decodable trait impl in progress

src/rlp/faces.rs

@@ -1,15 +1,43 @@
+use std::fmt;
+use std::error::Error as StdError;
+use bytes::FromBytesError;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum DecoderError {
+	FromBytesError(FromBytesError),
+	RlpIsTooShort,
+	RlpExpectedToBeList,
+	RlpExpectedToBeData,
+}
+
+impl StdError for DecoderError {
+	fn description(&self) -> &str {
+		"builder error"
+	}
+}
+
+impl fmt::Display for DecoderError {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		fmt::Debug::fmt(&self, f)
+	}
+}
+
+impl From<FromBytesError> for DecoderError {
+	fn from(err: FromBytesError) -> DecoderError {
+		DecoderError::FromBytesError(err)
+	}
+}
+
 pub trait Decoder {
-	type Error;
+	fn read_value<T, F>(&self, f: F) -> Result<T, DecoderError>
+		where F: FnOnce(&[u8]) -> Result<T, DecoderError>;
 
-	fn read_value<T, F>(&self, f: F) -> Result<T, Self::Error>
-		where F: FnOnce(&[u8]) -> Result<T, Self::Error>;
-
-	fn read_list<T, F>(&self, f: F) -> Result<T, Self::Error>
-		where F: FnOnce(&[Self]) -> Result<T, Self::Error>;
+	fn read_list<T, F>(&self, f: F) -> Result<T, DecoderError>
+		where F: FnOnce(&[Self]) -> Result<T, DecoderError>;
 }
 
 pub trait Decodable: Sized {
-	fn decode<T, D>(decoder: &D) -> Result<T, D::Error>  where D: Decoder;
+	fn decode<T, D>(decoder: &D) -> Result<T, DecoderError>  where D: Decoder;
 }
 
 pub trait View<'a, 'view>: Sized {
@@ -18,7 +46,6 @@ pub trait View<'a, 'view>: Sized {
 	type Data;
 	type Item;
 	type Iter;
-	type Error;
 
 	/// Creates a new instance of `Rlp` reader
 	fn new(bytes: &'a [u8]) -> Self;
@@ -179,7 +206,7 @@ pub trait View<'a, 'view>: Sized {
 	/// ```
 	fn iter(&'view self) -> Self::Iter;
 
-	fn as_val<T>(&self) -> Result<T, Self::Error> where T: Decodable;
+	fn as_val<T>(&self) -> Result<T, DecoderError> where T: Decodable;
 }
 
 pub trait Encoder {

src/rlp/mod.rs

@@ -1,8 +1,40 @@
+//! Rlp serialization module 
+//! 
+//! Allows encoding, decoding, and view onto rlp-slice 
+//!
+//!# What should you use when?
+//!
+//!### Use `encode` function when: 
+//! * You want to encode something inline.
+//! * You do not work on big set of data.
+//! * You want to encode whole data structure at once.
+//!
+//!### Use `decode` function when:
+//! * You want to decode something inline.
+//! * You do not work on big set of data.
+//! * You want to decode whole rlp at once.
+//!
+//!### Use `RlpStream` when:
+//! * You want to encode something in portions.
+//! * You encode a big set of data.
+//!
+//!### Use `Rlp` when:
+//! * You are working on trusted data (not corrupted).
+//! * You want to get view onto rlp-slice.
+//! * You don't want to decode whole rlp at once.
+//!
+//!### Use `UntrustedRlp` when: 
+//! * You are working on untrusted data (~corrupted).
+//! * You need to handle data corruption errors.
+//! * You are working on input data.
+//! * You want to get view onto rlp-slice.
+//! * You don't want to decode whole rlp at once.
+
 pub mod old;
 
 pub mod faces;
-pub mod coders;
 pub mod rlp;
 pub mod untrusted_rlp;
+pub mod rlpstream;
 
 pub use self::old::*;

src/rlp/rlp.rs

@@ -1,4 +1,4 @@
-use super::faces::{View, Decodable};
+use super::faces::{View, Decodable, DecoderError};
 use super::untrusted_rlp::*;
 
 impl<'a> From<UntrustedRlp<'a>> for Rlp<'a> {
@@ -22,7 +22,6 @@ impl<'a, 'view> View<'a, 'view> for Rlp<'a> where 'a: 'view {
 	type Data = &'a [u8];
 	type Item = Rlp<'a>;
 	type Iter = RlpIterator<'a, 'view>;
-	type Error = DecoderError;
 	
 	/// Create a new instance of `Rlp`
 	fn new(bytes: &'a [u8]) -> Rlp<'a> {
@@ -83,14 +82,14 @@ impl<'a, 'view> View<'a, 'view> for Rlp<'a> where 'a: 'view {
 		self.into_iter()
 	}
 
