Make { || ... } sugar for any type of closure, inferred

21 files changed, 392 insertions, 242 deletions

diff --git a/src/comp/middle/alias.rs b/src/comp/middle/alias.rs
index 3616ba9e867..4e9d1c4d343 100644
--- a/src/comp/middle/alias.rs
+++ b/src/comp/middle/alias.rs
@@ -61,7 +61,7 @@ fn check_crate(tcx: ty::ctxt, crate: @ast::crate) -> (copy_map, ref_map) {
                copy_map: std::map::new_int_hash(),
                ref_map: std::map::new_int_hash(),
                mutable silent: false};
-    let v = @{visit_fn: bind visit_fn(cx, _, _, _, _, _, _, _),
+    let v = @{visit_fn_body: bind visit_fn_body(cx, _, _, _, _, _, _, _),
               visit_expr: bind visit_expr(cx, _, _, _),
               visit_block: bind visit_block(cx, _, _, _)
               with *visit::default_visitor::<scope>()};
@@ -71,10 +71,12 @@ fn check_crate(tcx: ty::ctxt, crate: @ast::crate) -> (copy_map, ref_map) {
     ret (cx.copy_map, cx.ref_map);
 }
 
-fn visit_fn(cx: @ctx, f: ast::_fn, _tp: [ast::ty_param], sp: span,
-            _name: fn_ident, id: ast::node_id, sc: scope, v: vt<scope>) {
-    visit::visit_fn_decl(f.decl, sc, v);
-    let args = ty::ty_fn_args(cx.tcx, ty::node_id_to_type(cx.tcx, id));
+fn visit_fn_body(cx: @ctx, decl: ast::fn_decl, body: ast::blk,
+                 sp: span, _name: ast::fn_ident,
+                 id: ast::node_id, sc: scope, v: vt<scope>) {
+    visit::visit_fn_decl(decl, sc, v);
+    let fty = ty::node_id_to_type(cx.tcx, id);
+    let args = ty::ty_fn_args(cx.tcx, fty);
     for arg in args {
         if arg.mode == ast::by_val &&
            ty::type_has_dynamic_size(cx.tcx, arg.ty) {
@@ -84,11 +86,12 @@ fn visit_fn(cx: @ctx, f: ast::_fn, _tp: [ast::ty_param], sp: span,
 
     // Blocks need to obey any restrictions from the enclosing scope, and may
     // be called multiple times.
-    if f.proto == ast::proto_block {
-        check_loop(*cx, sc) {|| v.visit_block(f.body, sc, v);}
+    let proto = ty::ty_fn_proto(cx.tcx, fty);
+    if proto == ast::proto_block {
+        check_loop(*cx, sc) {|| v.visit_block(body, sc, v);}
     } else {
         let sc = {bs: [], invalid: @mutable list::nil};
-        v.visit_block(f.body, sc, v);
+        v.visit_block(body, sc, v);
     }
 }
 
diff --git a/src/comp/middle/ast_map.rs b/src/comp/middle/ast_map.rs
index 0d0eb086989..a18267569a3 100644
--- a/src/comp/middle/ast_map.rs
+++ b/src/comp/middle/ast_map.rs
@@ -32,7 +32,7 @@ fn map_crate(c: crate) -> map {
         (@{visit_item: bind map_item(cx, _),
            visit_native_item: bind map_native_item(cx, _),
            visit_expr: bind map_expr(cx, _),
-           visit_fn: bind map_fn(cx, _, _, _, _, _),
+           visit_fn_body: bind map_fn_body(cx, _, _, _, _, _),
            visit_local: bind map_local(cx, _),
            visit_arm: bind map_arm(cx, _)
            with *visit::default_simple_visitor()});
@@ -40,9 +40,9 @@ fn map_crate(c: crate) -> map {
     ret cx.map;
 }
 
-fn map_fn(cx: ctx, f: _fn, _tp: [ty_param], _sp: codemap::span,
-          _name: fn_ident, _id: node_id) {
-    for a in f.decl.inputs {
+fn map_fn_body(cx: ctx, decl: fn_decl, _body: blk,
+               _sp: codemap::span, _n: fn_ident, _id: node_id) {
+    for a in decl.inputs {
         cx.map.insert(a.id, node_arg(a, cx.local_id));
         cx.local_id += 1u;
     }
diff --git a/src/comp/middle/debuginfo.rs b/src/comp/middle/debuginfo.rs
index c11f65dc34f..96868cd0bf0 100644
--- a/src/comp/middle/debuginfo.rs
+++ b/src/comp/middle/debuginfo.rs
@@ -740,6 +740,9 @@ fn create_function(fcx: @fn_ctxt) -> @metadata<subprogram_md> {
           ast::expr_fn(f, _) {
             (dbg_cx.names.next("fn"), f.decl.output, expr.id)
           }
+          ast::expr_fn_block(decl, _) {
+            (dbg_cx.names.next("fn"), decl.output, expr.id)
+          }
         }
       }
     };
diff --git a/src/comp/middle/freevars.rs b/src/comp/middle/freevars.rs
index a7a791e52b0..f7688d35077 100644
--- a/src/comp/middle/freevars.rs
+++ b/src/comp/middle/freevars.rs
@@ -28,8 +28,8 @@ type freevar_map = hashmap<ast::node_id, freevar_info>;
 // Since we want to be able to collect upvars in some arbitrary piece
 // of the AST, we take a walker function that we invoke with a visitor
 // in order to start the search.
-fn collect_freevars(def_map: resolve::def_map, walker: fn@(visit::vt<int>)) ->
-   freevar_info {
+fn collect_freevars(def_map: resolve::def_map, blk: ast::blk)
+    -> freevar_info {
     let seen = new_int_hash();
     let refs = @mutable [];
 
@@ -43,6 +43,9 @@ fn collect_freevars(def_map: resolve::def_map, walker: fn@(visit::vt<int>)) ->
                     visit::visit_expr(expr, depth + 1, v);
                 }
               }
+              ast::expr_fn_block(_, _) {
+                visit::visit_expr(expr, depth + 1, v);
+              }
               ast::expr_path(path) {
                 let def = def_map.get(expr.id), i = 0;
                 while i < depth {
@@ -64,8 +67,9 @@ fn collect_freevars(def_map: resolve::def_map, walker: fn@(visit::vt<int>)) ->
             }
         };
 
-    walker(visit::mk_vt(@{visit_item: ignore_item, visit_expr: walk_expr
-                             with *visit::default_visitor()}));
+    let v = visit::mk_vt(@{visit_item: ignore_item, visit_expr: walk_expr
+                           with *visit::default_visitor()});
+    v.visit_block(blk, 1, v);
     ret @*refs;
 }
 
@@ -78,20 +82,16 @@ fn annotate_freevars(def_map: resolve::def_map, crate: @ast::crate) ->
    freevar_map {
     let freevars = new_int_hash();
 
-    let walk_fn =
-        lambda (f: ast::_fn, tps: [ast::ty_param], sp: span, i: ast::fn_ident,
-                nid: ast::node_id) {
-            let start_walk =
-                lambda (v: visit::vt<int>) {
-                    v.visit_fn(f, tps, sp, i, nid, 1, v);
-                };
-            let vars = collect_freevars(def_map, start_walk);
-            freevars.insert(nid, vars);
-        };
+    let walk_fn_body = lambda (_decl: ast::fn_decl, blk: ast::blk,
+                               _sp: span, _nm: ast::fn_ident,
+                               nid: ast::node_id) {
+        let vars = collect_freevars(def_map, blk);
+        freevars.insert(nid, vars);
+    };
 
     let visitor =
-        visit::mk_simple_visitor(@{visit_fn: walk_fn
-                                      with *visit::default_simple_visitor()});
+        visit::mk_simple_visitor(@{visit_fn_body: walk_fn_body
+                                   with *visit::default_simple_visitor()});
     visit::visit_crate(*crate, (), visitor);
 
     ret freevars;
diff --git a/src/comp/middle/last_use.rs b/src/comp/middle/last_use.rs
index c6879898cc3..7423cc70f0e 100644
--- a/src/comp/middle/last_use.rs
+++ b/src/comp/middle/last_use.rs
@@ -1,5 +1,6 @@
 import syntax::{visit, ast_util};
 import syntax::ast::*;
+import syntax::codemap::span;
 import std::list::{list, nil, cons, tail};
 import core::{vec, option};
 import std::list;
@@ -42,7 +43,7 @@ type ctx = {last_uses: std::map::hashmap<node_id, bool>,
 fn find_last_uses(c: @crate, def_map: resolve::def_map,
                   ref_map: alias::ref_map, tcx: ty::ctxt) -> last_uses {
     let v = visit::mk_vt(@{visit_expr: visit_expr,
-                           visit_fn: visit_fn
+                           visit_fn_body: visit_fn_body
                            with *visit::default_visitor()});
     let cx = {last_uses: std::map::new_int_hash(),
               def_map: def_map,
@@ -136,6 +137,7 @@ fn visit_expr(ex: @expr, cx: ctx, v: visit::vt<ctx>) {
             alt arg.node {
               //NDM--register captured as uses
               expr_fn(_, captured) { fns += [arg]; }
+              expr_fn_block(_, _) { fns += [arg]; }
               _ {
                 alt arg_ts[i].mode {
                   by_mut_ref. { clear_if_path(cx, arg, v, false); }
@@ -151,16 +153,19 @@ fn visit_expr(ex: @expr, cx: ctx, v: visit::vt<ctx>) {
     }
 }
 
