2 files changed, 60 insertions, 23 deletions

diff --git a/src/encoder/mod.rs b/src/encoder/mod.rs
index 304bac6..0f13b81 100644
--- a/src/encoder/mod.rs
+++ b/src/encoder/mod.rs
@@ -35,7 +35,7 @@ use {Value, Table};
 /// assert_eq!(e.toml.get(&"foo".to_string()), Some(&Value::Integer(4)))
 /// # }
 /// ```
-#[derive(Default)]
+#[derive(Default, Debug)]
 pub struct Encoder {
     /// Output TOML that is emitted. The current version of this encoder forces
     /// the top-level representation of a structure to be a table.
@@ -66,8 +66,9 @@ pub enum Error {
     Custom(String),
 }
 
-#[derive(PartialEq)]
-enum State {
+#[derive(PartialEq, Debug)]
+#[doc(hidden)]
+pub enum State {
     Start,
     NextKey(String),
     NextArray(Vec<Value>),
@@ -115,8 +116,16 @@ impl Encoder {
     fn seq<F>(&mut self, f: F) -> Result<(), Error>
         where F: FnOnce(&mut Encoder) -> Result<(), Error>
     {
-        let old = mem::replace(&mut self.state, State::NextArray(Vec::new()));
+        let old = try!(self.seq_begin());
         try!(f(self));
+        self.seq_end(old)
+    }
+
+    fn seq_begin(&mut self) -> Result<State, Error> {
+        Ok(mem::replace(&mut self.state, State::NextArray(Vec::new())))
+    }
+
+    fn seq_end(&mut self, old: State) -> Result<(), Error> {
         match mem::replace(&mut self.state, old) {
             State::NextArray(v) => self.emit_value(Value::Array(v)),
             _ => unreachable!(),
@@ -145,6 +154,30 @@ impl Encoder {
         }
     }
 
+    fn table_begin(&mut self) -> Result<Self, Error> {
+        match self.state {
+            State::NextMapKey => Err(Error::InvalidMapKeyLocation),
+            _ => Ok(mem::replace(self, Encoder::new()))
+        }
+    }
+
+    fn table_end(&mut self, mut state: Self) -> Result<(), Error> {
+        match state.state {
+            State::NextKey(key) => {
+                mem::swap(&mut self.toml, &mut state.toml);
+                self.toml.insert(key, Value::Table(state.toml));
+            },
+            State::NextArray(mut arr) => {
+                mem::swap(&mut self.toml, &mut state.toml);
+                arr.push(Value::Table(state.toml));
+                self.state = State::NextArray(arr);
+            },
+            State::Start => {},
+            State::NextMapKey => unreachable!(),
+        }
+        Ok(())
+    }
+
     fn table_key<F>(&mut self, f: F) -> Result<(), Error>
         where F: FnOnce(&mut Encoder) -> Result<(), Error>
     {
diff --git a/src/encoder/serde.rs b/src/encoder/serde.rs
index a782cd2..49a6e2d 100644
--- a/src/encoder/serde.rs
+++ b/src/encoder/serde.rs
@@ -1,9 +1,11 @@
 use serde::ser;
 use Value;
-use super::{Encoder, Error};
+use super::{Encoder, Error, State};
 
 impl ser::Serializer for Encoder {
     type Error = Error;
+    type MapState = Self;
+    type SeqState = State;
 
     fn serialize_bool(&mut self, v: bool) -> Result<(), Error> {
         self.emit_value(Value::Boolean(v))
@@ -34,26 +36,19 @@ impl ser::Serializer for Encoder {
     {
         value.serialize(self)
     }
-    fn serialize_seq<V>(&mut self, mut visitor: V) -> Result<(), Error>
-        where V: ser::SeqVisitor
-    {
-        self.seq(|me| {
-            while try!(visitor.visit(me)).is_some() {}
-            Ok(())
-        })
+    fn serialize_seq(&mut self, _len: Option<usize>) -> Result<State, Error> {
+        self.seq_begin()
     }
     fn serialize_seq_elt<T>(&mut self, value: T) -> Result<(), Error>
         where T: ser::Serialize
     {
         value.serialize(self)
     }
-    fn serialize_map<V>(&mut self, mut visitor: V) -> Result<(), Error>
-        where V: ser::MapVisitor
-    {
-        self.table(|me| {
-            while try!(visitor.visit(me)).is_some() {}
-            Ok(())
-        })
+    fn serialize_seq_end(&mut self, _len: Option<usize>, state: State) -> Result<(), Error> {
+        self.seq_end(state)
+    }
+    fn serialize_map(&mut self, _len: Option<usize>) -> Result<Self, Error> {
+        self.table_begin()
     }
     fn serialize_map_elt<K, V>(&mut self, key: K, value: V) -> Result<(), Error>
         where K: ser::Serialize, V: ser::Serialize
@@ -62,6 +57,9 @@ impl ser::Serializer for Encoder {
         try!(value.serialize(self));
         Ok(())
     }
+    fn serialize_map_end(&mut self, _len: Option<usize>, state: Self) -> Result<(), Error> {
+        self.table_end(state)
+    }
     fn serialize_newtype_struct<T>(&mut self,
                                    _name: &'static str,
                                    value: T) -> Result<(), Self::Error>
@@ -93,12 +91,18 @@ impl ser::Serialize for Value {
             Value::Boolean(b) => e.serialize_bool(b),
             Value::Datetime(ref s) => e.serialize_str(s),
             Value::Array(ref a) => {
-                e.serialize_seq(ser::impls::SeqIteratorVisitor::new(a.iter(),
-                                                                Some(a.len())))
+                let state = try!(e.serialize_seq(Some(a.len())));
+                for el in a.iter() {
+                    try!(e.serialize_seq_elt(el));
+                }
+                e.serialize_seq_end(Some(a.len()), state)
             }
             Value::Table(ref t) => {
-                e.serialize_map(ser::impls::MapIteratorVisitor::new(t.iter(),
-                                                                Some(t.len())))
+                let state = try!(e.serialize_map(Some(t.len())));
+                for (k, v) in t.iter() {
+                    try!(e.serialize_map_elt(k, v));
+                }
+                e.serialize_map_end(Some(t.len()), state)
             }
         }
     }