s/block()/fn()/g

21 files changed, 40 insertions, 47 deletions

diff --git a/src/comp/metadata/cstore.rs b/src/comp/metadata/cstore.rs
index 3c75df586be..e3201834a3d 100644
--- a/src/comp/metadata/cstore.rs
+++ b/src/comp/metadata/cstore.rs
@@ -93,7 +93,7 @@ fn have_crate_data(cstore: cstore, cnum: ast::crate_num) -> bool {
     ret p(cstore).metas.contains_key(cnum);
 }
 
-fn iter_crate_data(cstore: cstore, i: block(ast::crate_num, crate_metadata)) {
+fn iter_crate_data(cstore: cstore, i: fn(ast::crate_num, crate_metadata)) {
     p(cstore).metas.items {|k,v| i(k, v);};
 }
 
diff --git a/src/comp/metadata/decoder.rs b/src/comp/metadata/decoder.rs
index 9855fa75d42..bdd4623bbea 100644
--- a/src/comp/metadata/decoder.rs
+++ b/src/comp/metadata/decoder.rs
@@ -460,7 +460,7 @@ fn list_crate_items(bytes: @[u8], md: ebml::doc, out: io::writer) {
     out.write_str("\n");
 }
 
-fn iter_crate_items(bytes: @[u8], proc: block(str, ast::def_id)) {
+fn iter_crate_items(bytes: @[u8], proc: fn(str, ast::def_id)) {
     let md = ebml::new_doc(bytes);
     let paths = ebml::get_doc(md, tag_paths);
     let index = ebml::get_doc(paths, tag_index);
diff --git a/src/comp/metadata/encoder.rs b/src/comp/metadata/encoder.rs
index 279f761dfb2..cc79e6a2bf0 100644
--- a/src/comp/metadata/encoder.rs
+++ b/src/comp/metadata/encoder.rs
@@ -486,7 +486,7 @@ fn create_index<T: copy>(index: [entry<T>], hash_fn: fn@(T) -> uint) ->
 }
 
 fn encode_index<T>(ebml_w: ebml::writer, buckets: [@[entry<T>]],
-                   write_fn: block(io::writer, T)) {
+                   write_fn: fn(io::writer, T)) {
     let writer = ebml_w.writer;
     ebml::start_tag(ebml_w, tag_index);
     let bucket_locs: [uint] = [];
diff --git a/src/comp/metadata/tydecode.rs b/src/comp/metadata/tydecode.rs
index 266b319fe29..2e4e5cdc66d 100644
--- a/src/comp/metadata/tydecode.rs
+++ b/src/comp/metadata/tydecode.rs
@@ -16,7 +16,7 @@ export parse_bounds_data;
 // data buffer. Whatever format you choose should not contain pipe characters.
 
 // Callback to translate defs to strs or back:
-type conv_did = block(ast::def_id) -> ast::def_id;
+type conv_did = fn(ast::def_id) -> ast::def_id;
 
 type pstate = {data: @[u8], crate: int, mutable pos: uint, tcx: ty::ctxt};
 
@@ -138,7 +138,7 @@ fn parse_ty_constr_arg(st: @pstate) -> ast::constr_arg_general_<@path> {
 }
 
 fn parse_constr<T: copy>(st: @pstate, conv: conv_did,
-                         pser: block(@pstate) -> ast::constr_arg_general_<T>)
+                         pser: fn(@pstate) -> ast::constr_arg_general_<T>)
     -> @ty::constr_general<T> {
     let sp = ast_util::dummy_sp(); // FIXME: use a real span
     let args: [@sp_constr_arg<T>] = [];
diff --git a/src/comp/middle/alias.rs b/src/comp/middle/alias.rs
index d2c75bc182e..ea301228db6 100644
--- a/src/comp/middle/alias.rs
+++ b/src/comp/middle/alias.rs
@@ -436,7 +436,7 @@ fn check_if(c: @ast::expr, then: ast::blk, els: option::t<@ast::expr>,
     *sc.invalid = append_invalid(*sc.invalid, then_invalid, orig_invalid);
 }
 
