rustc: Switch mutability from being a type constructor to a field annotation

2 files changed, 60 insertions, 48 deletions

diff --git a/src/comp/front/ast.rs b/src/comp/front/ast.rs
index 1970f788..e519d03b 100644
--- a/src/comp/front/ast.rs
+++ b/src/comp/front/ast.rs
@@ -168,7 +168,6 @@ tag unop {
     bitnot;
     not;
     neg;
-    _mutable;
 }
 
 fn unop_to_str(unop op) -> str {
@@ -178,7 +177,6 @@ fn unop_to_str(unop op) -> str {
         case (bitnot) {ret "~";}
         case (not) {ret "!";}
         case (neg) {ret "-";}
-        case (_mutable) {ret "mutable";}
     }
 }
 
@@ -215,7 +213,7 @@ type field = rec(mutability mut, ident ident, @expr expr);
 
 type expr = spanned[expr_];
 tag expr_ {
-    expr_vec(vec[@expr], ann);
+    expr_vec(vec[@expr], mutability, ann);
     expr_tup(vec[elt], ann);
     expr_rec(vec[field], option.t[@expr], ann);
     expr_call(@expr, vec[@expr], ann);
@@ -263,7 +261,8 @@ tag lit_ {
 // NB: If you change this, you'll probably want to change the corresponding
 // type structure in middle/ty.rs as well.
 
-type ty_field = rec(ident ident, @ty ty);
+type mt = rec(@ty ty, mutability mut);
+type ty_field = rec(ident ident, mt mt);
 type ty_arg = rec(mode mode, @ty ty);
 // TODO: effect
 type ty_method = rec(proto proto, ident ident,
@@ -277,16 +276,15 @@ tag ty_ {
     ty_machine(util.common.ty_mach);
     ty_char;
     ty_str;
-    ty_box(@ty);
-    ty_vec(@ty);
+    ty_box(mt);
+    ty_vec(mt);
     ty_port(@ty);
     ty_chan(@ty);
-    ty_tup(vec[@ty]);
+    ty_tup(vec[mt]);
     ty_rec(vec[ty_field]);
     ty_fn(proto, vec[ty_arg], @ty);        // TODO: effect
     ty_obj(vec[ty_method]);
     ty_path(path, option.t[def]);
-    ty_mutable(@ty);
     ty_type;
     ty_constr(@ty, vec[@constr]);
 }
diff --git a/src/comp/front/parser.rs b/src/comp/front/parser.rs
index db09301c..71f0f2d8 100644
--- a/src/comp/front/parser.rs
+++ b/src/comp/front/parser.rs
@@ -189,6 +189,11 @@ impure fn parse_ty_fn(ast.proto proto, parser p,
         if (p.peek() == token.BINOP(token.AND)) {
             p.bump();
             mode = ast.alias;
+
+            if (p.peek() == token.MUTABLE) {
+                p.bump();
+                // TODO: handle mutable alias args
+            }
         } else {
             mode = ast.val;
         }
@@ -262,10 +267,16 @@ impure fn parse_ty_obj(parser p, &mutable ast.span hi) -> ast.ty_ {
     ret ast.ty_obj(meths.node);
 }
 
+impure fn parse_mt(parser p) -> ast.mt {
+    auto mut = parse_mutability(p);
+    auto t = parse_ty(p);
+    ret rec(ty=t, mut=mut);
+}
+
 impure fn parse_ty_field(parser p) -> ast.ty_field {
-    auto ty = parse_ty(p);
+    auto mt = parse_mt(p);
     auto id = parse_ident(p);
-    ret rec(ident=id, ty=ty);
+    ret rec(ident=id, mt=mt);
 }
 
 impure fn parse_constr_arg(parser p) -> @ast.constr_arg {
@@ -360,25 +371,25 @@ impure fn parse_ty(parser p) -> @ast.ty {
 
         case (token.AT) {
             p.bump();
-            auto t0 = parse_ty(p);
-            hi = t0.span;
-            t = ast.ty_box(t0);
+            auto mt = parse_mt(p);
+            hi = mt.ty.span;
+            t = ast.ty_box(mt);
         }
 
         case (token.VEC) {
             p.bump();
             expect(p, token.LBRACKET);
-            t = ast.ty_vec(parse_ty(p));
+            t = ast.ty_vec(parse_mt(p));
             hi = p.get_span();
             expect(p, token.RBRACKET);
         }
 
         case (token.TUP) {
             p.bump();
-            auto f = parse_ty; // FIXME: trans_const_lval bug
-            auto elems = parse_seq[@ast.ty] (token.LPAREN,
-                                             token.RPAREN,
-                                             some(token.COMMA), f, p);
+            auto f = parse_mt; // FIXME: trans_const_lval bug
+            auto elems = parse_seq[ast.mt] (token.LPAREN,
+                                            token.RPAREN,
+                                            some(token.COMMA), f, p);
             hi = elems.span;
             t = ast.ty_tup(elems.node);
         }
@@ -395,13 +406,6 @@ impure fn parse_ty(parser p) -> @ast.ty {
             t = ast.ty_rec(elems.node);
         }
 
