BTreeSet<T>
+    where T: Deserialize + Eq + Ord,
+{
+    fn deserialize<D>(deserializer: &mut D) -> Result<BTreeSet<T>, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(BTreeSetVisitor::new())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct HashSetVisitor<T> {
+    marker: PhantomData<T>,
+}
+
+impl<T> HashSetVisitor<T> {
+    pub fn new() -> Self {
+        HashSetVisitor {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<T> Visitor for HashSetVisitor<T>
+    where T: Deserialize + Eq + Hash,
+{
+    type Value = HashSet<T>;
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<HashSet<T>, E>
+        where E: Error,
+    {
+        Ok(HashSet::new())
+    }
+
+    #[inline]
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<HashSet<T>, V::Error>
+        where V: SeqVisitor,
+    {
+        let (len, _) = visitor.size_hint();
+        let mut values = HashSet::with_capacity(len);
+
+        while let Some(value) = try!(visitor.visit()) {
+            values.insert(value);
+        }
+
+        try!(visitor.end());
+
+        Ok(values)
+    }
+}
+
+impl<T> Deserialize for HashSet<T>
+    where T: Deserialize + Eq + Hash,
+{
+    fn deserialize<D>(deserializer: &mut D) -> Result<HashSet<T>, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(HashSetVisitor::new())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct VecVisitor<T> {
+    marker: PhantomData<T>,
+}
+
+impl<T> VecVisitor<T> {
+    pub fn new() -> Self {
+        VecVisitor {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<T> Visitor for VecVisitor<T> where T: Deserialize {
+    type Value = Vec<T>;
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<Vec<T>, E>
+        where E: Error,
+    {
+        Ok(Vec::new())
+    }
+
+    #[inline]
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<Vec<T>, V::Error>
+        where V: SeqVisitor,
+    {
+        let (len, _) = visitor.size_hint();
+        let mut values = Vec::with_capacity(len);
+
+        while let Some(value) = try!(visitor.visit()) {
+            values.push(value);
+        }
+
+        try!(visitor.end());
+
+        Ok(values)
+    }
+}
+
+impl<T> Deserialize for Vec<T>
+    where T: Deserialize,
+{
+    fn deserialize<D>(deserializer: &mut D) -> Result<Vec<T>, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit_seq(VecVisitor::new())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct ArrayVisitor0<T> {
+    marker: PhantomData<T>,
+}
+
+impl<T> ArrayVisitor0<T> {
+    pub fn new() -> Self {
+        ArrayVisitor0 {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<T> Visitor for ArrayVisitor0<T> where T: Deserialize + Default {
+    type Value = [T; 0];
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<[T; 0], E>
+        where E: Error,
+    {
+        Ok([T::default(); 0])
+    }
+
+    #[inline]
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<[T; 0], V::Error>
+        where V: SeqVisitor,
+    {
+        try!(visitor.end());
+        Ok([T::default(); 0])
+    }
+}
+
+impl<T> Deserialize for [T; 0]
+    where T: Deserialize + Default
+{
+    fn deserialize<D>(deserializer: &mut D) -> Result<[T; 0], D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(ArrayVisitor0::new())
+    }
+}
+
+macro_rules! array_impls {
+    ($($visitor:ident, $len:expr => ($($name:ident),+),)+) => {
+        $(
+            struct $visitor<T> {
+                marker: PhantomData<T>,
+            }
+
+            impl<T> $visitor<T> {
+                pub fn new() -> Self {
+                    $visitor {
+                        marker: PhantomData
+                    }
+                }
+            }
+
+            impl<T> Visitor for $visitor<T> where T: Deserialize {
+                type Value = [T; $len];
+
+                #[inline]
+                fn visit_seq<V>(&mut self, mut visitor: V) -> Result<[T; $len], V::Error>
+                    where V: SeqVisitor,
+                {
+                    $(
+                        let $name = match try!(visitor.visit()) {
+                            Some(val) => val,
+                            None => { return Err(Error::end_of_stream_error()); }
+                        };
+                    )+;
+
+                    try!(visitor.end());
+
+                    Ok([$($name,)+])
+                }
+            }
+
+            impl<T> Deserialize for [T; $len]
+                where T: Deserialize,
+            {
+                fn deserialize<D>(deserializer: &mut D) -> Result<[T; $len], D::Error>
+                    where D: Deserializer,
+                {
+                    deserializer.visit($visitor::new())
+                }
+            }
+        )+
+    }
+}
+
+array_impls! {
+    ArrayVisitor1, 1 => (a),
+    ArrayVisitor2, 2 => (a, b),
+    ArrayVisitor3, 3 => (a, b, c),
+    ArrayVisitor4, 4 => (a, b, c, d),
+    ArrayVisitor5, 5 => (a, b, c, d, e),
+    ArrayVisitor6, 6 => (a, b, c, d, e, f),
+    ArrayVisitor7, 7 => (a, b, c, d, e, f, g),
+    ArrayVisitor8, 8 => (a, b, c, d, e, f, g, h),
+    ArrayVisitor9, 9 => (a, b, c, d, e, f, g, h, i),
+    ArrayVisitor10, 10 => (a, b, c, d, e, f, g, h, i, j),
+    ArrayVisitor11, 11 => (a, b, c, d, e, f, g, h, i, j, k),
+    ArrayVisitor12, 12 => (a, b, c, d, e, f, g, h, i, j, k, l),
+    ArrayVisitor13, 13 => (a, b, c, d, e, f, g, h, i, j, k, l, m),
+    ArrayVisitor14, 14 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n),
+    ArrayVisitor15, 15 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o),
+    ArrayVisitor16, 16 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p),
+    ArrayVisitor17, 17 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q),
+    ArrayVisitor18, 18 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r),
+    ArrayVisitor19, 19 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s),
+    ArrayVisitor20, 20 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s ,t),
+    ArrayVisitor21, 21 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u),
+    ArrayVisitor22, 22 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v),
+    ArrayVisitor23, 23 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w),
+    ArrayVisitor24, 24 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x),
+    ArrayVisitor25, 25 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y),
+    ArrayVisitor26, 26 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y, z),
+    ArrayVisitor27, 27 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y, z, aa),
+    ArrayVisitor28, 28 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y, z, aa, ab),
+    ArrayVisitor29, 29 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y, z, aa, ab, ac),
+    ArrayVisitor30, 30 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y, z, aa, ab, ac, ad),
+    ArrayVisitor31, 31 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y, z, aa, ab, ac, ad, ae),
+    ArrayVisitor32, 32 => (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x,
+                           y, z, aa, ab, ac, ad, ae, af),
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+macro_rules! tuple_impls {
+    () => {};
+    ($($visitor:ident => ($($name:ident),+),)+) => {
+        $(
+            struct $visitor<$($name,)+> {
+                marker: PhantomData<($($name,)+)>,
+            }
+
+            impl<
+                $($name: Deserialize,)+
+            > Visitor for $visitor<$($name,)+> {
+                type Value = ($($name,)+);
+
+                #[inline]
+                #[allow(non_snake_case)]
+                fn visit_seq<V>(&mut self, mut visitor: V) -> Result<($($name,)+), V::Error>
+                    where V: SeqVisitor,
+                {
+                    $(
+                        let $name = match try!(visitor.visit()) {
+                            Some(value) => value,
+                            None => { return Err(Error::end_of_stream_error()); }
+                        };
+                     )+;
+
+                    try!(visitor.end());
+
+                    Ok(($($name,)+))
+                }
+            }
+
+            impl<
+                $($name: Deserialize),+
+            > Deserialize for ($($name,)+) {
+                #[inline]
+                fn deserialize<D>(deserializer: &mut D) -> Result<($($name,)+), D::Error>
+                    where D: Deserializer,
+                {
+                    deserializer.visit_seq($visitor { marker: PhantomData })
+                }
+            }
+        )+
+    }
+}
+
+tuple_impls! {
+    TupleVisitor1 => (T0),
+    TupleVisitor2 => (T0, T1),
+    TupleVisitor3 => (T0, T1, T2),
+    TupleVisitor4 => (T0, T1, T2, T3),
+    TupleVisitor5 => (T0, T1, T2, T3, T4),
+    TupleVisitor6 => (T0, T1, T2, T3, T4, T5),
+    TupleVisitor7 => (T0, T1, T2, T3, T4, T5, T6),
+    TupleVisitor8 => (T0, T1, T2, T3, T4, T5, T6, T7),
+    TupleVisitor9 => (T0, T1, T2, T3, T4, T5, T6, T7, T8),
+    TupleVisitor10 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9),
+    TupleVisitor11 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10),
+    TupleVisitor12 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11),
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct BTreeMapVisitor<K, V> {
+    marker: PhantomData<BTreeMap<K, V>>,
+}
+
+impl<K, V> BTreeMapVisitor<K, V> {
+    #[inline]
+    pub fn new() -> Self {
+        BTreeMapVisitor {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<K, V> Visitor for BTreeMapVisitor<K, V>
+    where K: Deserialize + Ord,
+          V: Deserialize
+{
+    type Value = BTreeMap<K, V>;
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<BTreeMap<K, V>, E>
+        where E: Error,
+    {
+        Ok(BTreeMap::new())
+    }
+
+    #[inline]
+    fn visit_map<Visitor>(&mut self, mut visitor: Visitor) -> Result<BTreeMap<K, V>, Visitor::Error>
+        where Visitor: MapVisitor,
+    {
+        let mut values = BTreeMap::new();
+
+        while let Some((key, value)) = try!(visitor.visit()) {
+            values.insert(key, value);
+        }
+
+        try!(visitor.end());
+
+        Ok(values)
+    }
+}
+
+impl<K, V> Deserialize for BTreeMap<K, V>
+    where K: Deserialize + Eq + Ord,
+          V: Deserialize,
+{
+    fn deserialize<D>(deserializer: &mut D) -> Result<BTreeMap<K, V>, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(BTreeMapVisitor::new())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct HashMapVisitor<K, V> {
+    marker: PhantomData<HashMap<K, V>>,
+}
+
+impl<K, V> HashMapVisitor<K, V> {
+    #[inline]
+    pub fn new() -> Self {
+        HashMapVisitor {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<K, V> Visitor for HashMapVisitor<K, V>
+    where K: Deserialize + Eq + Hash,
+          V: Deserialize,
+{
+    type Value = HashMap<K, V>;
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<HashMap<K, V>, E>
+        where E: Error,
+    {
+        Ok(HashMap::new())
+    }
+
+    #[inline]
+    fn visit_map<V_>(&mut self, mut visitor: V_) -> Result<HashMap<K, V>, V_::Error>
+        where V_: MapVisitor,
+    {
+        let (len, _) = visitor.size_hint();
+        let mut values = HashMap::with_capacity(len);
+
+        while let Some((key, value)) = try!(visitor.visit()) {
+            values.insert(key, value);
+        }
+
+        try!(visitor.end());
+
+        Ok(values)
+    }
+}
+
+impl<K, V> Deserialize for HashMap<K, V>
+    where K: Deserialize + Eq + Hash,
+          V: Deserialize,
+{
+    fn deserialize<D>(deserializer: &mut D) -> Result<HashMap<K, V>, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(HashMapVisitor::new())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+// FIXME: `VecMap` is unstable.
+/*
+pub struct VecMapVisitor<V> {
+    marker: PhantomData<VecMap<V>>,
+}
+
+impl<V> VecMapVisitor<V> {
+    #[inline]
+    pub fn new() -> Self {
+        VecMapVisitor {
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<V> Visitor for VecMapVisitor<V>
+    where V: Deserialize,
+{
+    type Value = VecMap<V>;
+
+    #[inline]
+    fn visit_unit<E>(&mut self) -> Result<VecMap<V>, E>
+        where E: Error,
+    {
+        Ok(VecMap::new())
+    }
+
+    #[inline]
+    fn visit_map<V_>(&mut self, mut visitor: V_) -> Result<VecMap<V>, V_::Error>
+        where V_: MapVisitor,
+    {
+        let (len, _) = visitor.size_hint();
+        let mut values = VecMap::with_capacity(len);
+
+        while let Some((key, value)) = try!(visitor.visit()) {
+            values.insert(key, value);
+        }
+
+        try!(visitor.end());
+
+        Ok(values)
+    }
+}
+
+impl<V> Deserialize for VecMap<V>
+    where V: Deserialize,
+{
+    fn deserialize<D>(deserializer: &mut D) -> Result<VecMap<V>, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(VecMapVisitor::new())
+    }
+}
+*/
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct PathBufVisitor;
+
+impl Visitor for PathBufVisitor {
+    type Value = path::PathBuf;
+
+    fn visit_str<E>(&mut self, v: &str) -> Result<path::PathBuf, E>
+        where E: Error,
+    {
+        Ok(From::from(v))
+    }
+
+    fn visit_string<E>(&mut self, v: String) -> Result<path::PathBuf, E>
+        where E: Error,
+    {
+        self.visit_str(&v)
+    }
+}
+
+impl Deserialize for path::PathBuf {
+    fn deserialize<D>(deserializer: &mut D) -> Result<path::PathBuf, D::Error>
+        where D: Deserializer,
+    {
+        deserializer.visit(PathBufVisitor)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<T: Deserialize> Deserialize for Box<T> {
+    fn deserialize<D>(deserializer: &mut D) -> Result<Box<T>, D::Error>
+        where D: Deserializer,
+    {
+        let val = try!(Deserialize::deserialize(deserializer));
+        Ok(Box::new(val))
+    }
+}
+
+impl<T: Deserialize> Deserialize for Arc<T> {
+    fn deserialize<D>(deserializer: &mut D) -> Result<Arc<T>, D::Error>
+        where D: Deserializer,
+    {
+        let val = try!(Deserialize::deserialize(deserializer));
+        Ok(Arc::new(val))
+    }
+}
+
+impl<T: Deserialize> Deserialize for Rc<T> {
+    fn deserialize<D>(deserializer: &mut D) -> Result<Rc<T>, D::Error>
+        where D: Deserializer,
+    {
+        let val = try!(Deserialize::deserialize(deserializer));
+        Ok(Rc::new(val))
+    }
+}