-fn check_loop(cx: ctx, sc: scope, checker: block()) {
+fn check_loop(cx: ctx, sc: scope, checker: fn()) {
     let orig_invalid = filter_invalid(*sc.invalid, sc.bs);
     checker();
     let new_invalid = filter_invalid(*sc.invalid, sc.bs);
diff --git a/src/comp/middle/debuginfo.rs b/src/comp/middle/debuginfo.rs
index cfde53fa820..fdc1c51cbd6 100644
--- a/src/comp/middle/debuginfo.rs
+++ b/src/comp/middle/debuginfo.rs
@@ -140,7 +140,7 @@ fn md_from_metadata<T>(val: debug_metadata) -> T unsafe {
 }
 
 fn cached_metadata<T: copy>(cache: metadata_cache, mdtag: int,
-                           eq: block(md: T) -> bool) -> option::t<T> unsafe {
+                           eq: fn(md: T) -> bool) -> option::t<T> unsafe {
     if cache.contains_key(mdtag) {
         let items = cache.get(mdtag);
         for item in items {
diff --git a/src/comp/middle/kind.rs b/src/comp/middle/kind.rs
index 600389b3058..db35362f3ea 100644
--- a/src/comp/middle/kind.rs
+++ b/src/comp/middle/kind.rs
@@ -58,7 +58,7 @@ fn check_crate(tcx: ty::ctxt, method_map: typeck::method_map,
 // variables. `id` is the node_id for some expression that creates the
 // closure.
 fn with_appropriate_checker(cx: ctx, id: node_id,
-                            b: block(fn@(ctx, ty::t, sp: span))) {
+                            b: fn(fn@(ctx, ty::t, sp: span))) {
     let fty = ty::node_id_to_monotype(cx.tcx, id);
     alt ty::ty_fn_proto(cx.tcx, fty) {
       proto_uniq { b(check_send); }
diff --git a/src/comp/middle/last_use.rs b/src/comp/middle/last_use.rs
index 60b8bfd9879..af078afe53f 100644
--- a/src/comp/middle/last_use.rs
+++ b/src/comp/middle/last_use.rs
@@ -203,7 +203,7 @@ fn visit_fn(fk: visit::fn_kind, decl: fn_decl, body: blk,
     }
 }
 
-fn visit_block(tp: block_type, cx: ctx, visit: block()) {
+fn visit_block(tp: block_type, cx: ctx, visit: fn()) {
     let local = @{type: tp, mutable second: false, mutable exits: []};
     cx.blocks = cons(local, @cx.blocks);
     visit();
diff --git a/src/comp/middle/lint.rs b/src/comp/middle/lint.rs
index 7cba82e80be..838764171f0 100644
--- a/src/comp/middle/lint.rs
+++ b/src/comp/middle/lint.rs
@@ -26,7 +26,7 @@ impl opt_ for option {
 }
 
 // FIXME: Copied from driver.rs, to work around a bug(#1566)
-fn time(do_it: bool, what: str, thunk: block()) {
+fn time(do_it: bool, what: str, thunk: fn()) {
     if !do_it{ ret thunk(); }
     let start = std::time::precise_time_s();
     thunk();
diff --git a/src/comp/middle/pat_util.rs b/src/comp/middle/pat_util.rs
index b949dce004d..9e50355f43e 100644
--- a/src/comp/middle/pat_util.rs
+++ b/src/comp/middle/pat_util.rs
@@ -91,7 +91,7 @@ fn pat_id_map(tcx: ty::ctxt, pat: @pat) -> pat_id_map {
 // This does *not* normalize. The pattern should be already normalized
 // if you want to get a normalized pattern out of it.
 // Could return a constrained type in order to express that (future work)
-fn pat_bindings(pat: @pat, it: block(@pat)) {
+fn pat_bindings(pat: @pat, it: fn(@pat)) {
   alt pat.node {
       pat_ident(_, option::none) { it(pat); }
       pat_ident(_, option::some(sub)) { it(pat); pat_bindings(sub, it); }
diff --git a/src/comp/middle/resolve.rs b/src/comp/middle/resolve.rs
index 3b49f8c33ad..1d54ed27997 100644
--- a/src/comp/middle/resolve.rs
+++ b/src/comp/middle/resolve.rs
@@ -632,7 +632,7 @@ fn resolve_constr(e: @env, c: @ast::constr, sc: scopes, _v: vt<scopes>) {
 fn resolve_import(e: env, defid: ast::def_id, name: ast::ident,
                   ids: [ast::ident], sp: codemap::span, sc: scopes) {
     fn register(e: env, id: node_id, cx: ctxt, sp: codemap::span,
-                name: ast::ident, lookup: block(namespace) -> option::t<def>,
+                name: ast::ident, lookup: fn(namespace) -> option::t<def>,
                 impls: [@_impl]) {
         let val = lookup(ns_val(ns_any_value)), typ = lookup(ns_type),
             md = lookup(ns_module);
@@ -1712,7 +1712,7 @@ fn add_name(ch: checker, sp: span, name: ident) {
 