-fn visit_fn(f: _fn, tps: [ty_param], sp: syntax::codemap::span,
-            ident: fn_ident, id: node_id, cx: ctx, v: visit::vt<ctx>) {
-    if f.proto == proto_block {
+fn visit_fn_body(decl: fn_decl, body: blk,
+                 sp: span, nm: fn_ident, id: node_id,
+                 cx: ctx, v: visit::vt<ctx>) {
+    let fty = ty::node_id_to_type(cx.tcx, id);
+    let proto = ty::ty_fn_proto(cx.tcx, fty);
+    if proto == proto_block {
         visit_block(func, cx, {||
-            visit::visit_fn(f, tps, sp, ident, id, cx, v);
+            visit::visit_fn_body(decl, body, sp, nm, id, cx, v);
         });
     } else {
         let old = nil;
         cx.blocks <-> old;
-        visit::visit_fn(f, tps, sp, ident, id, cx, v);
+        visit::visit_fn_body(decl, body, sp, nm, id, cx, v);
         cx.blocks <-> old;
         leave_fn(cx);
     }
diff --git a/src/comp/middle/mut.rs b/src/comp/middle/mut.rs
index d9b78d27cfb..41bc218e176 100644
--- a/src/comp/middle/mut.rs
+++ b/src/comp/middle/mut.rs
@@ -171,7 +171,7 @@ fn check_lval(cx: @ctx, dest: @expr, msg: msg) {
     alt dest.node {
       expr_path(p) {
         let def = cx.tcx.def_map.get(dest.id);
-        alt is_immutable_def(def) {
+        alt is_immutable_def(cx, def) {
           some(name) { mk_err(cx, dest.span, msg, name); }
           _ { }
         }
@@ -258,7 +258,7 @@ fn check_bind(cx: @ctx, f: @expr, args: [option::t<@expr>]) {
     }
 }
 
-fn is_immutable_def(def: def) -> option::t<str> {
+fn is_immutable_def(cx: @ctx, def: def) -> option::t<str> {
     alt def {
       def_fn(_, _) | def_mod(_) | def_native_mod(_) | def_const(_) |
       def_use(_) {
@@ -268,8 +268,13 @@ fn is_immutable_def(def: def) -> option::t<str> {
       def_arg(_, mode_infer.) { some("argument") }
       def_obj_field(_, imm.) { some("immutable object field") }
       def_self(_) { some("self argument") }
-      def_upvar(_, inner, mut) {
-        if !mut { some("upvar") } else { is_immutable_def(*inner) }
+      def_upvar(_, inner, node_id) {
+        let ty = ty::node_id_to_monotype(cx.tcx, node_id);
+        let proto = ty::ty_fn_proto(cx.tcx, ty);
+        ret alt proto {
+          proto_block. { is_immutable_def(cx, *inner) }
+          _ { some("upvar") }
+        };
       }
       def_binding(_) { some("binding") }
       def_local(_, let_ref.) { some("by-reference binding") }
diff --git a/src/comp/middle/resolve.rs b/src/comp/middle/resolve.rs
index df57c71b367..384b44a24cf 100644
--- a/src/comp/middle/resolve.rs
+++ b/src/comp/middle/resolve.rs
@@ -31,7 +31,8 @@ export _impl, iscopes, method_info;
 tag scope {
     scope_crate;
     scope_item(@ast::item);
-    scope_fn(ast::fn_decl, ast::proto, [ast::ty_param]);
+    scope_bare_fn(ast::fn_decl, node_id, [ast::ty_param]);
+    scope_fn_expr(ast::fn_decl, node_id, [ast::ty_param]);
     scope_native_item(@ast::native_item);
     scope_loop(@ast::local); // there's only 1 decl per loop.
     scope_block(ast::blk, @mutable uint, @mutable uint);
@@ -335,8 +336,11 @@ fn resolve_names(e: @env, c: @ast::crate) {
           visit_expr: bind walk_expr(e, _, _, _),
           visit_ty: bind walk_ty(e, _, _, _),
           visit_constr: bind walk_constr(e, _, _, _, _, _),
-          visit_fn: bind visit_fn_with_scope(e, _, _, _, _, _, _, _)
-             with *visit::default_visitor()};
+          visit_fn_proto:
+              bind visit_fn_proto_with_scope(e, _, _, _, _, _, _, _),
+          visit_fn_block:
+              bind visit_fn_block_with_scope(e, _, _, _, _, _, _)
+          with *visit::default_visitor()};
     visit::visit_crate(*c, cons(scope_crate, @nil), visit::mk_vt(v));
     e.used_imports.track = false;
     e.sess.abort_if_errors();
@@ -400,8 +404,8 @@ fn visit_item_with_scope(i: @ast::item, sc: scopes, v: vt<scopes>) {
       ast::item_impl(tps, sty, methods) {
         visit::visit_ty(sty, sc, v);
         for m in methods {
-            v.visit_fn(m.node.meth, tps + m.node.tps, m.span,
-                       some(m.node.ident), m.node.id, sc, v);
+            v.visit_fn_proto(m.node.meth, tps + m.node.tps, m.span,
+                             some(m.node.ident), m.node.id, sc, v);
         }
       }
       _ { visit::visit_item(i, sc, v); }
@@ -413,9 +417,9 @@ fn visit_native_item_with_scope(ni: @ast::native_item, sc: scopes,
     visit::visit_native_item(ni, cons(scope_native_item(ni), @sc), v);
 }
 
-fn visit_fn_with_scope(e: @env, f: ast::_fn, tp: [ast::ty_param], sp: span,
-                       name: fn_ident, id: node_id, sc: scopes,
-                       v: vt<scopes>) {
+fn visit_fn_proto_with_scope(e: @env, f: ast::_fn, tp: [ast::ty_param],
+                             sp: span, name: fn_ident, id: node_id,
+                             sc: scopes, v: vt<scopes>) {
     // is this a main fn declaration?
     alt name {
       some(nm) {
@@ -431,8 +435,21 @@ fn visit_fn_with_scope(e: @env, f: ast::_fn, tp: [ast::ty_param], sp: span,
     // here's where we need to set up the mapping
     // for f's constrs in the table.
     for c: @ast::constr in f.decl.constraints { resolve_constr(e, c, sc, v); }
-    visit::visit_fn(f, tp, sp, name, id,
-                    cons(scope_fn(f.decl, f.proto, tp), @sc), v);
+    let scope = alt f.proto {
+      ast::proto_bare. { scope_bare_fn(f.decl, id, tp) }
+      _ { scope_fn_expr(f.decl, id, tp) }
+    };
+
+    visit::visit_fn_proto(f, tp, sp, name, id, cons(scope, @sc), v);
+}
+
+fn visit_fn_block_with_scope(_e: @env, decl: fn_decl, blk: ast::blk,
+                             span: span, id: node_id,
+                             sc: scopes, v: vt<scopes>) {
+    let scope = scope_fn_expr(decl, id, []);
+    log ("scope=", scope);
+    visit::visit_fn_block(decl, blk, span, id, cons(scope, @sc), v);
+    log ("unscope");
 }
 
 fn visit_block_with_scope(b: ast::blk, sc: scopes, v: vt<scopes>) {
@@ -648,7 +665,8 @@ fn unresolved_err(e: env, cx: ctxt, sp: span, name: ident, kind: str) {
             alt sc {
               cons(cur, rest) {
                 alt cur {
-                  scope_crate. | scope_fn(_, _, _) |
+                  scope_crate. | scope_bare_fn(_, _, _) |
+                  scope_fn_expr(_, _, _) |
                   scope_item(@{node: ast::item_mod(_), _}) {
                     ret some(cur);
                   }
@@ -734,23 +752,17 @@ fn lookup_in_scope_strict(e: env, sc: scopes, sp: span, name: ident,
 
 fn scope_is_fn(sc: scope) -> bool {
     ret alt sc {
-          scope_fn(_, ast::proto_bare., _) |
-          scope_native_item(_) {
-            true
-          }
-          _ { false }
-        };
+      scope_bare_fn(_, _, _) | scope_native_item(_) { true }
+      _ { false }
+    };
 }
 
