make bind syntax unnecessary: just use _ for one of the arguments

src/comp/syntax/parse/parser.rs

@@ -854,15 +854,9 @@ fn parse_bottom_expr(p: parser) -> pexpr {
         ret pexpr(mk_mac_expr(p, lo, p.span.hi, ast::mac_ellipsis));
     } else if eat_word(p, "bind") {
         let e = parse_expr_res(p, RESTRICT_NO_CALL_EXPRS);
-        fn parse_expr_opt(p: parser) -> option<@ast::expr> {
-            alt p.token {
-              token::UNDERSCORE { p.bump(); ret none; }
-              _ { ret some(parse_expr(p)); }
-            }
-        }
         let es =
             parse_seq(token::LPAREN, token::RPAREN, seq_sep(token::COMMA),
-                      parse_expr_opt, p);
+                      parse_expr_or_hole, p);
         hi = es.span.hi;
         ex = ast::expr_bind(e, es.node);
     } else if p.token == token::POUND {
@@ -1036,10 +1030,18 @@ fn parse_dot_or_call_expr_with(p: parser, e0: pexpr) -> pexpr {
         alt p.token {
           // expr(...)
           token::LPAREN if permits_call(p) {
-            let es = parse_seq(token::LPAREN, token::RPAREN,
-                               seq_sep(token::COMMA), parse_expr, p);
-            hi = es.span.hi;
-            let nd = ast::expr_call(to_expr(e), es.node, false);
+            let es_opt =
+                parse_seq(token::LPAREN, token::RPAREN,
+                          seq_sep(token::COMMA), parse_expr_or_hole, p);
+            hi = es_opt.span.hi;
+
+            let nd =
+                if vec::any(es_opt.node, {|e| option::is_none(e) }) {
+                    ast::expr_bind(to_expr(e), es_opt.node)
+                } else {
+                    let es = vec::map(es_opt.node) {|e| option::get(e) };
+                    ast::expr_call(to_expr(e), es, false)
+                };
             e = mk_pexpr(p, lo, hi, nd);
           }
 
@@ -1388,6 +1390,13 @@ fn parse_expr(p: parser) -> @ast::expr {
     ret parse_expr_res(p, UNRESTRICTED);
 }
 
+fn parse_expr_or_hole(p: parser) -> option<@ast::expr> {
+    alt p.token {
+      token::UNDERSCORE { p.bump(); ret none; }
+      _ { ret some(parse_expr(p)); }
+    }
+}
+
 fn parse_expr_res(p: parser, r: restriction) -> @ast::expr {
     let old = p.restriction;
     p.restriction = r;

src/comp/syntax/print/pprust.rs

@@ -846,7 +846,12 @@ fn print_expr(s: ps, &&expr: @ast::expr) {
               _ { word(s.s, "_"); }
             }
         }
-        word_nbsp(s, "bind");
+
+        // "bind" keyword is only needed if there are no "_" arguments.
+        if !vec::any(args) {|arg| option::is_none(arg) } {
+            word_nbsp(s, "bind");
+        }
+
         print_expr(s, func);
         popen(s);
         commasep(s, inconsistent, args, print_opt);

src/test/run-pass/bind-parameterized-args-2.rs

@@ -1,7 +1,7 @@
 fn main() {
     fn echo<T>(c: int, x: fn@(T)) { #error("wee"); }
 