serde/src/de/mod.rs

@@ -0,0 +1,478 @@
+//! Generic deserialization framework.
+
+pub mod impls;
+pub mod value;
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Error {
+    fn syntax_error() -> Self;
+
+    fn end_of_stream_error() -> Self;
+
+    fn unknown_field_error(field: &str) -> Self;
+
+    fn missing_field_error(field: &'static str) -> Self;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Deserialize {
+    /// Deserialize this value given this `Deserializer`.
+    fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error>
+        where D: Deserializer;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+/// `Deserializer` is an abstract trait that can deserialize values into a `Visitor`.
+pub trait Deserializer {
+    type Error: Error;
+
+    /// The `visit` method walks a visitor through a value as it is being deserialized.
+    fn visit<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor;
+
+    /// The `visit_option` method allows a `Deserialize` type to inform the `Deserializer` that
+    /// it's expecting an optional value. This allows deserializers that encode an optional value
+    /// as a nullable value to convert the null value into a `None`, and a regular value as
+    /// `Some(value)`.
+    #[inline]
+    fn visit_option<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor,
+    {
+        self.visit(visitor)
+    }
+
+    /// The `visit_seq` method allows a `Deserialize` type to inform the `Deserializer` that it's
+    /// expecting a sequence of values. This allows deserializers to parse sequences that aren't
+    /// tagged as sequences.
+    #[inline]
+    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor,
+    {
+        self.visit(visitor)
+    }
+
+    /// The `visit_map` method allows a `Deserialize` type to inform the `Deserializer` that it's
+    /// expecting a map of values. This allows deserializers to parse sequences that aren't tagged
+    /// as maps.
+    #[inline]
+    fn visit_map<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor,
+    {
+        self.visit(visitor)
+    }
+
+    /// The `visit_named_unit` method allows a `Deserialize` type to inform the `Deserializer` that
+    /// it's expecting a named unit. This allows deserializers to a named unit that aren't tagged
+    /// as a named unit.
+    #[inline]
+    fn visit_named_unit<V>(&mut self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor,
+    {
+        self.visit(visitor)
+    }
+
+    /// The `visit_named_seq` method allows a `Deserialize` type to inform the `Deserializer` that
+    /// it's expecting a named sequence of values. This allows deserializers to parse sequences
+    /// that aren't tagged as sequences.
+    #[inline]
+    fn visit_named_seq<V>(&mut self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor,
+    {
+        self.visit_seq(visitor)
+    }
+
+    /// The `visit_named_map` method allows a `Deserialize` type to inform the `Deserializer` that
+    /// it's expecting a map of values. This allows deserializers to parse sequences that aren't
+    /// tagged as maps.
+    #[inline]
+    fn visit_named_map<V>(&mut self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor,
+    {
+        self.visit_map(visitor)
+    }
+
+    /// The `visit_enum` method allows a `Deserialize` type to inform the `Deserializer` that it's
+    /// expecting an enum value. This allows deserializers that provide a custom enumeration
+    /// serialization to properly deserialize the type.
+    #[inline]
+    fn visit_enum<V>(&mut self, _enum: &str, _visitor: V) -> Result<V::Value, Self::Error>
+        where V: EnumVisitor,
+    {
+        Err(Error::syntax_error())
+    }
+
+    /// The `visit_bytes` method allows a `Deserialize` type to inform the `Deserializer` that it's
+    /// expecting a `Vec<u8>`. This allows deserializers that provide a custom byte vector
+    /// serialization to properly deserialize the type.
+    #[inline]
+    fn visit_bytes<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor,
+    {
+        self.visit(visitor)
+    }
+
+    /// Specify a format string for the deserializer.
+    ///
+    /// The deserializer format is used to determine which format
+    /// specific field attributes should be used with the
+    /// deserializer.
+    fn format() -> &'static str {
+        ""
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Visitor {
+    type Value: Deserialize;
+
+    fn visit_bool<E>(&mut self, _v: bool) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_isize<E>(&mut self, v: isize) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_i64(v as i64)
+    }
+
+    fn visit_i8<E>(&mut self, v: i8) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_i64(v as i64)
+    }
+
+    fn visit_i16<E>(&mut self, v: i16) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_i64(v as i64)
+    }
+
+    fn visit_i32<E>(&mut self, v: i32) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_i64(v as i64)
+    }
+
+    fn visit_i64<E>(&mut self, _v: i64) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_usize<E>(&mut self, v: usize) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_u64(v as u64)
+    }
+
+    fn visit_u8<E>(&mut self, v: u8) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_u64(v as u64)
+    }
+
+    fn visit_u16<E>(&mut self, v: u16) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_u64(v as u64)
+    }
+
+    fn visit_u32<E>(&mut self, v: u32) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_u64(v as u64)
+    }
+
+    fn visit_u64<E>(&mut self, _v: u64) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_f32<E>(&mut self, v: f32) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_f64(v as f64)
+    }
+
+    fn visit_f64<E>(&mut self, _v: f64) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    #[inline]
+    fn visit_char<E>(&mut self, v: char) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        // FIXME: this allocation is required in order to be compatible with stable rust, which
+        // doesn't support encoding a `char` into a stack buffer.
+        self.visit_string(v.to_string())
+    }
+
+    fn visit_str<E>(&mut self, _v: &str) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    #[inline]
+    fn visit_string<E>(&mut self, v: String) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_str(&v)
+    }
+
+    fn visit_unit<E>(&mut self) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    #[inline]
+    fn visit_named_unit<E>(&mut self, _name: &str) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_unit()
+    }
+
+    fn visit_none<E>(&mut self) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_some<D>(&mut self, _deserializer: &mut D) -> Result<Self::Value, D::Error>
+        where D: Deserializer,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_seq<V>(&mut self, _visitor: V) -> Result<Self::Value, V::Error>
+        where V: SeqVisitor,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_map<V>(&mut self, _visitor: V) -> Result<Self::Value, V::Error>
+        where V: MapVisitor,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_bytes<E>(&mut self, _v: &[u8]) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        Err(Error::syntax_error())
+    }
+
+    fn visit_byte_buf<E>(&mut self, v: Vec<u8>) -> Result<Self::Value, E>
+        where E: Error,
+    {
+        self.visit_bytes(&v)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait SeqVisitor {
+    type Error: Error;
+
+    fn visit<T>(&mut self) -> Result<Option<T>, Self::Error>
+        where T: Deserialize;
+
+    fn end(&mut self) -> Result<(), Self::Error>;
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+}
+
+impl<'a, V> SeqVisitor for &'a mut V where V: SeqVisitor {
+    type Error = V::Error;
+
+    #[inline]
+    fn visit<T>(&mut self) -> Result<Option<T>, V::Error>
+        where T: Deserialize
+    {
+        (**self).visit()
+    }
+
+    #[inline]
+    fn end(&mut self) -> Result<(), V::Error> {
+        (**self).end()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (**self).size_hint()
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait MapVisitor {
+    type Error: Error;
+
+    #[inline]
+    fn visit<K, V>(&mut self) -> Result<Option<(K, V)>, Self::Error>
+        where K: Deserialize,
+              V: Deserialize,
+    {
+        match try!(self.visit_key()) {
+            Some(key) => {
+                let value = try!(self.visit_value());
+                Ok(Some((key, value)))
+            }
+            None => Ok(None)
+        }
+    }
+
+    fn visit_key<K>(&mut self) -> Result<Option<K>, Self::Error>
+        where K: Deserialize;
+
+    fn visit_value<V>(&mut self) -> Result<V, Self::Error>
+        where V: Deserialize;
+
+    fn end(&mut self) -> Result<(), Self::Error>;
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, None)
+    }
+
+    fn missing_field<V>(&mut self, field: &'static str) -> Result<V, Self::Error>
+        where V: Deserialize,
+    {
+        Err(Error::missing_field_error(field))
+    }
+}
+
+impl<'a, V_> MapVisitor for &'a mut V_ where V_: MapVisitor {
+    type Error = V_::Error;
+
+    #[inline]
+    fn visit<K, V>(&mut self) -> Result<Option<(K, V)>, V_::Error>
+        where K: Deserialize,
+              V: Deserialize,
+    {
+        (**self).visit()
+    }
+
+    #[inline]
+    fn visit_key<K>(&mut self) -> Result<Option<K>, V_::Error>
+        where K: Deserialize
+    {
+        (**self).visit_key()
+    }
+
+    #[inline]
+    fn visit_value<V>(&mut self) -> Result<V, V_::Error>
+        where V: Deserialize
+    {
+        (**self).visit_value()
+    }
+
+    #[inline]
+    fn end(&mut self) -> Result<(), V_::Error> {
+        (**self).end()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (**self).size_hint()
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+/// `EnumVisitor` is a visitor that is created by the `Deserialize` and passed to the
+/// `Deserializer` in order to deserialize enums.
+pub trait EnumVisitor {
+    type Value;
+
+    fn visit<V>(&mut self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: VariantVisitor;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+/// `VariantVisitor` is a visitor that is created by the `Deserializer` and passed to the
+/// `Deserialize` in order to deserialize a specific enum variant.
+pub trait VariantVisitor {
+    type Error: Error;
+
+    /// `visit_variant` is called to identify which variant to deserialize.
+    fn visit_variant<V>(&mut self) -> Result<V, Self::Error>
+        where V: Deserialize;
+
+    /// `visit_unit` is called when deserializing a variant with no values.
+    fn visit_unit(&mut self) -> Result<(), Self::Error> {
+        Err(Error::syntax_error())
+    }
+
+    /// `visit_seq` is called when deserializing a tuple-like variant.
+    fn visit_seq<V>(&mut self, _visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        Err(Error::syntax_error())
+    }
+
+    /// `visit_map` is called when deserializing a struct-like variant.
+    fn visit_map<V>(&mut self, _visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        Err(Error::syntax_error())
+    }
+}
+
+impl<'a, T> VariantVisitor for &'a mut T where T: VariantVisitor {
+    type Error = T::Error;
+
+    fn visit_variant<V>(&mut self) -> Result<V, T::Error>
+        where V: Deserialize
+    {
+        (**self).visit_variant()
+    }
+
+    fn visit_unit(&mut self) -> Result<(), T::Error> {
+        (**self).visit_unit()
+    }
+
+    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, T::Error>
+        where V: Visitor,
+    {
+        (**self).visit_seq(visitor)
+    }
+
+    fn visit_map<V>(&mut self, visitor: V) -> Result<V::Value, T::Error>
+        where V: Visitor,
+    {
+        (**self).visit_map(visitor)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait EnumSeqVisitor {
+    type Value;
+
+    fn visit<V>(&mut self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: SeqVisitor;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait EnumMapVisitor {
+    type Value;
+
+    fn visit<V>(&mut self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: MapVisitor;
+}

serde/src/de/value.rs

@@ -0,0 +1,465 @@
+use std::collections::{
+    BTreeMap,
+    BTreeSet,
+    HashMap,
+    HashSet,
+    btree_map,
+    btree_set,
+    hash_map,
+    hash_set,
+};
+use std::hash::Hash;
+use std::vec;
+
+use de;
+use bytes;
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub enum Error {
+    SyntaxError,
+    EndOfStreamError,
+    UnknownFieldError(String),
+    MissingFieldError(&'static str),
+}
+
+impl de::Error for Error {
+    fn syntax_error() -> Self { Error::SyntaxError }
+    fn end_of_stream_error() -> Self { Error::EndOfStreamError }
+    fn unknown_field_error(field: &str) -> Self { Error::UnknownFieldError(field.to_string()) }
+    fn missing_field_error(field: &'static str) -> Self { Error::MissingFieldError(field) }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait ValueDeserializer {
+    type Deserializer: de::Deserializer<Error=Error>;
+
+    fn into_deserializer(self) -> Self::Deserializer;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl ValueDeserializer for () {
+    type Deserializer = UnitDeserializer;
+
+    fn into_deserializer(self) -> UnitDeserializer {
+        UnitDeserializer
+    }
+}
+
+/// A helper deserializer that deserializes a `()`.
+pub struct UnitDeserializer;
+
+impl de::Deserializer for UnitDeserializer {
+    type Error = Error;
+
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        visitor.visit_unit()
+    }
+
+    fn visit_option<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        visitor.visit_none()
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+macro_rules! primitive_deserializer {
+    ($ty:ty, $name:ident, $method:ident) => {
+        pub struct $name(Option<$ty>);
+
+        impl ValueDeserializer for $ty {
+            type Deserializer = $name;
+
+            fn into_deserializer(self) -> $name {
+                $name(Some(self))
+            }
+        }
+
+        impl de::Deserializer for $name {
+            type Error = Error;
+
+            fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+                where V: de::Visitor,
+            {
+                match self.0.take() {
+                    Some(v) => visitor.$method(v),
+                    None => Err(de::Error::end_of_stream_error()),
+                }
+            }
+        }
+    }
+}
+
+primitive_deserializer!(bool, BoolDeserializer, visit_bool);
+primitive_deserializer!(i8, I8Deserializer, visit_i8);
+primitive_deserializer!(i16, I16Deserializer, visit_i16);
+primitive_deserializer!(i32, I32Deserializer, visit_i32);
+primitive_deserializer!(i64, I64Deserializer, visit_i64);
+primitive_deserializer!(isize, IsizeDeserializer, visit_isize);
+primitive_deserializer!(u8, U8Deserializer, visit_u8);
+primitive_deserializer!(u16, U16Deserializer, visit_u16);
+primitive_deserializer!(u32, U32Deserializer, visit_u32);
+primitive_deserializer!(u64, U64Deserializer, visit_u64);
+primitive_deserializer!(usize, UsizeDeserializer, visit_usize);
+primitive_deserializer!(f32, F32Deserializer, visit_f32);
+primitive_deserializer!(f64, F64Deserializer, visit_f64);
+primitive_deserializer!(char, CharDeserializer, visit_char);
+
+///////////////////////////////////////////////////////////////////////////////
+
+/// A helper deserializer that deserializes a `&str`.
+pub struct StrDeserializer<'a>(Option<&'a str>);
+
+impl<'a> ValueDeserializer for &'a str {
+    type Deserializer = StrDeserializer<'a>;
+
+    fn into_deserializer(self) -> StrDeserializer<'a> {
+        StrDeserializer(Some(self))
+    }
+}
+
+impl<'a> de::Deserializer for StrDeserializer<'a> {
+    type Error = Error;
+
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        match self.0.take() {
+            Some(v) => visitor.visit_str(v),
+            None => Err(de::Error::end_of_stream_error()),
+        }
+    }
+
+    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::EnumVisitor,
+    {
+        visitor.visit(self)
+    }
+}
+
+impl<'a> de::VariantVisitor for StrDeserializer<'a> {
+    type Error = Error;
+
+    fn visit_variant<T>(&mut self) -> Result<T, Error>
+        where T: de::Deserialize,
+    {
+        de::Deserialize::deserialize(self)
+    }
+
+    fn visit_unit(&mut self) -> Result<(), Error> {
+        Ok(())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+/// A helper deserializer that deserializes a `String`.
+pub struct StringDeserializer(Option<String>);
+
+impl ValueDeserializer for String {
+    type Deserializer = StringDeserializer;
+
+    fn into_deserializer(self) -> StringDeserializer {
+        StringDeserializer(Some(self))
+    }
+}
+
+impl de::Deserializer for StringDeserializer {
+    type Error = Error;
+
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        match self.0.take() {
+            Some(string) => visitor.visit_string(string),
+            None => Err(de::Error::end_of_stream_error()),
+        }
+    }
+
+    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::EnumVisitor,
+    {
+        visitor.visit(self)
+    }
+}
+
+impl<'a> de::VariantVisitor for StringDeserializer {
+    type Error = Error;
+
+    fn visit_variant<T>(&mut self) -> Result<T, Error>
+        where T: de::Deserialize,
+    {
+        de::Deserialize::deserialize(self)
+    }
+
+    fn visit_unit(&mut self) -> Result<(), Error> {
+        Ok(())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct SeqDeserializer<I> {
+    iter: I,
+    len: usize,
+}
+
+impl<I> SeqDeserializer<I> {
+    pub fn new(iter: I, len: usize) -> Self {
+        SeqDeserializer {
+            iter: iter,
+            len: len,
+        }
+    }
+}
+
+impl<I, T> de::Deserializer for SeqDeserializer<I>
+    where I: Iterator<Item=T>,
+          T: ValueDeserializer,
+{
+    type Error = Error;
+
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        visitor.visit_seq(self)
+    }
+}
+
+impl<I, T> de::SeqVisitor for SeqDeserializer<I>
+    where I: Iterator<Item=T>,
+          T: ValueDeserializer,
+{
+    type Error = Error;
+
+    fn visit<V>(&mut self) -> Result<Option<V>, Error>
+        where V: de::Deserialize
+    {
+        match self.iter.next() {
+            Some(value) => {
+                self.len -= 1;
+                let mut de = value.into_deserializer();
+                Ok(Some(try!(de::Deserialize::deserialize(&mut de))))
+            }
+            None => Ok(None),
+        }
+    }
+
+    fn end(&mut self) -> Result<(), Error> {
+        if self.len == 0 {
+            Ok(())
+        } else {
+            Err(de::Error::end_of_stream_error())
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len, Some(self.len))
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<T> ValueDeserializer for Vec<T>
+    where T: ValueDeserializer,
+{
+    type Deserializer = SeqDeserializer<vec::IntoIter<T>>;
+
+    fn into_deserializer(self) -> SeqDeserializer<vec::IntoIter<T>> {
+        let len = self.len();
+        SeqDeserializer::new(self.into_iter(), len)
+    }
+}
+
+impl<T> ValueDeserializer for BTreeSet<T>
+    where T: ValueDeserializer + Eq + Ord,
+{
+    type Deserializer = SeqDeserializer<btree_set::IntoIter<T>>;
+
+    fn into_deserializer(self) -> SeqDeserializer<btree_set::IntoIter<T>> {
+        let len = self.len();
+        SeqDeserializer::new(self.into_iter(), len)
+    }
+}
+
+impl<T> ValueDeserializer for HashSet<T>
+    where T: ValueDeserializer + Eq + Hash,
+{
+    type Deserializer = SeqDeserializer<hash_set::IntoIter<T>>;
+
+    fn into_deserializer(self) -> SeqDeserializer<hash_set::IntoIter<T>> {
+        let len = self.len();
+        SeqDeserializer::new(self.into_iter(), len)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct MapDeserializer<I, K, V>
+    where I: Iterator<Item=(K, V)>,
+          K: ValueDeserializer,
+          V: ValueDeserializer,
+{
+    iter: I,
+    value: Option<V>,
+    len: usize,
+}
+
+impl<I, K, V> MapDeserializer<I, K, V>
+    where I: Iterator<Item=(K, V)>,
+          K: ValueDeserializer,
+          V: ValueDeserializer,
+{
+    pub fn new(iter: I, len: usize) -> Self {
+        MapDeserializer {
+            iter: iter,
+            value: None,
+            len: len,
+        }
+    }
+}
+
+impl<I, K, V> de::Deserializer for MapDeserializer<I, K, V>
+    where I: Iterator<Item=(K, V)>,
+          K: ValueDeserializer,
+          V: ValueDeserializer,
+{
+    type Error = Error;
+
+    fn visit<V_>(&mut self, mut visitor: V_) -> Result<V_::Value, Error>
+        where V_: de::Visitor,
+    {
+        visitor.visit_map(self)
+    }
+}
+
+impl<I, K, V> de::MapVisitor for MapDeserializer<I, K, V>
+    where I: Iterator<Item=(K, V)>,
+          K: ValueDeserializer,
+          V: ValueDeserializer,
+{
+    type Error = Error;
+
+    fn visit_key<T>(&mut self) -> Result<Option<T>, Error>
+        where T: de::Deserialize,
+    {
+        match self.iter.next() {
+            Some((key, value)) => {
+                self.len -= 1;
+                self.value = Some(value);
+                let mut de = key.into_deserializer();
+                Ok(Some(try!(de::Deserialize::deserialize(&mut de))))
+            }
+            None => Ok(None),
+        }
+    }
+
+    fn visit_value<T>(&mut self) -> Result<T, Error>
+        where T: de::Deserialize,
+    {
+        match self.value.take() {
+            Some(value) => {
+                let mut de = value.into_deserializer();
+                de::Deserialize::deserialize(&mut de)
+            }
+            None => Err(de::Error::syntax_error())
+        }
+    }
+
+    fn end(&mut self) -> Result<(), Error> {
+        if self.len == 0 {
+            Ok(())
+        } else {
+            Err(de::Error::end_of_stream_error())
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len, Some(self.len))
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<K, V> ValueDeserializer for BTreeMap<K, V>
+    where K: ValueDeserializer + Eq + Ord,
+          V: ValueDeserializer,
+{
+    type Deserializer = MapDeserializer<btree_map::IntoIter<K, V>, K, V>;
+
+    fn into_deserializer(self) -> MapDeserializer<btree_map::IntoIter<K, V>, K, V> {
+        let len = self.len();
+        MapDeserializer::new(self.into_iter(), len)
+    }
+}
+
+impl<K, V> ValueDeserializer for HashMap<K, V>
+    where K: ValueDeserializer + Eq + Hash,
+          V: ValueDeserializer,
+{
+    type Deserializer = MapDeserializer<hash_map::IntoIter<K, V>, K, V>;
+
+    fn into_deserializer(self) -> MapDeserializer<hash_map::IntoIter<K, V>, K, V> {
+        let len = self.len();
+        MapDeserializer::new(self.into_iter(), len)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<'a> ValueDeserializer for bytes::Bytes<'a>
+{
+    type Deserializer = BytesDeserializer<'a>;
+
+    fn into_deserializer(self) -> BytesDeserializer<'a> {
+        BytesDeserializer(Some(self.into()))
+    }
+}
+
+pub struct BytesDeserializer<'a> (Option<&'a [u8]>);
+
+impl<'a> de::Deserializer for BytesDeserializer<'a> {
+    type Error = Error;
+
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        match self.0.take() {
+            Some(bytes) => visitor.visit_bytes(bytes),
+            None => Err(de::Error::end_of_stream_error()),
+        }
+    }
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl ValueDeserializer for bytes::ByteBuf
+{
+    type Deserializer = ByteBufDeserializer;
+
+    fn into_deserializer(self) -> Self::Deserializer {
+        ByteBufDeserializer(Some(self.into()))
+    }
+}
+
+pub struct ByteBufDeserializer(Option<Vec<u8>>);
+
+impl de::Deserializer for ByteBufDeserializer {
+    type Error = Error;
+
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        match self.0.take() {
+            Some(bytes) => visitor.visit_byte_buf(bytes),
+            None => Err(de::Error::end_of_stream_error()),
+        }
+    }
+}