 // Returns:
 //   none - does not close
-//   some(true) - closes and permits mutation
-//   some(false) - closes but no mutation
-fn scope_closes(sc: scope) -> option::t<bool> {
+//   some(node_id) - closes via the expr w/ node_id
+fn scope_closes(sc: scope) -> option::t<node_id> {
     alt sc {
-      scope_fn(_, ast::proto_block., _) { some(true) }
-      scope_fn(_, ast::proto_send., _) { some(false) }
-      scope_fn(_, ast::proto_shared(_), _) { some(false) }
+      scope_fn_expr(_, node_id, _) { some(node_id) }
       _ { none }
     }
 }
@@ -823,7 +835,8 @@ fn lookup_in_scope(e: env, sc: scopes, sp: span, name: ident, ns: namespace)
               }
             }
           }
-          scope_fn(decl, _, ty_params) {
+          scope_bare_fn(decl, _, ty_params) |
+          scope_fn_expr(decl, _, ty_params) {
             ret lookup_in_fn(name, decl, ty_params, ns);
           }
           scope_loop(local) {
@@ -887,7 +900,10 @@ fn lookup_in_scope(e: env, sc: scopes, sp: span, name: ident, ns: namespace)
                 left_fn_level2 = true;
             } else if ns == ns_value || ns == ns_type {
                 left_fn = scope_is_fn(hd);
-                alt scope_closes(hd) { some(mut) { closing += [mut]; } _ { } }
+                alt scope_closes(hd) {
+                  some(node_id) { closing += [node_id]; }
+                  _ { }
+                }
             }
             sc = *tl;
           }
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index aa72cb98ad3..8ccda0daa4d 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -3558,6 +3558,19 @@ fn trans_expr(bcx: @block_ctxt, e: @ast::expr, dest: dest) -> @block_ctxt {
         ret trans_closure::trans_expr_fn(
             bcx, f, e.span, e.id, *cap_clause, dest);
       }
+      ast::expr_fn_block(decl, body) {
+        alt ty::struct(tcx, ty::expr_ty(tcx, e)) {
+          ty::ty_fn(proto, _, _, _, _) {
+            let f: ast::_fn = { decl: decl, proto: proto, body: body };
+            let cap_clause = { copies: [], moves: [] };
+            ret trans_closure::trans_expr_fn(
+                bcx, f, e.span, e.id, cap_clause, dest);
+          }
+          _ {
+            fail "Type of fn block is not a function!";
+          }
+        }
+      }
       ast::expr_bind(f, args) {
         ret trans_closure::trans_bind(
             bcx, f, args, e.id, dest);
diff --git a/src/comp/middle/tstate/annotate.rs b/src/comp/middle/tstate/annotate.rs
index 0ca72c569a2..389fbf1c76d 100644
--- a/src/comp/middle/tstate/annotate.rs
+++ b/src/comp/middle/tstate/annotate.rs
@@ -32,15 +32,14 @@ fn collect_ids_local(l: @local, rs: @mutable [node_id]) {
     *rs += pat_binding_ids(l.node.pat);
 }
 
-fn node_ids_in_fn(f: _fn, tps: [ty_param], sp: span, i: fn_ident, id: node_id,
-                  rs: @mutable [node_id]) {
+fn node_ids_in_fn(body: blk, rs: @mutable [node_id]) {
     let collect_ids =
         visit::mk_simple_visitor(@{visit_expr: bind collect_ids_expr(_, rs),
                                    visit_block: bind collect_ids_block(_, rs),
                                    visit_stmt: bind collect_ids_stmt(_, rs),
                                    visit_local: bind collect_ids_local(_, rs)
                                       with *visit::default_simple_visitor()});
-    visit::visit_fn(f, tps, sp, i, id, (), collect_ids);
+    collect_ids.visit_block(body, (), collect_ids);
 }
 
 fn init_vecs(ccx: crate_ctxt, node_ids: [node_id], len: uint) {
@@ -50,25 +49,24 @@ fn init_vecs(ccx: crate_ctxt, node_ids: [node_id], len: uint) {
     }
 }
 
-fn visit_fn(ccx: crate_ctxt, num_constraints: uint, f: _fn, tps: [ty_param],
-            sp: span, i: fn_ident, id: node_id) {
+fn visit_fn(ccx: crate_ctxt, num_constraints: uint, body: blk) {
     let node_ids: @mutable [node_id] = @mutable [];
-    node_ids_in_fn(f, tps, sp, i, id, node_ids);
+    node_ids_in_fn(body, node_ids);
     let node_id_vec = *node_ids;
     init_vecs(ccx, node_id_vec, num_constraints);
 }
 
-fn annotate_in_fn(ccx: crate_ctxt, f: _fn, tps: [ty_param], sp: span,
-                  i: fn_ident, id: node_id) {
+fn annotate_in_fn_body(ccx: crate_ctxt, _decl: fn_decl, body: blk,
+                       _sp: span, _n: fn_ident, id: node_id) {
     let f_info = get_fn_info(ccx, id);
-    visit_fn(ccx, num_constraints(f_info), f, tps, sp, i, id);
+    visit_fn(ccx, num_constraints(f_info), body);
 }
 
 fn annotate_crate(ccx: crate_ctxt, crate: crate) {
     let do_ann =
-        visit::mk_simple_visitor(@{visit_fn:
-                                       bind annotate_in_fn(ccx, _, _, _, _, _)
-                                      with *visit::default_simple_visitor()});
+        visit::mk_simple_visitor(
+            @{visit_fn_body: bind annotate_in_fn_body(ccx, _, _, _, _, _)
+              with *visit::default_simple_visitor()});
     visit::visit_crate(crate, (), do_ann);
 }
 //
diff --git a/src/comp/middle/tstate/auxiliary.rs b/src/comp/middle/tstate/auxiliary.rs
index d105a7dd579..c2d1732c86e 100644
--- a/src/comp/middle/tstate/auxiliary.rs
+++ b/src/comp/middle/tstate/auxiliary.rs
@@ -1003,8 +1003,9 @@ fn op_to_oper_ty(io: init_op) -> oper_type {
 }
 
 // default function visitor
-fn do_nothing<T>(_f: _fn, _tp: [ty_param], _sp: span, _i: fn_ident,
-                 _iid: node_id, _cx: T, _v: visit::vt<T>) {
+fn do_nothing<T>(_decl: fn_decl, _body: blk,
+                 _sp: span, _i: fn_ident, _id: node_id,
+                 _t: T, _v: visit::vt<T>) {
 }
 
 
diff --git a/src/comp/middle/tstate/bitvectors.rs b/src/comp/middle/tstate/bitvectors.rs
index 9cfe4e3c178..ac21c592951 100644
--- a/src/comp/middle/tstate/bitvectors.rs
+++ b/src/comp/middle/tstate/bitvectors.rs
@@ -151,7 +151,7 @@ fn relax_precond_block(fcx: fn_ctxt, i: node_id, b: blk) {
           visit_stmt: relax_precond_stmt,
           visit_item:
               fn (_i: @item, _cx: relax_ctxt, _vt: visit::vt<relax_ctxt>) { },
-          visit_fn: bind do_nothing(_, _, _, _, _, _, _)
+          visit_fn_body: bind do_nothing(_, _, _, _, _, _, _)
              with *visitor};
     let v1 = visit::mk_vt(visitor);
     v1.visit_block(b, cx, v1);
diff --git a/src/comp/middle/tstate/ck.rs b/src/comp/middle/tstate/ck.rs
index e8a1d2e938e..72b5d6fbab3 100644
--- a/src/comp/middle/tstate/ck.rs
+++ b/src/comp/middle/tstate/ck.rs
@@ -95,45 +95,47 @@ fn check_states_stmt(s: @stmt, fcx: fn_ctxt, v: visit::vt<fn_ctxt>) {
     }
 }
 
-fn check_states_against_conditions(fcx: fn_ctxt, f: _fn, tps: [ast::ty_param],
-                                   id: node_id, sp: span, i: fn_ident) {
+fn check_states_against_conditions(fcx: fn_ctxt,
+                                   f_decl: ast::fn_decl,
+                                   f_body: ast::blk,
+                                   sp: span,
+                                   nm: fn_ident,
+                                   id: node_id) {
     /* Postorder traversal instead of pre is important
        because we want the smallest possible erroneous statement
        or expression. */
 
-    let visitor = visit::default_visitor::<fn_ctxt>();
-
-    visitor =
+    let visitor = visit::mk_vt(
         @{visit_stmt: check_states_stmt,
           visit_expr: check_states_expr,
-          visit_fn: bind do_nothing(_, _, _, _, _, _, _)
-              with *visitor};
-    visit::visit_fn(f, tps, sp, i, id, fcx, visit::mk_vt(visitor));
+          visit_fn_body: bind do_nothing::<fn_ctxt>(_, _, _, _, _, _, _)
+          with *visit::default_visitor::<fn_ctxt>()});
+    visit::visit_fn_body(f_decl, f_body, sp, nm, id, fcx, visitor);
 