 fn ident_id(&&i: ident) -> ident { ret i; }
 
-fn ensure_unique<T>(e: env, sp: span, elts: [T], id: block(T) -> ident,
+fn ensure_unique<T>(e: env, sp: span, elts: [T], id: fn(T) -> ident,
                     kind: str) {
     let ch = checker(e, kind);
     for elt: T in elts { add_name(ch, sp, id(elt)); }
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index 8919237b688..8de5d7257e2 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -3233,8 +3233,8 @@ fn invoke_full(bcx: @block_ctxt, llfn: ValueRef, llargs: [ValueRef],
 fn invoke_(bcx: @block_ctxt, llfn: ValueRef, llargs: [ValueRef],
            to_zero: [{v: ValueRef, t: ty::t}],
            to_revoke: [{v: ValueRef, t: ty::t}],
-           invoker: block(@block_ctxt, ValueRef, [ValueRef],
-                          BasicBlockRef, BasicBlockRef)) -> @block_ctxt {
+           invoker: fn(@block_ctxt, ValueRef, [ValueRef],
+                       BasicBlockRef, BasicBlockRef)) -> @block_ctxt {
     // FIXME: May be worth turning this into a plain call when there are no
     // cleanups to run
     if bcx.unreachable { ret bcx; }
@@ -4106,7 +4106,7 @@ fn trans_fn_cleanups(fcx: @fn_ctxt, cx: @block_ctxt) {
     }
 }
 
-fn block_locals(b: ast::blk, it: block(@ast::local)) {
+fn block_locals(b: ast::blk, it: fn(@ast::local)) {
     for s: @ast::stmt in b.node.stmts {
         alt s.node {
           ast::stmt_decl(d, _) {
@@ -4423,7 +4423,7 @@ enum self_arg { impl_self(ty::t), no_self, }
 fn trans_closure(cx: @local_ctxt, sp: span, decl: ast::fn_decl,
                  body: ast::blk, llfndecl: ValueRef,
                  ty_self: self_arg, ty_params: [ast::ty_param],
-                 id: ast::node_id, maybe_load_env: block(@fn_ctxt)) {
+                 id: ast::node_id, maybe_load_env: fn(@fn_ctxt)) {
     set_uwtable(llfndecl);
 
     // Set up arguments to the function.
diff --git a/src/comp/middle/trans_closure.rs b/src/comp/middle/trans_closure.rs
index 7fece0cefdf..3f7c8181ab5 100644
--- a/src/comp/middle/trans_closure.rs
+++ b/src/comp/middle/trans_closure.rs
@@ -57,7 +57,7 @@ import shape::{size_of};
 // closure is allocated in the task heap and is reference counted.
 // For a block, the closure is allocated on the stack.  Note that in
 // all cases we allocate space for a ref count just to make our lives
-// easier when upcasting to block(T)->U, in the shape code, and so
+// easier when upcasting to fn(T)->U, in the shape code, and so
 // forth.
 //
 // ## Opaque Closures ##
@@ -637,7 +637,7 @@ fn trans_bind_1(cx: @block_ctxt, outgoing_fty: ty::t,
 fn make_null_test(
     in_bcx: @block_ctxt,
     ptr: ValueRef,
-    blk: block(@block_ctxt) -> @block_ctxt)
+    blk: fn(@block_ctxt) -> @block_ctxt)
     -> @block_ctxt {
     let not_null_bcx = new_sub_block_ctxt(in_bcx, "not null");
     let next_bcx = new_sub_block_ctxt(in_bcx, "next");
diff --git a/src/comp/middle/trans_impl.rs b/src/comp/middle/trans_impl.rs
index 2e2e245a1c1..ff4a8db24a7 100644
--- a/src/comp/middle/trans_impl.rs
+++ b/src/comp/middle/trans_impl.rs
@@ -157,7 +157,7 @@ fn trans_vtable(ccx: @crate_ctxt, id: ast::node_id, name: str,
 }
 
