Move hash table iteration over to block-taking functions

Issue #1056

9 files changed, 82 insertions, 86 deletions

diff --git a/src/comp/metadata/cstore.rs b/src/comp/metadata/cstore.rs
index ee80b11fb5b..f005b0bb991 100644
--- a/src/comp/metadata/cstore.rs
+++ b/src/comp/metadata/cstore.rs
@@ -72,12 +72,8 @@ fn have_crate_data(cstore: cstore, cnum: ast::crate_num) -> bool {
     ret p(cstore).metas.contains_key(cnum);
 }
 
-iter iter_crate_data(cstore: cstore) ->
-     @{key: ast::crate_num, val: crate_metadata} {
-    for each kv: @{key: ast::crate_num, val: crate_metadata} in
-             p(cstore).metas.items() {
-        put kv;
-    }
+fn iter_crate_data(cstore: cstore, i: block(ast::crate_num, crate_metadata)) {
+    p(cstore).metas.items {|k,v| i(k, v);};
 }
 
 fn add_used_crate_file(cstore: cstore, lib: str) {
diff --git a/src/comp/metadata/encoder.rs b/src/comp/metadata/encoder.rs
index 3617005a400..f392d2367e4 100644
--- a/src/comp/metadata/encoder.rs
+++ b/src/comp/metadata/encoder.rs
@@ -371,20 +371,19 @@ fn encode_info_for_items(ecx: @encode_ctxt, ebml_w: ebml::writer) ->
    [entry<int>] {
     let index: [entry<int>] = [];
     ebml::start_tag(ebml_w, tag_items_data);
-    for each kvp: @{key: node_id, val: middle::ast_map::ast_node} in
-             ecx.ccx.ast_map.items() {
-        alt kvp.val {
+    ecx.ccx.ast_map.items {|key, val|
+        alt val {
           middle::ast_map::node_item(i) {
-            index += [{val: kvp.key, pos: ebml_w.writer.tell()}];
+            index += [{val: key, pos: ebml_w.writer.tell()}];
             encode_info_for_item(ecx, ebml_w, i, index);
           }
           middle::ast_map::node_native_item(i) {
-            index += [{val: kvp.key, pos: ebml_w.writer.tell()}];
+            index += [{val: key, pos: ebml_w.writer.tell()}];
             encode_info_for_native_item(ecx, ebml_w, i);
           }
           _ { }
         }
-    }
+    };
     ebml::end_tag(ebml_w);
     ret index;
 }
@@ -544,9 +543,9 @@ fn encode_crate_deps(ebml_w: ebml::writer, cstore: cstore::cstore) {
 
         // Pull the cnums and names out of cstore
         let pairs: [mutable numname] = [mutable];
-        for each hashkv: hashkv in cstore::iter_crate_data(cstore) {
-            pairs += [mutable {crate: hashkv.key, ident: hashkv.val.name}];
-        }
+        cstore::iter_crate_data(cstore) {|key, val|
+            pairs += [mutable {crate: key, ident: val.name}];
+        };
 
         // Sort by cnum
         fn lteq(kv1: numname, kv2: numname) -> bool { kv1.crate <= kv2.crate }
diff --git a/src/comp/middle/ast_map.rs b/src/comp/middle/ast_map.rs
index 9b89ec63331..d141a2a86e2 100644
--- a/src/comp/middle/ast_map.rs
+++ b/src/comp/middle/ast_map.rs
@@ -86,14 +86,13 @@ fn new_smallintmap_int_adapter<@V>() -> std::map::hashmap<int, V> {
 // the entire codebase adapting all the callsites to the different
 // interface.
 // FIXME: hashmap and smallintmap should support the same interface.
-fn new_smallintmap_adapter<@K,
-                           @V>(key_idx: fn(K) -> uint, idx_key: fn(uint) -> K)
-   -> std::map::hashmap<K, V> {
+fn new_smallintmap_adapter<@K, @V>(key_idx: fn(K) -> uint,
+                                   idx_key: fn(uint) -> K)
+    -> std::map::hashmap<K, V> {
 
