diff --git a/serde2/src/bin.rs b/serde2/src/bin.rs
index 3c0f6464..d9543dec 100644
--- a/serde2/src/bin.rs
+++ b/serde2/src/bin.rs
@@ -14,7 +14,7 @@ struct Foo {
 
 impl<S: serde2::VisitorState<R>, R> serde2::Serialize<S, R> for Foo {
     fn serialize(&self, state: &mut S) -> R {
-        state.serialize_struct("Foo", FooSerialize {
+        state.visit_struct("Foo", FooSerialize {
             value: self,
             state: 0,
         })
@@ -31,15 +31,15 @@ impl<'a, S: serde2::VisitorState<R>, R> serde2::Visitor<S, R> for FooSerialize<'
         match self.state {
             0 => {
                 self.state += 1;
-                Some(state.serialize_map_elt(true, "x", &self.value.x))
+                Some(state.visit_map_elt(true, "x", &self.value.x))
             }
             1 => {
                 self.state += 1;
-                Some(state.serialize_map_elt(false, "y", &self.value.y))
+                Some(state.visit_map_elt(false, "y", &self.value.y))
             }
             2 => {
                 self.state += 1;
-                Some(state.serialize_map_elt(false, "z", &self.value.z))
+                Some(state.visit_map_elt(false, "z", &self.value.z))
             }
             _ => {
                 None
diff --git a/serde2/src/json/mod.rs b/serde2/src/json/mod.rs
new file mode 100644
index 00000000..60bd0789
--- /dev/null
+++ b/serde2/src/json/mod.rs
@@ -0,0 +1,3 @@
+pub use ser::Serializer;
+
+pub mod ser;
diff --git a/serde2/src/json/ser.rs b/serde2/src/json/ser.rs
new file mode 100644
index 00000000..790924b0
--- /dev/null
+++ b/serde2/src/json/ser.rs
@@ -0,0 +1,208 @@
+use std::io;
+use std::num::{FPNaN, FPInfinite};
+use std::f64;
+
+use super::super::ser as ser;
+
+/// A structure for implementing serialization to JSON.
+pub struct Serializer<W> {
+    writer: W,
+}
+
+impl<W: Writer> Serializer<W> {
+    /// Creates a new JSON serializer whose output will be written to the writer
+    /// specified.
+    pub fn new(writer: W) -> Serializer<W> {
+        Serializer {
+            writer: writer,
+        }
+    }
+
+    /// Unwrap the Writer from the Serializer.
+    pub fn unwrap(self) -> W {
+        self.writer
+    }
+}
+
+impl<W: Writer> ser::VisitorState<io::IoResult<()>> for Serializer<W> {
+    #[inline]
+    fn visit_null(&mut self) -> io::IoResult<()> {
+        self.writer.write_str("null")
+    }
+
+    #[inline]
+    fn visit_bool(&mut self, value: bool) -> io::IoResult<()> {
+        if value {
+            self.writer.write_str("true")
+        } else {
+            self.writer.write_str("false")
+        }
+    }
+
+    #[inline]
+    fn visit_i64(&mut self, value: i64) -> io::IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_u64(&mut self, value: u64) -> io::IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    #[inline]
+    fn visit_f64(&mut self, value: f64) -> io::IoResult<()> {
+        fmt_f64_or_null(&mut self.writer, value)
+    }
+
+    #[inline]
+    fn visit_char(&mut self, v: char) -> io::IoResult<()> {
+        escape_char(&mut self.writer, v)
+    }
+
+    #[inline]
+    fn visit_str(&mut self, value: &'static str) -> io::IoResult<()> {
+        escape_str(&mut self.writer, value)
+    }
+
+    fn visit_seq<
+        T: ser::Serialize<Serializer<W>, io::IoResult<()>>,
+        Iter: Iterator<T>
+    >(&mut self, mut iter: Iter) -> io::IoResult<()> {
+        try!(write!(self.writer, "["));
+        let mut first = true;
+        for elt in iter {
+            try!(self.visit_seq_elt(first, elt));
+            first = false;
+
+        }
+        write!(self.writer, "]")
+    }
+
+    fn visit_seq_elt<
+        T: ser::Serialize<Serializer<W>, io::IoResult<()>>
+    >(&mut self, first: bool, value: T) -> io::IoResult<()> {
+        if !first {
+            try!(write!(self.writer, ", "));
+        }
+
+        value.serialize(self)
+    }
+
+    fn visit_tuple<
+        V: ser::Visitor<Serializer<W>, io::IoResult<()>>
+    >(&mut self, mut visitor: V) -> io::IoResult<()> {
+        try!(write!(self.writer, "["));
+        loop {
+            match visitor.visit(self) {
+                Some(Ok(())) => { }
+                Some(Err(err)) => { return Err(err); }
+                None => { break; }
+            }
+        }
+        write!(self.writer, "]")
+    }
+
+    fn visit_tuple_struct<
+        V: ser::Visitor<Serializer<W>, io::IoResult<()>>
+    >(&mut self, _name: &'static str, visitor: V) -> io::IoResult<()> {
+        self.visit_tuple(visitor)
+    }
+
+
+    fn visit_enum<
+        V: ser::Visitor<Serializer<W>, io::IoResult<()>>