 fn trans_wrapper(ccx: @crate_ctxt, pt: [ast::ident], llfty: TypeRef,
-                 fill: block(ValueRef, @block_ctxt) -> @block_ctxt)
+                 fill: fn(ValueRef, @block_ctxt) -> @block_ctxt)
     -> ValueRef {
     let lcx = @{path: pt, module_path: [], ccx: ccx};
     let name = link::mangle_internal_name_by_path(ccx, pt);
diff --git a/src/comp/middle/trans_vec.rs b/src/comp/middle/trans_vec.rs
index 68207867071..c31da3cfecd 100644
--- a/src/comp/middle/trans_vec.rs
+++ b/src/comp/middle/trans_vec.rs
@@ -258,7 +258,7 @@ fn trans_add(bcx: @block_ctxt, vec_ty: ty::t, lhs: ValueRef,
 
 type val_and_ty_fn = fn@(@block_ctxt, ValueRef, ty::t) -> result;
 
-type iter_vec_block = block(@block_ctxt, ValueRef, ty::t) -> @block_ctxt;
+type iter_vec_block = fn(@block_ctxt, ValueRef, ty::t) -> @block_ctxt;
 
 fn iter_vec_raw(bcx: @block_ctxt, vptr: ValueRef, vec_ty: ty::t,
                 fill: ValueRef, f: iter_vec_block) -> @block_ctxt {
diff --git a/src/comp/middle/tstate/auxiliary.rs b/src/comp/middle/tstate/auxiliary.rs
index c6af04460ff..b367b5b6cb3 100644
--- a/src/comp/middle/tstate/auxiliary.rs
+++ b/src/comp/middle/tstate/auxiliary.rs
@@ -968,7 +968,7 @@ fn non_init_constraint_mentions(_fcx: fn_ctxt, c: norm_constraint, v: node_id)
 }
 
 fn args_mention<T>(args: [@constr_arg_use],
-                   q: block([T], node_id) -> bool,
+                   q: fn([T], node_id) -> bool,
                    s: [T]) -> bool {
     /*
       FIXME
diff --git a/src/comp/middle/ty.rs b/src/comp/middle/ty.rs
index b7751fc235e..2af258d120a 100644
--- a/src/comp/middle/ty.rs
+++ b/src/comp/middle/ty.rs
@@ -1083,7 +1083,7 @@ fn type_is_native(cx: ctxt, ty: t) -> bool {
     alt struct(cx, ty) { ty_native(_) { ret true; } _ { ret false; } }
 }
 
-fn type_structurally_contains(cx: ctxt, ty: t, test: block(sty) -> bool) ->
+fn type_structurally_contains(cx: ctxt, ty: t, test: fn(sty) -> bool) ->
    bool {
     let sty = struct(cx, ty);
     if test(sty) { ret true; }
@@ -1420,7 +1420,7 @@ fn hash_type_structure(st: sty) -> uint {
 
 fn hash_raw_ty(&&rt: @raw_t) -> uint { ret rt.hash; }
 
-fn arg_eq<T>(eq: block(T, T) -> bool,
+fn arg_eq<T>(eq: fn(T, T) -> bool,
              a: @sp_constr_arg<T>,
              b: @sp_constr_arg<T>)
    -> bool {
@@ -1439,7 +1439,7 @@ fn arg_eq<T>(eq: block(T, T) -> bool,
     }
 }
 
-fn args_eq<T>(eq: block(T, T) -> bool,
+fn args_eq<T>(eq: fn(T, T) -> bool,
               a: [@sp_constr_arg<T>],
               b: [@sp_constr_arg<T>]) -> bool {
     let i: uint = 0u;
@@ -1930,7 +1930,6 @@ mod unify {
         fn sub_proto(p_sub: ast::proto, p_sup: ast::proto) -> bool {
             ret alt (p_sub, p_sup) {
               (_, ast::proto_any) { true }
-              (_, ast::proto_block) { true } /* NDM temporary */
               (ast::proto_bare, _) { true }
 
