box patterns, expect for the trans part

src/comp/middle/alias.rs

@@ -312,6 +312,7 @@ fn arm_defnums(&ast::arm arm) -> vec[node_id] {
             case (ast::pat_rec(?fields, _)) {
                 for (ast::field_pat f in fields) { walk_pat(found, f.pat); }
             }
+            case (ast::pat_box(?inner)) { walk_pat(found, inner); }
             case (_) { }
         }
     }

src/comp/middle/resolve.rs

@@ -311,6 +311,7 @@ fn resolve_names(&@env e, &@ast::crate c) {
             case (ast::pat_rec(?fields, _)) {
                 for (ast::field_pat f in fields) { walk_pat(e, sc, f.pat); }
             }
+            case (ast::pat_box(?inner)) { walk_pat(e, sc, inner); }
             case (_) { }
         }
     }
@@ -727,6 +728,7 @@ fn lookup_in_pat(&ident name, &ast::pat pat) -> option::t[def] {
                 if (!option::is_none(found)) { ret found; }
             }
         }
+        case (ast::pat_box(?inner)) { ret lookup_in_pat(name, *inner); }
     }
     ret none[def];
 }
@@ -1268,6 +1270,7 @@ fn check_arm(@env e, &ast::arm a, &() x, &vt[()] v) {
             case (ast::pat_rec(?fields, _)) {
                 for (ast::field_pat f in fields) { walk_pat(ch, f.pat); }
             }
+            case (ast::pat_box(?inner)) { walk_pat(ch, inner); }
             case (_) { }
         }
     }

src/comp/middle/typeck.rs

@@ -1435,6 +1435,20 @@ fn check_pat(&@fn_ctxt fcx, &ast::pat_id_map map, &@ast::pat pat,
             }
             write::ty_only_fixup(fcx, pat.id, expected);
         }
+        case (ast::pat_box(?inner)) {
+            alt (structure_of(fcx, pat.span, expected)) {
+                case (ty::ty_box(?e_inner)) {
+                    check_pat(fcx, map, inner, e_inner.ty);
+                    write::ty_only_fixup(fcx, pat.id, expected);
+                }
+                case (_) {
+                    fcx.ccx.tcx.sess.span_fatal
+                        (pat.span, "mismatched types: expected " +
+                         ty_to_str(fcx.ccx.tcx, expected) +
+                         " found box");
+                }
+            }
+        }
     }
 }
 

src/comp/syntax/ast.rs

@@ -126,6 +126,7 @@ tag pat_ {
     pat_lit(@lit);
     pat_tag(path, (@pat)[]);
     pat_rec(field_pat[], bool);
+    pat_box(@pat);
 }
 
 type pat_id_map = std::map::hashmap[str, ast::node_id];
@@ -143,6 +144,7 @@ fn pat_id_map(&@pat pat) -> pat_id_map {
             pat_rec(?fields, _) {
                 for (field_pat f in fields) { walk(map, f.pat); }
             }
+            pat_box(?inner) { walk(map, inner); }
             _ {}
         }
     }

src/comp/syntax/fold.rs

@@ -292,6 +292,7 @@ fn noop_fold_pat(&pat_ p, ast_fold fld) -> pat_ {
             }
             pat_rec(fs, etc)
         }
+        case (pat_box(?inner)) { pat_box(fld.fold_pat(inner)) }
     };
 }
 

src/comp/syntax/parse/parser.rs

@@ -1459,6 +1459,12 @@ fn parse_pat(&parser p) -> @ast::pat {
                 }
             }
         }
+        case (token::AT) {
+            p.bump();
+            auto sub = parse_pat(p);
+            pat = ast::pat_box(sub);
+            hi = sub.span.hi;
+        }
         case (token::LBRACE) {
             p.bump();
             auto fields = ~[];
@@ -2313,9 +2319,8 @@ fn parse_rest_import_name(&parser p, ast::ident first,
         }
         alt (p.peek()) {
             case (token::IDENT(_, _)) { identifiers += ~[parse_ident(p)]; }
-            case (
-                 //the lexer can't tell the different kinds of stars apart ) :
-                 token::BINOP(token::STAR)) {
+            //the lexer can't tell the different kinds of stars apart ) :
+            case (token::BINOP(token::STAR)) {
                 glob = true;
                 p.bump();
             }

src/comp/syntax/print/pprust.rs

@@ -1136,6 +1136,10 @@ fn print_pat(&ps s, &@ast::pat pat) {
             }
             word(s.s, "}");
         }
+        case (ast::pat_box(?inner)) {
+            word(s.s, "@");
+            print_pat(s, inner);
+        }
     }
     s.ann.post(ann_node);
 }

src/comp/syntax/visit.rs

@@ -200,6 +200,7 @@ fn visit_pat[E](&@pat p, &E e, &vt[E] v) {
         case (pat_rec(?fields, _)) {
             for (field_pat f in fields) { v.visit_pat(f.pat, e, v); }
         }
+        case (pat_box(?inner)) { v.visit_pat(inner, e, v); }
         case (_) { }
     }
 }

src/comp/syntax/walk.rs

@@ -192,6 +192,7 @@ fn walk_pat(&ast_visitor v, &@ast::pat p) {
         case (ast::pat_rec(?fields, _)) {
             for (ast::field_pat f in fields) { walk_pat(v, f.pat); }
         }
+        case (ast::pat_box(?inner)) { walk_pat(v, inner); }
         case (_) { }
     }
     v.visit_pat_post(p);