-	fn as_val<T>(&self) -> Result<T, Self::Error> where T: Decodable {
+	fn as_val<T>(&self) -> Result<T, DecoderError> where T: Decodable {
 		self.rlp.as_val()
 	}
 }
 
 impl <'a, 'view> Rlp<'a> where 'a: 'view {
 	fn reader_as_val<T, R>(r: &R) -> T where R: View<'a, 'view>, T: Decodable {
-		let res: Result<T, R::Error> = r.as_val();
+		let res: Result<T, DecoderError> = r.as_val();
 		res.unwrap_or_else(|_| panic!())
 	}
 

src/rlp/untrusted_rlp.rs

@@ -1,8 +1,6 @@
-use std::fmt;
 use std::cell::Cell;
-use std::error::Error as StdError;
-use bytes::{FromBytes, FromBytesError};
-use super::faces::{View, Decoder, Decodable};
+use bytes::{FromBytes};
+use super::faces::{View, Decoder, Decodable, DecoderError};
 
 /// rlp offset
 #[derive(Copy, Clone, Debug)]
@@ -42,31 +40,6 @@ impl PayloadInfo {
 	}
 }
 
-#[derive(Debug, PartialEq, Eq)]
-pub enum DecoderError {
-	FromBytesError(FromBytesError),
-	RlpIsTooShort,
-	RlpExpectedToBeList,
-	RlpExpectedToBeData,
-}
-impl StdError for DecoderError {
-	fn description(&self) -> &str {
-		"builder error"
-	}
-}
-
-impl fmt::Display for DecoderError {
-	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		fmt::Debug::fmt(&self, f)
-	}
-}
-
-impl From<FromBytesError> for DecoderError {
-	fn from(err: FromBytesError) -> DecoderError {
-		DecoderError::FromBytesError(err)
-	}
-}
-
 /// Data-oriented view onto rlp-slice.
 /// 
 /// This is immutable structere. No operations change it.
@@ -94,7 +67,6 @@ impl<'a, 'view> View<'a, 'view> for UntrustedRlp<'a> where 'a: 'view {
 	type Data = Result<&'a [u8], DecoderError>;
 	type Item = Result<UntrustedRlp<'a>, DecoderError>;
 	type Iter = UntrustedRlpIterator<'a, 'view>;
-	type Error = DecoderError;
 
 	//returns new instance of `UntrustedRlp`
 	fn new(bytes: &'a [u8]) -> UntrustedRlp<'a> {
@@ -200,7 +172,7 @@ impl<'a, 'view> View<'a, 'view> for UntrustedRlp<'a> where 'a: 'view {
 		self.into_iter()
 	}
 
-	fn as_val<T>(&self) -> Result<T, Self::Error> where T: Decodable {
+	fn as_val<T>(&self) -> Result<T, DecoderError> where T: Decodable {
 		// optimize, so it doesn't use clone (although This clone is cheap)
 		T::decode(&BasicDecoder::new(self.clone()))
 	}
@@ -305,10 +277,8 @@ impl<'a> BasicDecoder<'a> {
 }
 
 impl<'a> Decoder for BasicDecoder<'a> {
-	type Error = DecoderError;
-
-	fn read_value<T, F>(&self, f: F) -> Result<T, Self::Error>
-		where F: FnOnce(&[u8]) -> Result<T, Self::Error> {
+	fn read_value<T, F>(&self, f: F) -> Result<T, DecoderError>
+		where F: FnOnce(&[u8]) -> Result<T, DecoderError> {
 
 		let bytes = self.rlp.raw();
 
@@ -331,8 +301,8 @@ impl<'a> Decoder for BasicDecoder<'a> {
 		}
 	}
 
-	fn read_list<T, F>(&self, f: F) -> Result<T, Self::Error>
-		where F: FnOnce(&[Self]) -> Result<T, Self::Error> {
+	fn read_list<T, F>(&self, f: F) -> Result<T, DecoderError>
+		where F: FnOnce(&[Self]) -> Result<T, DecoderError> {
 
 		let v: Vec<BasicDecoder<'a>> = self.rlp.iter()
 			.map(| i | BasicDecoder::new(i))
@@ -341,3 +311,20 @@ impl<'a> Decoder for BasicDecoder<'a> {
 	}
 }
 
+impl<T> Decodable for T where T: FromBytes {
+	fn decode<R, D>(decoder: &D) -> Result<R, DecoderError>  where D: Decoder {
+		unimplemented!()
+	}
+}
+
+impl<T> Decodable for Vec<T> where T: Decodable {
+	fn decode<R, D>(decoder: &D) -> Result<R, DecoderError>  where D: Decoder {
+		unimplemented!()
+	}
+}
+
+impl Decodable for Vec<u8> {
+	fn decode<R, D>(decoder: &D) -> Result<R, DecoderError>  where D: Decoder {
+		unimplemented!()
+	}
+}