     /* Check that the return value is initialized */
-    let post = aux::block_poststate(fcx.ccx, f.body);
+    let post = aux::block_poststate(fcx.ccx, f_body);
     if !promises(fcx, post, fcx.enclosing.i_return) &&
        !type_is_nil(fcx.ccx.tcx, ret_ty_of_fn(fcx.ccx.tcx, id)) &&
-       f.decl.cf == return_val {
-        fcx.ccx.tcx.sess.span_err(f.body.span,
+       f_decl.cf == return_val {
+        fcx.ccx.tcx.sess.span_err(f_body.span,
                                   "In function " + fcx.name +
                                       ", not all control paths \
                                         return a value");
-        fcx.ccx.tcx.sess.span_fatal(f.decl.output.span,
+        fcx.ccx.tcx.sess.span_fatal(f_decl.output.span,
                                     "see declared return type of '" +
-                                        ty_to_str(f.decl.output) + "'");
-    } else if f.decl.cf == noreturn {
+                                    ty_to_str(f_decl.output) + "'");
+    } else if f_decl.cf == noreturn {
 
         // check that this really always fails
         // Note that it's ok for i_diverge and i_return to both be true.
         // In fact, i_diverge implies i_return. (But not vice versa!)
 
         if !promises(fcx, post, fcx.enclosing.i_diverge) {
-            fcx.ccx.tcx.sess.span_fatal(f.body.span,
+            fcx.ccx.tcx.sess.span_fatal(f_body.span,
                                         "In non-returning function " +
-                                            fcx.name +
-                                            ", some control paths may \
-                                           return to the caller");
+                                        fcx.name +
+                                        ", some control paths may \
+                                         return to the caller");
         }
     }
 
@@ -141,29 +143,34 @@ fn check_states_against_conditions(fcx: fn_ctxt, f: _fn, tps: [ast::ty_param],
     check_unused_vars(fcx);
 }
 
-fn check_fn_states(fcx: fn_ctxt, f: _fn, tps: [ast::ty_param], id: node_id,
-                   sp: span, i: fn_ident) {
+fn check_fn_states(fcx: fn_ctxt,
+                   f_decl: ast::fn_decl,
+                   f_body: ast::blk,
+                   sp: span,
+                   nm: fn_ident,
+                   id: node_id) {
     /* Compute the pre- and post-states for this function */
 
     // Fixpoint iteration
-    while find_pre_post_state_fn(fcx, f) { }
+    while find_pre_post_state_fn(fcx, f_decl, f_body) { }
 
     /* Now compare each expr's pre-state to its precondition
        and post-state to its postcondition */
 
-    check_states_against_conditions(fcx, f, tps, id, sp, i);
+    check_states_against_conditions(fcx, f_decl, f_body, sp, nm, id);
 }
 
-fn fn_states(f: _fn, tps: [ast::ty_param], sp: span, i: fn_ident, id: node_id,
+fn fn_states(f_decl: ast::fn_decl, f_body: ast::blk,
+             sp: span, i: ast::fn_ident, id: node_id,
              ccx: crate_ctxt, v: visit::vt<crate_ctxt>) {
-    visit::visit_fn(f, tps, sp, i, id, ccx, v);
+    visit::visit_fn_body(f_decl, f_body, sp, i, id, ccx, v);
     /* Look up the var-to-bit-num map for this function */
 
     assert (ccx.fm.contains_key(id));
     let f_info = ccx.fm.get(id);
-    let name = option::from_maybe("anon", i);
+    let name = option::from_maybe("anon", i); // XXXX
     let fcx = {enclosing: f_info, id: id, name: name, ccx: ccx};
-    check_fn_states(fcx, f, tps, id, sp, i);
+    check_fn_states(fcx, f_decl, f_body, sp, i, id)
 }
 
 fn check_crate(cx: ty::ctxt, crate: @crate) {
@@ -177,12 +184,13 @@ fn check_crate(cx: ty::ctxt, crate: @crate) {
     /* Compute the pre and postcondition for every subexpression */
 
     let vtor = visit::default_visitor::<crate_ctxt>();
-    vtor = @{visit_fn: fn_pre_post with *vtor};
+    vtor = @{visit_fn_body: fn_pre_post with *vtor};
     visit::visit_crate(*crate, ccx, visit::mk_vt(vtor));
 
     /* Check the pre- and postcondition against the pre- and poststate
        for every expression */
-    vtor = @{visit_fn: fn_states with *vtor};
+    let vtor = visit::default_visitor::<crate_ctxt>();
+    vtor = @{visit_fn_body: fn_states with *vtor};
     visit::visit_crate(*crate, ccx, visit::mk_vt(vtor));
 }
 //
diff --git a/src/comp/middle/tstate/collect_locals.rs b/src/comp/middle/tstate/collect_locals.rs
index 14999d8ad97..125a165b9aa 100644
--- a/src/comp/middle/tstate/collect_locals.rs
+++ b/src/comp/middle/tstate/collect_locals.rs
@@ -44,7 +44,11 @@ fn collect_pred(e: @expr, cx: ctxt, v: visit::vt<ctxt>) {
     visit::visit_expr(e, cx, v);
 }
 
-fn find_locals(tcx: ty::ctxt, f: _fn, tps: [ty_param], sp: span, i: fn_ident,
+fn find_locals(tcx: ty::ctxt,
+               f_decl: fn_decl,
+               f_body: blk,
+               sp: span,
+               n: fn_ident,
                id: node_id) -> ctxt {
     let cx: ctxt = {cs: @mutable [], tcx: tcx};
     let visitor = visit::default_visitor::<ctxt>();
@@ -52,9 +56,10 @@ fn find_locals(tcx: ty::ctxt, f: _fn, tps: [ty_param], sp: span, i: fn_ident,
     visitor =
         @{visit_local: collect_local,
           visit_expr: collect_pred,
-          visit_fn: bind do_nothing(_, _, _, _, _, _, _)
-              with *visitor};
-    visit::visit_fn(f, tps, sp, i, id, cx, visit::mk_vt(visitor));
+          visit_fn_body: bind do_nothing(_, _, _, _, _, _, _)
+          with *visitor};
+    visit::visit_fn_body(f_decl, f_body, sp,
+                         n, id, cx, visit::mk_vt(visitor));
     ret cx;
 }
 
@@ -90,13 +95,17 @@ fn add_constraint(tcx: ty::ctxt, c: sp_constr, next: uint, tbl: constr_map) ->
 
 /* builds a table mapping each local var defined in f
    to a bit number in the precondition/postcondition vectors */
-fn mk_fn_info(ccx: crate_ctxt, f: _fn, tp: [ty_param], f_sp: span,
-              f_name: fn_ident, id: node_id) {
+fn mk_fn_info(ccx: crate_ctxt,
+              f_decl: fn_decl,
+              f_body: blk,
+              f_sp: span,
+              f_name: fn_ident,
+              id: node_id) {
     let name = fn_ident_to_string(id, f_name);
     let res_map = @new_def_hash::<constraint>();
     let next: uint = 0u;
 
-    let cx: ctxt = find_locals(ccx.tcx, f, tp, f_sp, f_name, id);
+    let cx: ctxt = find_locals(ccx.tcx, f_decl, f_body, f_sp, f_name, id);
     /* now we have to add bit nums for both the constraints
        and the variables... */
 
@@ -106,17 +115,19 @@ fn mk_fn_info(ccx: crate_ctxt, f: _fn, tp: [ty_param], f_sp: span,
     /* if this function has any constraints, instantiate them to the
        argument names and add them */
     let sc;
-    for c: @constr in f.decl.constraints {
-        sc = ast_constr_to_sp_constr(cx.tcx, f.decl.inputs, c);
+    for c: @constr in f_decl.constraints {
+        sc = ast_constr_to_sp_constr(cx.tcx, f_decl.inputs, c);
         next = add_constraint(cx.tcx, sc, next, res_map);
     }
 
     /* Need to add constraints for args too, b/c they
     can be deinitialized */
-    for a: arg in f.decl.inputs {
-        next =
-            add_constraint(cx.tcx, respan(f_sp, ninit(a.id, a.ident)), next,
-                           res_map);
+    for a: arg in f_decl.inputs {
+        next = add_constraint(
+            cx.tcx,
+            respan(f_sp, ninit(a.id, a.ident)),
+            next,
+            res_map);
     }
 