-    let y = bind echo(42, _);
+    let y = echo(42, _);
 
     y(fn@(&&i: str) { });
 }

src/test/run-pass/bind-parameterized-args.rs

@@ -1,7 +1,7 @@
 fn main() {
     fn echo<T>(c: int, x: [T]) { }
 
-    let y: fn@([int]) = bind echo(42, _);
+    let y: fn@([int]) = echo(42, _);
 
     y([1]);
 }

src/test/run-pass/bind-trivial.rs

@@ -5,7 +5,7 @@
 fn f(n: int) -> int { ret n; }
 
 fn main() {
-    let g: fn@(int) -> int = bind f(_);
+    let g: fn@(int) -> int = f(_);
     let i: int = g(42);
     assert (i == 42);
 }

src/test/run-pass/drop-bind-thunk-args.rs

@@ -2,4 +2,4 @@
 
 fn f(x: @int) { }
 
-fn main() { let x = @10; let ff = bind f(_); ff(x); ff(x); }
+fn main() { let x = @10; let ff = f(_); ff(x); ff(x); }

src/test/run-pass/drop-parametric-closure-with-bound-box.rs

@@ -2,4 +2,4 @@
 
 fn f<T>(i: @uint, t: T) { }
 
-fn main() { let x = bind f::<char>(@0xdeafbeefu, _); }
+fn main() { let x = f::<char>(@0xdeafbeefu, _); }

src/test/run-pass/expr-alt-generic-box1.rs

@@ -11,7 +11,7 @@ fn test_generic<T>(expected: @T, eq: compare<T>) {
 
 fn test_box() {
     fn compare_box(b1: @bool, b2: @bool) -> bool { ret *b1 == *b2; }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<bool>(@true, eq);
 }
 

src/test/run-pass/expr-alt-generic-box2.rs

@@ -11,7 +11,7 @@ fn test_generic<T: copy>(expected: T, eq: compare<T>) {
 
 fn test_vec() {
     fn compare_box(&&v1: @int, &&v2: @int) -> bool { ret v1 == v2; }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<@int>(@1, eq);
 }
 

src/test/run-pass/expr-alt-generic-unique1.rs

@@ -10,7 +10,7 @@ fn test_generic<T: copy>(expected: ~T, eq: compare<T>) {
 
 fn test_box() {
     fn compare_box(b1: ~bool, b2: ~bool) -> bool { ret *b1 == *b2; }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<bool>(~true, eq);
 }
 

src/test/run-pass/expr-alt-generic-unique2.rs

@@ -11,7 +11,7 @@ fn test_generic<T: copy>(expected: T, eq: compare<T>) {
 
 fn test_vec() {
     fn compare_box(&&v1: ~int, &&v2: ~int) -> bool { ret v1 == v2; }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<~int>(~1, eq);
 }
 

src/test/run-pass/expr-alt-generic.rs

@@ -11,7 +11,7 @@ fn test_generic<T: copy>(expected: T, eq: compare<T>) {
 
 fn test_bool() {
     fn compare_bool(&&b1: bool, &&b2: bool) -> bool { ret b1 == b2; }
-    let eq = bind compare_bool(_, _);
+    let eq = compare_bool(_, _);
     test_generic::<bool>(true, eq);
 }
 
@@ -19,7 +19,7 @@ fn test_rec() {
     type t = {a: int, b: int};
 
     fn compare_rec(t1: t, t2: t) -> bool { ret t1 == t2; }
-    let eq = bind compare_rec(_, _);
+    let eq = compare_rec(_, _);
     test_generic::<t>({a: 1, b: 2}, eq);
 }
 

src/test/run-pass/expr-block-generic-box1.rs

@@ -15,7 +15,7 @@ fn test_box() {
         log(debug, *b2);
         ret *b1 == *b2;
     }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<bool>(@true, eq);
 }
 

src/test/run-pass/expr-block-generic-box2.rs

@@ -11,7 +11,7 @@ fn test_generic<T: copy>(expected: T, eq: compare<T>) {
 
 fn test_vec() {
     fn compare_vec(&&v1: @int, &&v2: @int) -> bool { ret v1 == v2; }
-    let eq = bind compare_vec(_, _);
+    let eq = compare_vec(_, _);
     test_generic::<@int>(@1, eq);
 }
 

src/test/run-pass/expr-block-generic-unique1.rs

@@ -14,7 +14,7 @@ fn test_box() {
         log(debug, *b2);
         ret *b1 == *b2;
     }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<bool>(~true, eq);
 }
 