serde/src/iter.rs

@@ -0,0 +1,57 @@
+use std::io;
+use std::iter::Peekable;
+
+pub struct LineColIterator<Iter: Iterator<Item=io::Result<u8>>> {
+    iter: Iter,
+    line: usize,
+    col: usize,
+}
+
+impl<Iter: Iterator<Item=io::Result<u8>>> LineColIterator<Iter> {
+    pub fn new(iter: Iter) -> LineColIterator<Iter> {
+        LineColIterator {
+            iter: iter,
+            line: 1,
+            col: 0,
+        }
+    }
+
+    /// Report the current line inside the iterator.
+    pub fn line(&self) -> usize { self.line }
+
+    /// Report the current column inside the iterator.
+    pub fn col(&self) -> usize { self.col }
+
+    /// Gets a reference to the underlying iterator.
+    pub fn get_ref(&self) -> &Iter { &self.iter }
+
+    /// Gets a mutable reference to the underlying iterator.
+    pub fn get_mut(&mut self) -> &mut Iter { &mut self.iter }
+
+    /// Unwraps this `LineColIterator`, returning the underlying iterator.
+    pub fn into_inner(self) -> Iter { self.iter }
+}
+
+impl<Iter: Iterator<Item=io::Result<u8>>> LineColIterator<Peekable<Iter>> {
+    /// peeks at the next value
+    pub fn peek(&mut self) -> Option<&io::Result<u8>> { self.iter.peek() }
+}
+
+impl<Iter: Iterator<Item=io::Result<u8>>> Iterator for LineColIterator<Iter> {
+    type Item = io::Result<u8>;
+    fn next(&mut self) -> Option<io::Result<u8>> {
+        match self.iter.next() {
+            None => None,
+            Some(Ok(b'\n')) => {
+                self.line += 1;
+                self.col = 0;
+                Some(Ok(b'\n'))
+            },
+            Some(Ok(c)) => {
+                self.col += 1;
+                Some(Ok(c))
+            },
+            Some(Err(e)) => Some(Err(e)),
+        }
+    }
+}

serde/src/json/builder.rs

@@ -0,0 +1,84 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::collections::BTreeMap;
+
+use ser::{self, Serialize};
+use json::value::{self, Value};
+
+pub struct ArrayBuilder {
+    array: Vec<Value>,
+}
+
+impl ArrayBuilder {
+    pub fn new() -> ArrayBuilder {
+        ArrayBuilder { array: Vec::new() }
+    }
+
+    pub fn unwrap(self) -> Value {
+        Value::Array(self.array)
+    }
+
+    pub fn push<T: ser::Serialize>(mut self, v: T) -> ArrayBuilder {
+        self.array.push(value::to_value(&v));
+        self
+    }
+
+    pub fn push_array<F>(mut self, f: F) -> ArrayBuilder where
+        F: FnOnce(ArrayBuilder) -> ArrayBuilder
+    {
+        let builder = ArrayBuilder::new();
+        self.array.push(f(builder).unwrap());
+        self
+    }
+
+    pub fn push_object<F>(mut self, f: F) -> ArrayBuilder where
+        F: FnOnce(ObjectBuilder) -> ObjectBuilder
+    {
+        let builder = ObjectBuilder::new();
+        self.array.push(f(builder).unwrap());
+        self
+    }
+}
+
+pub struct ObjectBuilder {
+    object: BTreeMap<String, Value>,
+}
+
+impl ObjectBuilder {
+    pub fn new() -> ObjectBuilder {
+        ObjectBuilder { object: BTreeMap::new() }
+    }
+
+    pub fn unwrap(self) -> Value {
+        Value::Object(self.object)
+    }
+
+    pub fn insert<V: ser::Serialize>(mut self, k: String, v: V) -> ObjectBuilder {
+        self.object.insert(k, value::to_value(&v));
+        self
+    }
+
+    pub fn insert_array<F>(mut self, key: String, f: F) -> ObjectBuilder where
+        F: FnOnce(ArrayBuilder) -> ArrayBuilder
+    {
+        let builder = ArrayBuilder::new();
+        self.object.insert(key, f(builder).unwrap());
+        self
+    }
+
+    pub fn insert_object<F>(mut self, key: String, f: F) -> ObjectBuilder where
+        F: FnOnce(ObjectBuilder) -> ObjectBuilder
+    {
+        let builder = ObjectBuilder::new();
+        self.object.insert(key, f(builder).unwrap());
+        self
+    }
+}

