From 6a9011d2e307cd4181941f104aa558834dc44d1e Mon Sep 17 00:00:00 2001
From: Colin Sherratt <colin.sherratt@gmail.com>
Date: Sat, 24 Jan 2015 19:27:19 -0500
Subject: [PATCH] Update to using Debug over Show. Update the Error impls.

---
 src/reader.rs | 10 +++++-----
 src/test.rs   |  4 ++--
 src/writer.rs | 24 +++++++++++++++++-------
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/src/reader.rs b/src/reader.rs
index 4e6d76f..c9c4169 100644
--- a/src/reader.rs
+++ b/src/reader.rs
@@ -13,7 +13,7 @@ pub struct InvalidEncoding {
     detail: Option<String>,
 }
 
-impl fmt::String for InvalidEncoding {
+impl fmt::Display for InvalidEncoding {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             InvalidEncoding { detail: None, desc } =>
@@ -43,7 +43,7 @@ pub enum DecodingError {
     SizeLimit
 }
 
-impl fmt::String for DecodingError {
+impl fmt::Display for DecodingError {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             DecodingError::IoError(ref ioerr) =>
@@ -71,10 +71,10 @@ impl Error for DecodingError {
         }
     }
 
-    fn detail(&self) -> Option<String> {
+    fn cause(&self) -> Option<&Error> {
         match *self {
-            DecodingError::IoError(ref err)     => err.detail(),
-            DecodingError::InvalidEncoding(ref ib) => ib.detail.clone(),
+            DecodingError::IoError(ref err)     => err.cause(),
+            DecodingError::InvalidEncoding(_) => None,
             DecodingError::SizeLimit => None
         }
     }
diff --git a/src/test.rs b/src/test.rs
index 9dac3f4..fb4735b 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -1,6 +1,6 @@
 extern crate "rustc-serialize" as serialize;
 
-use std::fmt::Show;
+use std::fmt::Debug;
 use std::collections::HashMap;
 
 use rustc_serialize::{
@@ -20,7 +20,7 @@ use super::{
 };
 use super::SizeLimit::{Infinite, Bounded};
 
-fn the_same<'a, V>(element: V) where V: Encodable, V: Decodable, V: PartialEq, V: Show {
+fn the_same<'a, V>(element: V) where V: Encodable, V: Decodable, V: PartialEq, V: Debug {
     assert!(element == decode(encode(&element, Infinite).unwrap().as_slice()).unwrap());
 }
 
diff --git a/src/writer.rs b/src/writer.rs
index d7e1b76..340d433 100644
--- a/src/writer.rs
+++ b/src/writer.rs
@@ -1,6 +1,7 @@
 use std::io::{Writer, IoError};
 use std::error::Error;
 use std::num::Int;
+use std::fmt;
 
 use rustc_serialize::Encoder;
 
@@ -10,7 +11,7 @@ pub type EncodingResult<T> = Result<T, EncodingError>;
 
 
 /// An error that can be produced during encoding.
-#[derive(Show)]
+#[derive(Debug)]
 pub enum EncodingError {
     /// An error originating from the underlying `Writer`.
     IoError(IoError),
@@ -39,6 +40,15 @@ fn wrap_io(err: IoError) -> EncodingError {
     EncodingError::IoError(err)
 }
 
+impl fmt::Display for EncodingError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        match *self {
+            EncodingError::IoError(ref err) => write!(f, "IoError: {}", err),
+            EncodingError::SizeLimit => write!(f, "SizeLimit")
+        }
+    }
+}
+
 impl Error for EncodingError {
     fn description(&self) -> &str {
         match *self {
@@ -47,9 +57,9 @@ impl Error for EncodingError {
         }
     }
 
-    fn detail(&self) -> Option<String> {
+    fn cause(&self) -> Option<&Error> {
         match *self {
-            EncodingError::IoError(ref err)     => err.detail(),
+            EncodingError::IoError(ref err)     => err.cause(),
             EncodingError::SizeLimit => None
         }
     }
@@ -221,8 +231,8 @@ impl<'a, W: Writer> Encoder for EncoderWriter<'a, W> {
             try!(self.emit_usize(len));
             f(self)
         }
-    fn emit_map_elt_key<F>(&mut self, _: usize, mut f: F) -> EncodingResult<()> where
-        F: FnMut(&mut EncoderWriter<'a, W>) -> EncodingResult<()> {
+    fn emit_map_elt_key<F>(&mut self, _: usize, f: F) -> EncodingResult<()> where
+        F: FnOnce(&mut EncoderWriter<'a, W>) -> EncodingResult<()> {
             f(self)
         }
     fn emit_map_elt_val<F>(&mut self, _: usize, f: F) -> EncodingResult<()> where
@@ -361,8 +371,8 @@ impl Encoder for SizeChecker {
             try!(self.emit_usize(len));
             f(self)
         }
-    fn emit_map_elt_key<F>(&mut self, _: usize, mut f: F) -> EncodingResult<()> where
-        F: FnMut(&mut SizeChecker) -> EncodingResult<()> {
+    fn emit_map_elt_key<F>(&mut self, _: usize, f: F) -> EncodingResult<()> where
+        F: FnOnce(&mut SizeChecker) -> EncodingResult<()> {
             f(self)
         }
     fn emit_map_elt_val<F>(&mut self, _: usize, f: F) -> EncodingResult<()> where