src/test/run-pass/expr-block-generic-unique2.rs

@@ -11,7 +11,7 @@ fn test_generic<T: copy>(expected: T, eq: compare<T>) {
 
 fn test_vec() {
     fn compare_vec(&&v1: ~int, &&v2: ~int) -> bool { ret v1 == v2; }
-    let eq = bind compare_vec(_, _);
+    let eq = compare_vec(_, _);
     test_generic::<~int>(~1, eq);
 }
 

src/test/run-pass/expr-block-generic.rs

@@ -13,7 +13,7 @@ fn test_generic<T: copy>(expected: T, eq: compare<T>) {
 
 fn test_bool() {
     fn compare_bool(&&b1: bool, &&b2: bool) -> bool { ret b1 == b2; }
-    let eq = bind compare_bool(_, _);
+    let eq = compare_bool(_, _);
     test_generic::<bool>(true, eq);
 }
 
@@ -21,7 +21,7 @@ fn test_rec() {
     type t = {a: int, b: int};
 
     fn compare_rec(t1: t, t2: t) -> bool { ret t1 == t2; }
-    let eq = bind compare_rec(_, _);
+    let eq = compare_rec(_, _);
     test_generic::<t>({a: 1, b: 2}, eq);
 }
 

src/test/run-pass/expr-if-generic-box1.rs

@@ -11,7 +11,7 @@ fn test_generic<T>(expected: @T, not_expected: @T, eq: compare<T>) {
 
 fn test_box() {
     fn compare_box(b1: @bool, b2: @bool) -> bool { ret *b1 == *b2; }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<bool>(@true, @false, eq);
 }
 

src/test/run-pass/expr-if-generic-box2.rs

@@ -11,7 +11,7 @@ fn test_generic<T: copy>(expected: T, not_expected: T, eq: compare<T>) {
 
 fn test_vec() {
     fn compare_box(&&v1: @int, &&v2: @int) -> bool { ret v1 == v2; }
-    let eq = bind compare_box(_, _);
+    let eq = compare_box(_, _);
     test_generic::<@int>(@1, @2, eq);
 }
 

src/test/run-pass/expr-if-generic.rs

@@ -13,7 +13,7 @@ fn test_generic<T: copy>(expected: T, not_expected: T, eq: compare<T>) {
 
 fn test_bool() {
     fn compare_bool(&&b1: bool, &&b2: bool) -> bool { ret b1 == b2; }
-    let eq = bind compare_bool(_, _);
+    let eq = compare_bool(_, _);
     test_generic::<bool>(true, false, eq);
 }
 
@@ -21,7 +21,7 @@ fn test_rec() {
     type t = {a: int, b: int};
 
     fn compare_rec(t1: t, t2: t) -> bool { ret t1 == t2; }
-    let eq = bind compare_rec(_, _);
+    let eq = compare_rec(_, _);
     test_generic::<t>({a: 1, b: 2}, {a: 2, b: 3}, eq);
 }
 

src/test/run-pass/fixed-point-bind-box.rs

@@ -1,9 +1,9 @@
 fn fix_help<A, B>(f: native fn(fn@(A) -> B, A) -> B, x: A) -> B {
-    ret f(bind fix_help(f, _), x);
+    ret f(fix_help(f, _), x);
 }
 
 fn fix<A, B>(f: native fn(fn@(A) -> B, A) -> B) -> fn@(A) -> B {
-    ret bind fix_help(f, _);
+    ret fix_help(f, _);
 }
 
 fn fact_(f: fn@(&&int) -> int, &&n: int) -> int {

src/test/run-pass/fixed-point-bind-unique.rs

@@ -1,9 +1,9 @@
 fn fix_help<A, B: send>(f: native fn(fn@(A) -> B, A) -> B, x: A) -> B {
-    ret f(bind fix_help(f, _), x);
+    ret f(fix_help(f, _), x);
 }
 
 fn fix<A, B: send>(f: native fn(fn@(A) -> B, A) -> B) -> fn@(A) -> B {
-    ret bind fix_help(f, _);
+    ret fix_help(f, _);
 }
 
 fn fact_(f: fn@(&&int) -> int, &&n: int) -> int {

src/test/run-pass/fun-call-variants.rs

@@ -7,7 +7,7 @@ fn main() {
     let a: int = direct(3); // direct
     let b: int = ho(direct); // indirect unbound
 