serde/src/json/de.rs

@@ -0,0 +1,687 @@
+use std::char;
+use std::io;
+use std::str;
+
+use de;
+use iter::LineColIterator;
+
+use super::error::{Error, ErrorCode};
+
+pub struct Deserializer<Iter: Iterator<Item=io::Result<u8>>> {
+    rdr: LineColIterator<Iter>,
+    ch: Option<u8>,
+    str_buf: Vec<u8>,
+}
+
+impl<Iter> Deserializer<Iter>
+    where Iter: Iterator<Item=io::Result<u8>>,
+{
+    /// Creates the JSON parser from an `std::iter::Iterator`.
+    #[inline]
+    pub fn new(rdr: Iter) -> Result<Deserializer<Iter>, Error> {
+        let mut deserializer = Deserializer {
+            rdr: LineColIterator::new(rdr),
+            ch: None,
+            str_buf: Vec::with_capacity(128),
+        };
+
+        try!(deserializer.bump());
+
+        Ok(deserializer)
+    }
+
+    #[inline]
+    pub fn end(&mut self) -> Result<(), Error> {
+        try!(self.parse_whitespace());
+        if self.eof() {
+            Ok(())
+        } else {
+            Err(self.error(ErrorCode::TrailingCharacters))
+        }
+    }
+
+    fn eof(&self) -> bool { self.ch.is_none() }
+
+    fn ch_or_null(&self) -> u8 { self.ch.unwrap_or(b'\x00') }
+
+    fn bump(&mut self) -> Result<(), Error> {
+        self.ch = match self.rdr.next() {
+            Some(Err(err)) => { return Err(Error::IoError(err)); }
+            Some(Ok(ch)) => Some(ch),
+            None => None,
+        };
+
+        Ok(())
+    }
+
+    fn next_char(&mut self) -> Result<Option<u8>, Error> {
+        try!(self.bump());
+        Ok(self.ch)
+    }
+
+    fn ch_is(&self, c: u8) -> bool {
+        self.ch == Some(c)
+    }
+
+    fn error(&mut self, reason: ErrorCode) -> Error {
+        Error::SyntaxError(reason, self.rdr.line(), self.rdr.col())
+    }
+
+    fn parse_whitespace(&mut self) -> Result<(), Error> {
+        while self.ch_is(b' ') ||
+              self.ch_is(b'\n') ||
+              self.ch_is(b'\t') ||
+              self.ch_is(b'\r') { try!(self.bump()); }
+
+        Ok(())
+    }
+
+    fn parse_value<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        try!(self.parse_whitespace());
+
+        if self.eof() {
+            return Err(self.error(ErrorCode::EOFWhileParsingValue));
+        }
+
+        let value = match self.ch_or_null() {
+            b'n' => {
+                try!(self.parse_ident(b"ull"));
+                visitor.visit_unit()
+            }
+            b't' => {
+                try!(self.parse_ident(b"rue"));
+                visitor.visit_bool(true)
+            }
+            b'f' => {
+                try!(self.parse_ident(b"alse"));
+                visitor.visit_bool(false)
+            }
+            b'0' ... b'9' | b'-' => self.parse_number(visitor),
+            b'"' => {
+                try!(self.parse_string());
+                let s = str::from_utf8(&self.str_buf).unwrap();
+                visitor.visit_str(s)
+            }
+            b'[' => {
+                try!(self.bump());
+                visitor.visit_seq(SeqVisitor::new(self))
+            }
+            b'{' => {
+                try!(self.bump());
+                visitor.visit_map(MapVisitor::new(self))
+            }
+            _ => {
+                Err(self.error(ErrorCode::ExpectedSomeValue))
+            }
+        };
+
+        match value {
+            Ok(value) => Ok(value),
+            Err(Error::SyntaxError(code, _, _)) => Err(self.error(code)),
+            Err(err) => Err(err),
+        }
+    }
+
+    fn parse_ident(&mut self, ident: &[u8]) -> Result<(), Error> {
+        for c in ident {
+            if Some(*c) != try!(self.next_char()) {
+                return Err(self.error(ErrorCode::ExpectedSomeIdent));
+            }
+        }
+
+        try!(self.bump());
+        Ok(())
+    }
+
+    fn parse_number<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        let mut neg = false;
+
+        if self.ch_is(b'-') {
+            try!(self.bump());
+            neg = true;
+        }
+
+        let res = try!(self.parse_integer());
+
+        if self.ch_is(b'.') || self.ch_is(b'e') || self.ch_is(b'E') {
+            let mut res = res as f64;
+
+            if self.ch_is(b'.') {
+                res = try!(self.parse_decimal(res));
+            }
+
+            if self.ch_is(b'e') || self.ch_is(b'E') {
+                res = try!(self.parse_exponent(res));
+            }
+
+            if neg {
+                visitor.visit_f64(-res)
+            } else {
+                visitor.visit_f64(res)
+            }
+        } else {
+            if neg {
+                let res = -(res as i64);
+
+                // Make sure we didn't underflow.
+                if res > 0 {
+                    Err(self.error(ErrorCode::InvalidNumber))
+                } else {
+                    visitor.visit_i64(res)
+                }
+            } else {
+                visitor.visit_u64(res)
+            }
+        }
+    }
+
+    fn parse_integer(&mut self) -> Result<u64, Error> {
+        let mut accum: u64 = 0;
+
+        match self.ch_or_null() {
+            b'0' => {
+                try!(self.bump());
+
+                // There can be only one leading '0'.
+                match self.ch_or_null() {
+                    b'0' ... b'9' => {
+                        return Err(self.error(ErrorCode::InvalidNumber));
+                    }
+                    _ => ()
+                }
+            },
+            b'1' ... b'9' => {
+                while !self.eof() {
+                    match self.ch_or_null() {
+                        c @ b'0' ... b'9' => {
+                            macro_rules! try_or_invalid {
+                                ($e: expr) => {
+                                    match $e {
+                                        Some(v) => v,
+                                        None => { return Err(self.error(ErrorCode::InvalidNumber)); }
+                                    }
+                                }
+                            }
+                            accum = try_or_invalid!(accum.checked_mul(10));
+                            accum = try_or_invalid!(accum.checked_add((c as u64) - ('0' as u64)));
+
+                            try!(self.bump());
+                        }
+                        _ => break,
+                    }
+                }
+            }
+            _ => { return Err(self.error(ErrorCode::InvalidNumber)); }
+        }
+
+        Ok(accum)
+    }
+
+    fn parse_decimal(&mut self, res: f64) -> Result<f64, Error> {
+        try!(self.bump());
+
+        // Make sure a digit follows the decimal place.
+        match self.ch_or_null() {
+            b'0' ... b'9' => (),
+             _ => { return Err(self.error(ErrorCode::InvalidNumber)); }
+        }
+
+        let mut res = res;
+        let mut dec = 1.0;
+        while !self.eof() {
+            match self.ch_or_null() {
+                c @ b'0' ... b'9' => {
+                    dec /= 10.0;
+                    res += (((c as u64) - (b'0' as u64)) as f64) * dec;
+                    try!(self.bump());
+                }
+                _ => break,
+            }
+        }
+
+        Ok(res)
+    }
+
+    fn parse_exponent(&mut self, mut res: f64) -> Result<f64, Error> {
+        try!(self.bump());
+
+        let mut exp = 0;
+        let mut neg_exp = false;
+
+        if self.ch_is(b'+') {
+            try!(self.bump());
+        } else if self.ch_is(b'-') {
+            try!(self.bump());
+            neg_exp = true;
+        }
+
+        // Make sure a digit follows the exponent place.
+        match self.ch_or_null() {
+            b'0' ... b'9' => (),
+            _ => { return Err(self.error(ErrorCode::InvalidNumber)); }
+        }
+        while !self.eof() {
+            match self.ch_or_null() {
+                c @ b'0' ... b'9' => {
+                    exp *= 10;
+                    exp += (c as i32) - (b'0' as i32);
+
+                    try!(self.bump());
+                }
+                _ => break
+            }
+        }
+
+        let exp: f64 = 10_f64.powi(exp);
+        if neg_exp {
+            res /= exp;
+        } else {
+            res *= exp;
+        }
+
+        Ok(res)
+    }
+
+    fn decode_hex_escape(&mut self) -> Result<u16, Error> {
+        let mut i = 0;
+        let mut n = 0u16;
+        while i < 4 && !self.eof() {
+            try!(self.bump());
+            n = match self.ch_or_null() {
+                c @ b'0' ... b'9' => n * 16_u16 + ((c as u16) - (b'0' as u16)),
+                b'a' | b'A' => n * 16_u16 + 10_u16,
+                b'b' | b'B' => n * 16_u16 + 11_u16,
+                b'c' | b'C' => n * 16_u16 + 12_u16,
+                b'd' | b'D' => n * 16_u16 + 13_u16,
+                b'e' | b'E' => n * 16_u16 + 14_u16,
+                b'f' | b'F' => n * 16_u16 + 15_u16,
+                _ => { return Err(self.error(ErrorCode::InvalidEscape)); }
+            };
+
+            i += 1;
+        }
+
+        // Error out if we didn't parse 4 digits.
+        if i != 4 {
+            return Err(self.error(ErrorCode::InvalidEscape));
+        }
+
+        Ok(n)
+    }
+
+    fn parse_string(&mut self) -> Result<(), Error> {
+        self.str_buf.clear();
+
+        loop {
+            let ch = match try!(self.next_char()) {
+                Some(ch) => ch,
+                None => { return Err(self.error(ErrorCode::EOFWhileParsingString)); }
+            };
+
+            match ch {
+                b'"' => {
+                    try!(self.bump());
+                    return Ok(());
+                }
+                b'\\' => {
+                    let ch = match try!(self.next_char()) {
+                        Some(ch) => ch,
+                        None => { return Err(self.error(ErrorCode::EOFWhileParsingString)); }
+                    };
+
+                    match ch {
+                        b'"' => self.str_buf.push(b'"'),
+                        b'\\' => self.str_buf.push(b'\\'),
+                        b'/' => self.str_buf.push(b'/'),
+                        b'b' => self.str_buf.push(b'\x08'),
+                        b'f' => self.str_buf.push(b'\x0c'),
+                        b'n' => self.str_buf.push(b'\n'),
+                        b'r' => self.str_buf.push(b'\r'),
+                        b't' => self.str_buf.push(b'\t'),
+                        b'u' => {
+                            let c = match try!(self.decode_hex_escape()) {
+                                0xDC00 ... 0xDFFF => {
+                                    return Err(self.error(ErrorCode::LoneLeadingSurrogateInHexEscape));
+                                }
+
+                                // Non-BMP characters are encoded as a sequence of
+                                // two hex escapes, representing UTF-16 surrogates.
+                                n1 @ 0xD800 ... 0xDBFF => {
+                                    match (try!(self.next_char()), try!(self.next_char())) {
+                                        (Some(b'\\'), Some(b'u')) => (),
+                                        _ => {
+                                            return Err(self.error(ErrorCode::UnexpectedEndOfHexEscape));
+                                        }
+                                    }
+
+                                    let n2 = try!(self.decode_hex_escape());
+
+                                    if n2 < 0xDC00 || n2 > 0xDFFF {
+                                        return Err(self.error(ErrorCode::LoneLeadingSurrogateInHexEscape));
+                                    }
+
+                                    let n = (((n1 - 0xD800) as u32) << 10 |
+                                              (n2 - 0xDC00) as u32) + 0x1_0000;
+
+                                    match char::from_u32(n as u32) {
+                                        Some(c) => c,
+                                        None => {
+                                            return Err(self.error(ErrorCode::InvalidUnicodeCodePoint));
+                                        }
+                                    }
+                                }
+
+                                n => {
+                                    match char::from_u32(n as u32) {
+                                        Some(c) => c,
+                                        None => {
+                                            return Err(self.error(ErrorCode::InvalidUnicodeCodePoint));
+                                        }
+                                    }
+                                }
+                            };
+
+                            // FIXME: this allocation is required in order to be compatible with stable
+                            // rust, which doesn't support encoding a `char` into a stack buffer.
+                            let buf = c.to_string();
+                            self.str_buf.extend(buf.bytes());
+                        }
+                        _ => {
+                            return Err(self.error(ErrorCode::InvalidEscape));
+                        }
+                    }
+                }
+                ch => {
+                    self.str_buf.push(ch);
+                }
+            }
+        }
+    }
+
+    fn parse_object_colon(&mut self) -> Result<(), Error> {
+        try!(self.parse_whitespace());
+
+        if self.ch_is(b':') {
+            try!(self.bump());
+            Ok(())
+        } else if self.eof() {
+            Err(self.error(ErrorCode::EOFWhileParsingObject))
+        } else {
+            Err(self.error(ErrorCode::ExpectedColon))
+        }
+    }
+}
+