     /* add the special i_diverge and i_return constraints
@@ -137,7 +148,7 @@ fn mk_fn_info(ccx: crate_ctxt, f: _fn, tp: [ty_param], f_sp: span,
     let rslt =
         {constrs: res_map,
          num_constraints: next,
-         cf: f.decl.cf,
+         cf: f_decl.cf,
          i_return: ninit(id, name),
          i_diverge: ninit(diverges_id, diverges_name),
          used_vars: v};
@@ -152,9 +163,9 @@ fn mk_fn_info(ccx: crate_ctxt, f: _fn, tp: [ty_param], f_sp: span,
    to bit number) */
 fn mk_f_to_fn_info(ccx: crate_ctxt, c: @crate) {
     let visitor =
-        visit::mk_simple_visitor(@{visit_fn:
+        visit::mk_simple_visitor(@{visit_fn_body:
                                        bind mk_fn_info(ccx, _, _, _, _, _)
-                                      with *visit::default_simple_visitor()});
+                                   with *visit::default_simple_visitor()});
     visit::visit_crate(*c, (), visitor);
 }
 //
diff --git a/src/comp/middle/tstate/pre_post_conditions.rs b/src/comp/middle/tstate/pre_post_conditions.rs
index 862c7867feb..5a89a8fd017 100644
--- a/src/comp/middle/tstate/pre_post_conditions.rs
+++ b/src/comp/middle/tstate/pre_post_conditions.rs
@@ -33,7 +33,7 @@ fn find_pre_post_method(ccx: crate_ctxt, m: @method) {
          id: m.node.id,
          name: m.node.ident,
          ccx: ccx};
-    find_pre_post_fn(fcx, m.node.meth);
+    find_pre_post_fn(fcx, m.node.meth.body);
 }
 
 fn find_pre_post_item(ccx: crate_ctxt, i: item) {
@@ -60,7 +60,7 @@ fn find_pre_post_item(ccx: crate_ctxt, i: item) {
         assert (ccx.fm.contains_key(i.id));
         let fcx =
             {enclosing: ccx.fm.get(i.id), id: i.id, name: i.ident, ccx: ccx};
-        find_pre_post_fn(fcx, f);
+        find_pre_post_fn(fcx, f.body);
       }
       item_mod(m) { find_pre_post_mod(m); }
       item_native_mod(nm) { find_pre_post_native_mod(nm); }
@@ -72,7 +72,7 @@ fn find_pre_post_item(ccx: crate_ctxt, i: item) {
              id: dtor_id,
              name: i.ident,
              ccx: ccx};
-        find_pre_post_fn(fcx, dtor);
+        find_pre_post_fn(fcx, dtor.body);
       }
       item_obj(o, _, _) {for m in o.methods { find_pre_post_method(ccx, m); }}
       item_impl(_, _, ms) { for m in ms { find_pre_post_method(ccx, m); } }
@@ -298,6 +298,15 @@ fn forget_args_moved_in(fcx: fn_ctxt, parent: @expr, modes: [ty::mode],
     }
 }
 
+fn find_pre_post_expr_fn_upvars(fcx: fn_ctxt, e: @expr) {
+    let rslt = expr_pp(fcx.ccx, e);
+    clear_pp(rslt);
+    for def in *freevars::get_freevars(fcx.ccx.tcx, e.id) {
+        log ("handle_var_def: def=", def);
+        handle_var_def(fcx, rslt, def.def, "upvar");
+    }
+}
+
 /* Fills in annotations as a side effect. Does not rebuild the expr */
 fn find_pre_post_expr(fcx: fn_ctxt, e: @expr) {
     let enclosing = fcx.enclosing;
@@ -340,12 +349,7 @@ fn find_pre_post_expr(fcx: fn_ctxt, e: @expr) {
         copy_pre_post(fcx.ccx, e.id, arg);
       }
       expr_fn(f, cap_clause) {
-        let rslt = expr_pp(fcx.ccx, e);
-        clear_pp(rslt);
-        for def in *freevars::get_freevars(fcx.ccx.tcx, e.id) {
-            log ("handle_var_def: def=", def);
-            handle_var_def(fcx, rslt, def.def, "upvar");
-        }
+        find_pre_post_expr_fn_upvars(fcx, e);
 
         let use_cap_item = lambda(&&cap_item: @capture_item) {
             let d = local_node_id_to_local_def_id(fcx, cap_item.id);
@@ -358,9 +362,9 @@ fn find_pre_post_expr(fcx: fn_ctxt, e: @expr) {
             log ("forget_in_postcond: ", cap_item);
             forget_in_postcond(fcx, e.id, cap_item.id);
         }
-
-        let ann = node_id_to_ts_ann(fcx.ccx, e.id);
-        log_cond(tritv::to_vec(ann.conditions.postcondition));
+      }
+      expr_fn_block(_, _) {
+        find_pre_post_expr_fn_upvars(fcx, e);
       }
       expr_block(b) {
         find_pre_post_block(fcx, b);
@@ -711,32 +715,33 @@ fn find_pre_post_block(fcx: fn_ctxt, b: blk) {
     set_pre_and_post(fcx.ccx, b.node.id, block_precond, block_postcond);
 }
 
-fn find_pre_post_fn(fcx: fn_ctxt, f: _fn) {
+fn find_pre_post_fn(fcx: fn_ctxt, body: blk) {
     // hack
     use_var(fcx, tsconstr_to_node_id(fcx.enclosing.i_return));
     use_var(fcx, tsconstr_to_node_id(fcx.enclosing.i_diverge));
 
-    find_pre_post_block(fcx, f.body);
-
+    find_pre_post_block(fcx, body);
 
     // Treat the tail expression as a return statement
-    alt f.body.node.expr {
+    alt body.node.expr {
       some(tailexpr) { set_postcond_false(fcx.ccx, tailexpr.id); }
       none. {/* fallthrough */ }
     }
 }
 
-fn fn_pre_post(f: _fn, tps: [ty_param], sp: span, i: fn_ident, id: node_id,
+fn fn_pre_post(decl: fn_decl, body: blk, sp: span,
+               i: fn_ident, id: node_id,
                ccx: crate_ctxt, v: visit::vt<crate_ctxt>) {
-    visit::visit_fn(f, tps, sp, i, id, ccx, v);
+    visit::visit_fn_body(decl, body, sp, i, id, ccx, v);
     assert (ccx.fm.contains_key(id));
     let fcx =
         {enclosing: ccx.fm.get(id),
          id: id,
          name: fn_ident_to_string(id, i),
          ccx: ccx};
-    find_pre_post_fn(fcx, f);
+    find_pre_post_fn(fcx, body);
 }
+
 //
 // Local Variables:
 // mode: rust
diff --git a/src/comp/middle/tstate/states.rs b/src/comp/middle/tstate/states.rs
index 209899c26b1..16bf445790d 100644
--- a/src/comp/middle/tstate/states.rs
+++ b/src/comp/middle/tstate/states.rs
@@ -374,6 +374,7 @@ fn find_pre_post_state_expr(fcx: fn_ctxt, pres: prestate, e: @expr) -> bool {
       expr_fn(_, cap_clause) {
         ret find_pre_post_state_cap_clause(fcx, e.id, pres, *cap_clause);
       }
+      expr_fn_block(_, _) { ret pure_exp(fcx.ccx, e.id, pres); }
       expr_block(b) {
         ret find_pre_post_state_block(fcx, pres, b) |
                 set_prestate_ann(fcx.ccx, e.id, pres) |
@@ -732,28 +733,30 @@ fn find_pre_post_state_block(fcx: fn_ctxt, pres0: prestate, b: blk) -> bool {
     ret changed;
 }
 
-fn find_pre_post_state_fn(fcx: fn_ctxt, f: _fn) -> bool {
+fn find_pre_post_state_fn(fcx: fn_ctxt,
+                          f_decl: fn_decl,
+                          f_body: blk) -> bool {
     let num_constrs = num_constraints(fcx.enclosing);
     // All constraints are considered false until proven otherwise.
     // This ensures that intersect works correctly.
-    kill_all_prestate(fcx, f.body.node.id);
+    kill_all_prestate(fcx, f_body.node.id);
 
     // Arguments start out initialized
-    let block_pre = block_prestate(fcx.ccx, f.body);
-    for a: arg in f.decl.inputs {
+    let block_pre = block_prestate(fcx.ccx, f_body);
+    for a: arg in f_decl.inputs {
         set_in_prestate_constr(fcx, ninit(a.id, a.ident), block_pre);
     }
 
     // Instantiate any constraints on the arguments so we can use them
-    for c: @constr in f.decl.constraints {
-        let tsc = ast_constr_to_ts_constr(fcx.ccx.tcx, f.decl.inputs, c);
+    for c: @constr in f_decl.constraints {
+        let tsc = ast_constr_to_ts_constr(fcx.ccx.tcx, f_decl.inputs, c);
         set_in_prestate_constr(fcx, tsc, block_pre);
     }
 
