auto merge of #4922 : jbclements/rust/add-deriving-eq-to-asts, r=catamorphism

r?

Apply deriving_eq to the data structures in ast.rs, and get rid of the custom definitions of eq that were everywhere. resulting ast.rs is about 400 lines shorter.

Also: add a few test cases and a bunch of comments.

Also: change ast_ty_to_ty_cache to use node ids rather than ast::ty's. I believe this was a suggestion related to my changes, and it appears to pass all tests.

Also: tiny doc fix, remove references to crate keywords.

src/libsyntax/parse/parser.rs

@@ -182,7 +182,8 @@ pure fn maybe_append(+lhs: ~[attribute], rhs: Option<~[attribute]>)
 
 /* ident is handled by common.rs */
 
-pub fn Parser(sess: parse_sess,
+pub fn Parser(sess: parse_sess
+              ,
               cfg: ast::crate_cfg,
               +rdr: reader) -> Parser {
 
@@ -1238,6 +1239,8 @@ pub impl Parser {
         return e;
     }
 
+    // parse an optional separator followed by a kleene-style
+    // repetition token (+ or *).
     fn parse_sep_and_zerok() -> (Option<token::Token>, bool) {
         if self.token == token::BINOP(token::STAR)
             || self.token == token::BINOP(token::PLUS) {
@@ -1258,20 +1261,18 @@ pub impl Parser {
         }
     }
 
+    // parse a single token tree from the input.
     fn parse_token_tree() -> token_tree {
         maybe_whole!(deref self, nt_tt);
 
-        fn parse_tt_tok(p: Parser, delim_ok: bool) -> token_tree {
+        fn parse_non_delim_tt_tok(p: Parser) -> token_tree {
             maybe_whole!(deref p, nt_tt);
             match p.token {
               token::RPAREN | token::RBRACE | token::RBRACKET
-              if !delim_ok => {
+              => {
                 p.fatal(~"incorrect close delimiter: `"
                            + token_to_str(p.reader, p.token) + ~"`");
               }
-              token::EOF => {
-                p.fatal(~"file ended in the middle of a macro invocation");
-              }
               /* we ought to allow different depths of unquotation */
               token::DOLLAR if p.quote_depth > 0u => {
                 p.bump();
@@ -1282,32 +1283,43 @@ pub impl Parser {
                                           seq_sep_none(),
                                           |p| p.parse_token_tree());
                     let (s, z) = p.parse_sep_and_zerok();
-                    return tt_seq(mk_sp(sp.lo ,p.span.hi), seq.node, s, z);
+                    tt_seq(mk_sp(sp.lo ,p.span.hi), seq.node, s, z)
                 } else {
-                    return tt_nonterminal(sp, p.parse_ident());
+                    tt_nonterminal(sp, p.parse_ident())
                 }
               }
-              _ => { /* ok */ }
+              _ => {
+                  parse_any_tt_tok(p)
+              }
             }
-            let res = tt_tok(p.span, p.token);
-            p.bump();
-            return res;
         }
 
-        return match self.token {
+        // turn the next token into a tt_tok:
+        fn parse_any_tt_tok(p: Parser) -> token_tree{
+            let res = tt_tok(p.span, p.token);
+            p.bump();
+            res
+        }
+
+        match self.token {
+          token::EOF => {
+                self.fatal(~"file ended in the middle of a macro invocation");
+          }
           token::LPAREN | token::LBRACE | token::LBRACKET => {
               // tjc: ??????
             let ket = token::flip_delimiter(copy self.token);
             tt_delim(vec::append(
-                ~[parse_tt_tok(self, true)],
+                // the open delimiter:
+                ~[parse_any_tt_tok(self)],
                 vec::append(
                     self.parse_seq_to_before_end(
                         ket, seq_sep_none(),
                         |p| p.parse_token_tree()),
-                    ~[parse_tt_tok(self, true)])))
+                    // the close delimiter:
+                    ~[parse_any_tt_tok(self)])))
           }
-          _ => parse_tt_tok(self, false)
-        };
+          _ => parse_non_delim_tt_tok(self)
+        }
     }
 
     fn parse_all_token_trees() -> ~[token_tree] {
@@ -3999,6 +4011,7 @@ pub impl Parser {
     }
 }
 
+
 //
 // Local Variables:
 // mode: rust