               // Equal prototypes are always subprotos:
@@ -2083,7 +2082,7 @@ mod unify {
     }
 
     fn unify_tps(cx: @ctxt, expected_tps: [t], actual_tps: [t],
-                 variance: variance, finish: block([t]) -> result) -> result {
+                 variance: variance, finish: fn([t]) -> result) -> result {
         let result_tps = [], i = 0u;
         for exp in expected_tps {
             let act = actual_tps[i];
diff --git a/src/comp/syntax/ext/simplext.rs b/src/comp/syntax/ext/simplext.rs
index dcaf16c973e..5477c495883 100644
--- a/src/comp/syntax/ext/simplext.rs
+++ b/src/comp/syntax/ext/simplext.rs
@@ -241,7 +241,7 @@ fn follow_for_trans(cx: ext_ctxt, mmaybe: option::t<arb_depth<matchable>>,
 }
 
 /* helper for transcribe_exprs: what vars from `b` occur in `e`? */
-fn free_vars(b: bindings, e: @expr, it: block(ident)) {
+fn free_vars(b: bindings, e: @expr, it: fn(ident)) {
     let idents: hashmap<ident, ()> = new_str_hash::<()>();
     fn mark_ident(&&i: ident, _fld: ast_fold, b: bindings,
                   idents: hashmap<ident, ()>) -> ident {
@@ -536,7 +536,7 @@ fn block_to_ident(blk: blk_) -> option::t<ident> {
 
 fn p_t_s_r_mac(cx: ext_ctxt, mac: ast::mac, s: selector, b: binders) {
     fn select_pt_1(cx: ext_ctxt, m: matchable,
-                   fn_m: block(ast::mac) -> match_result) -> match_result {
+                   fn_m: fn(ast::mac) -> match_result) -> match_result {
         ret alt m {
               match_expr(e) {
                 alt e.node { expr_mac(mac) { fn_m(mac) } _ { none } }
diff --git a/src/comp/syntax/parse/parser.rs b/src/comp/syntax/parse/parser.rs
index cb7e1144334..5a4925486d9 100644
--- a/src/comp/syntax/parse/parser.rs
+++ b/src/comp/syntax/parse/parser.rs
@@ -149,7 +149,7 @@ fn bad_expr_word_table() -> hashmap<str, ()> {
     for word in ["mod", "if", "else", "while", "do", "alt", "for", "break",
                  "cont", "ret", "be", "fail", "type", "resource", "check",
                  "assert", "claim", "native", "fn", "pure",
-                 "unsafe", "block", "import", "export", "let", "const",
+                 "unsafe", "import", "export", "let", "const",
                  "log", "copy", "sendfn", "impl", "iface", "enum"] {
         words.insert(word, ());
     }
@@ -366,7 +366,7 @@ fn parse_constr_in_type(p: parser) -> @ast::ty_constr {
 }
 
 
-fn parse_constrs<T: copy>(pser: block(parser) -> @ast::constr_general<T>,
+fn parse_constrs<T: copy>(pser: fn(parser) -> @ast::constr_general<T>,
                          p: parser) ->
    [@ast::constr_general<T>] {
     let constrs: [@ast::constr_general<T>] = [];
@@ -504,9 +504,6 @@ fn parse_ty(p: parser, colons_before_params: bool) -> @ast::ty {
           _ { /* fallthrough */ }
         }
         t = parse_ty_fn(proto, p);
-    } else if eat_word(p, "block") {
-        //p.warn("block is deprecated, use fn& or fn");
-        t = parse_ty_fn(ast::proto_block, p);
     } else if eat_word(p, "native") {
         expect_word(p, "fn");
         t = parse_ty_fn(ast::proto_bare, p);
@@ -545,7 +542,7 @@ fn parse_fn_block_arg(p: parser) -> ast::arg {
 }
 
 fn parse_seq_to_before_gt<T: copy>(sep: option::t<token::token>,
-                                  f: block(parser) -> T,
+                                  f: fn(parser) -> T,
                                   p: parser) -> [T] {
     let first = true;
     let v = [];
@@ -562,7 +559,7 @@ fn parse_seq_to_before_gt<T: copy>(sep: option::t<token::token>,
 }
 
 fn parse_seq_to_gt<T: copy>(sep: option::t<token::token>,
-                           f: block(parser) -> T, p: parser) -> [T] {
+                           f: fn(parser) -> T, p: parser) -> [T] {
     let v = parse_seq_to_before_gt(sep, f, p);
     expect_gt(p);
 