+    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> io::IoResult<()> {
+        self.visit_tuple(visitor)
+    }
+
+    fn visit_map<
+        K: ser::Serialize<Serializer<W>, io::IoResult<()>>,
+        V: ser::Serialize<Serializer<W>, io::IoResult<()>>,
+        Iter: Iterator<(K, V)>
+    >(&mut self, mut iter: Iter) -> io::IoResult<()> {
+        try!(write!(self.writer, "{{"));
+        let mut first = true;
+        for (key, value) in iter {
+            try!(self.visit_map_elt(first, &key, &value))
+            first = false;
+        }
+        write!(self.writer, "}}")
+    }
+
+    fn visit_map_elt<
+        K: ser::Serialize<Serializer<W>, io::IoResult<()>>,
+        V: ser::Serialize<Serializer<W>, io::IoResult<()>>
+    >(&mut self, first: bool, key: K, value: V) -> io::IoResult<()> {
+        if !first {
+            try!(write!(self.writer, ", "));
+        }
+
+        try!(key.serialize(self));
+        try!(write!(self.writer, ": "));
+        value.serialize(self)
+    }
+
+    fn visit_struct<
+        V: ser::Visitor<Serializer<W>, io::IoResult<()>>
+    >(&mut self, _name: &'static str, mut visitor: V) -> io::IoResult<()> {
+        try!(write!(self.writer, "{{"));
+        loop {
+            match visitor.visit(self) {
+                Some(Ok(())) => { }
+                Some(Err(err)) => { return Err(err); }
+                None => { break; }
+            }
+        }
+        write!(self.writer, "}}")
+    }
+}
+
+pub fn escape_bytes<W: Writer>(wr: &mut W, bytes: &[u8]) -> io::IoResult<()> {
+    try!(wr.write_str("\""));
+
+    let mut start = 0;
+
+    for (i, byte) in bytes.iter().enumerate() {
+        let escaped = match *byte {
+            b'"' => "\\\"",
+            b'\\' => "\\\\",
+            b'\x08' => "\\b",
+            b'\x0c' => "\\f",
+            b'\n' => "\\n",
+            b'\r' => "\\r",
+            b'\t' => "\\t",
+            _ => { continue; }
+        };
+
+        if start < i {
+            try!(wr.write(bytes.slice(start, i)));
+        }
+
+        try!(wr.write_str(escaped));
+
+        start = i + 1;
+    }
+
+    if start != bytes.len() {
+        try!(wr.write(bytes.slice_from(start)));
+    }
+
+    wr.write_str("\"")
+}
+
+pub fn escape_str<W: Writer>(wr: &mut W, value: &str) -> io::IoResult<()> {
+    escape_bytes(wr, value.as_bytes())
+}
+
+pub fn escape_char<W: Writer>(wr: &mut W, value: char) -> io::IoResult<()> {
+    let mut buf = [0, .. 4];
+    value.encode_utf8(buf);
+    escape_bytes(wr, buf)
+}
+
+fn fmt_f64_or_null<W: Writer>(wr: &mut W, value: f64) -> io::IoResult<()> {
+    match value.classify() {
+        FPNaN | FPInfinite => wr.write_str("null"),
+        _ => wr.write_str(f64::to_str_digits(value, 6).as_slice()),
+    }
+}
diff --git a/serde2/src/json/value.rs b/serde2/src/json/value.rs
new file mode 100644
index 00000000..83c214f5
--- /dev/null
+++ b/serde2/src/json/value.rs
@@ -0,0 +1,122 @@
+#[deriving(PartialEq)]
+pub enum Json {
+    Integer(int),
+    String(String),
+    Array(Vec<Json>),
+    Object(TreeMap<String, Json>),
+}
+
+pub struct JsonSerializer {
+    key: Option<String>
+}
+
+impl JsonSerializer {
+    pub fn new() -> JsonSerializer {
+        JsonSerializer {
+            key: None
+        }
+    }
+}
+
+impl VisitorState<Json> for JsonSerializer {
+    fn visit_int(&mut self, value: int) -> Json {
+        Integer(value)
+    }
+
+    fn visit_str(&mut self, value: &'static str) -> Json {
+        String(value.to_string())
+    }
+
+    fn visit_seq<
+        T: Serialize<JsonSerializer, Json>,
+        Iter: Iterator<T>
+    >(&mut self, mut iter: Iter) -> Json {
+        let (len, _) = iter.size_hint();
+        let mut v = Vec::with_capacity(len);
+
+        let mut first = true;
+        for elt in iter {
+            v.push(self.visit_seq_elt(first, elt));
+            first = false;
+        }
+
+        Array(v)
+    }
+
+    fn visit_seq_elt<
+        T: Serialize<JsonSerializer, Json>
+    >(&mut self, _first: bool, value: T) -> Json {
+        value.serialize(self)
+    }
+
+    fn visit_tuple<
+        V: Visitor<JsonSerializer, Json>
+    >(&mut self, mut visitor: V) -> Json {
+        let (len, _) = visitor.size_hint();
+        let mut v = Vec::with_capacity(len);
+
+        loop {
+            match visitor.visit(self) {
+                Some(value) => { v.push(value); }
+                None => { break; }
+            }
+        }
+
+        Array(v)
+    }
+
+    fn visit_tuple_struct<
+        V: Visitor<JsonSerializer, Json>
+    >(&mut self, _name: &'static str, visitor: V) -> Json {
+        self.visit_tuple(visitor)
+    }
+
+    fn visit_enum<