-    obj adapter<@K,
-                @V>(map: smallintmap::smallintmap<V>,
-                    key_idx: fn(K) -> uint,
-                    idx_key: fn(uint) -> K) {
+    obj adapter<@K, @V>(map: smallintmap::smallintmap<V>,
+                        key_idx: fn(K) -> uint,
+                        idx_key: fn(uint) -> K) {
 
         fn size() -> uint { fail }
 
@@ -117,22 +116,29 @@ fn new_smallintmap_adapter<@K,
 
         fn rehash() { fail }
 
-        iter items() -> @{key: K, val: V} {
+        fn items(it: block(K, V)) {
             let idx = 0u;
-            for item: option::t<V> in map.v {
+            for item in map.v {
                 alt item {
                   option::some(elt) {
-                    let value = elt;
-                    let key = idx_key(idx);
-                    put @{key: key, val: value};
+                    it(idx_key(idx), elt);
                   }
                   option::none. { }
                 }
                 idx += 1u;
             }
         }
-        iter keys() -> K {
-            for each p: @{key: K, val: V} in self.items() { put p.key; }
+        fn keys(it: block(K)) {
+            let idx = 0u;
+            for item in map.v {
+                if item != option::none { it(idx_key(idx)); }
+                idx += 1u;
+            }
+        }
+        fn values(it: block(V)) {
+            for item in map.v {
+                alt item { option::some(elt) { it(elt); } _ {} }
+            }
         }
     }
 
diff --git a/src/comp/middle/resolve.rs b/src/comp/middle/resolve.rs
index 2d3fcb46406..1203a3e3419 100644
--- a/src/comp/middle/resolve.rs
+++ b/src/comp/middle/resolve.rs
@@ -48,12 +48,8 @@ type scopes = list<scope>;
 tag import_state {
     todo(ast::node_id, ast::ident, [ast::ident], codemap::span, scopes);
     resolving(span);
-    resolved(option::t<def>,
-
-             /* value */
-             option::t<def>,
-
-             /* type */
+    resolved(option::t<def>, /* value */
+             option::t<def>, /* type */
              option::t<def>); /* module */
 }
 
@@ -241,15 +237,14 @@ fn map_crate(e: @env, c: @ast::crate) {
 }
 
 fn resolve_imports(e: env) {
-    for each it: @{key: ast::node_id, val: import_state} in e.imports.items()
-             {
-        alt it.val {
+    e.imports.values {|v|
+        alt v {
           todo(node_id, name, path, span, scopes) {
             resolve_import(e, local_def(node_id), name, path, span, scopes);
           }
           resolved(_, _, _) { }
         }
-    }
+    };
     e.sess.abort_if_errors();
 }
 
@@ -1188,12 +1183,9 @@ fn lookup_external(e: env, cnum: int, ids: [ident], ns: namespace) ->
 fn check_for_collisions(e: @env, c: ast::crate) {
     // Module indices make checking those relatively simple -- just check each
     // name for multiple entities in the same namespace.
-    for each m: @{key: ast::node_id, val: @indexed_mod} in e.mod_map.items() {
-        for each name: @{key: ident, val: list<mod_index_entry>} in
-                 m.val.index.items() {
-            check_mod_name(*e, name.key, name.val);
-        }
-    }
+    e.mod_map.values {|val|
+        val.index.items {|k, v| check_mod_name(*e, k, v); };
+    };
     // Other scopes have to be checked the hard way.
     let v =
         @{visit_item: bind check_item(e, _, _, _),
@@ -1426,7 +1418,7 @@ fn check_bad_exports(e: @env) {
                                                     ns_type, inside));
     }
 