-    let changed = find_pre_post_state_block(fcx, block_pre, f.body);
+    let changed = find_pre_post_state_block(fcx, block_pre, f_body);
 
     // Treat the tail expression as a return statement
-    alt f.body.node.expr {
+    alt f_body.node.expr {
       some(tailexpr) {
 
         // We don't want to clear the diverges bit for bottom typed things,
@@ -763,7 +766,7 @@ fn find_pre_post_state_fn(fcx: fn_ctxt, f: _fn) -> bool {
             let post = false_postcond(num_constrs);
             // except for the "diverges" bit...
             kill_poststate_(fcx, fcx.enclosing.i_diverge, post);
-            set_poststate_ann(fcx.ccx, f.body.node.id, post);
+            set_poststate_ann(fcx.ccx, f_body.node.id, post);
         }
       }
       none. {/* fallthrough */ }
@@ -772,7 +775,7 @@ fn find_pre_post_state_fn(fcx: fn_ctxt, f: _fn) -> bool {
     /*
         log_err "find_pre_post_state_fn";
         log_err changed;
-        fcx.ccx.tcx.sess.span_note(f.body.span, fcx.name);
+        fcx.ccx.tcx.sess.span_note(f_body.span, fcx.name);
     */
 
     ret changed;
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index dc3cee75c23..d852e893800 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -999,8 +999,9 @@ mod writeback {
         if !wbcx.success { ret; }
         resolve_type_vars_for_node(wbcx, e.span, e.id);
         alt e.node {
-          ast::expr_fn(f, _) { // NDM captures?
-            for input in f.decl.inputs {
+          ast::expr_fn({decl: decl, _}, _) |
+          ast::expr_fn_block(decl, _) {
+            for input in decl.inputs {
                 resolve_type_vars_for_node(wbcx, e.span, input.id);
             }
           }
@@ -1077,7 +1078,10 @@ type gather_result =
      next_var_id: @mutable int};
 
 // Used only as a helper for check_fn.
-fn gather_locals(ccx: @crate_ctxt, f: ast::_fn, id: ast::node_id,
+fn gather_locals(ccx: @crate_ctxt,
+                 decl: ast::fn_decl,
+                 body: ast::blk,
+                 id: ast::node_id,
                  old_fcx: option::t<@fn_ctxt>) -> gather_result {
     let {vb: vb, locals: locals, nvi: nvi} =
         alt old_fcx {
@@ -1121,7 +1125,7 @@ fn gather_locals(ccx: @crate_ctxt, f: ast::_fn, id: ast::node_id,
     let args = ty::ty_fn_args(ccx.tcx, ty::node_id_to_type(ccx.tcx, id));
     let i = 0u;
     for arg: ty::arg in args {
-        assign(f.decl.inputs[i].id, some(arg.ty));
+        assign(decl.inputs[i].id, some(arg.ty));
         i += 1u;
     }
 
@@ -1144,20 +1148,20 @@ fn gather_locals(ccx: @crate_ctxt, f: ast::_fn, id: ast::node_id,
         };
 
     // Don't descend into fns and items
-    fn visit_fn<E>(_f: ast::_fn, _tp: [ast::ty_param], _sp: span,
-                   _i: ast::fn_ident, _id: ast::node_id, _e: E,
-                   _v: visit::vt<E>) {
+    fn visit_fn_body<T>(_decl: ast::fn_decl, _body: ast::blk,
+                        _sp: span, _nm: ast::fn_ident, _id: ast::node_id,
+                        _t: T, _v: visit::vt<T>) {
     }
     fn visit_item<E>(_i: @ast::item, _e: E, _v: visit::vt<E>) { }
 
     let visit =
         @{visit_local: visit_local,
           visit_pat: visit_pat,
-          visit_fn: bind visit_fn(_, _, _, _, _, _, _),
+          visit_fn_body: bind visit_fn_body(_, _, _, _, _, _, _),
           visit_item: bind visit_item(_, _, _)
               with *visit::default_visitor()};
 
-    visit::visit_block(f.body, (), visit::mk_vt(visit));
+    visit::visit_block(body, (), visit::mk_vt(visit));
     ret {var_bindings: vb,
          locals: locals,
          next_var_id: nvi};
@@ -1496,6 +1500,32 @@ fn lookup_method(fcx: @fn_ctxt, isc: resolve::iscopes,
     result
 }
 
+fn check_expr_fn_with_unifier(fcx: @fn_ctxt,
+                              expr: @ast::expr,
+                              decl: ast::fn_decl,
+                              proto: ast::proto,
+                              body: ast::blk,
+                              unify: unifier,
+                              expected: ty::t) {
+    let tcx = fcx.ccx.tcx;
+
+    let fty = ty_of_fn_decl(tcx, m_check_tyvar(fcx), decl,
+                            proto, [], none).ty;
+
+    write::ty_only_fixup(fcx, expr.id, fty);
+
+    // Unify the type of the function with the expected type before we
+    // typecheck the body so that we have more information about the
+    // argument types in the body. This is needed to make binops and
+    // record projection work on type inferred arguments.
+    unify(fcx, expr.span, expected, fty);
+
+    check_fn1(fcx.ccx, decl, proto, body, expr.id, some(fcx));
+    if proto == ast::proto_block {
+        write::ty_only_fixup(fcx, expr.id, expected);
+    }
+}
+
 fn check_expr_with_unifier(fcx: @fn_ctxt, expr: @ast::expr, unify: unifier,
                            expected: ty::t) -> bool {
     //log_err "typechecking expr " + syntax::print::pprust::expr_to_str(expr);
@@ -1563,7 +1593,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt, expr: @ast::expr, unify: unifier,
                       some(a) {
                         let is_block =
                             alt a.node {
-                              ast::expr_fn(_, _) { true }
+                              ast::expr_fn_block(_, _) { true }
                               _ { false }
                             };
                         if is_block == check_blocks {
@@ -1940,24 +1970,21 @@ fn check_expr_with_unifier(fcx: @fn_ctxt, expr: @ast::expr, unify: unifier,
         write::ty_only_fixup(fcx, id, result_ty);
       }
       ast::expr_fn(f, captures) {
-        let fty = ty_of_fn_decl(tcx, m_check_tyvar(fcx), f.decl,
-                                 f.proto, [], none).ty;
-
-        write::ty_only_fixup(fcx, id, fty);
-
-        // Unify the type of the function with the expected type before we
-        // typecheck the body so that we have more information about the
-        // argument types in the body. This is needed to make binops and
-        // record projection work on type inferred arguments.
-        unify(fcx, expr.span, expected, fty);
-
-        check_fn(fcx.ccx, f, id, some(fcx));
-        if f.proto == ast::proto_block {
-            write::ty_only_fixup(fcx, id, expected);
-        }
-
+        check_expr_fn_with_unifier(fcx, expr, f.decl,
+                                   f.proto, f.body,
+                                   unify, expected);
         capture::check_capture_clause(tcx, expr.id, f.proto, *captures);
       }
+      ast::expr_fn_block(decl, body) {
+        // Take the prototype from the expected type, but default to block:
+        let proto = alt ty::struct(tcx, expected) {
+          ty::ty_fn(proto, _, _, _, _) { proto }
+          _ { ast::proto_block }
+        };
+        check_expr_fn_with_unifier(fcx, expr, decl,
+                                   proto, body,
+                                   unify, expected);
+      }
       ast::expr_block(b) {
         // If this is an unchecked block, turn off purity-checking
         bot = check_block(fcx, b);
@@ -2581,12 +2608,19 @@ fn check_constraints(fcx: @fn_ctxt, cs: [@ast::constr], args: [ast::arg]) {
     }
 }
 
-fn check_fn(ccx: @crate_ctxt, f: ast::_fn, id: ast::node_id,
+fn check_fn(ccx: @crate_ctxt,
+            f: ast::_fn,
+            id: ast::node_id,
             old_fcx: option::t<@fn_ctxt>) {
+    check_fn1(ccx, f.decl, f.proto, f.body, id, old_fcx);
+}
 
-    let decl = f.decl;
-    let body = f.body;
-
+fn check_fn1(ccx: @crate_ctxt,
+             decl: ast::fn_decl,
+             proto: ast::proto,
+             body: ast::blk,
+             id: ast::node_id,
+             old_fcx: option::t<@fn_ctxt>) {
     // If old_fcx is some(...), this is a block fn { |x| ... }.
     // In that case, the purity is inherited from the context.
     let purity = alt old_fcx {
@@ -2594,12 +2628,12 @@ fn check_fn(ccx: @crate_ctxt, f: ast::_fn, id: ast::node_id,
       some(f) { assert decl.purity == ast::impure_fn; f.purity }
     };
 