+        V: Visitor<JsonSerializer, Json>
+    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> Json {
+        self.visit_tuple(visitor)
+    }
+
+    fn visit_map<
+        K: Serialize<JsonSerializer, Json>,
+        V: Serialize<JsonSerializer, Json>,
+        Iter: Iterator<(K, V)>
+    >(&mut self, mut iter: Iter) -> Json {
+        let mut v = TreeMap::new();
+        let mut first = true;
+
+        for (key, value) in iter {
+            let value = self.visit_map_elt(first, key, value);
+            v.insert(self.key.take().unwrap(), value);
+            first = false;
+        }
+
+        Object(v)
+    }
+
+    fn visit_map_elt<
+        K: Serialize<JsonSerializer, Json>,
+        V: Serialize<JsonSerializer, Json>
+    >(&mut self, _first: bool, key: K, value: V) -> Json {
+        match key.serialize(self) {
+            String(key) => { self.key = Some(key); }
+            _ => { fail!() }
+        }
+        value.serialize(self)
+    }
+
+    fn visit_struct<
+        V: Visitor<JsonSerializer, Json>
+    >(&mut self, _name: &'static str, mut visitor: V) -> Json {
+        let mut v = TreeMap::new();
+
+        loop {
+            match visitor.visit(self) {
+                Some(value) => { v.insert(self.key.take().unwrap(), value); }
+                None => { break; }
+            }
+        }
+
+        Object(v)
+    }
+}
diff --git a/serde2/src/lib.rs b/serde2/src/lib.rs
index 51a1f917..3cbe1060 100644
--- a/serde2/src/lib.rs
+++ b/serde2/src/lib.rs
@@ -1,560 +1,7 @@
-use std::io::IoResult;
-use std::io;
-use std::collections::TreeMap;
+pub use ser::{Serialize, Serializer};
+pub use ser::{Visitor, VisitorState};
+pub use ser::FormatState;
+pub use ser::GatherTokens;
 
-///////////////////////////////////////////////////////////////////////////////
-
-pub trait Serialize<S, R> {
-    fn serialize(&self, state: &mut S) -> R;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-pub trait Serializer<S, R> {
-    fn hash<T: Serialize<S, R>>(&self, value: &T) -> R;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-pub trait Visitor<S, R> {
-    fn visit(&mut self, state: &mut S) -> Option<R>;
-
-    fn size_hint(&self) -> (uint, Option<uint>) {
-        (0, None)
-    }
-}
-
-pub trait VisitorState<R> {
-    fn serialize_int(&mut self, value: int) -> R;
-
-    fn serialize_str(&mut self, value: &'static str) -> R;
-
-    fn serialize_seq<
-        T: Serialize<Self, R>,
-        Iter: Iterator<T>
-    >(&mut self, iter: Iter) -> R;
-
-    fn serialize_seq_elt<
-        T: Serialize<Self, R>
-    >(&mut self, first: bool, value: T) -> R;
-
-    fn serialize_tuple<
-        V: Visitor<Self, R>
-    >(&mut self, visitor: V) -> R;
-
-    fn serialize_tuple_struct<
-        V: Visitor<Self, R>
-    >(&mut self, name: &'static str, mut visitor: V) -> R;
-
-    fn serialize_enum<
-        V: Visitor<Self, R>
-    >(&mut self, name: &'static str, variant: &'static str, visitor: V) -> R;
-
-    fn serialize_map<
-        K: Serialize<Self, R>,
-        V: Serialize<Self, R>,
-        Iter: Iterator<(K, V)>
-    >(&mut self, iter: Iter) -> R;
-
-    fn serialize_map_elt<
-        K: Serialize<Self, R>,
-        V: Serialize<Self, R>
-    >(&mut self, first: bool, key: K, value: V) -> R;
-
-    fn serialize_struct<
-        V: Visitor<Self, R>
-    >(&mut self, name: &'static str, visitor: V) -> R;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-impl<S: VisitorState<R>, R> Serialize<S, R> for int {
-    fn serialize(&self, state: &mut S) -> R {
-        state.serialize_int(*self)
-    }
-}
-
-impl<S: VisitorState<R>, R> Serialize<S, R> for &'static str {
-    fn serialize(&self, state: &mut S) -> R {
-        state.serialize_str(*self)
-    }
-}
-
-impl<
-    S: VisitorState<R>,
-    R,
-    T: Serialize<S, R>
-> Serialize<S, R> for Vec<T> {
-    fn serialize(&self, state: &mut S) -> R {
-        state.serialize_seq(self.iter())
-    }
-}
-
-impl<
-    S: VisitorState<R>,
-    R,
-    K: Serialize<S, R> + Ord,
-    V: Serialize<S, R>
-> Serialize<S, R> for TreeMap<K, V> {
-    fn serialize(&self, state: &mut S) -> R {
-        state.serialize_map(self.iter())
-    }
-}
-
-impl<
-    'a,
-    S: VisitorState<R>,
-    R,
-    T0: Serialize<S, R>,
-    T1: Serialize<S, R>
-> Serialize<S, R> for (T0, T1) {
-    fn serialize(&self, state: &mut S) -> R {
-        state.serialize_tuple(Tuple2Serialize { value: self, state: 0 })
-    }
-}
-
-struct Tuple2Serialize<'a, T0, T1> {
-    value: &'a (T0, T1),
-    state: uint,
-}
-
-impl<
-    'a,
-    S: VisitorState<R>,
-    R,
-    T0: Serialize<S, R>,
-    T1: Serialize<S, R>