+impl<Iter> de::Deserializer for Deserializer<Iter>
+    where Iter: Iterator<Item=io::Result<u8>>,
+{
+    type Error = Error;
+
+    #[inline]
+    fn visit<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        self.parse_value(visitor)
+    }
+
+    #[inline]
+    fn visit_option<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        try!(self.parse_whitespace());
+
+        if self.eof() {
+            return Err(self.error(ErrorCode::EOFWhileParsingValue));
+        }
+
+        if self.ch_is(b'n') {
+            try!(self.parse_ident(b"ull"));
+            visitor.visit_none()
+        } else {
+            visitor.visit_some(self)
+        }
+    }
+
+    #[inline]
+    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::EnumVisitor,
+    {
+        try!(self.parse_whitespace());
+
+        if self.ch_is(b'{') {
+            try!(self.bump());
+            try!(self.parse_whitespace());
+
+            let value = {
+                try!(visitor.visit(&mut *self))
+            };
+
+            try!(self.parse_whitespace());
+
+            if self.ch_is(b'}') {
+                try!(self.bump());
+                Ok(value)
+            } else {
+                Err(self.error(ErrorCode::ExpectedSomeValue))
+            }
+        } else {
+            Err(self.error(ErrorCode::ExpectedSomeValue))
+        }
+    }
+
+    #[inline]
+    fn format() -> &'static str {
+        "json"
+    }
+}
+
+struct SeqVisitor<'a, Iter: 'a + Iterator<Item=io::Result<u8>>> {
+    de: &'a mut Deserializer<Iter>,
+    first: bool,
+}
+
+impl<'a, Iter: Iterator<Item=io::Result<u8>>> SeqVisitor<'a, Iter> {
+    fn new(de: &'a mut Deserializer<Iter>) -> Self {
+        SeqVisitor {
+            de: de,
+            first: true,
+        }
+    }
+}
+
+impl<'a, Iter> de::SeqVisitor for SeqVisitor<'a, Iter>
+    where Iter: Iterator<Item=io::Result<u8>>,
+{
+    type Error = Error;
+
+    fn visit<T>(&mut self) -> Result<Option<T>, Error>
+        where T: de::Deserialize,
+    {
+        try!(self.de.parse_whitespace());
+
+        if self.de.ch_is(b']') {
+            return Ok(None);
+        }
+
+        if self.first {
+            self.first = false;
+        } else {
+            if self.de.ch_is(b',') {
+                try!(self.de.bump());
+            } else if self.de.eof() {
+                return Err(self.de.error(ErrorCode::EOFWhileParsingList));
+            } else {
+                return Err(self.de.error(ErrorCode::ExpectedListCommaOrEnd));
+            }
+        }
+
+        let value = try!(de::Deserialize::deserialize(self.de));
+        Ok(Some(value))
+    }
+
+    fn end(&mut self) -> Result<(), Error> {
+        try!(self.de.parse_whitespace());
+
+        if self.de.ch_is(b']') {
+            self.de.bump()
+        } else if self.de.eof() {
+            Err(self.de.error(ErrorCode::EOFWhileParsingList))
+        } else {
+            Err(self.de.error(ErrorCode::TrailingCharacters))
+        }
+    }
+}
+
+struct MapVisitor<'a, Iter: 'a + Iterator<Item=io::Result<u8>>> {
+    de: &'a mut Deserializer<Iter>,
+    first: bool,
+}
+
+impl<'a, Iter: Iterator<Item=io::Result<u8>>> MapVisitor<'a, Iter> {
+    fn new(de: &'a mut Deserializer<Iter>) -> Self {
+        MapVisitor {
+            de: de,
+            first: true,
+        }
+    }
+}
+
+impl<'a, Iter> de::MapVisitor for MapVisitor<'a, Iter>
+    where Iter: Iterator<Item=io::Result<u8>>
+{
+    type Error = Error;
+
+    fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
+        where K: de::Deserialize,
+    {
+        try!(self.de.parse_whitespace());
+
+        if self.de.ch_is(b'}') {
+            return Ok(None);
+        }
+
+        if self.first {
+            self.first = false;
+        } else {
+            if self.de.ch_is(b',') {
+                try!(self.de.bump());
+                try!(self.de.parse_whitespace());
+            } else if self.de.eof() {
+                return Err(self.de.error(ErrorCode::EOFWhileParsingObject));
+            } else {
+                return Err(self.de.error(ErrorCode::ExpectedObjectCommaOrEnd));
+            }
+        }
+
+        if self.de.eof() {
+            return Err(self.de.error(ErrorCode::EOFWhileParsingValue));
+        }
+
+        if !self.de.ch_is(b'"') {
+            return Err(self.de.error(ErrorCode::KeyMustBeAString));
+        }
+
+        Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+    }
+
+    fn visit_value<V>(&mut self) -> Result<V, Error>
+        where V: de::Deserialize,
+    {
+        try!(self.de.parse_object_colon());
+
+        Ok(try!(de::Deserialize::deserialize(self.de)))
+    }
+
+    fn end(&mut self) -> Result<(), Error> {
+        try!(self.de.parse_whitespace());
+
+        if self.de.ch_is(b'}') {
+            try!(self.de.bump());
+            Ok(())
+        } else if self.de.eof() {
+            Err(self.de.error(ErrorCode::EOFWhileParsingObject))
+        } else {
+            Err(self.de.error(ErrorCode::TrailingCharacters))
+        }
+    }
+
+    fn missing_field<V>(&mut self, _field: &'static str) -> Result<V, Error>
+        where V: de::Deserialize,
+    {
+        let mut de = de::value::ValueDeserializer::into_deserializer(());
+        Ok(try!(de::Deserialize::deserialize(&mut de)))
+    }
+}
+
+impl<Iter> de::VariantVisitor for Deserializer<Iter>
+    where Iter: Iterator<Item=io::Result<u8>>,
+{
+    type Error = Error;
+
+    fn visit_variant<V>(&mut self) -> Result<V, Error>
+        where V: de::Deserialize
+    {
+        de::Deserialize::deserialize(self)
+    }
+
+    fn visit_unit(&mut self) -> Result<(), Error> {
+        try!(self.parse_object_colon());
+
+        de::Deserialize::deserialize(self)
+    }
+
+    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        try!(self.parse_object_colon());
+
+        de::Deserializer::visit(self, visitor)
+    }
+
+    fn visit_map<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        try!(self.parse_object_colon());
+
+        de::Deserializer::visit(self, visitor)
+    }
+}
+
+/// Decodes a json value from a `std::io::Read`.
+pub fn from_iter<I, T>(iter: I) -> Result<T, Error>
+    where I: Iterator<Item=io::Result<u8>>,
+          T: de::Deserialize,
+{
+    let mut de = try!(Deserializer::new(iter));
+    let value = try!(de::Deserialize::deserialize(&mut de));
+
+    // Make sure the whole stream has been consumed.
+    try!(de.end());
+    Ok(value)
+}
+
+/// Decodes a json value from a `std::io::Read`.
+pub fn from_reader<R, T>(rdr: R) -> Result<T, Error>
+    where R: io::Read,
+          T: de::Deserialize,
+{
+    from_iter(rdr.bytes())
+}
+
+/// Decodes a json value from a `&str`.
+pub fn from_slice<T>(v: &[u8]) -> Result<T, Error>
+    where T: de::Deserialize
+{
+    from_iter(v.iter().map(|byte| Ok(*byte)))
+}
+
+/// Decodes a json value from a `&str`.
+pub fn from_str<T>(s: &str) -> Result<T, Error>
+    where T: de::Deserialize
+{
+    from_slice(s.as_bytes())
+}

serde/src/json/error.rs

@@ -0,0 +1,185 @@
+use std::error;
+use std::fmt;
+use std::io;
+
+use de;
+
+/// The errors that can arise while parsing a JSON stream.
+#[derive(Clone, PartialEq)]
+pub enum ErrorCode {
+    EOFWhileParsingList,
+    EOFWhileParsingObject,
+    EOFWhileParsingString,
+    EOFWhileParsingValue,
+    ExpectedColon,
+    ExpectedConversion,
+    ExpectedEnumEnd,
+    ExpectedEnumEndToken,
+    ExpectedEnumMapStart,
+    ExpectedEnumToken,
+    ExpectedEnumVariantString,
+    ExpectedListCommaOrEnd,
+    ExpectedName,
+    ExpectedObjectCommaOrEnd,
+    ExpectedSomeIdent,
+    ExpectedSomeValue,
+    InvalidEscape,
+    InvalidNumber,
+    InvalidUnicodeCodePoint,
+    KeyMustBeAString,
+    LoneLeadingSurrogateInHexEscape,
+    UnknownField(String),
+    MissingField(&'static str),
+    NotFourDigit,
+    NotUtf8,
+    TrailingCharacters,
+    UnexpectedEndOfHexEscape,
+    UnknownVariant,
+    UnrecognizedHex,
+}
+
+impl fmt::Debug for ErrorCode {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use std::fmt::Debug;
+
+        match *self {
+            //ErrorCode::ConversionError(ref token) => write!(f, "failed to convert {}", token),
+            ErrorCode::EOFWhileParsingList => "EOF While parsing list".fmt(f),
+            ErrorCode::EOFWhileParsingObject => "EOF While parsing object".fmt(f),
+            ErrorCode::EOFWhileParsingString => "EOF While parsing string".fmt(f),
+            ErrorCode::EOFWhileParsingValue => "EOF While parsing value".fmt(f),
+            ErrorCode::ExpectedColon => "expected `:`".fmt(f),
+            ErrorCode::ExpectedConversion => "expected conversion".fmt(f),
+            ErrorCode::ExpectedEnumEnd => "expected enum end".fmt(f),
+            ErrorCode::ExpectedEnumEndToken => "expected enum map end".fmt(f),
+            ErrorCode::ExpectedEnumMapStart => "expected enum map start".fmt(f),
+            ErrorCode::ExpectedEnumToken => "expected enum token".fmt(f),
+            ErrorCode::ExpectedEnumVariantString => "expected variant".fmt(f),
+            ErrorCode::ExpectedListCommaOrEnd => "expected `,` or `]`".fmt(f),
+            ErrorCode::ExpectedName => "expected name".fmt(f),
+            ErrorCode::ExpectedObjectCommaOrEnd => "expected `,` or `}`".fmt(f),
+            ErrorCode::ExpectedSomeIdent => "expected ident".fmt(f),
+            ErrorCode::ExpectedSomeValue => "expected value".fmt(f),
+            //ErrorCode::ExpectedTokens(ref token, tokens) => write!(f, "expected {}, found {}", tokens, token),
+            ErrorCode::InvalidEscape => "invalid escape".fmt(f),
+            ErrorCode::InvalidNumber => "invalid number".fmt(f),
+            ErrorCode::InvalidUnicodeCodePoint => "invalid unicode code point".fmt(f),
+            ErrorCode::KeyMustBeAString => "key must be a string".fmt(f),
+            ErrorCode::LoneLeadingSurrogateInHexEscape => "lone leading surrogate in hex escape".fmt(f),
+            ErrorCode::UnknownField(ref field) => write!(f, "unknown field \"{}\"", field),
+            ErrorCode::MissingField(ref field) => write!(f, "missing field \"{}\"", field),
+            ErrorCode::NotFourDigit => "invalid \\u escape (not four digits)".fmt(f),
+            ErrorCode::NotUtf8 => "contents not utf-8".fmt(f),
+            ErrorCode::TrailingCharacters => "trailing characters".fmt(f),
+            ErrorCode::UnexpectedEndOfHexEscape => "unexpected end of hex escape".fmt(f),
+            //ErrorCode::UnexpectedName(ref name) => write!(f, "unexpected name {}", name),
+            ErrorCode::UnknownVariant => "unknown variant".fmt(f),
+            ErrorCode::UnrecognizedHex => "invalid \\u escape (unrecognized hex)".fmt(f),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum Error {
+    /// msg, line, col
+    SyntaxError(ErrorCode, usize, usize),
+    IoError(io::Error),
+    /*
+    ExpectedError(String, String),
+    */
+    MissingFieldError(&'static str),
+    /*
+    UnknownVariantError(String),
+    */
+}
+
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        match *self {
+            Error::SyntaxError(..) => "syntax error",
+            Error::IoError(ref error) => error::Error::description(error),
+            /*
+            Error::ExpectedError(ref expected, _) => &expected,
+            */
+            Error::MissingFieldError(_) => "missing field",
+            /*
+            Error::UnknownVariantError(_) => "unknown variant",
+            */
+        }
+    }
+
+    fn cause(&self) -> Option<&error::Error> {
+        match *self {
+            Error::IoError(ref error) => Some(error),
+            _ => None,
+        }
+    }
+
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Error::SyntaxError(ref code, line, col) => {
+                write!(fmt, "{:?} at line {} column {}", code, line, col)
+            }
+            Error::IoError(ref error) => fmt::Display::fmt(error, fmt),
+            /*
+            Error::ExpectedError(ref expected, ref found) => {
+                Some(format!("expected {}, found {}", expected, found))
+            }
+            */
+            Error::MissingFieldError(ref field) => {
+                write!(fmt, "missing field {}", field)
+            }
+            /*
+            Error::UnknownVariantError(ref variant) => {
+                Some(format!("unknown variant {}", variant))
+            }
+            */
+        }
+    }
+}
+
+impl From<io::Error> for Error {
+    fn from(error: io::Error) -> Error {
+        Error::IoError(error)
+    }
+}
+
+impl From<de::value::Error> for Error {
+    fn from(error: de::value::Error) -> Error {
+        match error {
+            de::value::Error::SyntaxError => {
+                de::Error::syntax_error()
+            }
+            de::value::Error::EndOfStreamError => {
+                de::Error::end_of_stream_error()
+            }
+            de::value::Error::UnknownFieldError(field) => {
+                Error::SyntaxError(ErrorCode::UnknownField(field), 0, 0)
+            }
+            de::value::Error::MissingFieldError(field) => {
+                de::Error::missing_field_error(field)
+            }
+        }
+    }
+}
+
+impl de::Error for Error {
+    fn syntax_error() -> Error {
+        Error::SyntaxError(ErrorCode::ExpectedSomeValue, 0, 0)
+    }
+
+    fn end_of_stream_error() -> Error {
+        Error::SyntaxError(ErrorCode::EOFWhileParsingValue, 0, 0)
+    }
+
+    fn unknown_field_error(field: &str) -> Error {
+        Error::SyntaxError(ErrorCode::UnknownField(field.to_string()), 0, 0)
+    }
+
+    fn missing_field_error(field: &'static str) -> Error {
+        Error::MissingFieldError(field)
+    }
+}

