Remove 'implements' keyword in favour of :, part of #2301.

Author: graydon

src/libsyntax/parse/parser.rs

@@ -1979,7 +1979,7 @@ class parser {
         let rp = self.parse_region_param();
         let ty_params = self.parse_ty_params();
         let class_path = self.ident_to_path_tys(class_name, rp, ty_params);
-        let ifaces : [@iface_ref] = if self.eat_keyword("implements")
+        let ifaces : [@iface_ref] = if self.eat(token::COLON)
             { self.parse_iface_ref_list() }
         else { [] };
         self.expect(token::LBRACE);

src/libsyntax/parse/token.rs

@@ -251,7 +251,6 @@ fn contextual_keyword_table() -> hashmap<str, ()> {
     let keys = [
         "as",
         "else",
-        "implements",
         "move",
         "of",
         "priv", "pub",

src/libsyntax/print/pprust.rs

@@ -527,9 +527,11 @@ fn print_item(s: ps, &&item: @ast::item) {
           word_nbsp(s, *item.ident);
           print_region_param(s, rp);
           print_type_params(s, tps);
-          word_space(s, "implements");
-          commasep(s, inconsistent, ifaces, {|s, p|
-                      print_path(s, p.path, false)});
+          if vec::len(ifaces) != 0u {
+              word_space(s, ":");
+              commasep(s, inconsistent, ifaces, {|s, p|
+                  print_path(s, p.path, false)});
+          }
           bopen(s);
           hardbreak_if_not_bol(s);
           maybe_print_comment(s, ctor.span.lo);

src/test/auxiliary/cci_class_cast.rs

@@ -3,7 +3,7 @@ import to_str::to_str;
 
 mod kitty {
 
-class cat implements to_str {
+class cat : to_str {
   priv {
     let mut meows : uint;
     fn meow() {

src/test/compile-fail/class-cast-to-iface.rs

@@ -3,7 +3,7 @@ iface noisy {
   fn speak();
 }
 
-class cat implements noisy {
+class cat : noisy {
   priv {
     let mut meows : uint;
     fn meow() {

src/test/compile-fail/class-implements-bad-iface.rs

@@ -1,5 +1,5 @@
 // error-pattern:unresolved typename: nonexistent
-class cat implements nonexistent {
+class cat : nonexistent {
   let meows: uint;
   new(in_x : uint) { self.meows = in_x; }
 }

src/test/compile-fail/class-implements-int.rs

@@ -1,4 +1,4 @@
-class cat implements int { //! ERROR can only implement interface types
+class cat : int { //! ERROR can only implement interface types
   let meows: uint;
   new(in_x : uint) { self.meows = in_x; }
 }

src/test/compile-fail/class-method-missing.rs

@@ -3,7 +3,7 @@ iface animal {
   fn eat();
 }
 
-class cat implements animal {
+class cat : animal {
   let meows: uint;
   new(in_x : uint) { self.meows = in_x; }
 }

src/test/run-pass/class-cast-to-iface-cross-crate.rs

@@ -1,7 +1,7 @@
 import to_str::*;
 import to_str::to_str;
 
-class cat implements to_str {
+class cat : to_str {
   priv {
     let mut meows : uint;
     fn meow() {

src/test/run-pass/class-cast-to-iface-multiple-types.rs

@@ -2,7 +2,7 @@ iface noisy {
   fn speak() -> int;
 }
 
-class dog implements noisy {
+class dog : noisy {
   priv {
     let barks : @mut uint;
     fn bark() -> int {
@@ -26,7 +26,7 @@ class dog implements noisy {
   fn speak() -> int { self.bark() }
 }
 
-class cat implements noisy {
+class cat : noisy {
   priv {
     let meows : @mut uint;
     fn meow() -> uint {

src/test/run-pass/class-cast-to-iface.rs

@@ -2,7 +2,7 @@ iface noisy {
   fn speak();
 }
 
-class cat implements noisy {
+class cat : noisy {
   priv {
     let mut meows : uint;
     fn meow() {

src/test/run-pass/class-iface-bounded-param.rs

@@ -2,7 +2,7 @@ use std;
 import std::map::{map, hashmap, int_hash};
 
 class keys<K: copy, V: copy, M: copy map<K,V>>
-    implements iter::base_iter<K> {
+    : iter::base_iter<K> {
 
     let map: M;
 

src/test/run-pass/class-impl-parameterized-iface.rs

@@ -2,7 +2,7 @@
 use std;
 import std::map::*;
 
-class cat implements map<int, bool> {
+class cat : map<int, bool> {
   priv {
     // Yes, you can have negative meows
     let mut meows : int;

src/test/run-pass/class-impl-very-parameterized-iface.rs

@@ -7,7 +7,7 @@ enum cat_type { tuxedo, tabby, tortoiseshell }
 // for any int value that's less than the meows field
 
 // ok: T should be in scope when resolving the iface ref for map
-class cat<T: copy> implements map<int, T> {
+class cat<T: copy> : map<int, T> {
   priv {
     // Yes, you can have negative meows
     let mut meows : int;

src/test/run-pass/class-implement-iface-cross-crate.rs

@@ -3,7 +3,7 @@
 use cci_class_iface;
 import cci_class_iface::animals::*;
 
-class cat implements noisy {
+class cat : noisy {
   priv {
     let mut meows : uint;
     fn meow() {

src/test/run-pass/class-implement-ifaces.rs

@@ -2,7 +2,7 @@ iface noisy {
   fn speak();
 }
 
-class cat implements noisy {
+class cat : noisy {
   priv {
     let mut meows : uint;
     fn meow() {

src/test/run-pass/class-implements-multiple-ifaces.rs

@@ -24,7 +24,7 @@ fn vec_includes<T>(xs: [T], x: T) -> bool {
 }
 
 // vtables other than the 1st one don't seem to work
-class cat implements noisy, scratchy, bitey {
+class cat : noisy, scratchy, bitey {
   priv {
     let meows : @mut uint;
     let scratched : dvec<furniture>;