-> Visitor<S, R> for Tuple2Serialize<'a, T0, T1> {
-    fn visit(&mut self, state: &mut S) -> Option<R> {
-        match self.state {
-            0 => {
-                self.state += 1;
-                let (ref value, _) = *self.value;
-                Some(state.serialize_seq_elt(true, value))
-            }
-            1 => {
-                self.state += 1;
-                let (_, ref value) = *self.value;
-                Some(state.serialize_seq_elt(false, value))
-            }
-            _ => {
-                None
-            }
-        }
-    }
-
-    fn size_hint(&self) -> (uint, Option<uint>) {
-        let size = 2 - self.state;
-        (size, Some(size))
-    }
-}
-
-impl<
-    'a,
-    S: VisitorState<R>,
-    R,
-    T: Serialize<S, R>
-> Serialize<S, R> for &'a T {
-    fn serialize(&self, state: &mut S) -> R {
-        (**self).serialize(state)
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-#[deriving(Show)]
-pub enum Token {
-    Int(int),
-    Str(&'static str),
-    SeqStart(uint),
-    MapStart(uint),
-    StructStart(&'static str, uint),
-    End,
-}
-
-pub trait TokenState<R>: VisitorState<R> {
-    fn serialize(&mut self, token: Token) -> R;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-pub struct GatherTokens {
-    tokens: Vec<Token>,
-}
-
-impl GatherTokens {
-    pub fn new() -> GatherTokens {
-        GatherTokens {
-            tokens: Vec::new(),
-        }
-    }
-
-    pub fn unwrap(self) -> Vec<Token> {
-        self.tokens
-    }
-}
-
-impl TokenState<()> for GatherTokens {
-    fn serialize(&mut self, token: Token) -> () {
-        self.tokens.push(token);
-    }
-}
-
-impl VisitorState<()> for GatherTokens {
-    fn serialize_int(&mut self, value: int) -> () {
-        self.serialize(Int(value))
-    }
-
-    fn serialize_str(&mut self, value: &'static str) -> () {
-        self.serialize(Str(value))
-    }
-
-    fn serialize_seq<
-        T: Serialize<GatherTokens, ()>,
-        Iter: Iterator<T>
-    >(&mut self, mut iter: Iter) -> () {
-        let (len, _) = iter.size_hint();
-        self.serialize(SeqStart(len));
-        let mut first = false;
-        for elt in iter {
-            self.serialize_seq_elt(first, elt);
-
-            if first {
-                first = false;
-            }
-        }
-        self.serialize(End)
-    }
-
-    fn serialize_seq_elt<
-        T: Serialize<GatherTokens, ()>
-    >(&mut self, _first: bool, value: T) -> () {
-        value.serialize(self);
-    }
-
-    fn serialize_tuple<
-        V: Visitor<GatherTokens, ()>
-    >(&mut self, mut visitor: V) -> () {
-        let (len, _) = visitor.size_hint();
-        self.tokens.push(SeqStart(len));
-        loop {
-            match visitor.visit(self) {
-                Some(()) => { }
-                None => { break; }
-            }
-        }
-        self.tokens.push(End)
-    }
-
-    fn serialize_tuple_struct<
-        V: Visitor<GatherTokens, ()>
-    >(&mut self, _name: &'static str, visitor: V) -> () {
-        self.serialize_tuple(visitor)
-    }
-
-    fn serialize_enum<
-        V: Visitor<GatherTokens, ()>
-    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> () {
-        self.serialize_tuple(visitor)
-    }
-
-    fn serialize_map<
-        K: Serialize<GatherTokens, ()>,
-        V: Serialize<GatherTokens, ()>,
-        Iter: Iterator<(K, V)>
-    >(&mut self, mut iter: Iter) -> () {
-        let (len, _) = iter.size_hint();
-        self.serialize(MapStart(len));
-        let mut first = true;
-        for (key, value) in iter {
-            self.serialize_map_elt(first, key, value);
-            first = false;
-        }
-        self.serialize(End)
-    }
-
-    fn serialize_map_elt<
-        K: Serialize<GatherTokens, ()>,
-        V: Serialize<GatherTokens, ()>
-    >(&mut self, _first: bool, key: K, value: V) -> () {
-        key.serialize(self);
-        value.serialize(self);
-    }
-
-    fn serialize_struct<
-        V: Visitor<GatherTokens, ()>
-    >(&mut self, name: &'static str, mut visitor: V) -> () {
-        let (len, _) = visitor.size_hint();
-        self.serialize(StructStart(name, len));
-        loop {
-            match visitor.visit(self) {
-                Some(()) => { }
-                None => { break; }
-            }
-        }
-        self.serialize(End)
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-pub struct FormatState<W: Writer> {
-    writer: W,
-}
-
-impl<W: Writer> FormatState<W> {
-    pub fn new(writer: W) -> FormatState<W> {
-        FormatState {
-            writer: writer,
-        }
-    }
-
-    pub fn unwrap(self) -> W {
