For #2229, recognize 'again' in place of 'cont', final change pending snapshot.

Author: graydon

doc/rust.md

@@ -209,9 +209,9 @@ import export use mod
 The keywords in [source files](#source-files) are the following strings:
 
 ~~~~~~~~ {.keyword}
-alt assert
+alt again assert
 break
-check claim class const cont copy
+check claim class const copy
 drop
 else enum export extern
 fail false fn for
@@ -2034,19 +2034,19 @@ break_expr : "break" ;
 Executing a `break` expression immediately terminates the innermost loop
 enclosing it. It is only permitted in the body of a loop.
 
-### Continue expressions
+### Again expressions
 
 ~~~~~~~~{.ebnf .gram}
-break_expr : "cont" ;
+again_expr : "again" ;
 ~~~~~~~~
 
-Evaluating a `cont` expression immediately terminates the current iteration of
+Evaluating an `again` expression immediately terminates the current iteration of
 the innermost loop enclosing it, returning control to the loop *head*. In the
 case of a `while` loop, the head is the conditional expression controlling the
-loop. In the case of a `for` loop, the head is the vector-element increment
-controlling the loop.
+loop. In the case of a `for` loop, the head is the call-expression controlling
+the loop.
 
-A `cont` expression is only permitted in the body of a loop.
+An `again` expression is only permitted in the body of a loop.
 
 
 ### For expressions

doc/tutorial.md

@@ -783,7 +783,7 @@ a specific value, are not allowed.
 
 `while` produces a loop that runs as long as its given condition
 (which must have type `bool`) evaluates to true. Inside a loop, the
-keyword `break` can be used to abort the loop, and `cont` can be used
+keyword `break` can be used to abort the loop, and `again` can be used
 to abort the current iteration and continue with the next.
 
 ~~~~
@@ -1187,7 +1187,7 @@ Empty argument lists can be omitted from `do` expressions.
 
 Most iteration in Rust is done with `for` loops. Like `do`,
 `for` is a nice syntax for doing control flow with closures.
-Additionally, within a `for` loop, `break, `cont`, and `ret`
+Additionally, within a `for` loop, `break, `again`, and `ret`
 work just as they do with `while` and `loop`.
 
 Consider again our `each` function, this time improved to
@@ -1221,8 +1221,8 @@ each(~[2, 4, 8, 5, 16], |n| {
 With `for`, functions like `each` can be treated more
 like builtin looping structures. When calling `each`
 in a `for` loop, instead of returning `false` to break
-out of the loop, you just write `break`. To continue
-to the next iteration, write `cont`.
+out of the loop, you just write `break`. To skip ahead
+to the next iteration, write `again`.
 
 ~~~~
 # import each = vec::each;

src/etc/emacs/rust-mode.el

@@ -56,9 +56,9 @@
 					"trait" "fn" "enum" "iface"
 					"impl"))
       (puthash word 'def table))
-    (dolist (word '("assert"
+    (dolist (word '("again" "assert"
                     "break"
-                    "check" "claim" "cont" "copy"
+                    "check" "claim" "copy"
                     "do" "drop"
                     "else" "export" "extern"
                     "fail" "for"

src/fuzzer/fuzzer.rs

@@ -42,7 +42,7 @@ fn common_exprs() -> ~[ast::expr] {
     }
 
     ~[dse(ast::expr_break),
-     dse(ast::expr_cont),
+     dse(ast::expr_again),
      dse(ast::expr_fail(option::none)),
      dse(ast::expr_fail(option::some(
          @dse(ast::expr_lit(@dsl(ast::lit_str(@"boo"))))))),

src/libsyntax/ast.rs

@@ -336,7 +336,7 @@ enum expr_ {
     expr_addr_of(mutability, @expr),
     expr_fail(option<@expr>),
     expr_break,
-    expr_cont,
+    expr_again,
     expr_ret(option<@expr>),
     expr_log(int, @expr, @expr),
 

src/libsyntax/fold.rs

@@ -464,7 +464,7 @@ fn noop_fold_expr(e: expr_, fld: ast_fold) -> expr_ {
           }
           expr_path(pth) { expr_path(fld.fold_path(pth)) }
           expr_fail(e) { expr_fail(option::map(e, fld.fold_expr)) }
-          expr_break | expr_cont { copy e }
+          expr_break | expr_again { copy e }
           expr_ret(e) { expr_ret(option::map(e, fld.fold_expr)) }
           expr_log(i, lv, e) { expr_log(i, fld.fold_expr(lv),
                                         fld.fold_expr(e)) }

src/libsyntax/parse/parser.rs

@@ -966,8 +966,9 @@ class parser {
         } else if self.eat_keyword("break") {
             ex = expr_break;
             hi = self.span.hi;
-        } else if self.eat_keyword("cont") {
-            ex = expr_cont;
+        } else if self.eat_keyword("cont") ||
+            self.eat_keyword("again") {
+            ex = expr_again;
             hi = self.span.hi;
         } else if self.eat_keyword("copy") {
             let e = self.parse_expr();

src/libsyntax/parse/token.rs

@@ -304,8 +304,7 @@ fn contextual_keyword_table() -> hashmap<str, ()> {
 fn restricted_keyword_table() -> hashmap<str, ()> {
     let words = str_hash();
     let keys = ~[
-        "alt",
-        "assert",
+        "alt", "again", "assert",
         "break",
         "check", "claim", "class", "const", "cont", "copy",
         "do", "drop",

src/libsyntax/print/pprust.rs

@@ -1063,7 +1063,7 @@ fn print_expr(s: ps, &&expr: @ast::expr) {
         }
       }
       ast::expr_break { word(s.s, "break"); }
-      ast::expr_cont { word(s.s, "cont"); }
+      ast::expr_again { word(s.s, "again"); }
       ast::expr_ret(result) {
         word(s.s, "ret");
         alt result {

src/libsyntax/visit.rs

@@ -421,7 +421,7 @@ fn visit_expr<E>(ex: @expr, e: E, v: vt<E>) {
       expr_path(p) { visit_path(p, e, v); }
       expr_fail(eo) { visit_expr_opt(eo, e, v); }
       expr_break { }
-      expr_cont { }
+      expr_again { }
       expr_ret(eo) { visit_expr_opt(eo, e, v); }
       expr_log(_, lv, x) {
         v.visit_expr(lv, e, v);