-    let gather_result = gather_locals(ccx, f, id, old_fcx);
+    let gather_result = gather_locals(ccx, decl, body, id, old_fcx);
     let fixups: [ast::node_id] = [];
     let fcx: @fn_ctxt =
         @{ret_ty: ty::ty_fn_ret(ccx.tcx, ty::node_id_to_type(ccx.tcx, id)),
           purity: purity,
-          proto: f.proto,
+          proto: proto,
           var_bindings: gather_result.var_bindings,
           locals: gather_result.locals,
           next_var_id: gather_result.next_var_id,
@@ -2622,7 +2656,7 @@ fn check_fn(ccx: @crate_ctxt, f: ast::_fn, id: ast::node_id,
     let args = ty::ty_fn_args(ccx.tcx, ty::node_id_to_type(ccx.tcx, id));
     let i = 0u;
     for arg: ty::arg in args {
-        write::ty_only_fixup(fcx, f.decl.inputs[i].id, arg.ty);
+        write::ty_only_fixup(fcx, decl.inputs[i].id, arg.ty);
         i += 1u;
     }
 
diff --git a/src/comp/syntax/ast.rs b/src/comp/syntax/ast.rs
index 4f6b5cf3744..ed9349166ed 100644
--- a/src/comp/syntax/ast.rs
+++ b/src/comp/syntax/ast.rs
@@ -42,7 +42,7 @@ tag def {
     def_use(def_id);
     def_native_ty(def_id);
     def_native_fn(def_id, purity);
-    def_upvar(def_id, @def, /* writable */bool);
+    def_upvar(def_id, @def, node_id); // node_id == expr_fn or expr_fn_block
 }
 
 // The set of meta_items that define the compilation environment of the crate,
@@ -227,6 +227,7 @@ tag expr_ {
     expr_do_while(blk, @expr);
     expr_alt(@expr, [arm]);
     expr_fn(_fn, @capture_clause);
+    expr_fn_block(fn_decl, blk);
     expr_block(blk);
 
     /*
@@ -261,10 +262,6 @@ tag expr_ {
     expr_mac(mac);
 }
 
-// AST nodes that represent a capture clause, which is used to declare
-// variables that are copied or moved explicitly into the closure.  In some
-// cases, local variables can also be copied implicitly into the closure if
-// they are used in the closure body.
 type capture_item = {
     id: int,
     name: ident, // Currently, can only capture a local var.
diff --git a/src/comp/syntax/fold.rs b/src/comp/syntax/fold.rs
index e55326dbdce..c3caa56a9e4 100644
--- a/src/comp/syntax/fold.rs
+++ b/src/comp/syntax/fold.rs
@@ -145,6 +145,14 @@ fn fold_mac_(m: mac, fld: ast_fold) -> mac {
          span: m.span};
 }
 
+fn fold_fn_decl(decl: ast::fn_decl, fld: ast_fold) -> ast::fn_decl {
+    ret {inputs: vec::map(decl.inputs, bind fold_arg_(_, fld)),
+         output: fld.fold_ty(decl.output),
+         purity: decl.purity,
+         il: decl.il,
+         cf: decl.cf,
+         constraints: vec::map(decl.constraints, fld.fold_constr)}
+}
 
 fn noop_fold_crate(c: crate_, fld: ast_fold) -> crate_ {
     let fold_meta_item = bind fold_meta_item_(_, fld);
@@ -385,8 +393,10 @@ fn noop_fold_expr(e: expr_, fld: ast_fold) -> expr_ {
           expr_alt(expr, arms) {
             expr_alt(fld.fold_expr(expr), vec::map(arms, fld.fold_arm))
           }
-          // NDM fold_captures
           expr_fn(f, captures) { expr_fn(fld.fold_fn(f), captures) }
+          expr_fn_block(decl, body) {
+            expr_fn_block(fold_fn_decl(decl, fld), fld.fold_block(body))
+          }
           expr_block(blk) { expr_block(fld.fold_block(blk)) }
           expr_move(el, er) {
             expr_move(fld.fold_expr(el), fld.fold_expr(er))
@@ -437,15 +447,7 @@ fn noop_fold_constr(c: constr_, fld: ast_fold) -> constr_ {
 
 // functions just don't get spans, for some reason
 fn noop_fold_fn(f: _fn, fld: ast_fold) -> _fn {
-    let fold_arg = bind fold_arg_(_, fld);
-
-    ret {decl:
-             {inputs: vec::map(f.decl.inputs, fold_arg),
-              output: fld.fold_ty(f.decl.output),
-              purity: f.decl.purity,
-              il: f.decl.il,
-              cf: f.decl.cf,
-              constraints: vec::map(f.decl.constraints, fld.fold_constr)},
+    ret {decl: fold_fn_decl(f.decl, fld),
          proto: f.proto,
          body: fld.fold_block(f.body)};
 }
diff --git a/src/comp/syntax/parse/parser.rs b/src/comp/syntax/parse/parser.rs
index 43270de4049..0a436a521c9 100644
--- a/src/comp/syntax/parse/parser.rs
+++ b/src/comp/syntax/parse/parser.rs
@@ -1317,9 +1317,7 @@ fn parse_fn_block_expr(p: parser) -> @ast::expr {
     let lo = p.get_last_lo_pos();
     let decl = parse_fn_block_decl(p);
     let body = parse_block_tail(p, lo, ast::default_blk);
-    let _fn = {decl: decl, proto: ast::proto_block, body: body};
-    let captures = @{copies: [], moves: []};
-    ret mk_expr(p, lo, body.span.hi, ast::expr_fn(_fn, captures));
+    ret mk_expr(p, lo, body.span.hi, ast::expr_fn_block(decl, body));
 }
 
 fn parse_else_expr(p: parser) -> @ast::expr {
diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index 92a5d228c26..5832140b230 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -827,24 +827,19 @@ fn print_expr(s: ps, &&expr: @ast::expr) {
         bclose_(s, expr.span, alt_indent_unit);
       }
       ast::expr_fn(f, captures) { // NDM captures
-
-        // If the return type is the magic ty_infer, then we need to
-        // pretty print as a lambda-block
-        if f.decl.output.node == ast::ty_infer {
-            // containing cbox, will be closed by print-block at }
-            cbox(s, indent_unit);
-            // head-box, will be closed by print-block at start
-            ibox(s, 0u);
-            word(s.s, "{");
-            print_fn_block_args(s, f.decl);
-            print_possibly_embedded_block(s, f.body, block_block_fn,
-                                          indent_unit);
-        } else {
-            head(s, proto_to_str(f.proto));
-            print_fn_args_and_ret(s, f.decl, []);
-            space(s.s);
-            print_block(s, f.body);
-        }
+        head(s, proto_to_str(f.proto));
+        print_fn_args_and_ret(s, f.decl, []);
+        space(s.s);
+        print_block(s, f.body);
+      }
+      ast::expr_fn_block(decl, body) {
+        // containing cbox, will be closed by print-block at }
+        cbox(s, indent_unit);
+        // head-box, will be closed by print-block at start
+        ibox(s, 0u);
+        word(s.s, "{");
+        print_fn_block_args(s, decl);
+        print_possibly_embedded_block(s, body, block_block_fn, indent_unit);
       }
       ast::expr_block(blk) {
         // containing cbox, will be closed by print-block at }
diff --git a/src/comp/syntax/visit.rs b/src/comp/syntax/visit.rs
index 7ca54272edf..3f0d7a27a51 100644
--- a/src/comp/syntax/visit.rs
+++ b/src/comp/syntax/visit.rs
@@ -31,7 +31,15 @@ type visitor<E> =
       visit_expr: fn@(@expr, E, vt<E>),
       visit_ty: fn@(@ty, E, vt<E>),
       visit_constr: fn@(@path, span, node_id, E, vt<E>),
-      visit_fn: fn@(_fn, [ty_param], span, fn_ident, node_id, E, vt<E>)};
+
+      // A function with a fully specified prototype:
+      visit_fn_proto: fn@(_fn, [ty_param], span, fn_ident, node_id, E, vt<E>),
+
+      // Function sugar like { || ... }:
+      visit_fn_block: fn@(fn_decl, blk, span, node_id, E, vt<E>),
+
+      // Invoked by both visit_fn_proto and visit_fn_block above.
+      visit_fn_body: fn@(fn_decl, blk, span, fn_ident, node_id, E, vt<E>)};
 
 fn default_visitor<E>() -> visitor<E> {
     ret @{visit_mod: bind visit_mod::<E>(_, _, _, _),
@@ -47,7 +55,9 @@ fn default_visitor<E>() -> visitor<E> {
           visit_expr: bind visit_expr::<E>(_, _, _),
           visit_ty: bind skip_ty::<E>(_, _, _),
           visit_constr: bind visit_constr::<E>(_, _, _, _, _),
-          visit_fn: bind visit_fn::<E>(_, _, _, _, _, _, _)};
+          visit_fn_proto: bind visit_fn_proto::<E>(_, _, _, _, _, _, _),
+          visit_fn_block: bind visit_fn_block::<E>(_, _, _, _, _, _),
+          visit_fn_body: bind visit_fn_body::<E>(_, _, _, _, _, _, _)};
 }
 