-        self.writer
-    }
-}
-
-impl<W: Writer> VisitorState<IoResult<()>> for FormatState<W> {
-    fn serialize_int(&mut self, value: int) -> IoResult<()> {
-        write!(self.writer, "{}", value)
-    }
-
-    fn serialize_str(&mut self, value: &'static str) -> IoResult<()> {
-        write!(self.writer, "{}", value)
-    }
-
-    fn serialize_seq<
-        T: Serialize<FormatState<W>, IoResult<()>>,
-        Iter: Iterator<T>
-    >(&mut self, mut iter: Iter) -> IoResult<()> {
-        try!(write!(self.writer, "["));
-        let mut first = true;
-        for elt in iter {
-            try!(self.serialize_seq_elt(first, elt));
-            first = false;
-
-        }
-        write!(self.writer, "]")
-    }
-
-    fn serialize_seq_elt<
-        T: Serialize<FormatState<W>, IoResult<()>>
-    >(&mut self, first: bool, value: T) -> IoResult<()> {
-        if !first {
-            try!(write!(self.writer, ", "));
-        }
-
-        value.serialize(self)
-    }
-
-    fn serialize_tuple<
-        V: Visitor<FormatState<W>, IoResult<()>>
-    >(&mut self, mut visitor: V) -> IoResult<()> {
-        try!(write!(self.writer, "["));
-        loop {
-            match visitor.visit(self) {
-                Some(Ok(())) => { }
-                Some(Err(err)) => { return Err(err); }
-                None => { break; }
-            }
-        }
-        write!(self.writer, "]")
-    }
-
-    fn serialize_tuple_struct<
-        V: Visitor<FormatState<W>, IoResult<()>>
-    >(&mut self, _name: &'static str, visitor: V) -> IoResult<()> {
-        self.serialize_tuple(visitor)
-    }
-
-
-    fn serialize_enum<
-        V: Visitor<FormatState<W>, IoResult<()>>
-    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> IoResult<()> {
-        self.serialize_tuple(visitor)
-    }
-
-    fn serialize_map<
-        K: Serialize<FormatState<W>, IoResult<()>>,
-        V: Serialize<FormatState<W>, IoResult<()>>,
-        Iter: Iterator<(K, V)>
-    >(&mut self, mut iter: Iter) -> IoResult<()> {
-        try!(write!(self.writer, "{{"));
-        let mut first = true;
-        for (key, value) in iter {
-            try!(self.serialize_map_elt(first, &key, &value))
-            first = false;
-        }
-        write!(self.writer, "}}")
-    }
-
-    fn serialize_map_elt<
-        K: Serialize<FormatState<W>, IoResult<()>>,
-        V: Serialize<FormatState<W>, IoResult<()>>
-    >(&mut self, first: bool, key: K, value: V) -> IoResult<()> {
-        if !first {
-            try!(write!(self.writer, ", "));
-        }
-
-        try!(key.serialize(self));
-        try!(write!(self.writer, ": "));
-        value.serialize(self)
-    }
-
-    fn serialize_struct<
-        V: Visitor<FormatState<W>, IoResult<()>>
-    >(&mut self, _name: &'static str, mut visitor: V) -> IoResult<()> {
-        try!(write!(self.writer, "{{"));
-        loop {
-            match visitor.visit(self) {
-                Some(Ok(())) => { }
-                Some(Err(err)) => { return Err(err); }
-                None => { break; }
-            }
-        }
-        write!(self.writer, "}}")
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-#[deriving(PartialEq)]
-pub enum Json {
-    Integer(int),
-    String(String),
-    Array(Vec<Json>),
-    Object(TreeMap<String, Json>),
-}
-
-pub struct JsonSerializer {
-    key: Option<String>
-}
-
-impl JsonSerializer {
-    pub fn new() -> JsonSerializer {
-        JsonSerializer {
-            key: None
-        }
-    }
-}
-
-impl VisitorState<Json> for JsonSerializer {
-    fn serialize_int(&mut self, value: int) -> Json {
-        Integer(value)
-    }
-
-    fn serialize_str(&mut self, value: &'static str) -> Json {
-        String(value.to_string())
-    }
-
-    fn serialize_seq<
-        T: Serialize<JsonSerializer, Json>,
-        Iter: Iterator<T>
-    >(&mut self, mut iter: Iter) -> Json {
-        let (len, _) = iter.size_hint();
-        let mut v = Vec::with_capacity(len);
-
-        let mut first = true;
-        for elt in iter {
-            v.push(self.serialize_seq_elt(first, elt));
-            first = false;
-        }
-
-        Array(v)
-    }
-
-    fn serialize_seq_elt<
-        T: Serialize<JsonSerializer, Json>
-    >(&mut self, _first: bool, value: T) -> Json {
-        value.serialize(self)
-    }
-
-    fn serialize_tuple<
-        V: Visitor<JsonSerializer, Json>
-    >(&mut self, mut visitor: V) -> Json {
-        let (len, _) = visitor.size_hint();
-        let mut v = Vec::with_capacity(len);
-
-        loop {
-            match visitor.visit(self) {
-                Some(value) => { v.push(value); }
-                None => { break; }
-            }
-        }
-
-        Array(v)
-    }
-
-    fn serialize_tuple_struct<
-        V: Visitor<JsonSerializer, Json>
-    >(&mut self, _name: &'static str, visitor: V) -> Json {
-        self.serialize_tuple(visitor)
-    }
-
-    fn serialize_enum<
-        V: Visitor<JsonSerializer, Json>
-    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> Json {
-        self.serialize_tuple(visitor)
-    }
-
-    fn serialize_map<
-        K: Serialize<JsonSerializer, Json>,
-        V: Serialize<JsonSerializer, Json>,
-        Iter: Iterator<(K, V)>
-    >(&mut self, mut iter: Iter) -> Json {
-        let mut v = TreeMap::new();
-        let mut first = true;
-
-        for (key, value) in iter {
-            let value = self.serialize_map_elt(first, key, value);
-            v.insert(self.key.take().unwrap(), value);
-            first = false;
-        }
-
-        Object(v)
-    }
-
-    fn serialize_map_elt<
-        K: Serialize<JsonSerializer, Json>,
-        V: Serialize<JsonSerializer, Json>
-    >(&mut self, _first: bool, key: K, value: V) -> Json {
-        match key.serialize(self) {
-            String(key) => { self.key = Some(key); }
-            _ => { fail!() }
-        }
-        value.serialize(self)
-    }
-
-    fn serialize_struct<
-        V: Visitor<JsonSerializer, Json>
-    >(&mut self, _name: &'static str, mut visitor: V) -> Json {
-        let mut v = TreeMap::new();
-
-        loop {
-            match visitor.visit(self) {
-                Some(value) => { v.insert(self.key.take().unwrap(), value); }
-                None => { break; }
-            }
-        }
-
-        Object(v)
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-pub fn to_format_vec<
-    T: Serialize<FormatState<io::MemWriter>, IoResult<()>>
->(value: &T) -> IoResult<Vec<u8>> {
-    let writer = io::MemWriter::new();
-    let mut state = FormatState::new(writer);
-    try!(value.serialize(&mut state));
-    Ok(state.unwrap().unwrap())
-}
-
-pub fn to_format_string<
-    T: Serialize<FormatState<io::MemWriter>, IoResult<()>>
->(value: &T) -> IoResult<Result<String, Vec<u8>>> {
-    let vec = try!(to_format_vec(value));
-    Ok(String::from_utf8(vec))
-}
+pub mod ser;
+//pub mod json;
diff --git a/serde2/src/ser.rs b/serde2/src/ser.rs
new file mode 100644
index 00000000..575e3686
--- /dev/null
+++ b/serde2/src/ser.rs
@@ -0,0 +1,490 @@
+use std::io::IoResult;
+use std::io;
+use std::collections::TreeMap;
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Serialize<S, R> {
+    fn serialize(&self, state: &mut S) -> R;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Serializer<S, R> {
+    fn hash<T: Serialize<S, R>>(&self, value: &T) -> R;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub trait Visitor<S, R> {
+    fn visit(&mut self, state: &mut S) -> Option<R>;
+
+    fn size_hint(&self) -> (uint, Option<uint>) {
+        (0, None)
+    }
+}
+
+pub trait VisitorState<R> {
+    fn visit_null(&mut self) -> R;
+
+    fn visit_bool(&mut self, v: bool) -> R;
+
+    #[inline]
+    fn visit_int(&mut self, v: int) -> R {
+        self.visit_i64(v as i64)
+    }
+
+    #[inline]
+    fn visit_i8(&mut self, v: i8) -> R {
+        self.visit_i64(v as i64)
+    }
+
+    #[inline]
+    fn visit_i16(&mut self, v: i16) -> R {
+        self.visit_i64(v as i64)
+    }
+
+    #[inline]
+    fn visit_i32(&mut self, v: i32) -> R {
+        self.visit_i64(v as i64)
+    }
+
+    #[inline]
+    fn visit_i64(&mut self, v: i64) -> R;
+
+    #[inline]
+    fn visit_uint(&mut self, v: uint) -> R {
+        self.visit_u64(v as u64)
+    }
+
+    #[inline]
+    fn visit_u8(&mut self, v: u8) -> R {
+        self.visit_u64(v as u64)
+    }
+
+    #[inline]
+    fn visit_u16(&mut self, v: u16) -> R {
+        self.visit_u64(v as u64)
+    }
+
+    #[inline]
+    fn visit_u32(&mut self, v: u32) -> R {
+        self.visit_u64(v as u64)
+    }
+
+    #[inline]
+    fn visit_u64(&mut self, v: u64) -> R;
+
+    #[inline]
+    fn visit_f32(&mut self, v: f32) -> R {
+        self.visit_f64(v as f64)
+    }
+
+    fn visit_f64(&mut self, v: f64) -> R;
+
+    fn visit_char(&mut self, value: char) -> R;
+
+    fn visit_str(&mut self, value: &'static str) -> R;
+
+    fn visit_seq<
+        V: Visitor<Self, R>
+    >(&mut self, visitor: V) -> R;
+
+    fn visit_named_seq<
+        V: Visitor<Self, R>
+    >(&mut self, _name: &'static str, visitor: V) -> R {
+        self.visit_seq(visitor)
+    }
+
+    fn visit_enum<
+        V: Visitor<Self, R>
+    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> R {
+        self.visit_seq(visitor)
+    }
