1 files changed, 152 insertions, 0 deletions
diff --git a/src/decoder/serde.rs b/src/decoder/serde.rs
new file mode 100644
index 0000000..6f60892
--- /dev/null
+++ b/src/decoder/serde.rs
@@ -0,0 +1,152 @@
+use serde::de;
+use Value;
+use super::{Decoder, DecodeError, DecodeErrorKind};
+
+struct DecodeValue(Value);
+struct MapVisitor<I>(I, Option<Value>);
+struct SubDecoder(Decoder);
+
+fn se2toml(err: de::value::Error, ty: &'static str) -> DecodeError {
+    match err {
+        de::value::Error::SyntaxError => de::Error::syntax_error(),
+        de::value::Error::EndOfStreamError => de::Error::end_of_stream_error(),
+        de::value::Error::MissingFieldError(s) => {
+            DecodeError {
+                field: Some(s.to_string()),
+                kind: DecodeErrorKind::ExpectedField(Some(ty)),
+            }
+        }
+    }
+}
+
+impl de::Deserializer for Decoder {
+    type Error = DecodeError;
+
+    fn visit<V>(&mut self, mut visitor: V) -> Result<V::Value, DecodeError>
+        where V: de::Visitor
+    {
+        match self.toml.take() {
+            Some(Value::String(s)) => {
+                visitor.visit_string(s).map_err(|e| se2toml(e, "string"))
+            }
+            Some(Value::Integer(i)) => {
+                visitor.visit_i64(i).map_err(|e| se2toml(e, "integer"))
+            }
+            Some(Value::Float(f)) => {
+                visitor.visit_f64(f).map_err(|e| se2toml(e, "float"))
+            }
+            Some(Value::Boolean(b)) => {
+                visitor.visit_bool(b).map_err(|e| se2toml(e, "bool"))
+            }
+            Some(Value::Datetime(s)) => {
+                visitor.visit_string(s).map_err(|e| se2toml(e, "date"))
+            }
+            Some(Value::Array(a)) => {
+                let len = a.len();
+                let iter = a.into_iter().map(DecodeValue);
+                let e = visitor.visit_seq(de::value::SeqDeserializer::new(iter,
+                                                                          len));
+                e.map_err(|e| se2toml(e, "array"))
+            }
+            Some(Value::Table(t)) => {
+                visitor.visit_map(MapVisitor(t.into_iter(), None))
+            }
+            None => Err(de::Error::end_of_stream_error()),
+        }
+    }
+
+    fn visit_option<V>(&mut self, mut visitor: V) -> Result<V::Value, DecodeError>
+        where V: de::Visitor
+    {
+        if self.toml.is_none() {
+            visitor.visit_none()
+        } else {
+            visitor.visit_some(self)
+        }
+    }
+
+    fn visit_seq<V>(&mut self, mut visitor: V) -> Result<V::Value, DecodeError>
+        where V: de::Visitor,
+    {
+        if self.toml.is_none() {
+            let iter = None::<i32>.into_iter();
+            let e = visitor.visit_seq(de::value::SeqDeserializer::new(iter, 0));
+            e.map_err(|e| se2toml(e, "array"))
+        } else {
+            self.visit(visitor)
+        }
+    }
+}
+
+impl de::Error for DecodeError {
+    fn syntax_error() -> DecodeError {
+        DecodeError { field: None, kind: DecodeErrorKind::SyntaxError }
+    }
+    fn end_of_stream_error() -> DecodeError {
+        DecodeError { field: None, kind: DecodeErrorKind::EndOfStream }
+    }
+    fn missing_field_error(name: &'static str) -> DecodeError {
+        DecodeError {
+            field: Some(name.to_string()),
+            kind: DecodeErrorKind::ExpectedField(None),
+        }
+    }
+}
+
+impl de::Deserializer for SubDecoder {
+    type Error = de::value::Error;
+
+    fn visit<V>(&mut self, visitor: V) -> Result<V::Value, de::value::Error>
+        where V: de::Visitor
+    {
+        self.0.visit(visitor).map_err(|e| {
+            match e.kind {
+                DecodeErrorKind::SyntaxError => de::value::Error::SyntaxError,
+                DecodeErrorKind::EndOfStream => de::value::Error::EndOfStreamError,
+                _ => de::value::Error::SyntaxError,
+            }
+        })
+    }
+}
+
+impl de::value::ValueDeserializer for DecodeValue {
+    type Deserializer = SubDecoder;
+
+    fn into_deserializer(self) -> SubDecoder {
+        SubDecoder(Decoder::new(self.0))
+    }
+}
+
+impl<I> de::MapVisitor for MapVisitor<I>
+    where I: Iterator<Item=(String, Value)>
+{
+    type Error = DecodeError;
+
+    fn visit_key<K>(&mut self) -> Result<Option<K>, DecodeError>
+        where K: de::Deserialize
+    {
+        match self.0.next() {
+            Some((k, v)) => {
+                self.1 = Some(v);
+                de::Deserialize::deserialize(&mut Decoder::new(Value::String(k)))
+                   .map(|v| Some(v))
+            }
+            None => Ok(None),
+        }
+
+    }
+
+    fn visit_value<V>(&mut self) -> Result<V, DecodeError>
+        where V: de::Deserialize
+    {
+        match self.1.take() {
+            Some(t) => de::Deserialize::deserialize(&mut Decoder::new(t)),
+            None => Err(de::Error::end_of_stream_error())
+        }
+    }
+
+    fn end(&mut self) -> Result<(), DecodeError> {
+        Ok(())
+    }
+
+}