serde/src/json/mod.rs

@@ -0,0 +1,113 @@
+//! JSON and serialization
+//!
+//! # What is JSON?
+//!
+//! JSON (JavaScript Object Notation) is a way to write data in JavaScript.  Like XML, it allows to
+//! encode structured data in a text format that can be easily read by humans.  Its simple syntax
+//! and native compatibility with JavaScript have made it a widely used format.
+//!
+//! Data types that can be encoded are JavaScript types (see the `serde::json:Value` enum for more
+//! details):
+//!
+//! * `Boolean`: equivalent to rust's `bool`
+//! * `I64`: equivalent to rust's `i64`
+//! * `U64`: equivalent to rust's `u64`
+//! * `F64`: equivalent to rust's `i64`
+//! * `String`: equivalent to rust's `String`
+//! * `Array`: equivalent to rust's `Vec<T>`, but also allowing objects of different types in the
+//!    same array
+//! * `Object`: equivalent to rust's `BTreeMap<String, serde::json::Value>`
+//! * `Null`
+//!
+//! An object is a series of string keys mapping to values, in `"key": value` format.  Arrays are
+//! enclosed in square brackets ([ ... ]) and objects in curly brackets ({ ... }).  A simple JSON
+//! document encoding a person, his/her age, address and phone numbers could look like
+//!
+//! ```ignore
+//! {
+//!     "FirstName": "John",
+//!     "LastName": "Doe",
+//!     "Age": 43,
+//!     "Address": {
+//!         "Street": "Downing Street 10",
+//!         "City": "London",
+//!         "Country": "Great Britain"
+//!     },
+//!     "PhoneNumbers": [
+//!         "+44 1234567",
+//!         "+44 2345678"
+//!     ]
+//! }
+//! ```
+//!
+//! # Type-based Serialization and Deserialization
+//!
+//! Serde provides a mechanism for low boilerplate serialization & deserialization of values to and
+//! from JSON via the serialization API.  To be able to serialize a piece of data, it must implement
+//! the `serde::Serialize` trait.  To be able to deserialize a piece of data, it must implement the
+//! `serde::Deserialize` trait.  Serde provides provides an annotation to automatically generate
+//! the code for these traits: `#[derive(Serialize, Deserialize)]`.
+//!
+//! The JSON API also provides an enum `serde::json::Value` and a method `to_value` to serialize
+//! objects.  A `serde::json::Value` value can be serialized as a string or buffer using the
+//! functions described above.  You can also use the `json::Serializer` object, which implements the
+//! `Serializer` trait.
+//!
+//! # Examples of use
+//!
+//! ## Parsing a `str` to `Value` and reading the result
+//!
+//! ```rust
+//! //#![feature(custom_derive, plugin)]
+//! //#![plugin(serde_macros)]
+//!
+//! extern crate serde;
+//!
+//! use serde::json::{self, Value};
+//!
+//! fn main() {
+//!     let data: Value = json::from_str("{\"foo\": 13, \"bar\": \"baz\"}").unwrap();
+//!     println!("data: {:?}", data);
+//!     // data: {"bar":"baz","foo":13}
+//!     println!("object? {}", data.is_object());
+//!     // object? true
+//!
+//!     let obj = data.as_object().unwrap();
+//!     let foo = obj.get("foo").unwrap();
+//!
+//!     println!("array? {:?}", foo.as_array());
+//!     // array? None
+//!     println!("u64? {:?}", foo.as_u64());
+//!     // u64? Some(13u64)
+//!
+//!     for (key, value) in obj.iter() {
+//!         println!("{}: {}", key, match *value {
+//!             Value::U64(v) => format!("{} (u64)", v),
+//!             Value::String(ref v) => format!("{} (string)", v),
+//!             _ => format!("other")
+//!         });
+//!     }
+//!     // bar: baz (string)
+//!     // foo: 13 (u64)
+//! }
+//! ```
+
+pub use self::de::{Deserializer, from_str};
+pub use self::error::{Error, ErrorCode};
+pub use self::ser::{
+    Serializer,
+    to_writer,
+    to_writer_pretty,
+    to_vec,
+    to_vec_pretty,
+    to_string,
+    to_string_pretty,
+    escape_str,
+};
+pub use self::value::{Value, to_value, from_value};
+
+pub mod builder;
+pub mod de;
+pub mod error;
+pub mod ser;
+pub mod value;

serde/src/json/ser.rs

@@ -0,0 +1,524 @@
+use std::io;
+use std::num::FpCategory;
+use std::string::FromUtf8Error;
+
+use ser;
+
+/// A structure for implementing serialization to JSON.
+pub struct Serializer<W, F=CompactFormatter> {
+    writer: W,
+    formatter: F,
+
+    /// `first` is used to signify if we should print a comma when we are walking through a
+    /// sequence.
+    first: bool,
+}
+
+impl<W> Serializer<W>
+    where W: io::Write,
+{
+    /// Creates a new JSON serializer.
+    #[inline]
+    pub fn new(writer: W) -> Self {
+        Serializer::with_formatter(writer, CompactFormatter)
+    }
+}
+
+impl<'a, W> Serializer<W, PrettyFormatter<'a>>
+    where W: io::Write,
+{
+    /// Creates a new JSON pretty print serializer.
+    #[inline]
+    pub fn pretty(writer: W) -> Self {
+        Serializer::with_formatter(writer, PrettyFormatter::new())
+    }
+}
+
+impl<W, F> Serializer<W, F>
+    where W: io::Write,
+          F: Formatter,
+{
+    /// Creates a new JSON visitor whose output will be written to the writer
+    /// specified.
+    #[inline]
+    pub fn with_formatter(writer: W, formatter: F) -> Self {
+        Serializer {
+            writer: writer,
+            formatter: formatter,
+            first: false,
+        }
+    }
+
+    /// Unwrap the `Writer` from the `Serializer`.
+    #[inline]
+    pub fn into_inner(self) -> W {
+        self.writer
+    }
+}
+
+impl<W, F> ser::Serializer for Serializer<W, F>
+    where W: io::Write,
+          F: Formatter,
+{
+    type Error = io::Error;
+
+    #[inline]
+    fn visit_bool(&mut self, value: bool) -> io::Result<()> {
+        if value {
+            self.writer.write_all(b"true")
+        } else {
+            self.writer.write_all(b"false")
+        }
+    }
+
+    #[inline]
+    fn visit_isize(&mut self, value: isize) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_i8(&mut self, value: i8) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_i16(&mut self, value: i16) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_i32(&mut self, value: i32) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_i64(&mut self, value: i64) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_usize(&mut self, value: usize) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_u8(&mut self, value: u8) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_u16(&mut self, value: u16) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_u32(&mut self, value: u32) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_u64(&mut self, value: u64) -> io::Result<()> {
+        write!(&mut self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_f32(&mut self, value: f32) -> io::Result<()> {
+        fmt_f32_or_null(&mut self.writer, value)
+    }
+
+    #[inline]
+    fn visit_f64(&mut self, value: f64) -> io::Result<()> {
+        fmt_f64_or_null(&mut self.writer, value)
+    }
+
+    #[inline]
+    fn visit_char(&mut self, value: char) -> io::Result<()> {
+        escape_char(&mut self.writer, value)
+    }
+
+    #[inline]
+    fn visit_str(&mut self, value: &str) -> io::Result<()> {
+        escape_str(&mut self.writer, value)
+    }
+
+    #[inline]
+    fn visit_none(&mut self) -> io::Result<()> {
+        self.visit_unit()
+    }
+
+    #[inline]
+    fn visit_some<V>(&mut self, value: V) -> io::Result<()>
+        where V: ser::Serialize
+    {
+        value.serialize(self)
+    }
+
+    #[inline]
+    fn visit_unit(&mut self) -> io::Result<()> {
+        self.writer.write_all(b"null")
+    }
+
+    #[inline]
+    fn visit_enum_unit(&mut self, _name: &str, variant: &str) -> io::Result<()> {
+        try!(self.formatter.open(&mut self.writer, b'{'));
+        try!(self.formatter.comma(&mut self.writer, true));
+        try!(self.visit_str(variant));
+        try!(self.formatter.colon(&mut self.writer));
+        try!(self.writer.write_all(b"[]"));
+        self.formatter.close(&mut self.writer, b'}')
+    }
+
+    #[inline]
+    fn visit_seq<V>(&mut self, mut visitor: V) -> io::Result<()>
+        where V: ser::SeqVisitor,
+    {
+        match visitor.len() {
+            Some(len) if len == 0 => {
+                self.writer.write_all(b"[]")
+            }
+            _ => {
+                try!(self.formatter.open(&mut self.writer, b'['));
+
+                self.first = true;
+
+                while let Some(()) = try!(visitor.visit(self)) { }
+
+                self.formatter.close(&mut self.writer, b']')
+            }
+        }
+
+    }
+
+    #[inline]
+    fn visit_enum_seq<V>(&mut self, _name: &str, variant: &str, visitor: V) -> io::Result<()>
+        where V: ser::SeqVisitor,
+    {
+        try!(self.formatter.open(&mut self.writer, b'{'));
+        try!(self.formatter.comma(&mut self.writer, true));
+        try!(self.visit_str(variant));
+        try!(self.formatter.colon(&mut self.writer));
+        try!(self.visit_seq(visitor));
+        self.formatter.close(&mut self.writer, b'}')
+    }
+
+    #[inline]
+    fn visit_seq_elt<T>(&mut self, value: T) -> io::Result<()>
+        where T: ser::Serialize,
+    {
+        try!(self.formatter.comma(&mut self.writer, self.first));
+        self.first = false;
+
+        value.serialize(self)
+    }
+
+    #[inline]
+    fn visit_map<V>(&mut self, mut visitor: V) -> io::Result<()>
+        where V: ser::MapVisitor,
+    {
+        match visitor.len() {
+            Some(len) if len == 0 => {
+                self.writer.write_all(b"{}")
+            }
+            _ => {
+                try!(self.formatter.open(&mut self.writer, b'{'));
+
+                self.first = true;
+
+                while let Some(()) = try!(visitor.visit(self)) { }
+
+                self.formatter.close(&mut self.writer, b'}')
+            }
+        }
+    }
+
+    #[inline]
+    fn visit_enum_map<V>(&mut self, _name: &str, variant: &str, visitor: V) -> io::Result<()>
+        where V: ser::MapVisitor,
+    {
+        try!(self.formatter.open(&mut self.writer, b'{'));
+        try!(self.formatter.comma(&mut self.writer, true));
+        try!(self.visit_str(variant));
+        try!(self.formatter.colon(&mut self.writer));
+        try!(self.visit_map(visitor));
+
+        self.formatter.close(&mut self.writer, b'}')
+    }
+
+    #[inline]
+    fn visit_map_elt<K, V>(&mut self, key: K, value: V) -> io::Result<()>
+        where K: ser::Serialize,
+              V: ser::Serialize,
+    {
+        try!(self.formatter.comma(&mut self.writer, self.first));
+        self.first = false;
+
+        try!(key.serialize(self));
+        try!(self.formatter.colon(&mut self.writer));
+        value.serialize(self)
+    }
+
+    #[inline]
+    fn format() -> &'static str {
+        "json"
+    }
+}
+
+pub trait Formatter {
+    fn open<W>(&mut self, writer: &mut W, ch: u8) -> io::Result<()>
+        where W: io::Write;
+
+    fn comma<W>(&mut self, writer: &mut W, first: bool) -> io::Result<()>
+        where W: io::Write;
+
+    fn colon<W>(&mut self, writer: &mut W) -> io::Result<()>
+        where W: io::Write;
+
+    fn close<W>(&mut self, writer: &mut W, ch: u8) -> io::Result<()>
+        where W: io::Write;
+}
+
+pub struct CompactFormatter;
+
+impl Formatter for CompactFormatter {
+    fn open<W>(&mut self, writer: &mut W, ch: u8) -> io::Result<()>
+        where W: io::Write,
+    {
+        writer.write_all(&[ch])
+    }
+
+    fn comma<W>(&mut self, writer: &mut W, first: bool) -> io::Result<()>
+        where W: io::Write,
+    {
+        if first {
+            Ok(())
+        } else {
+            writer.write_all(b",")
+        }
+    }
+
+    fn colon<W>(&mut self, writer: &mut W) -> io::Result<()>
+        where W: io::Write,
+    {
+        writer.write_all(b":")
+    }
+
+    fn close<W>(&mut self, writer: &mut W, ch: u8) -> io::Result<()>
+        where W: io::Write,
+    {
+        writer.write_all(&[ch])
+    }
+}
+
+pub struct PrettyFormatter<'a> {
+    current_indent: usize,
+    indent: &'a [u8],
+}
+
+impl<'a> PrettyFormatter<'a> {
+    fn new() -> Self {
+        PrettyFormatter::with_indent(b"  ")
+    }
+
+    fn with_indent(indent: &'a [u8]) -> Self {
+        PrettyFormatter {
+            current_indent: 0,
+            indent: indent,
+        }
+    }
+}
+
+impl<'a> Formatter for PrettyFormatter<'a> {
+    fn open<W>(&mut self, writer: &mut W, ch: u8) -> io::Result<()>
+        where W: io::Write,
+    {
+        self.current_indent += 1;
+        writer.write_all(&[ch])
+    }
+
+    fn comma<W>(&mut self, writer: &mut W, first: bool) -> io::Result<()>
+        where W: io::Write,
+    {
+        if first {
+            try!(writer.write_all(b"\n"));
+        } else {
+            try!(writer.write_all(b",\n"));
+        }
+
+        indent(writer, self.current_indent, self.indent)
+    }
+
+    fn colon<W>(&mut self, writer: &mut W) -> io::Result<()>
+        where W: io::Write,
+    {
+        writer.write_all(b": ")
+    }
+
+    fn close<W>(&mut self, writer: &mut W, ch: u8) -> io::Result<()>
+        where W: io::Write,
+    {
+        self.current_indent -= 1;
+        try!(writer.write(b"\n"));
+        try!(indent(writer, self.current_indent, self.indent));
+
+        writer.write_all(&[ch])
+    }
+}
+
+#[inline]
+pub fn escape_bytes<W>(wr: &mut W, bytes: &[u8]) -> io::Result<()>
+    where W: io::Write
+{
+    try!(wr.write_all(b"\""));
+
+    let mut start = 0;
+
+    for (i, byte) in bytes.iter().enumerate() {
+        let escaped = match *byte {
+            b'"' => b"\\\"",
+            b'\\' => b"\\\\",
+            b'\x08' => b"\\b",
+            b'\x0c' => b"\\f",
+            b'\n' => b"\\n",
+            b'\r' => b"\\r",
+            b'\t' => b"\\t",
+            _ => { continue; }
+        };
+
+        if start < i {
+            try!(wr.write_all(&bytes[start..i]));
+        }
+
+        try!(wr.write_all(escaped));
+
+        start = i + 1;
+    }
+
+    if start != bytes.len() {
+        try!(wr.write_all(&bytes[start..]));
+    }
+
+    try!(wr.write_all(b"\""));
+    Ok(())
+}
+
+#[inline]
+pub fn escape_str<W>(wr: &mut W, value: &str) -> io::Result<()>
+    where W: io::Write
+{
+    escape_bytes(wr, value.as_bytes())
+}
+
+#[inline]
+fn escape_char<W>(wr: &mut W, value: char) -> io::Result<()>
+    where W: io::Write
+{
+    // FIXME: this allocation is required in order to be compatible with stable
+    // rust, which doesn't support encoding a `char` into a stack buffer.
+    escape_bytes(wr, value.to_string().as_bytes())
+}
+
+fn fmt_f32_or_null<W>(wr: &mut W, value: f32) -> io::Result<()>
+    where W: io::Write
+{
+    match value.classify() {
+        FpCategory::Nan | FpCategory::Infinite => wr.write_all(b"null"),
+        _ => {
+            let s = format!("{:?}", value);
+            try!(wr.write_all(s.as_bytes()));
+            if !s.contains('.') {
+                try!(wr.write_all(b".0"))
+            }
+            Ok(())
+        }
+    }
+}
+
+fn fmt_f64_or_null<W>(wr: &mut W, value: f64) -> io::Result<()>
+    where W: io::Write
+{
+    match value.classify() {
+        FpCategory::Nan | FpCategory::Infinite => wr.write_all(b"null"),
+        _ => {
+            let s = format!("{:?}", value);
+            try!(wr.write_all(s.as_bytes()));
+            if !s.contains('.') {
+                try!(wr.write_all(b".0"))
+            }
+            Ok(())
+        }
+    }
+}
+
+/// Encode the specified struct into a json `[u8]` writer.
+#[inline]
+pub fn to_writer<W, T>(writer: &mut W, value: &T) -> io::Result<()>
+    where W: io::Write,
+          T: ser::Serialize,
+{
+    let mut ser = Serializer::new(writer);
+    try!(value.serialize(&mut ser));
+    Ok(())
+}
+
+/// Encode the specified struct into a json `[u8]` writer.
+#[inline]
+pub fn to_writer_pretty<W, T>(writer: &mut W, value: &T) -> io::Result<()>
+    where W: io::Write,
+          T: ser::Serialize,
+{
+    let mut ser = Serializer::pretty(writer);
+    try!(value.serialize(&mut ser));
+    Ok(())
+}
+
+/// Encode the specified struct into a json `[u8]` buffer.
+#[inline]
+pub fn to_vec<T>(value: &T) -> Vec<u8>
+    where T: ser::Serialize,
+{
+    // We are writing to a Vec, which doesn't fail. So we can ignore
+    // the error.
+    let mut writer = Vec::with_capacity(128);
+    to_writer(&mut writer, value).unwrap();
+    writer
+}
+
+/// Encode the specified struct into a json `[u8]` buffer.
+#[inline]
+pub fn to_vec_pretty<T>(value: &T) -> Vec<u8>
+    where T: ser::Serialize,
+{
+    // We are writing to a Vec, which doesn't fail. So we can ignore
+    // the error.
+    let mut writer = Vec::with_capacity(128);
+    to_writer_pretty(&mut writer, value).unwrap();
+    writer
+}
+
+/// Encode the specified struct into a json `String` buffer.
+#[inline]
+pub fn to_string<T>(value: &T) -> Result<String, FromUtf8Error>
+    where T: ser::Serialize
+{
+    let vec = to_vec(value);
+    String::from_utf8(vec)
+}
+
+/// Encode the specified struct into a json `String` buffer.
+#[inline]
+pub fn to_string_pretty<T>(value: &T) -> Result<String, FromUtf8Error>
+    where T: ser::Serialize
+{
+    let vec = to_vec_pretty(value);
+    String::from_utf8(vec)
+}
+
+fn indent<W>(wr: &mut W, n: usize, s: &[u8]) -> io::Result<()>
+    where W: io::Write,
+{
+    for _ in 0 .. n {
+        try!(wr.write_all(s));
+    }
+
+    Ok(())
+}

serde/src/json/value.rs

@@ -0,0 +1,915 @@
+use std::collections::{BTreeMap, btree_map};
+use std::fmt;
+use std::io;
+use std::str;
+use std::vec;
+
+use num::NumCast;
+
+use de;
+use ser;
+use super::error::Error;
+
+#[derive(Clone, PartialEq)]
+pub enum Value {
+    Null,
+    Bool(bool),
+    I64(i64),
+    U64(u64),
+    F64(f64),
+    String(String),
+    Array(Vec<Value>),
+    Object(BTreeMap<String, Value>),
+}
+
+impl Value {
+    /// If the `Value` is an Object, returns the value associated with the provided key.
+    /// Otherwise, returns None.
+    pub fn find<'a>(&'a self, key: &str) -> Option<&'a Value>{
+        match self {
+            &Value::Object(ref map) => map.get(key),
+            _ => None
+        }
+    }
+
+    /// Attempts to get a nested Value Object for each key in `keys`.
+    /// If any key is found not to exist, find_path will return None.
+    /// Otherwise, it will return the `Value` associated with the final key.
+    pub fn find_path<'a>(&'a self, keys: &[&str]) -> Option<&'a Value>{
+        let mut target = self;
+        for key in keys {
+            match target.find(key) {
+                Some(t) => { target = t; },
+                None => return None
+            }
+        }
+        Some(target)
+    }
+
+    /// Looks up a value by path.
+    ///
+    /// This is a convenience method that splits the path by `'.'`
+    /// and then feeds the sequence of keys into the `find_path`
+    /// method.
+    ///
+    /// ``` ignore
+    /// let obj: Value = json::from_str(r#"{"x": {"a": 1}}"#).unwrap();
+    ///
+    /// assert!(obj.lookup("x.a").unwrap() == &Value::U64(1));
+    /// ```
+    pub fn lookup<'a>(&'a self, path: &'a str) -> Option<&'a Value> {
+        let mut target = self;
+        for key in path.split('.') {
+            match target.find(key) {
+                Some(t) => { target = t; },
+                None => return None
+            }
+        }
+        Some(target)
+    }
+
+    /// If the `Value` is an Object, performs a depth-first search until
+    /// a value associated with the provided key is found. If no value is found
+    /// or the `Value` is not an Object, returns None.
+    pub fn search<'a>(&'a self, key: &str) -> Option<&'a Value> {
+        match self {
+            &Value::Object(ref map) => {
+                match map.get(key) {
+                    Some(json_value) => Some(json_value),
+                    None => {
+                        for (_, v) in map.iter() {
+                            match v.search(key) {
+                                x if x.is_some() => return x,
+                                _ => ()
+                            }
+                        }
+                        None
+                    }
+                }
+            },
+            _ => None
+        }
+    }
+
+    /// Returns true if the `Value` is an Object. Returns false otherwise.
+    pub fn is_object<'a>(&'a self) -> bool {
+        self.as_object().is_some()
+    }
+
+    /// If the `Value` is an Object, returns the associated BTreeMap.
+    /// Returns None otherwise.
+    pub fn as_object<'a>(&'a self) -> Option<&'a BTreeMap<String, Value>> {
+        match self {
+            &Value::Object(ref map) => Some(map),
+            _ => None
+        }
+    }
+
+    /// If the `Value` is an Object, returns the associated mutable BTreeMap.
+    /// Returns None otherwise.
+    pub fn as_object_mut<'a>(&'a mut self) -> Option<&'a mut BTreeMap<String, Value>> {
+        match self {
+            &mut Value::Object(ref mut map) => Some(map),
+            _ => None
+        }
+    }
+
+    /// Returns true if the `Value` is an Array. Returns false otherwise.
+    pub fn is_array<'a>(&'a self) -> bool {
+        self.as_array().is_some()
+    }
+
+    /// If the `Value` is an Array, returns the associated vector.
+    /// Returns None otherwise.
+    pub fn as_array<'a>(&'a self) -> Option<&'a Vec<Value>> {
+        match self {
+            &Value::Array(ref array) => Some(&*array),
+            _ => None
+        }
+    }
+
+    /// If the `Value` is an Array, returns the associated mutable vector.
+    /// Returns None otherwise.
+    pub fn as_array_mut<'a>(&'a mut self) -> Option<&'a mut Vec<Value>> {
+        match self {
+            &mut Value::Array(ref mut list) => Some(list),
+            _ => None
+        }
+    }
+
+    /// Returns true if the `Value` is a String. Returns false otherwise.
+    pub fn is_string<'a>(&'a self) -> bool {
+        self.as_string().is_some()
+    }
+
+    /// If the `Value` is a String, returns the associated str.
+    /// Returns None otherwise.
+    pub fn as_string<'a>(&'a self) -> Option<&'a str> {
+        match *self {
+            Value::String(ref s) => Some(&s),
+            _ => None
+        }
+    }
+
+    /// Returns true if the `Value` is a Number. Returns false otherwise.
+    pub fn is_number(&self) -> bool {
+        match *self {
+            Value::I64(_) | Value::U64(_) | Value::F64(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Returns true if the `Value` is a i64. Returns false otherwise.
+    pub fn is_i64(&self) -> bool {
+        match *self {
+            Value::I64(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Returns true if the `Value` is a u64. Returns false otherwise.
+    pub fn is_u64(&self) -> bool {
+        match *self {
+            Value::U64(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Returns true if the `Value` is a f64. Returns false otherwise.
+    pub fn is_f64(&self) -> bool {
+        match *self {
+            Value::F64(_) => true,
+            _ => false,
+        }
+    }
+
+    /// If the `Value` is a number, return or cast it to a i64.
+    /// Returns None otherwise.
+    pub fn as_i64(&self) -> Option<i64> {
+        match *self {
+            Value::I64(n) => Some(n),
+            Value::U64(n) => NumCast::from(n),
+            _ => None
+        }
+    }
+
+    /// If the `Value` is a number, return or cast it to a u64.
+    /// Returns None otherwise.
+    pub fn as_u64(&self) -> Option<u64> {
+        match *self {
+            Value::I64(n) => NumCast::from(n),
+            Value::U64(n) => Some(n),
+            _ => None
+        }
+    }
+
+    /// If the `Value` is a number, return or cast it to a f64.
+    /// Returns None otherwise.
+    pub fn as_f64(&self) -> Option<f64> {
+        match *self {
+            Value::I64(n) => NumCast::from(n),
+            Value::U64(n) => NumCast::from(n),
+            Value::F64(n) => Some(n),
+            _ => None
+        }
+    }
+
+    /// Returns true if the `Value` is a Boolean. Returns false otherwise.
+    pub fn is_boolean(&self) -> bool {
+        self.as_boolean().is_some()
+    }
+
+    /// If the `Value` is a Boolean, returns the associated bool.
+    /// Returns None otherwise.
+    pub fn as_boolean(&self) -> Option<bool> {
+        match self {
+            &Value::Bool(b) => Some(b),
+            _ => None
+        }
+    }
+
+    /// Returns true if the `Value` is a Null. Returns false otherwise.
+    pub fn is_null(&self) -> bool {
+        self.as_null().is_some()
+    }
+
+    /// If the `Value` is a Null, returns ().
+    /// Returns None otherwise.
+    pub fn as_null(&self) -> Option<()> {
+        match self {
+            &Value::Null => Some(()),
+            _ => None
+        }
+    }
+}
+
+impl ser::Serialize for Value {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: ser::Serializer,
+    {
+        match *self {
+            Value::Null => serializer.visit_unit(),
+            Value::Bool(v) => serializer.visit_bool(v),
+            Value::I64(v) => serializer.visit_i64(v),
+            Value::U64(v) => serializer.visit_u64(v),
+            Value::F64(v) => serializer.visit_f64(v),
+            Value::String(ref v) => serializer.visit_str(&v),
+            Value::Array(ref v) => v.serialize(serializer),
+            Value::Object(ref v) => v.serialize(serializer),
+        }
+    }
+}
+
+impl de::Deserialize for Value {
+    #[inline]
+    fn deserialize<D>(deserializer: &mut D) -> Result<Value, D::Error>
+        where D: de::Deserializer,
+    {
+        struct ValueVisitor;
+
+        impl de::Visitor for ValueVisitor {
+            type Value = Value;
+
+            #[inline]
+            fn visit_bool<E>(&mut self, value: bool) -> Result<Value, E> {
+                Ok(Value::Bool(value))
+            }
+
+            #[inline]
+            fn visit_i64<E>(&mut self, value: i64) -> Result<Value, E> {
+                if value < 0 {
+                    Ok(Value::I64(value))
+                } else {
+                    Ok(Value::U64(value as u64))
+                }
+            }
+
+            #[inline]
+            fn visit_u64<E>(&mut self, value: u64) -> Result<Value, E> {
+                Ok(Value::U64(value))
+            }
+
+            #[inline]
+            fn visit_f64<E>(&mut self, value: f64) -> Result<Value, E> {
+                Ok(Value::F64(value))
+            }
+
+            #[inline]
+            fn visit_str<E>(&mut self, value: &str) -> Result<Value, E>
+                where E: de::Error,
+            {
+                self.visit_string(value.to_string())
+            }
+
+            #[inline]
+            fn visit_string<E>(&mut self, value: String) -> Result<Value, E> {
+                Ok(Value::String(value))
+            }
+
+            #[inline]
+            fn visit_none<E>(&mut self) -> Result<Value, E> {
+                Ok(Value::Null)
+            }
+
+            #[inline]
+            fn visit_some<D>(&mut self, deserializer: &mut D) -> Result<Value, D::Error>
+                where D: de::Deserializer,
+            {
+                de::Deserialize::deserialize(deserializer)
+            }
+
+            #[inline]
+            fn visit_unit<E>(&mut self) -> Result<Value, E> {
+                Ok(Value::Null)
+            }
+
+            #[inline]
+            fn visit_seq<V>(&mut self, visitor: V) -> Result<Value, V::Error>
+                where V: de::SeqVisitor,
+            {
+                let values = try!(de::impls::VecVisitor::new().visit_seq(visitor));
+                Ok(Value::Array(values))
+            }
+
+            #[inline]
+            fn visit_map<V>(&mut self, visitor: V) -> Result<Value, V::Error>
+                where V: de::MapVisitor,
+            {
+                let values = try!(de::impls::BTreeMapVisitor::new().visit_map(visitor));
+                Ok(Value::Object(values))
+            }
+        }
+
+        deserializer.visit(ValueVisitor)
+    }
+}
+
+struct WriterFormatter<'a, 'b: 'a> {
+    inner: &'a mut fmt::Formatter<'b>,
+}
+
+impl<'a, 'b> io::Write for WriterFormatter<'a, 'b> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        match self.inner.write_str(str::from_utf8(buf).unwrap()) {
+            Ok(_) => Ok(buf.len()),
+            Err(_) => Err(io::Error::last_os_error()),
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl fmt::Debug for Value {
+    /// Serializes a json value into a string
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut wr = WriterFormatter { inner: f };
+        super::ser::to_writer(&mut wr, self).map_err(|_| fmt::Error)
+    }
+}
+
+#[derive(Debug)]
+enum State {
+    Value(Value),
+    Array(Vec<Value>),
+    Object(BTreeMap<String, Value>),
+}
+
+pub struct Serializer {
+    state: Vec<State>,
+}
+
+impl Serializer {
+    pub fn new() -> Serializer {
+        Serializer {
+            state: Vec::with_capacity(4),
+        }
+    }
+
+    pub fn unwrap(mut self) -> Value {
+        match self.state.pop().unwrap() {
+            State::Value(value) => value,
+            state => panic!("expected value, found {:?}", state),
+        }
+    }
+}
+
+impl ser::Serializer for Serializer {
+    type Error = ();
+
+    #[inline]
+    fn visit_bool(&mut self, value: bool) -> Result<(), ()> {
+        self.state.push(State::Value(Value::Bool(value)));
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_i64(&mut self, value: i64) -> Result<(), ()> {
+        if value < 0 {
+            self.state.push(State::Value(Value::I64(value)));
+        } else {
+            self.state.push(State::Value(Value::U64(value as u64)));
+        }
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_u64(&mut self, value: u64) -> Result<(), ()> {
+        self.state.push(State::Value(Value::U64(value)));
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_f64(&mut self, value: f64) -> Result<(), ()> {
+        self.state.push(State::Value(Value::F64(value as f64)));
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_char(&mut self, value: char) -> Result<(), ()> {
+        self.state.push(State::Value(Value::String(value.to_string())));
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_str(&mut self, value: &str) -> Result<(), ()> {
+        self.state.push(State::Value(Value::String(value.to_string())));
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_none(&mut self) -> Result<(), ()> {
+        self.visit_unit()
+    }
+
+    #[inline]
+    fn visit_some<V>(&mut self, value: V) -> Result<(), ()>
+        where V: ser::Serialize,
+    {
+        value.serialize(self)
+    }
+
+    #[inline]
+    fn visit_unit(&mut self) -> Result<(), ()> {
+        self.state.push(State::Value(Value::Null));
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_enum_unit(&mut self, _name: &str, variant: &str) -> Result<(), ()> {
+        let mut values = BTreeMap::new();
+        values.insert(variant.to_string(), Value::Array(vec![]));
+
+        self.state.push(State::Value(Value::Object(values)));
+
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<(), ()>
+        where V: ser::SeqVisitor,
+    {
+        let len = visitor.len().unwrap_or(0);
+        let values = Vec::with_capacity(len);
+
+        self.state.push(State::Array(values));
+
+        while let Some(()) = try!(visitor.visit(self)) { }
+
+        let values = match self.state.pop().unwrap() {
+            State::Array(values) => values,
+            state => panic!("Expected array, found {:?}", state),
+        };
+
+        self.state.push(State::Value(Value::Array(values)));
+
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_enum_seq<V>(&mut self, _name: &str, variant: &str, visitor: V) -> Result<(), ()>
+        where V: ser::SeqVisitor,
+    {
+        try!(self.visit_seq(visitor));
+
+        let value = match self.state.pop().unwrap() {
+            State::Value(value) => value,
+            state => panic!("expected value, found {:?}", state),
+        };
+
+        let mut object = BTreeMap::new();
+
+        object.insert(variant.to_string(), value);
+
+        self.state.push(State::Value(Value::Object(object)));
+
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_seq_elt<T>(&mut self, value: T) -> Result<(), ()>
+        where T: ser::Serialize,
+    {
+        try!(value.serialize(self));
+
+        let value = match self.state.pop().unwrap() {
+            State::Value(value) => value,
+            state => panic!("expected value, found {:?}", state),
+        };
+
+        match *self.state.last_mut().unwrap() {
+            State::Array(ref mut values) => { values.push(value); }
+            ref state => panic!("expected array, found {:?}", state),
+        }
+
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_map<V>(&mut self, mut visitor: V) -> Result<(), ()>
+        where V: ser::MapVisitor,
+    {
+        let values = BTreeMap::new();
+
+        self.state.push(State::Object(values));
+
+        while let Some(()) = try!(visitor.visit(self)) { }
+
+        let values = match self.state.pop().unwrap() {
+            State::Object(values) => values,
+            state => panic!("expected object, found {:?}", state),
+        };
+
+        self.state.push(State::Value(Value::Object(values)));
+
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_enum_map<V>(&mut self, _name: &str, variant: &str, visitor: V) -> Result<(), ()>
+        where V: ser::MapVisitor,
+    {
+        try!(self.visit_map(visitor));
+
+        let value = match self.state.pop().unwrap() {
+            State::Value(value) => value,
+            state => panic!("expected value, found {:?}", state),
+        };
+
+        let mut object = BTreeMap::new();
+
+        object.insert(variant.to_string(), value);
+
+        self.state.push(State::Value(Value::Object(object)));
+
+        Ok(())
+    }
+
+    #[inline]
+    fn visit_map_elt<K, V>(&mut self, key: K, value: V) -> Result<(), ()>
+        where K: ser::Serialize,
+              V: ser::Serialize,
+    {
+        try!(key.serialize(self));
+
+        let key = match self.state.pop().unwrap() {
+            State::Value(Value::String(value)) => value,
+            state => panic!("expected key, found {:?}", state),
+        };
+
+        try!(value.serialize(self));
+
+        let value = match self.state.pop().unwrap() {
+            State::Value(value) => value,
+            state => panic!("expected value, found {:?}", state),
+        };
+
+        match *self.state.last_mut().unwrap() {
+            State::Object(ref mut values) => { values.insert(key, value); }
+            ref state => panic!("expected object, found {:?}", state),
+        }
+
+        Ok(())
+    }
+
+    #[inline]
+    fn format() -> &'static str {
+        "json"
+    }
+}
+
+pub struct Deserializer {
+    value: Option<Value>,
+}
+
+impl Deserializer {
+    /// Creates a new deserializer instance for deserializing the specified JSON value.
+    pub fn new(value: Value) -> Deserializer {
+        Deserializer {
+            value: Some(value),
+        }
+    }
+}
+
+impl de::Deserializer for Deserializer {
+    type Error = Error;
+
+    #[inline]
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        let value = match self.value.take() {
+            Some(value) => value,
+            None => { return Err(de::Error::end_of_stream_error()); }
+        };
+
+        match value {
+            Value::Null => visitor.visit_unit(),
+            Value::Bool(v) => visitor.visit_bool(v),
+            Value::I64(v) => visitor.visit_i64(v),
+            Value::U64(v) => visitor.visit_u64(v),
+            Value::F64(v) => visitor.visit_f64(v),
+            Value::String(v) => visitor.visit_string(v),
+            Value::Array(v) => {
+                let len = v.len();
+                visitor.visit_seq(SeqDeserializer {
+                    de: self,
+                    iter: v.into_iter(),
+                    len: len,
+                })
+            }
+            Value::Object(v) => {
+                let len = v.len();
+                visitor.visit_map(MapDeserializer {
+                    de: self,
+                    iter: v.into_iter(),
+                    value: None,
+                    len: len,
+                })
+            }
+        }
+    }
+
+    #[inline]
+    fn visit_option<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        match self.value {
+            Some(Value::Null) => visitor.visit_none(),
+            Some(_) => visitor.visit_some(self),
+            None => Err(de::Error::end_of_stream_error()),
+        }
+    }
+
+    #[inline]
+    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::EnumVisitor,
+    {
+        let value = match self.value.take() {
+            Some(Value::Object(value)) => value,
+            Some(_) => { return Err(de::Error::syntax_error()); }
+            None => { return Err(de::Error::end_of_stream_error()); }
+        };
+
+        let mut iter = value.into_iter();
+
+        let value = match iter.next() {
+            Some((variant, Value::Array(fields))) => {
+                self.value = Some(Value::String(variant));
+
+                let len = fields.len();
+                try!(visitor.visit(SeqDeserializer {
+                    de: self,
+                    iter: fields.into_iter(),
+                    len: len,
+                }))
+            }
+            Some((variant, Value::Object(fields))) => {
+                let len = fields.len();
+                try!(visitor.visit(MapDeserializer {
+                    de: self,
+                    iter: fields.into_iter(),
+                    value: Some(Value::String(variant)),
+                    len: len,
+                }))
+            }
+            Some(_) => { return Err(de::Error::syntax_error()); }
+            None => { return Err(de::Error::syntax_error()); }
+        };
+
+        match iter.next() {
+            Some(_) => Err(de::Error::syntax_error()),
+            None => Ok(value)
+        }
+    }
+
+    #[inline]
+    fn format() -> &'static str {
+        "json"
+    }
+}
+
+struct SeqDeserializer<'a> {
+    de: &'a mut Deserializer,
+    iter: vec::IntoIter<Value>,
+    len: usize,
+}
+
+impl<'a> de::Deserializer for SeqDeserializer<'a> {
+    type Error = Error;
+
+    #[inline]
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        if self.len == 0 {
+            visitor.visit_unit()
+        } else {
+            visitor.visit_seq(self)
+        }
+    }
+}
+
+impl<'a> de::SeqVisitor for SeqDeserializer<'a> {
+    type Error = Error;
+
+    fn visit<T>(&mut self) -> Result<Option<T>, Error>
+        where T: de::Deserialize
+    {
+        match self.iter.next() {
+            Some(value) => {
+                self.len -= 1;
+                self.de.value = Some(value);
+                Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+            }
+            None => Ok(None),
+        }
+    }
+
+    fn end(&mut self) -> Result<(), Error> {
+        if self.len == 0 {
+            Ok(())
+        } else {
+            Err(de::Error::end_of_stream_error())
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len, Some(self.len))
+    }
+}
+
+impl<'a> de::VariantVisitor for SeqDeserializer<'a> {
+    type Error = Error;
+
+    fn visit_variant<V>(&mut self) -> Result<V, Error>
+        where V: de::Deserialize,
+    {
+        de::Deserialize::deserialize(self.de)
+    }
+
+    fn visit_unit(&mut self) -> Result<(), Error>
+    {
+        de::Deserialize::deserialize(self)
+    }
+
+    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        de::Deserializer::visit(self, visitor)
+    }
+
+    fn visit_map<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        de::Deserializer::visit(self, visitor)
+    }
+}
+
+struct MapDeserializer<'a> {
+    de: &'a mut Deserializer,
+    iter: btree_map::IntoIter<String, Value>,
+    value: Option<Value>,
+    len: usize,
+}
+
+impl<'a> de::MapVisitor for MapDeserializer<'a> {
+    type Error = Error;
+
+    fn visit_key<T>(&mut self) -> Result<Option<T>, Error>
+        where T: de::Deserialize
+    {
+        match self.iter.next() {
+            Some((key, value)) => {
+                self.len -= 1;
+                self.value = Some(value);
+                self.de.value = Some(Value::String(key));
+                Ok(Some(try!(de::Deserialize::deserialize(self.de))))
+            }
+            None => Ok(None),
+        }
+    }
+
+    fn visit_value<T>(&mut self) -> Result<T, Error>
+        where T: de::Deserialize
+    {
+        let value = self.value.take().unwrap();
+        self.de.value = Some(value);
+        Ok(try!(de::Deserialize::deserialize(self.de)))
+    }
+
+    fn end(&mut self) -> Result<(), Error> {
+        if self.len == 0 {
+            Ok(())
+        } else {
+            Err(de::Error::end_of_stream_error())
+        }
+    }
+
+    fn missing_field<V>(&mut self, _field: &'static str) -> Result<V, Error>
+        where V: de::Deserialize,
+    {
+        // See if the type can deserialize from a unit.
+        struct UnitDeserializer;
+
+        impl de::Deserializer for UnitDeserializer {
+            type Error = Error;
+
+            fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+                where V: de::Visitor,
+            {
+                visitor.visit_unit()
+            }
+
+            fn visit_option<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+                where V: de::Visitor,
+            {
+                visitor.visit_none()
+            }
+        }
+
+        Ok(try!(de::Deserialize::deserialize(&mut UnitDeserializer)))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len, Some(self.len))
+    }
+}
+
+impl<'a> de::Deserializer for MapDeserializer<'a> {
+    type Error = Error;
+
+    #[inline]
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        println!("MapDeserializer!");
+        visitor.visit_map(self)
+    }
+}
+
+impl<'a> de::VariantVisitor for MapDeserializer<'a> {
+    type Error = Error;
+
+    fn visit_variant<V>(&mut self) -> Result<V, Error>
+        where V: de::Deserialize,
+    {
+        self.de.value = self.value.take();
+        de::Deserialize::deserialize(self.de)
+    }
+
+    fn visit_unit(&mut self) -> Result<(), Error> {
+        de::Deserialize::deserialize(self)
+    }
+
+    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        de::Deserializer::visit(self, visitor)
+    }
+
+    fn visit_map<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        de::Deserializer::visit(self, visitor)
+    }
+}
+
+/// Shortcut function to encode a `T` into a JSON `Value`
+pub fn to_value<T>(value: &T) -> Value
+    where T: ser::Serialize
+{
+    let mut ser = Serializer::new();
+    value.serialize(&mut ser).ok().unwrap();
+    ser.unwrap()
+}
+
+/// Shortcut function to decode a JSON `Value` into a `T`
+pub fn from_value<T>(value: Value) -> Result<T, Error>
+    where T: de::Deserialize
+{
+    let mut de = Deserializer::new(value);
+    de::Deserialize::deserialize(&mut de)
+}

serde/src/lib.rs

@@ -0,0 +1,19 @@
+//! Serde Serialization Framework
+//!
+//! Serde is a powerful framework that enables serialization libraries to generically serialize
+//! Rust data structures without the overhead of runtime type information. In many situations, the
+//! handshake protocol between serializers and serializees can be completely optimized away,
+//! leaving serde to perform roughly the same speed as a hand written serializer for a specific
+//! type.
+#![doc(html_root_url="http://erickt.github.io/rust-serde")]
+
+extern crate num;
+
+pub use ser::{Serialize, Serializer};
+pub use de::{Deserialize, Deserializer, Error};
+
+pub mod bytes;
+pub mod de;
+pub mod iter;
+pub mod json;
+pub mod ser;

