rustc: Make functions output a type, not a slot

Author: pcwalton

src/comp/front/ast.rs

@@ -129,7 +129,7 @@ type slot = rec(@ty ty, mode mode, option[slot_id] id);
 type input = rec(slot slot, ident ident);
 
 type _fn = rec(vec[input] inputs,
-               slot output,
+               ty output,
                block body);
 
 type _mod = hashmap[ident,@item];

src/comp/front/parser.rs

@@ -603,13 +603,12 @@ io fn parse_fn(parser p) -> tup(ast.ident, @ast.item) {
          some(token.COMMA),
          pf, p);
 
-    let ast.slot output;
+    let ast.ty output;
     if (p.peek() == token.RARROW) {
         p.bump();
-        output = rec(ty=parse_ty(p), mode=ast.val, id=none[ast.slot_id]);
+        output = *parse_ty(p);
     } else {
-        output = rec(ty=@spanned(lo, inputs.span, ast.ty_nil),
-                     mode=ast.val, id=none[ast.slot_id]);
+        output = spanned(lo, inputs.span, ast.ty_nil);
     }
 
     auto body = parse_block(p);

src/comp/middle/fold.rs

@@ -120,7 +120,7 @@ type ast_fold[ENV] =
          vec[@stmt] stmts) -> block)              fold_block,
 
      (fn(&ENV e, vec[ast.input] inputs,
-         &slot output, block body) -> ast._fn)    fold_fn,
+         &ty output, block body) -> ast._fn)      fold_fn,
 
      (fn(&ENV e, &ast._mod m) -> ast._mod)        fold_mod,
 
@@ -310,10 +310,10 @@ fn fold_fn[ENV](&ENV env, ast_fold[ENV] fld, &ast._fn f) -> ast._fn {
 
     let operator[ast.input,ast.input] fi = bind fold_input[ENV](env, fld, _);
     auto inputs = _vec.map[ast.input, ast.input](fi, f.inputs);
-    auto output = fold_slot[ENV](env, fld, f.output);
+    auto output = fold_ty[ENV](env, fld, @f.output);
     auto body = fold_block[ENV](env, fld, f.body);
 
-    ret fld.fold_fn(env, inputs, output, body);
+    ret fld.fold_fn(env, inputs, *output, body);
 }
 
 fn fold_item[ENV](&ENV env, ast_fold[ENV] fld, @item i) -> @item {
@@ -539,7 +539,7 @@ fn identity_fold_block[ENV](&ENV e, &span sp, vec[@stmt] stmts) -> block {
 
 fn identity_fold_fn[ENV](&ENV e,
                          vec[ast.input] inputs,
-                         &slot output,
+                         &ast.ty output,
                          block body) -> ast._fn {
     ret rec(inputs=inputs, output=output, body=body);
 }