rustc: Resolve pattern bindings

2 files changed, 22 insertions, 2 deletions

diff --git a/src/comp/front/ast.rs b/src/comp/front/ast.rs
index 71065150..11db3eed 100644
--- a/src/comp/front/ast.rs
+++ b/src/comp/front/ast.rs
@@ -33,6 +33,7 @@ tag def {
     def_variant(def_id /* tag */, def_id /* variant */);
     def_ty(def_id);
     def_ty_arg(def_id);
+    def_binding(def_id);
 }
 
 type crate = spanned[crate_];
@@ -124,7 +125,7 @@ tag decl_ {
     decl_item(@item);
 }
 
-type arm = rec(@pat pat, block block);
+type arm = rec(@pat pat, block block, hashmap[ident,def_id] index);
 
 type elt = rec(mutability mut, @expr expr);
 type field = rec(mutability mut, ident ident, @expr expr);
diff --git a/src/comp/front/parser.rs b/src/comp/front/parser.rs
index f8db2f71..decb28e1 100644
--- a/src/comp/front/parser.rs
+++ b/src/comp/front/parser.rs
@@ -817,8 +817,9 @@ impure fn parse_alt_expr(parser p) -> @ast.expr {
                 expect(p, token.LPAREN);
                 auto pat = parse_pat(p);
                 expect(p, token.RPAREN);
+                auto index = index_arm(pat);
                 auto block = parse_block(p);
-                arms += vec(rec(pat=pat, block=block));
+                arms += vec(rec(pat=pat, block=block, index=index));
             }
             case (token.RBRACE) { /* empty */ }
             case (?tok) {
@@ -1082,6 +1083,24 @@ fn index_block(vec[@ast.stmt] stmts, option.t[@ast.expr] expr) -> ast.block_ {
     ret rec(stmts=stmts, expr=expr, index=index);
 }
 
+fn index_arm(@ast.pat pat) -> hashmap[ast.ident,ast.def_id] {
+    fn do_index_arm(&hashmap[ast.ident,ast.def_id] index, @ast.pat pat) {
+        alt (pat.node) {
+            case (ast.pat_bind(?i, ?def_id, _)) { index.insert(i, def_id); }
+            case (ast.pat_wild(_)) { /* empty */ }
+            case (ast.pat_tag(_, ?pats, _)) {
+                for (@ast.pat p in pats) {
+                    do_index_arm(index, p);
+                }
+            }
+        }
+    }
+
+    auto index = new_str_hash[ast.def_id]();
+    do_index_arm(index, pat);
+    ret index;
+}
+
 fn stmt_to_expr(@ast.stmt stmt) -> option.t[@ast.expr] {
     alt (stmt.node) {
         case (ast.stmt_expr(?e)) { ret some[@ast.expr](e); }