serde/src/ser/impls.rs

@@ -0,0 +1,537 @@
+use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
+use std::hash::Hash;
+use std::path;
+use std::rc::Rc;
+use std::sync::Arc;
+
+use super::{
+    Serialize,
+    Serializer,
+    SeqVisitor,
+    MapVisitor,
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+macro_rules! impl_visit {
+    ($ty:ty, $method:ident) => {
+        impl Serialize for $ty {
+            #[inline]
+            fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+                where S: Serializer,
+            {
+                serializer.$method(*self)
+            }
+        }
+    }
+}
+
+impl_visit!(bool, visit_bool);
+impl_visit!(isize, visit_isize);
+impl_visit!(i8, visit_i8);
+impl_visit!(i16, visit_i16);
+impl_visit!(i32, visit_i32);
+impl_visit!(i64, visit_i64);
+impl_visit!(usize, visit_usize);
+impl_visit!(u8, visit_u8);
+impl_visit!(u16, visit_u16);
+impl_visit!(u32, visit_u32);
+impl_visit!(u64, visit_u64);
+impl_visit!(f32, visit_f32);
+impl_visit!(f64, visit_f64);
+impl_visit!(char, visit_char);
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl Serialize for str {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_str(self)
+    }
+}
+
+impl Serialize for String {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        (&self[..]).serialize(serializer)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<T> Serialize for Option<T> where T: Serialize {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        match *self {
+            Some(ref value) => serializer.visit_some(value),
+            None => serializer.visit_none(),
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct SeqIteratorVisitor<Iter> {
+    iter: Iter,
+    len: Option<usize>,
+}
+
+impl<T, Iter> SeqIteratorVisitor<Iter>
+    where Iter: Iterator<Item=T>
+{
+    #[inline]
+    pub fn new(iter: Iter, len: Option<usize>) -> SeqIteratorVisitor<Iter> {
+        SeqIteratorVisitor {
+            iter: iter,
+            len: len,
+        }
+    }
+}
+
+impl<T, Iter> SeqVisitor for SeqIteratorVisitor<Iter>
+    where T: Serialize,
+          Iter: Iterator<Item=T>,
+{
+    #[inline]
+    fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
+        where S: Serializer,
+    {
+        match self.iter.next() {
+            Some(value) => {
+                let value = try!(serializer.visit_seq_elt(value));
+                Ok(Some(value))
+            }
+            None => Ok(None),
+        }
+    }
+
+    #[inline]
+    fn len(&self) -> Option<usize> {
+        self.len
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<'a, T> Serialize for &'a [T]
+    where T: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_seq(SeqIteratorVisitor::new(self.iter(), Some(self.len())))
+    }
+}
+
+macro_rules! array_impls {
+    ($len:expr) => {
+        impl<T> Serialize for [T; $len] where T: Serialize {
+            #[inline]
+            fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+                where S: Serializer,
+            {
+                serializer.visit_seq(SeqIteratorVisitor::new(self.iter(), Some($len)))
+            }
+        }
+    }
+}
+
+array_impls!(0);
+array_impls!(1);
+array_impls!(2);
+array_impls!(3);
+array_impls!(4);
+array_impls!(5);
+array_impls!(6);
+array_impls!(7);
+array_impls!(8);
+array_impls!(9);
+array_impls!(10);
+array_impls!(11);
+array_impls!(12);
+array_impls!(13);
+array_impls!(14);
+array_impls!(15);
+array_impls!(16);
+array_impls!(17);
+array_impls!(18);
+array_impls!(19);
+array_impls!(20);
+array_impls!(21);
+array_impls!(22);
+array_impls!(23);
+array_impls!(24);
+array_impls!(25);
+array_impls!(26);
+array_impls!(27);
+array_impls!(28);
+array_impls!(29);
+array_impls!(30);
+array_impls!(31);
+array_impls!(32);
+
+impl<T> Serialize for Vec<T> where T: Serialize {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        (&self[..]).serialize(serializer)
+    }
+}
+
+impl<T> Serialize for BTreeSet<T>
+    where T: Serialize + Ord,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_seq(SeqIteratorVisitor::new(self.iter(), Some(self.len())))
+    }
+}
+
+impl<T> Serialize for HashSet<T>
+    where T: Serialize + Eq + Hash,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_seq(SeqIteratorVisitor::new(self.iter(), Some(self.len())))
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl Serialize for () {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_unit()
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+// FIXME(rust #19630) Remove this work-around
+macro_rules! e {
+    ($e:expr) => { $e }
+}
+
+macro_rules! tuple_impls {
+    ($(
+        $TupleVisitor:ident ($len:expr, $($T:ident),+) {
+            $($state:pat => $idx:tt,)+
+        }
+    )+) => {
+        $(
+            pub struct $TupleVisitor<'a, $($T: 'a),+> {
+                tuple: &'a ($($T,)+),
+                state: u8,
+            }
+
+            impl<'a, $($T: 'a),+> $TupleVisitor<'a, $($T),+> {
+                pub fn new(tuple: &'a ($($T,)+)) -> $TupleVisitor<'a, $($T),+> {
+                    $TupleVisitor {
+                        tuple: tuple,
+                        state: 0,
+                    }
+                }
+            }
+
+            impl<'a, $($T),+> SeqVisitor for $TupleVisitor<'a, $($T),+>
+                where $($T: Serialize),+
+            {
+                fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
+                    where S: Serializer,
+                {
+                    match self.state {
+                        $(
+                            $state => {
+                                self.state += 1;
+                                Ok(Some(try!(serializer.visit_seq_elt(&e!(self.tuple.$idx)))))
+                            }
+                        )+
+                        _ => {
+                            Ok(None)
+                        }
+                    }
+                }
+
+                fn len(&self) -> Option<usize> {
+                    Some($len)
+                }
+            }
+
+            impl<$($T),+> Serialize for ($($T,)+)
+                where $($T: Serialize),+
+            {
+                #[inline]
+                fn serialize<S: Serializer>(&self, serializer: &mut S) -> Result<(), S::Error> {
+                    serializer.visit_seq($TupleVisitor::new(self))
+                }
+            }
+        )+
+    }
+}
+
+tuple_impls! {
+    TupleVisitor1 (1, T0) {
+        0 => 0,
+    }
+    TupleVisitor2 (2, T0, T1) {
+        0 => 0,
+        1 => 1,
+    }
+    TupleVisitor3 (3, T0, T1, T2) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+    }
+    TupleVisitor4 (4, T0, T1, T2, T3) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+    }
+    TupleVisitor5 (5, T0, T1, T2, T3, T4) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+    }
+    TupleVisitor6 (6, T0, T1, T2, T3, T4, T5) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+        5 => 5,
+    }
+    TupleVisitor7 (7, T0, T1, T2, T3, T4, T5, T6) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+        5 => 5,
+        6 => 6,
+    }
+    TupleVisitor8 (8, T0, T1, T2, T3, T4, T5, T6, T7) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+        5 => 5,
+        6 => 6,
+        7 => 7,
+    }
+    TupleVisitor9 (9, T0, T1, T2, T3, T4, T5, T6, T7, T8) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+        5 => 5,
+        6 => 6,
+        7 => 7,
+        8 => 8,
+    }
+    TupleVisitor10 (10, T0, T1, T2, T3, T4, T5, T6, T7, T8, T9) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+        5 => 5,
+        6 => 6,
+        7 => 7,
+        8 => 8,
+        9 => 9,
+    }
+    TupleVisitor11 (11, T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+        5 => 5,
+        6 => 6,
+        7 => 7,
+        8 => 8,
+        9 => 9,
+        10 => 10,
+    }
+    TupleVisitor12 (12, T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11) {
+        0 => 0,
+        1 => 1,
+        2 => 2,
+        3 => 3,
+        4 => 4,
+        5 => 5,
+        6 => 6,
+        7 => 7,
+        8 => 8,
+        9 => 9,
+        10 => 10,
+        11 => 11,
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct MapIteratorVisitor<Iter> {
+    iter: Iter,
+    len: Option<usize>,
+}
+
+impl<K, V, Iter> MapIteratorVisitor<Iter>
+    where Iter: Iterator<Item=(K, V)>
+{
+    #[inline]
+    pub fn new(iter: Iter, len: Option<usize>) -> MapIteratorVisitor<Iter> {
+        MapIteratorVisitor {
+            iter: iter,
+            len: len,
+        }
+    }
+}
+
+impl<K, V, I> MapVisitor for MapIteratorVisitor<I>
+    where K: Serialize,
+          V: Serialize,
+          I: Iterator<Item=(K, V)>,
+{
+    #[inline]
+    fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
+        where S: Serializer,
+    {
+        match self.iter.next() {
+            Some((key, value)) => {
+                let value = try!(serializer.visit_map_elt(key, value));
+                Ok(Some(value))
+            }
+            None => Ok(None)
+        }
+    }
+
+    #[inline]
+    fn len(&self) -> Option<usize> {
+        self.len
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<K, V> Serialize for BTreeMap<K, V>
+    where K: Serialize + Ord,
+          V: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_map(MapIteratorVisitor::new(self.iter(), Some(self.len())))
+    }
+}
+
+impl<K, V> Serialize for HashMap<K, V>
+    where K: Serialize + Eq + Hash,
+          V: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_map(MapIteratorVisitor::new(self.iter(), Some(self.len())))
+    }
+}
+
+// FIXME: `VecMap` is unstable.
+/*
+impl<V> Serialize for VecMap<V>
+    where V: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        serializer.visit_map(MapIteratorVisitor::new(self.iter(), Some(self.len())))
+    }
+}
+*/
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<'a, T: ?Sized> Serialize for &'a T where T: Serialize {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        (**self).serialize(serializer)
+    }
+}
+
+impl<'a, T: ?Sized> Serialize for &'a mut T where T: Serialize {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        (**self).serialize(serializer)
+    }
+}
+
+impl<T: ?Sized> Serialize for Box<T> where T: Serialize {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        (**self).serialize(serializer)
+    }
+}
+
+impl<T> Serialize for Rc<T> where T: Serialize, {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        (**self).serialize(serializer)
+    }
+}
+
+impl<T> Serialize for Arc<T> where T: Serialize, {
+    #[inline]
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        (**self).serialize(serializer)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl Serialize for path::Path {
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        self.to_str().unwrap().serialize(serializer)
+    }
+}
+
+impl Serialize for path::PathBuf {
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer,
+    {
+        self.to_str().unwrap().serialize(serializer)
+    }
+}

serde/src/ser/mod.rs

@@ -0,0 +1,212 @@
+//! Generic serialization framework.
+
+pub mod impls;
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Serialize {
+    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        where S: Serializer;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Serializer {
+    type Error;
+
+    /// `visit_bool` serializes a `bool` value.
+    fn visit_bool(&mut self, v: bool) -> Result<(), Self::Error>;
+
+    /// `visit_isize` serializes a `isize` value. By default it casts the value to a `i64` and
+    /// passes it to the `visit_i64` method.
+    #[inline]
+    fn visit_isize(&mut self, v: isize) -> Result<(), Self::Error> {
+        self.visit_i64(v as i64)
+    }
+
+    /// `visit_i8` serializes a `i8` value. By default it casts the value to a `i64` and
+    /// passes it to the `visit_i64` method.
+    #[inline]
+    fn visit_i8(&mut self, v: i8) -> Result<(), Self::Error> {
+        self.visit_i64(v as i64)
+    }
+
+    /// `visit_i16` serializes a `i16` value. By default it casts the value to a `i64` and
+    /// passes it to the `visit_i64` method.
+    #[inline]
+    fn visit_i16(&mut self, v: i16) -> Result<(), Self::Error> {
+        self.visit_i64(v as i64)
+    }
+
+    /// `visit_i32` serializes a `i32` value. By default it casts the value to a `i64` and
+    /// passes it to the `visit_i64` method.
+    #[inline]
+    fn visit_i32(&mut self, v: i32) -> Result<(), Self::Error> {
+        self.visit_i64(v as i64)
+    }
+
+    /// `visit_i64` serializes a `i64` value.
+    #[inline]
+    fn visit_i64(&mut self, v: i64) -> Result<(), Self::Error>;
+
+    /// `visit_usize` serializes a `usize` value. By default it casts the value to a `u64` and
+    /// passes it to the `visit_u64` method.
+    #[inline]
+    fn visit_usize(&mut self, v: usize) -> Result<(), Self::Error> {
+        self.visit_u64(v as u64)
+    }
+
+    /// `visit_u8` serializes a `u8` value. By default it casts the value to a `u64` and passes
+    /// it to the `visit_u64` method.
+    #[inline]
+    fn visit_u8(&mut self, v: u8) -> Result<(), Self::Error> {
+        self.visit_u64(v as u64)
+    }
+
+    /// `visit_u32` serializes a `u32` value. By default it casts the value to a `u64` and passes
+    /// it to the `visit_u64` method.
+    #[inline]
+    fn visit_u16(&mut self, v: u16) -> Result<(), Self::Error> {
+        self.visit_u64(v as u64)
+    }
+
+    /// `visit_u32` serializes a `u32` value. By default it casts the value to a `u64` and passes
+    /// it to the `visit_u64` method.
+    #[inline]
+    fn visit_u32(&mut self, v: u32) -> Result<(), Self::Error> {
+        self.visit_u64(v as u64)
+    }
+
+    /// `visit_u64` serializes a `u64` value.
+    #[inline]
+    fn visit_u64(&mut self, v: u64) -> Result<(), Self::Error>;
+
+    /// `visit_f32` serializes a `f32` value. By default it casts the value to a `f64` and passes
+    /// it to the `visit_f64` method.
+    #[inline]
+    fn visit_f32(&mut self, v: f32) -> Result<(), Self::Error> {
+        self.visit_f64(v as f64)
+    }
+
+    /// `visit_f64` serializes a `f64` value.
+    fn visit_f64(&mut self, v: f64) -> Result<(), Self::Error>;
+
+    /// `visit_char` serializes a character. By default it serializes it as a `&str` containing a
+    /// single character.
+    #[inline]
+    fn visit_char(&mut self, v: char) -> Result<(), Self::Error> {
+        // FIXME: this allocation is required in order to be compatible with stable rust, which
+        // doesn't support encoding a `char` into a stack buffer.
+        self.visit_str(&v.to_string())
+    }
+
+    /// `visit_str` serializes a `&str`.
+    fn visit_str(&mut self, value: &str) -> Result<(), Self::Error>;
+
+    /// `visit_bytes` is a hook that enables those serialization formats that support serializing
+    /// byte slices separately from generic arrays. By default it serializes as a regular array.
+    #[inline]
+    fn visit_bytes(&mut self, value: &[u8]) -> Result<(), Self::Error> {
+        self.visit_seq(impls::SeqIteratorVisitor::new(value.iter(), Some(value.len())))
+    }
+
+    fn visit_unit(&mut self) -> Result<(), Self::Error>;
+
+    #[inline]
+    fn visit_named_unit(&mut self, _name: &str) -> Result<(), Self::Error> {
+        self.visit_unit()
+    }
+
+    #[inline]
+    fn visit_enum_unit(&mut self,
+                       _name: &str,
+                       _variant: &str) -> Result<(), Self::Error> {
+        self.visit_unit()
+    }
+
+    fn visit_none(&mut self) -> Result<(), Self::Error>;
+
+    fn visit_some<V>(&mut self, value: V) -> Result<(), Self::Error>
+        where V: Serialize;
+
+    fn visit_seq<V>(&mut self, visitor: V) -> Result<(), Self::Error>
+        where V: SeqVisitor;
+
+    #[inline]
+    fn visit_named_seq<V>(&mut self,
+                          _name: &'static str,
+                          visitor: V) -> Result<(), Self::Error>
+        where V: SeqVisitor,
+    {
+        self.visit_seq(visitor)
+    }
+
+    #[inline]
+    fn visit_enum_seq<V>(&mut self,
+                         _name: &'static str,
+                         _variant: &'static str,
+                         visitor: V) -> Result<(), Self::Error>
+        where V: SeqVisitor,
+    {
+        self.visit_seq(visitor)
+    }
+
+    fn visit_seq_elt<T>(&mut self, value: T) -> Result<(), Self::Error>
+        where T: Serialize;
+
+    fn visit_map<V>(&mut self, visitor: V) -> Result<(), Self::Error>
+        where V: MapVisitor;
+
+    #[inline]
+    fn visit_named_map<V>(&mut self,
+                          _name: &'static str,
+                          visitor: V) -> Result<(), Self::Error>
+        where V: MapVisitor,
+    {
+        self.visit_map(visitor)
+    }
+
+    #[inline]
+    fn visit_enum_map<V>(&mut self,
+                          _name: &'static str,
+                          _variant: &'static str,
+                          visitor: V) -> Result<(), Self::Error>
+        where V: MapVisitor,
+    {
+        self.visit_map(visitor)
+    }
+
+    fn visit_map_elt<K, V>(&mut self, key: K, value: V) -> Result<(), Self::Error>
+        where K: Serialize,
+              V: Serialize;
+
+    /// Specify a format string for the serializer.
+    ///
+    /// The serializer format is used to determine which format
+    /// specific field attributes should be used with the serializer.
+    fn format() -> &'static str {
+        ""
+    }
+}
+
+pub trait SeqVisitor {
+    fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
+        where S: Serializer;
+
+    /// Return the length of the sequence if known.
+    #[inline]
+    fn len(&self) -> Option<usize> {
+        None
+    }
+}
+
+pub trait MapVisitor {
+    fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
+        where S: Serializer;
+
+    /// Return the length of the map if known.
+    #[inline]
+    fn len(&self) -> Option<usize> {
+        None
+    }
+}