Revert "renamed read_nil to read_unit"

This reverts commit 37d0600.

Author: kenta7777

src/librustc/ty/codec.rs

@@ -298,7 +298,7 @@ macro_rules! implement_ty_decoder {
                 type Error = String;
 
                 __impl_decoder_methods! {
-                    read_unit -> ();
+                    read_nil -> ();
 
                     read_u128 -> u128;
                     read_u64 -> u64;

src/libserialize/json.rs

@@ -2128,7 +2128,7 @@ macro_rules! read_primitive {
 impl ::Decoder for Decoder {
     type Error = DecoderError;
 
-    fn read_unit(&mut self) -> DecodeResult<()> {
+    fn read_nil(&mut self) -> DecodeResult<()> {
         expect!(self.pop(), Null)
     }
 

src/libserialize/opaque.rs

@@ -228,7 +228,7 @@ impl<'a> serialize::Decoder for Decoder<'a> {
     type Error = String;
 
     #[inline]
-    fn read_unit(&mut self) -> Result<(), Self::Error> {
+    fn read_nil(&mut self) -> Result<(), Self::Error> {
         Ok(())
     }
 

src/libserialize/serialize.rs

@@ -167,7 +167,7 @@ pub trait Decoder {
     type Error;
 
     // Primitive types:
-    fn read_unit(&mut self) -> Result<(), Self::Error>;
+    fn read_nil(&mut self) -> Result<(), Self::Error>;
     fn read_usize(&mut self) -> Result<usize, Self::Error>;
     fn read_u128(&mut self) -> Result<u128, Self::Error>;
     fn read_u64(&mut self) -> Result<u64, Self::Error>;
@@ -543,7 +543,7 @@ impl Encodable for () {
 
 impl Decodable for () {
     fn decode<D: Decoder>(d: &mut D) -> Result<(), D::Error> {
-        d.read_unit()
+        d.read_nil()
     }
 }