---

yaml
---
r: 14725
b: refs/heads/try
c: 0c5fdc8
h: refs/heads/master
i:
  14723: a443333
v: v3

Author: catamorphism

[refs]

@@ -2,5 +2,5 @@
 refs/heads/master: 61b1875c16de39c166b0f4d54bba19f9c6777d1a
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 4a81779abd786ff22d71434c6d9a5917ea4cdfff
-refs/heads/try: 8047c0cd68baaee21ac89ac7d933bc84b7ebcf3e
+refs/heads/try: 0c5fdc8745cd0bc5fbf9272301d3aafa2eb8f331
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105

branches/try/src/libcore/path.rs

@@ -170,7 +170,7 @@ fn splitext(p: path) -> (str, str) {
         if vec::len(parts) > 1u {
             let base = str::connect(vec::init(parts), ".");
             // We just checked that parts is non-empty, so this is safe
-            let ext = "." + vec::last_unsafe(parts);
+            let ext = "." + vec::last(parts);
 
             fn is_dotfile(base: str) -> bool {
                 str::is_empty(base)

branches/try/src/libcore/vec.rs

@@ -187,27 +187,24 @@ fn init<T: copy>(v: [const T]) -> [T] {
 /*
 Function: last
 
-Returns the last element of a vector
-
-Returns:
+Returns the last element of a `v`, failing if the vector is empty.
 
-An option containing the last element of `v` if `v` is not empty, or
-none if `v` is empty.
 */
-pure fn last<T: copy>(v: [const T]) -> option<T> {
-    if len(v) == 0u { ret none; }
-    ret some(v[len(v) - 1u]);
+pure fn last<T: copy>(v: [const T]) -> T {
+    if len(v) == 0u { fail "last_unsafe: empty vector" }
+    v[len(v) - 1u]
 }
 
 /*
-Function: last_unsafe
+Function: last_opt
 
-Returns the last element of a `v`, failing if the vector is empty.
+Returns some(x) where `x` is the last element of a vector `v`,
+or none if the vector is empty.
 
 */
-pure fn last_unsafe<T: copy>(v: [const T]) -> T {
-    if len(v) == 0u { fail "last_unsafe: empty vector" }
-    v[len(v) - 1u]
+pure fn last_opt<T: copy>(v: [const T]) -> option<T> {
+    if len(v) == 0u { ret none; }
+    some(v[len(v) - 1u])
 }
 
 /*
@@ -1270,11 +1267,11 @@ mod tests {
 
     #[test]
     fn test_last() {
-        let n = last([]);
+        let n = last_opt([]);
         assert (n == none);
-        n = last([1, 2, 3]);
+        n = last_opt([1, 2, 3]);
         assert (n == some(3));
-        n = last([1, 2, 3, 4, 5]);
+        n = last_opt([1, 2, 3, 4, 5]);
         assert (n == some(5));
     }
 

branches/try/src/libstd/fs.rs

@@ -271,7 +271,7 @@ fn splitext(p: path) -> (str, str) {
         if vec::len(parts) > 1u {
             let base = str::connect(vec::init(parts), ".");
             // We just checked that parts is non-empty
-            let ext = "." + vec::last_unsafe(parts);
+            let ext = "." + vec::last(parts);
 
             fn is_dotfile(base: str) -> bool {
                 str::is_empty(base)

branches/try/src/rustc/front/attr.rs

@@ -256,7 +256,7 @@ fn meta_item_from_list(
     name: str
 ) -> option<@ast::meta_item> {
     let items = attr::find_meta_items_by_name(items, name);
-    vec::last(items)
+    vec::last_opt(items)
 }
 
 fn meta_item_value_from_list(

branches/try/src/rustc/metadata/creader.rs

@@ -144,7 +144,7 @@ fn find_library_crate(sess: session::session, ident: ast::ident,
     let crate_name =
         {
             let name_items = attr::find_meta_items_by_name(metas, "name");
-            alt vec::last(name_items) {
+            alt vec::last_opt(name_items) {
               some(i) {
                 alt attr::get_meta_item_value_str(i) {
                   some(n) { n }