-    for each @{val: val, _} in e.mod_map.items() {
+    e.mod_map.values {|val|
         alt val.m {
           some(m) {
             for vi in m.view_items {
@@ -1447,7 +1439,7 @@ fn check_bad_exports(e: @env) {
           }
           none. { }
         }
-    }
+    };
 }
 
 // Local Variables:
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index de5c3cb5398..87ddd1df145 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -1249,10 +1249,10 @@ fn make_generic_glue(cx: @local_ctxt, sp: span, t: ty::t, llfn: ValueRef,
 }
 
 fn emit_tydescs(ccx: @crate_ctxt) {
-    for each pair: @{key: ty::t, val: @tydesc_info} in ccx.tydescs.items() {
+    ccx.tydescs.items {|key, val|
         let glue_fn_ty = T_ptr(T_glue_fn(*ccx));
         let cmp_fn_ty = T_ptr(T_cmp_glue_fn(*ccx));
-        let ti = pair.val;
+        let ti = val;
         let take_glue =
             alt ti.take_glue {
               none. { ccx.stats.n_null_glues += 1u; C_null(glue_fn_ty) }
@@ -1274,7 +1274,7 @@ fn emit_tydescs(ccx: @crate_ctxt) {
               some(v) { ccx.stats.n_real_glues += 1u; v }
             };
 
-        let shape = shape::shape_of(ccx, pair.key, ti.ty_params,
+        let shape = shape::shape_of(ccx, key, ti.ty_params,
                                     ti.is_obj_body);
         let shape_tables =
             llvm::LLVMConstPointerCast(ccx.shape_cx.llshapetables,
@@ -1303,7 +1303,7 @@ fn emit_tydescs(ccx: @crate_ctxt) {
         llvm::LLVMSetGlobalConstant(gvar, True);
         llvm::LLVMSetLinkage(gvar,
                              lib::llvm::LLVMInternalLinkage as llvm::Linkage);
-    }
+    };
 }
 
