pre-intern some fixed names so they can be used as constants

Author: paulstansifer

src/libsyntax/parse/token.rs

@@ -279,9 +279,18 @@ pure fn is_bar(t: token) -> bool {
 
 type ident_interner = util::interner::interner<@~str>;
 
+mod special_idents {
+    const underscore : uint = 0u;
+    const anon : uint = 1u;
+    const destr : uint = 2u; // 'drop', but that's reserved
+}
+
 fn mk_ident_interner() -> ident_interner {
-    let rv = @interner::mk::<@~str>(|x| str::hash(*x),
-                                    |x,y| str::eq(*x, *y));
+    /* the indices here must correspond to the numbers in special_idents */
+    let init_vec = ~[@~"_", @~"anon", @~"drop"];
+
+    let rv = @interner::mk_prefill::<@~str>(|x| str::hash(*x),
+                                            |x,y| str::eq(*x, *y), init_vec);
     rv
 }
 

src/libsyntax/util/interner.rs

@@ -18,6 +18,15 @@ fn mk<T: const copy>(+hasher: hashfn<T>, +eqer: eqfn<T>) -> interner<T> {
     return hi as interner::<T>;
 }
 
+fn mk_prefill<T: const copy>(hasher: hashfn<T>, eqer: eqfn<T>,
+                             init: ~[T]) -> interner<T> {
+
+    let rv = mk(hasher, eqer);
+    for init.each() |v| { rv.intern(v); }
+    return rv;
+}
+
+
 /* when traits can extend traits, we should extend index<uint,T> to get [] */
 trait interner<T: const copy> {
     fn intern(T) -> uint;