-        case (token.MUTABLE) {
-            p.bump();
-            auto t0 = parse_ty(p);
-            hi = t0.span;
-            t = ast.ty_mutable(t0);
-        }
-
         case (token.FN) {
             auto flo = p.get_span();
             p.bump();
@@ -463,20 +467,22 @@ impure fn parse_arg(parser p) -> ast.arg {
     if (p.peek() == token.BINOP(token.AND)) {
         m = ast.alias;
         p.bump();
+
+        if (p.peek() == token.MUTABLE) {
+            // TODO: handle mutable alias args
+            p.bump();
+        }
     }
     let @ast.ty t = parse_ty(p);
     let ast.ident i = parse_ident(p);
     ret rec(mode=m, ty=t, ident=i, id=p.next_def_id());
 }
 
-impure fn parse_seq[T](token.token bra,
-                      token.token ket,
-                      option.t[token.token] sep,
-                      (impure fn(parser) -> T) f,
-                      parser p) -> util.common.spanned[vec[T]] {
+impure fn parse_seq_to_end[T](token.token ket,
+                              option.t[token.token] sep,
+                              (impure fn(parser) -> T) f,
+                              parser p) -> vec[T] {
     let bool first = true;
-    auto lo = p.get_span();
-    expect(p, bra);
     let vec[T] v = vec();
     while (p.peek() != ket) {
         alt(sep) {
@@ -494,9 +500,20 @@ impure fn parse_seq[T](token.token bra,
         let T t = f(p);
         v += vec(t);
     }
-    auto hi = p.get_span();
     expect(p, ket);
-    ret spanned(lo, hi, v);
+    ret v;
+}
+
+impure fn parse_seq[T](token.token bra,
+                      token.token ket,
+                      option.t[token.token] sep,
+                      (impure fn(parser) -> T) f,
+                      parser p) -> util.common.spanned[vec[T]] {
+    auto lo = p.get_span();
+    expect(p, bra);
+    auto result = parse_seq_to_end[T](ket, sep, f, p);
+    auto hi = p.get_span();
+    ret spanned(lo, hi, result);
 }
 
 impure fn parse_lit(parser p) -> ast.lit {
@@ -667,12 +684,15 @@ impure fn parse_bottom_expr(parser p) -> @ast.expr {
         case (token.VEC) {
             p.bump();
             auto pf = parse_expr;
-            auto es = parse_seq[@ast.expr](token.LPAREN,
-                                           token.RPAREN,
-                                           some(token.COMMA),
-                                           pf, p);
-            hi = es.span;
-            ex = ast.expr_vec(es.node, ast.ann_none);
+
+            expect(p, token.LPAREN);
+            auto mut = parse_mutability(p);
+
+            auto es = parse_seq_to_end[@ast.expr](token.RPAREN,
+                                                  some(token.COMMA),
+                                                  pf, p);
+            hi = p.get_span();
+            ex = ast.expr_vec(es, mut, ast.ann_none);
         }
 
         case (token.REC) {
@@ -1004,13 +1024,6 @@ impure fn parse_prefix_expr(parser p) -> @ast.expr {
             ex = ast.expr_unary(ast.box, e, ast.ann_none);
         }
 
-        case (token.MUTABLE) {
-            p.bump();
-            auto e = parse_prefix_expr(p);
-            hi = e.span;
-            ex = ast.expr_unary(ast._mutable, e, ast.ann_none);
-        }
-
         case (_) {
             ret parse_dot_or_call_expr(p);
         }
@@ -1558,7 +1571,7 @@ fn stmt_ends_with_semi(@ast.stmt stmt) -> bool {
         }
         case (ast.stmt_expr(?e)) {
             alt (e.node) {
-                case (ast.expr_vec(_,_))        { ret true; }
+                case (ast.expr_vec(_,_,_))      { ret true; }
                 case (ast.expr_tup(_,_))        { ret true; }
                 case (ast.expr_rec(_,_,_))      { ret true; }
                 case (ast.expr_call(_,_,_))     { ret true; }
@@ -1722,6 +1735,7 @@ impure fn parse_item_fn_or_iter(parser p, ast.effect eff) -> @ast.item {
 
 
 impure fn parse_obj_field(parser p) -> ast.obj_field {
+    auto mut = parse_mutability(p); // TODO: store this, use it in typeck
     auto ty = parse_ty(p);
     auto ident = parse_ident(p);
     ret rec(ty=ty, ident=ident, id=p.next_def_id(), ann=ast.ann_none);