@@ -570,7 +567,7 @@ fn parse_seq_to_gt<T: copy>(sep: option::t<token::token>,
 }
 
 fn parse_seq_lt_gt<T: copy>(sep: option::t<token::token>,
-                           f: block(parser) -> T,
+                           f: fn(parser) -> T,
                            p: parser) -> spanned<[T]> {
     let lo = p.span.lo;
     expect(p, token::LT);
@@ -581,7 +578,7 @@ fn parse_seq_lt_gt<T: copy>(sep: option::t<token::token>,
 }
 
 fn parse_seq_to_end<T: copy>(ket: token::token, sep: seq_sep,
-                            f: block(parser) -> T, p: parser) -> [T] {
+                            f: fn(parser) -> T, p: parser) -> [T] {
     let val = parse_seq_to_before_end(ket, sep, f, p);
     p.bump();
     ret val;
@@ -604,7 +601,7 @@ fn seq_sep_none() -> seq_sep {
 
 fn parse_seq_to_before_end<T: copy>(ket: token::token,
                                    sep: seq_sep,
-                                   f: block(parser) -> T, p: parser) -> [T] {
+                                   f: fn(parser) -> T, p: parser) -> [T] {
     let first: bool = true;
     let v: [T] = [];
     while p.token != ket {
@@ -620,7 +617,7 @@ fn parse_seq_to_before_end<T: copy>(ket: token::token,
 
 
 fn parse_seq<T: copy>(bra: token::token, ket: token::token,
-                     sep: seq_sep, f: block(parser) -> T,
+                     sep: seq_sep, f: fn(parser) -> T,
                      p: parser) -> spanned<[T]> {
     let lo = p.span.lo;
     expect(p, bra);
@@ -813,9 +810,6 @@ fn parse_bottom_expr(p: parser) -> pexpr {
           _ { /* fallthrough */ }
         }
         ret pexpr(parse_fn_expr(p, proto));
-    } else if eat_word(p, "block") {
-        p.warn("block is deprecated, use fn& or fn");
-        ret pexpr(parse_fn_expr(p, ast::proto_block));
     } else if eat_word(p, "unchecked") {
         ret pexpr(parse_block_expr(p, lo, ast::unchecked_blk));
     } else if eat_word(p, "unsafe") {
diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index 2ebcaa055a7..4327ccf9ac0 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -210,7 +210,7 @@ fn synth_comment(s: ps, text: str) {
     word(s.s, "*/");
 }
 
-fn commasep<IN>(s: ps, b: breaks, elts: [IN], op: block(ps, IN)) {
+fn commasep<IN>(s: ps, b: breaks, elts: [IN], op: fn(ps, IN)) {
     box(s, 0u, b);
     let first = true;
     for elt: IN in elts {
@@ -221,8 +221,8 @@ fn commasep<IN>(s: ps, b: breaks, elts: [IN], op: block(ps, IN)) {
 }
 
 
-fn commasep_cmnt<IN>(s: ps, b: breaks, elts: [IN], op: block(ps, IN),
-                     get_span: block(IN) -> codemap::span) {
+fn commasep_cmnt<IN>(s: ps, b: breaks, elts: [IN], op: fn(ps, IN),
+                     get_span: fn(IN) -> codemap::span) {
     box(s, 0u, b);
     let len = vec::len::<IN>(elts);
     let i = 0u;
diff --git a/src/comp/util/filesearch.rs b/src/comp/util/filesearch.rs
index ece3f17e747..60df64a2a35 100644
--- a/src/comp/util/filesearch.rs
+++ b/src/comp/util/filesearch.rs
@@ -18,7 +18,7 @@ export relative_target_lib_path;
 export get_cargo_root;
 export libdir;
 
-type pick<T> = block(path: fs::path) -> option::t<T>;
+type pick<T> = fn(path: fs::path) -> option::t<T>;
 
 fn pick_file(file: fs::path, path: fs::path) -> option::t<fs::path> {
     if fs::basename(path) == file { option::some(path) }