branches/try/src/rustc/middle/ast_map.rs

@@ -189,7 +189,7 @@ fn map_view_item(vi: @view_item, cx: ctx, _v: vt) {
               view_path_glob(pth, id) | view_path_list(pth, _, id) {
                   // should be a constraint on the type
                 assert (vec::is_not_empty(*pth));
-                (id, vec::last_unsafe(*pth))
+                (id, vec::last(*pth))
               }
             };
             cx.map.insert(id, node_export(vp, extend(cx, name)));

branches/try/src/rustc/middle/pat_util.rs

@@ -70,5 +70,5 @@ fn pat_binding_ids(dm: resolve::def_map, pat: @pat) -> [node_id] {
 
 fn path_to_ident(p: @path) -> ident {
   assert (vec::is_not_empty(p.node.idents)); // should be a constraint on path
-  vec::last_unsafe(p.node.idents)
+  vec::last(p.node.idents)
 }

branches/try/src/rustc/middle/tstate/bitvectors.rs

@@ -183,7 +183,7 @@ fn kill_poststate(fcx: fn_ctxt, id: node_id, c: tsconstr) -> bool {
 fn clear_in_poststate_expr(fcx: fn_ctxt, e: @expr, t: poststate) {
     alt e.node {
       expr_path(p) {
-        alt vec::last(p.node.idents) {
+        alt vec::last_opt(p.node.idents) {
           some(i) {
             alt local_node_id_to_def(fcx, e.id) {
               some(def_local(nid, _)) {

branches/try/src/rustc/middle/tstate/states.rs

@@ -406,7 +406,7 @@ fn find_pre_post_state_expr(fcx: fn_ctxt, pres: prestate, e: @expr) -> bool {
                                                     init_assign),
                                       exs, return_val);
 
-        let base_pres = alt vec::last(exs) { none { pres }
+        let base_pres = alt vec::last_opt(exs) { none { pres }
                           some(f) { expr_poststate(fcx.ccx, f) }};
         option::may(maybe_base, {|base|
             changed |= find_pre_post_state_expr(fcx, base_pres, base) |

branches/try/src/rustc/middle/typeck.rs

@@ -2642,7 +2642,7 @@ fn bind_params(fcx: @fn_ctxt, tp: ty::t, count: uint)
 }
 
 fn get_self_info(ccx: @crate_ctxt) -> option<self_info> {
-    ret vec::last(ccx.self_infos);
+    ret vec::last_opt(ccx.self_infos);
 }
 
 fn check_decl_initializer(fcx: @fn_ctxt, nid: ast::node_id,

branches/try/src/rustc/util/common.rs

@@ -89,7 +89,9 @@ fn local_rhs_span(l: @ast::local, def: span) -> span {
 }
 
 fn is_main_name(path: middle::ast_map::path) -> bool {
-    option::get(vec::last(path)) == middle::ast_map::path_name("main")
+    // FIXME: path should be a constrained type, so we know
+    // the call to last doesn't fail
+    vec::last(path) == middle::ast_map::path_name("main")
 }
 
 //

branches/try/src/rustdoc/reexport_pass.rs

@@ -163,7 +163,7 @@ fn build_reexport_path_map(srv: astsrv::srv, -def_map: def_map) -> path_map {
             };
           // should be a constraint on the node_export constructor
           // that guarantees path is non-empty
-            let name = alt check vec::last_unsafe(*path) {
+            let name = alt check vec::last(*path) {
               ast_map::path_name(nm) { nm }
             };
             let modpath = ast_map::path_to_str(vec::init(*path));

branches/try/src/test/run-pass/zip-same-length.rs

@@ -19,5 +19,5 @@ fn main() {
 
     check (is_not_empty(ps));
     assert (head(ps) == ('a', 1u));
-    assert (last_unsafe(ps) == (j as char, 10u));
+    assert (last(ps) == (j as char, 10u));
 }