-    let c: int = ho(bind direct(_)); // indirect bound
+    let c: int = ho(direct(_)); // indirect bound
     assert (a == b);
     assert (b == c);
 }

src/test/run-pass/generic-bind.rs

@@ -6,12 +6,12 @@ fn main() {
     let t = {_0: 1, _1: 2, _2: 3, _3: 4, _4: 5, _5: 6, _6: 7};
     assert (t._5 == 6);
     let f1 =
-        bind id::<{_0: int,
-                   _1: int,
-                   _2: int,
-                   _3: int,
-                   _4: int,
-                   _5: int,
-                   _6: int}>(_);
+        id::<{_0: int,
+              _1: int,
+              _2: int,
+              _3: int,
+              _4: int,
+              _5: int,
+              _6: int}>(_);
     assert (f1(t)._5 == 6);
 }

src/test/run-pass/hashmap-memory.rs

@@ -58,7 +58,7 @@ mod map_reduce {
             }
         }
 
-        map(input, bind emit(intermediates, ctrl, _, _));
+        map(input, emit(intermediates, ctrl, _, _));
         send(ctrl, mapper_done);
     }
 

src/test/run-pass/issue-333.rs

@@ -1,4 +1,4 @@
-fn quux<T: copy>(x: T) -> T { let f = bind id::<T>(_); ret f(x); }
+fn quux<T: copy>(x: T) -> T { let f = id::<T>(_); ret f(x); }
 
 fn id<T: copy>(x: T) -> T { ret x; }
 

src/test/run-pass/issue-898.rs

@@ -7,5 +7,5 @@ fn log_if<T>(c: native fn(T)->bool, e: T) {
 }
 
 fn main() {
-    (bind log_if(even, _))(2);
+    (log_if(even, _))(2);
 }

src/test/run-pass/rebind-fn.rs

@@ -1,5 +1,5 @@
 fn add(i: int, j: int) -> int { ret i + j; }
-fn binder(n: int) -> fn@() -> int { let f = bind add(n, _); ret bind f(2); }
+fn binder(n: int) -> fn@() -> int { let f = add(n, _); ret bind f(2); }
 fn main() {
     binder(5);
     let f = binder(1);

src/test/run-pass/task-comm-17.rs

@@ -1,9 +1,6 @@
-// xfail-test
 // Issue #922
 
-// This test is specifically about spawning temporary closures, which
-// isn't possible under the bare-fn regime. I'm keeping it around
-// until such time as we have unique closures.
+// This test is specifically about spawning temporary closures.
 
 use std;
 import task;
@@ -12,5 +9,5 @@ fn f() {
 }
 
 fn main() {
-    task::spawn(bind f());
+    task::spawn {|| f() };
 }

src/test/run-pass/unchecked-predicates.rs

@@ -18,7 +18,7 @@ fn pure_foldl<T: copy, U: copy>(ls: list<T>, u: U, f: fn(T, U) -> U) -> U {
 // fn from a pure fn
 pure fn pure_length<T: copy>(ls: list<T>) -> uint {
     fn count<T>(_t: T, &&u: uint) -> uint { u + 1u }
-    unchecked{ pure_foldl(ls, 0u, bind count(_, _)) }
+    unchecked{ pure_foldl(ls, 0u, count(_, _)) }
 }
 
 pure fn nonempty_list<T: copy>(ls: list<T>) -> bool { pure_length(ls) > 0u }