+
+    fn visit_seq_elt<
+        T: Serialize<Self, R>
+    >(&mut self, value: T) -> R;
+
+    fn visit_map<
+        V: Visitor<Self, R>
+    >(&mut self, visitor: V) -> R;
+
+    fn visit_named_map<
+        V: Visitor<Self, R>
+    >(&mut self, _name: &'static str, visitor: V) -> R {
+        self.visit_map(visitor)
+    }
+
+    fn visit_map_elt<
+        K: Serialize<Self, R>,
+        V: Serialize<Self, R>
+    >(&mut self, key: K, value: V) -> R;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<S: VisitorState<R>, R> Serialize<S, R> for int {
+    fn serialize(&self, state: &mut S) -> R {
+        state.visit_int(*self)
+    }
+}
+
+impl<S: VisitorState<R>, R> Serialize<S, R> for &'static str {
+    fn serialize(&self, state: &mut S) -> R {
+        state.visit_str(*self)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct IteratorVisitor<Iter> {
+    iter: Iter,
+}
+
+impl<T, Iter: Iterator<T>> IteratorVisitor<Iter> {
+    pub fn new(iter: Iter) -> IteratorVisitor<Iter> {
+        IteratorVisitor {
+            iter: iter,
+        }
+    }
+}
+
+impl<
+    T: Serialize<S, R>,
+    Iter: Iterator<T>,
+    S: VisitorState<R>,
+    R
+> Visitor<S, R> for IteratorVisitor<Iter> {
+    fn visit(&mut self, state: &mut S) -> Option<R> {
+        match self.iter.next() {
+            Some(value) => Some(state.visit_seq_elt(value)),
+            None => None
+        }
+    }
+
+    fn size_hint(&self) -> (uint, Option<uint>) {
+        self.iter.size_hint()
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<
+    S: VisitorState<R>,
+    R,
+    T: Serialize<S, R>
+> Serialize<S, R> for Vec<T> {
+    fn serialize(&self, state: &mut S) -> R {
+        state.visit_seq(self.iter())
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+impl<
+    S: VisitorState<R>,
+    R,
+    K: Serialize<S, R> + Ord,
+    V: Serialize<S, R>
+> Serialize<S, R> for TreeMap<K, V> {
+    fn serialize(&self, state: &mut S) -> R {
+        state.visit_map(self.iter())
+    }
+}
+
+impl<
+    'a,
+    S: VisitorState<R>,
+    R,
+    T0: Serialize<S, R>,
+    T1: Serialize<S, R>
+> Serialize<S, R> for (T0, T1) {
+    fn serialize(&self, state: &mut S) -> R {
+        state.visit_seq(Tuple2Serialize { value: self, state: 0 })
+    }
+}
+
+struct Tuple2Serialize<'a, T0, T1> {
+    value: &'a (T0, T1),
+    state: uint,
+}
+
+impl<
+    'a,
+    S: VisitorState<R>,
+    R,
+    T0: Serialize<S, R>,
+    T1: Serialize<S, R>
+> Visitor<S, R> for Tuple2Serialize<'a, T0, T1> {
+    fn visit(&mut self, state: &mut S) -> Option<R> {
+        match self.state {
+            0 => {
+                self.state += 1;
+                let (ref value, _) = *self.value;
+                Some(state.visit_seq_elt(true, value))
+            }
+            1 => {
+                self.state += 1;
+                let (_, ref value) = *self.value;
+                Some(state.visit_seq_elt(false, value))
+            }
+            _ => {
+                None
+            }
+        }
+    }
+
+    fn size_hint(&self) -> (uint, Option<uint>) {
+        let size = 2 - self.state;
+        (size, Some(size))
+    }
+}
+
+impl<
+    'a,
+    S: VisitorState<R>,
+    R,
+    T: Serialize<S, R>
+> Serialize<S, R> for &'a T {
+    fn serialize(&self, state: &mut S) -> R {
+        (**self).serialize(state)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#[deriving(Show)]
+pub enum Token {
+    Null,
+    Bool(bool),
+    Int(int),
+    I64(i64),
+    U64(u64),
+    F64(f64),
+    Char(char),
+    Str(&'static str),
+    SeqStart(uint),
+    MapStart(uint),
+    StructStart(&'static str, uint),
+    End,
+}
+
+pub trait TokenState<R>: VisitorState<R> {
+    fn serialize(&mut self, token: Token) -> R;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct GatherTokens {
+    tokens: Vec<Token>,
+}
+
+impl GatherTokens {
+    pub fn new() -> GatherTokens {
+        GatherTokens {
+            tokens: Vec::new(),
+        }
+    }
+
+    pub fn unwrap(self) -> Vec<Token> {
+        self.tokens
+    }
+}
+
+impl TokenState<()> for GatherTokens {
+    fn serialize(&mut self, token: Token) -> () {
+        self.tokens.push(token);
+    }
+}
+
+impl VisitorState<()> for GatherTokens {
+    fn visit_null(&mut self) -> () {
+        self.serialize(Null)
+    }
+
+    fn visit_bool(&mut self, value: bool) -> () {
+        self.serialize(Bool(value))
+    }
+
+    fn visit_i64(&mut self, value: i64) -> () {
+        self.serialize(I64(value))
+    }
+
+    fn visit_u64(&mut self, value: u64) -> () {
+        self.serialize(U64(value))
+    }
+
+    fn visit_f64(&mut self, value: f64) -> () {