 fn make_take_glue(cx: @block_ctxt, v: ValueRef, t: ty::t) {
@@ -6144,10 +6144,10 @@ fn create_module_map(ccx: @crate_ctxt) -> ValueRef {
     llvm::LLVMSetLinkage(map,
                          lib::llvm::LLVMInternalLinkage as llvm::Linkage);
     let elts: [ValueRef] = [];
-    for each item: @{key: str, val: ValueRef} in ccx.module_data.items() {
-        let elt = C_struct([p2i(C_cstr(ccx, item.key)), p2i(item.val)]);
+    ccx.module_data.items {|key, val|
+        let elt = C_struct([p2i(C_cstr(ccx, key)), p2i(val)]);
         elts += [elt];
-    }
+    };
     let term = C_struct([C_int(0), C_int(0)]);
     elts += [term];
     llvm::LLVMSetInitializer(map, C_array(elttype, elts));
diff --git a/src/comp/middle/trans_alt.rs b/src/comp/middle/trans_alt.rs
index 814a287bbc6..c6d59a72831 100644
--- a/src/comp/middle/trans_alt.rs
+++ b/src/comp/middle/trans_alt.rs
@@ -356,10 +356,10 @@ fn compile_submatch(bcx: @block_ctxt, m: match, vals: [ValueRef], f: mk_fail,
             Br(bcx, guard_cx.llbb);
             // Temporarily set bindings. They'll be rewritten to PHI nodes for
             // the actual arm block.
-            for each @{key: key, val: val} in data.id_map.items() {
+            data.id_map.items {|key, val|
                 let local = local_mem(option::get(assoc(key, m[0].bound)));
                 bcx.fcx.lllocals.insert(val, local);
-            }
+            };
             let {bcx: guard_bcx, val: guard_val} =
                 trans::trans_temp_expr(guard_cx, e);
             guard_bcx = trans::trans_block_cleanups(guard_bcx, guard_cx);
@@ -582,7 +582,7 @@ fn make_phi_bindings(bcx: @block_ctxt, map: [exit_node],
                      ids: ast_util::pat_id_map) -> bool {
     let our_block = bcx.llbb as uint;
     let success = true;
-    for each @{key: name, val: node_id} in ids.items() {
+    ids.items {|name, node_id|
         let llbbs = [];
         let vals = [];
         for ex: exit_node in map {
@@ -597,10 +597,10 @@ fn make_phi_bindings(bcx: @block_ctxt, map: [exit_node],
             let local = Phi(bcx, val_ty(vals[0]), vals, llbbs);
             bcx.fcx.lllocals.insert(node_id, local_mem(local));
         } else { success = false; }
-    }
+    };
     if success {
         // Copy references that the alias analysis considered unsafe
-        for each @{val: node_id, _} in ids.items() {
+        ids.values {|node_id|
             if bcx_ccx(bcx).copy_map.contains_key(node_id) {
                 let local = alt bcx.fcx.lllocals.get(node_id) {
                   local_mem(x) { x }
@@ -613,7 +613,7 @@ fn make_phi_bindings(bcx: @block_ctxt, map: [exit_node],
                 add_clean(bcx, alloc, e_ty);
                 bcx.fcx.lllocals.insert(node_id, local_mem(alloc));
             }
-        }
+        };
     } else {
         Unreachable(bcx);
     }
diff --git a/src/comp/middle/tstate/auxiliary.rs b/src/comp/middle/tstate/auxiliary.rs
index 99d3252a2dc..af4bb26a08a 100644
--- a/src/comp/middle/tstate/auxiliary.rs
+++ b/src/comp/middle/tstate/auxiliary.rs
@@ -539,10 +539,9 @@ fn norm_a_constraint(id: def_id, c: constraint) -> [norm_constraint] {
 // non-exhaustive match in trans.
 fn constraints(fcx: fn_ctxt) -> [norm_constraint] {
     let rslt: [norm_constraint] = [];
-    for each p: @{key: def_id, val: constraint} in
-             fcx.enclosing.constrs.items() {
-        rslt += norm_a_constraint(p.key, p.val);
-    }
+    fcx.enclosing.constrs.items {|key, val|
+        rslt += norm_a_constraint(key, val);
+    };
     ret rslt;
 }
 
@@ -861,17 +860,16 @@ fn copy_in_poststate_two(fcx: fn_ctxt, src_post: poststate,
     }
 
 
-    for each p: @{key: def_id, val: constraint} in
-             fcx.enclosing.constrs.items() {
+    fcx.enclosing.constrs.values {|val|
         // replace any occurrences of the src def_id with the
         // dest def_id
-        let insts = find_instances(fcx, subst, p.val);
+        let insts = find_instances(fcx, subst, val);
         for p: {from: uint, to: uint} in insts {
             if promises_(p.from, src_post) {
                 set_in_poststate_(p.to, target_post);
             }
         }
-    }
+    };
 }
 
 
diff --git a/src/comp/syntax/ext/simplext.rs b/src/comp/syntax/ext/simplext.rs
index d7b4214f2d0..d766ff11579 100644
--- a/src/comp/syntax/ext/simplext.rs
+++ b/src/comp/syntax/ext/simplext.rs
@@ -172,12 +172,12 @@ fn use_selectors_to_bind(b: binders, e: @expr) -> option::t<bindings> {
         alt sel(match_expr(e)) { none. { ret none; } _ { } }
     }
     let never_mind: bool = false;
-    for each pair: @{key: ident, val: selector} in b.real_binders.items() {
-        alt pair.val(match_expr(e)) {
+    b.real_binders.items {|key, val|
+        alt val(match_expr(e)) {
           none. { never_mind = true; }
-          some(mtc) { res.insert(pair.key, mtc); }
+          some(mtc) { res.insert(key, mtc); }
         }
-    }
+    };
     //HACK: `ret` doesn't work in `for each`
     if never_mind { ret none; }
     ret some(res);
@@ -243,7 +243,7 @@ fn follow_for_trans(cx: ext_ctxt, mmaybe: option::t<arb_depth<matchable>>,
 }
 
