impl Error for error types

src/chunk.rs

@@ -1,7 +1,11 @@
 use futures::{Async, Stream};
-use std::io::Cursor;
-use std::mem;
-use std::sync::Arc;
+use std::{
+    error::Error,
+    fmt::{Display, Formatter, Result as FmtResult},
+    io::Cursor,
+    mem,
+    sync::Arc
+};
 use ebml::EbmlEventSource;
 use webm::*;
 
@@ -92,6 +96,20 @@ pub enum ChunkingError<E> {
     OtherError(E)
 }
 
+impl<E: Display + Error> Display for ChunkingError<E> {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        write!(f, "Chunking error: {}", self.description())
+    }
+}
+impl<E: Error> Error for ChunkingError<E> {
+    fn description(&self) -> &str {
+        match self {
+            &ChunkingError::IoError(ref err) => err.description(),
+            &ChunkingError::OtherError(ref err) => err.description()
+        }
+    }
+}
+
 pub struct WebmChunker<S> {
     source: S,
     state: ChunkerState

src/ebml.rs

@@ -15,6 +15,21 @@ pub enum EbmlError {
     UnknownElementLength,
     CorruptPayload,
 }
+impl Display for EbmlError {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        write!(f, "{}", self.description())
+    }
+}
+impl ErrorTrait for EbmlError {
+    fn description(&self) -> &str {
+        match self {
+            &EbmlError::CorruptVarint => "EBML Varint could not be parsed",
+            &EbmlError::UnknownElementId => "EBML element ID was \"unknown\"",
+            &EbmlError::UnknownElementLength => "EBML element length was \"unknown\" for an element not allowing that",
+            &EbmlError::CorruptPayload => "EBML element payload could not be parsed",
+        }
+    }
+}
 
 #[derive(Debug, PartialEq)]
 pub enum WriteError {

src/stream_parser.rs

@@ -1,3 +1,8 @@
+use std::{
+    error::Error,
+    fmt::{Display, Formatter, Result as FmtResult}
+};
+
 use bytes::BytesMut;
 use bytes::BufMut;
 use futures::Async;
@@ -12,6 +17,19 @@ pub enum ParsingError<E> {
     EbmlError(EbmlError),
     OtherError(E)
 }
+impl<E: Display + Error> Display for ParsingError<E> {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        write!(f, "Parsing error: {}", self.description())
+    }
+}
+impl<E: Error> Error for ParsingError<E> {
+    fn description(&self) -> &str {
+        match self {
+            &ParsingError::EbmlError(ref err) => err.description(),
+            &ParsingError::OtherError(ref err) => err.description()
+        }
+    }
+}
 
 pub struct EbmlStreamingParser<S> {
     stream: S,