+        self.serialize(F64(value))
+    }
+
+    fn visit_char(&mut self, value: char) -> () {
+        self.serialize(Char(value))
+    }
+
+    fn visit_str(&mut self, value: &'static str) -> () {
+        self.serialize(Str(value))
+    }
+
+    fn visit_seq<
+        V: Visitor<GatherTokens, ()>
+    >(&mut self, mut visitor: V) -> () {
+        let (len, _) = visitor.size_hint();
+        self.tokens.push(SeqStart(len));
+        loop {
+            match visitor.visit(self) {
+                Some(()) => { }
+                None => { break; }
+            }
+        }
+        self.tokens.push(End)
+    }
+
+    fn visit_enum<
+        V: Visitor<GatherTokens, ()>
+    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> () {
+        self.visit_seq(visitor)
+    }
+
+    fn visit_map<
+        V: Visitor<GatherTokens, ()>
+    >(&mut self, mut visitor: V) -> () {
+        let (len, _) = visitor.size_hint();
+        self.serialize(MapStart(len));
+        loop {
+            match visitor.visit(self) {
+                Some(()) => { }
+                None => { break; }
+            }
+        }
+        self.serialize(End)
+    }
+
+    fn visit_named_map<
+        V: Visitor<GatherTokens, ()>
+    >(&mut self, name: &'static str, mut visitor: V) -> () {
+        let (len, _) = visitor.size_hint();
+        self.serialize(StructStart(name, len));
+        loop {
+            match visitor.visit(self) {
+                Some(()) => { }
+                None => { break; }
+            }
+        }
+        self.serialize(End)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub struct FormatState<W: Writer> {
+    writer: W,
+}
+
+impl<W: Writer> FormatState<W> {
+    pub fn new(writer: W) -> FormatState<W> {
+        FormatState {
+            writer: writer,
+        }
+    }
+
+    pub fn unwrap(self) -> W {
+        self.writer
+    }
+}
+
+impl<W: Writer> VisitorState<IoResult<()>> for FormatState<W> {
+    fn visit_null(&mut self) -> IoResult<()> {
+        write!(self.writer, "()")
+    }
+
+    fn visit_bool(&mut self, value: bool) -> IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    fn visit_i64(&mut self, value: i64) -> IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    fn visit_u64(&mut self, value: u64) -> IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    fn visit_f64(&mut self, value: f64) -> IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    fn visit_char(&mut self, value: char) -> io::IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    fn visit_str(&mut self, value: &'static str) -> IoResult<()> {
+        write!(self.writer, "{}", value)
+    }
+
+    fn visit_seq<
+        V: Visitor<FormatState<W>, IoResult<()>>
+    >(&mut self, mut visitor: V) -> IoResult<()> {
+        try!(write!(self.writer, "["));
+        loop {
+            match visitor.visit(self) {
+                Some(Ok(())) => { }
+                Some(Err(err)) => { return Err(err); }
+                None => { break; }
+            }
+        }
+        write!(self.writer, "]")
+    }
+
+    fn visit_enum<
+        V: Visitor<FormatState<W>, IoResult<()>>
+    >(&mut self, _name: &'static str, _variant: &'static str, visitor: V) -> IoResult<()> {
+        self.visit_tuple(visitor)
+    }
+
+    fn visit_map_elt<
+        K: Serialize<FormatState<W>, IoResult<()>>,
+        V: Serialize<FormatState<W>, IoResult<()>>
+    >(&mut self, first: bool, key: K, value: V) -> IoResult<()> {
+        if !first {
+            try!(write!(self.writer, ", "));
+        }
+
+        try!(key.serialize(self));
+        try!(write!(self.writer, ": "));
+        value.serialize(self)
+    }
+
+    fn visit_map<
+        V: Visitor<FormatState<W>, IoResult<()>>
+    >(&mut self, mut visitor: V) -> IoResult<()> {
+        try!(write!(self.writer, "{{"));
+        loop {
+            match visitor.visit(self) {
+                Some(Ok(())) => { }
+                Some(Err(err)) => { return Err(err); }
+                None => { break; }
+            }
+        }
+        write!(self.writer, "}}")
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+pub fn to_format_vec<
+    T: Serialize<FormatState<io::MemWriter>, IoResult<()>>
+>(value: &T) -> IoResult<Vec<u8>> {
+    let writer = io::MemWriter::new();
+    let mut state = FormatState::new(writer);
+    try!(value.serialize(&mut state));
+    Ok(state.unwrap().unwrap())
+}
+
+pub fn to_format_string<
+    T: Serialize<FormatState<io::MemWriter>, IoResult<()>>
+>(value: &T) -> IoResult<Result<String, Vec<u8>>> {
+    let vec = try!(to_format_vec(value));
+    Ok(String::from_utf8(vec))
+}