 /* helper for transcribe_exprs: what vars from `b` occur in `e`? */
-iter free_vars(b: bindings, e: @expr) -> ident {
+fn free_vars(b: bindings, e: @expr, it: block(ident)) {
     let idents: hashmap<ident, ()> = new_str_hash::<()>();
     fn mark_ident(&&i: ident, _fld: ast_fold, b: bindings,
                   idents: hashmap<ident, ()>) -> ident {
@@ -257,7 +257,7 @@ iter free_vars(b: bindings, e: @expr) -> ident {
             with *default_ast_fold()};
     let f = make_fold(f_pre);
     f.fold_expr(e); // ignore result
-    for each id: ident in idents.keys() { put id; }
+    idents.keys {|x| it(x); };
 }
 
 
@@ -273,7 +273,7 @@ fn transcribe_exprs(cx: ext_ctxt, b: bindings, idx_path: @mutable [uint],
             let repeat: option::t<{rep_count: uint, name: ident}> = none;
             /* we need to walk over all the free vars in lockstep, except for
             the leaves, which are just duplicated */
-            for each fv: ident in free_vars(b, repeat_me) {
+            free_vars(b, repeat_me) {|fv|
                 let cur_pos = follow(b.get(fv), idx_path);
                 alt cur_pos {
                   leaf(_) { }
@@ -295,7 +295,7 @@ fn transcribe_exprs(cx: ext_ctxt, b: bindings, idx_path: @mutable [uint],
                     }
                   }
                 }
-            }
+            };
             alt repeat {
               none. {
                 cx.span_fatal(repeat_me.span,
diff --git a/src/lib/map.rs b/src/lib/map.rs
index 3445f4b6c82..ef5e8acae46 100644
--- a/src/lib/map.rs
+++ b/src/lib/map.rs
@@ -14,8 +14,9 @@ type hashmap<K, V> =
         fn find(K) -> option::t<V>;
         fn remove(K) -> option::t<V>;
         fn rehash();
-        iter items() -> @{key: K, val: V};
-        iter keys() -> K;
+        fn items(block(K, V));
+        fn keys(block(K));
+        fn values(block(V));
     };
 type hashset<K> = hashmap<K, ()>;
 
@@ -111,8 +112,7 @@ fn mk_hashmap<@K, @V>(hasher: hashfn<K>, eqer: eqfn<K>) -> hashmap<K, V> {
             }
         }
     }
-    obj hashmap<@K,
-                @V>(hasher: hashfn<K>,
+    obj hashmap<@K, @V>(hasher: hashfn<K>,
                     eqer: eqfn<K>,
                     mutable bkts: [mutable bucket<K, V>],
                     mutable nbkts: uint,
@@ -177,14 +177,19 @@ fn mk_hashmap<@K, @V>(hasher: hashfn<K>, eqer: eqfn<K>) -> hashmap<K, V> {
             rehash(hasher, eqer, bkts, nbkts, newbkts, nbkts);
             bkts = newbkts;
         }
-        iter items() -> @{key: K, val: V} {
-            for b: bucket<K, V> in bkts {
-                alt b { some(k, v) { put @{key: k, val: v}; } _ { } }
+        fn items(it: block(K, V)) {
+            for b in bkts {
+                alt b { some(k, v) { it(copy k, copy v); } _ { } }
             }
         }
-        iter keys() -> K {
-            for b: bucket<K, V> in bkts {
-                alt b { some(k, _) { put k; } _ { } }
+        fn keys(it: block(K)) {
+            for b in bkts {
+                alt b { some(k, _) { it(copy k); } _ { } }
+            }
+        }
+        fn values(it: block(V)) {
+            for b in bkts {
+                alt b { some(_, v) { it(copy v); } _ { } }
             }
         }
     }