 fn visit_crate<E>(c: crate, e: E, v: vt<E>) {
@@ -83,7 +93,8 @@ fn visit_local<E>(loc: @local, e: E, v: vt<E>) {
 fn visit_item<E>(i: @item, e: E, v: vt<E>) {
     alt i.node {
       item_const(t, ex) { v.visit_ty(t, e, v); v.visit_expr(ex, e, v); }
-      item_fn(f, tp) { v.visit_fn(f, tp, i.span, some(i.ident), i.id, e, v); }
+      item_fn(f, tp) { v.visit_fn_proto(f, tp, i.span,
+                                        some(i.ident), i.id, e, v); }
       item_mod(m) { v.visit_mod(m, i.span, e, v); }
       item_native_mod(nm) {
         for vi: @view_item in nm.view_items { v.visit_view_item(vi, e, v); }
@@ -91,7 +102,7 @@ fn visit_item<E>(i: @item, e: E, v: vt<E>) {
       }
       item_ty(t, _) { v.visit_ty(t, e, v); }
       item_res(f, dtor_id, tps, _) {
-        v.visit_fn(f, tps, i.span, some(i.ident), dtor_id, e, v);
+        v.visit_fn_proto(f, tps, i.span, some(i.ident), dtor_id, e, v);
       }
       item_tag(variants, _) {
         for vr: variant in variants {
@@ -101,15 +112,15 @@ fn visit_item<E>(i: @item, e: E, v: vt<E>) {
       item_obj(ob, _, _) {
         for f: obj_field in ob.fields { v.visit_ty(f.ty, e, v); }
         for m: @method in ob.methods {
-            v.visit_fn(m.node.meth, m.node.tps, m.span, some(m.node.ident),
-                       m.node.id, e, v);
+            v.visit_fn_proto(m.node.meth, m.node.tps, m.span,
+                             some(m.node.ident), m.node.id, e, v);
         }
       }
       item_impl(_, ty, methods) {
         visit_ty(ty, e, v);
         for m in methods {
-            v.visit_fn(m.node.meth, m.node.tps, m.span, some(m.node.ident),
-                       m.node.id, e, v);
+            v.visit_fn_proto(m.node.meth, m.node.tps, m.span,
+                             some(m.node.ident), m.node.id, e, v);
         }
       }
     }
@@ -193,10 +204,21 @@ fn visit_fn_decl<E>(fd: fn_decl, e: E, v: vt<E>) {
     v.visit_ty(fd.output, e, v);
 }
 
-fn visit_fn<E>(f: _fn, _tp: [ty_param], _sp: span, _i: fn_ident, _id: node_id,
-               e: E, v: vt<E>) {
-    visit_fn_decl(f.decl, e, v);
-    v.visit_block(f.body, e, v);
+fn visit_fn_proto<E>(f: _fn, _tp: [ty_param], sp: span, i: fn_ident,
+                     id: node_id, e: E, v: vt<E>) {
+    v.visit_fn_body(f.decl, f.body, sp, i, id, e, v);
+}
+
+fn visit_fn_block<E>(decl: fn_decl, body: blk, sp: span, id: node_id,
+                     e: E, v: vt<E>) {
+    v.visit_fn_body(decl, body, sp, option::none, id, e, v);
+}
+
+fn visit_fn_body<E>(decl: fn_decl, body: blk, _sp: span,
+                    _name: fn_ident, _id: node_id,
+                    e: E, v: vt<E>) {
+    visit_fn_decl(decl, e, v);
+    v.visit_block(body, e, v);
 }
 
 fn visit_block<E>(b: ast::blk, e: E, v: vt<E>) {
@@ -284,8 +306,12 @@ fn visit_expr<E>(ex: @expr, e: E, v: vt<E>) {
         v.visit_expr(x, e, v);
         for a: arm in arms { v.visit_arm(a, e, v); }
       }
-      // NDM add visit routine?
-      expr_fn(f, captures) { v.visit_fn(f, [], ex.span, none, ex.id, e, v); }
+      expr_fn(f, captures) {
+        v.visit_fn_proto(f, [], ex.span, none, ex.id, e, v);
+      }
+      expr_fn_block(decl, body) {
+        v.visit_fn_block(decl, body, ex.span, ex.id, e, v);
+      }
       expr_block(b) { v.visit_block(b, e, v); }
       expr_assign(a, b) { v.visit_expr(b, e, v); v.visit_expr(a, e, v); }
       expr_copy(a) { v.visit_expr(a, e, v); }
@@ -324,8 +350,8 @@ fn visit_expr<E>(ex: @expr, e: E, v: vt<E>) {
           some(ex) { v.visit_expr(ex, e, v); }
         }
         for m: @method in anon_obj.methods {
-            v.visit_fn(m.node.meth, m.node.tps, m.span, some(m.node.ident),
-                       m.node.id, e, v);
+            v.visit_fn_proto(m.node.meth, m.node.tps, m.span,
+                             some(m.node.ident), m.node.id, e, v);
         }
       }
       expr_mac(mac) { visit_mac(mac, e, v); }
@@ -357,7 +383,9 @@ type simple_visitor =
       visit_expr: fn@(@expr),
       visit_ty: fn@(@ty),
       visit_constr: fn@(@path, span, node_id),
-      visit_fn: fn@(_fn, [ty_param], span, fn_ident, node_id)};
+      visit_fn_proto: fn@(_fn, [ty_param], span, fn_ident, node_id),
+      visit_fn_block: fn@(fn_decl, blk, span, node_id),
+      visit_fn_body: fn@(fn_decl, blk, span, fn_ident, node_id)};
 
 fn simple_ignore_ty(_t: @ty) {}
 
@@ -375,10 +403,15 @@ fn default_simple_visitor() -> simple_visitor {
           visit_expr: fn(_e: @expr) { },
           visit_ty: simple_ignore_ty,
           visit_constr: fn(_p: @path, _sp: span, _id: node_id) { },
-          visit_fn:
+          visit_fn_proto:
               fn(_f: _fn, _tps: [ty_param], _sp: span, _ident: fn_ident,
-                  _id: node_id) {
-              }};
+                  _id: node_id) { },
+          visit_fn_block:
+              fn(_f: fn_decl, _b: blk, _sp: span, _node_id: node_id) { },
+          visit_fn_body:
+              fn(_f: fn_decl, _b: blk, _sp: span,
+                 _nm: fn_ident, _node_id: node_id) { }
+         };
 }
 
 fn mk_simple_visitor(v: simple_visitor) -> vt<()> {
@@ -440,7 +473,21 @@ fn mk_simple_visitor(v: simple_visitor) -> vt<()> {
             tps: [ty_param], sp: span, ident: fn_ident, id: node_id, &&e: (),
             v: vt<()>) {
         f(ff, tps, sp, ident, id);
-        visit_fn(ff, tps, sp, ident, id, e, v);
+        visit_fn_proto(ff, tps, sp, ident, id, e, v);
+    }
+    fn v_fn_block(f: fn@(fn_decl, blk, span, node_id),
+                  fn_decl: fn_decl, blk: blk,
+                  sp: span, node_id: node_id,
+                  &&e: (), v: vt<()>) {
+        f(fn_decl, blk, sp, node_id);
+        visit_fn_block(fn_decl, blk, sp, node_id, e, v);
+    }
+    fn v_fn_body(f: fn@(fn_decl, blk, span, fn_ident, node_id),
+                 fn_decl: fn_decl, blk: blk,
+                 sp: span, name: fn_ident, node_id: node_id,
+                 &&e: (), v: vt<()>) {
+        f(fn_decl, blk, sp, name, node_id);
+        visit_fn_body(fn_decl, blk, sp, name, node_id, e, v);
     }
     let visit_ty = if v.visit_ty == simple_ignore_ty {
         bind skip_ty(_, _, _)
@@ -461,7 +508,13 @@ fn mk_simple_visitor(v: simple_visitor) -> vt<()> {
                 visit_expr: bind v_expr(v.visit_expr, _, _, _),
                 visit_ty: visit_ty,
                 visit_constr: bind v_constr(v.visit_constr, _, _, _, _, _),
-                visit_fn: bind v_fn(v.visit_fn, _, _, _, _, _, _, _)});
+                visit_fn_proto:
+                    bind v_fn(v.visit_fn_proto, _, _, _, _, _, _, _),
+                visit_fn_block:
+                    bind v_fn_block(v.visit_fn_block, _, _, _, _, _, _),
+                visit_fn_body:
+                    bind v_fn_body(v.visit_fn_body, _, _, _, _, _, _, _),
+               });
 }
 
 // Local Variables: