libsyntax: Change all uses of `&fn` to `||`.

src/libsyntax/abi.rs

@@ -84,7 +84,7 @@ pub struct AbiSet {
     AbiData {abi: RustIntrinsic, name: "rust-intrinsic", abi_arch: RustArch},
 ];
 
-fn each_abi(op: &fn(abi: Abi) -> bool) -> bool {
+fn each_abi(op: |abi: Abi| -> bool) -> bool {
     /*!
      *
      * Iterates through each of the defined ABIs.
@@ -201,7 +201,7 @@ pub fn add(&mut self, abi: Abi) {
         self.bits |= (1 << abi.index());
     }
 
-    pub fn each(&self, op: &fn(abi: Abi) -> bool) -> bool {
+    pub fn each(&self, op: |abi: Abi| -> bool) -> bool {
         each_abi(|abi| !self.contains(abi) || op(abi))
     }
 

src/libsyntax/ast_map.rs

@@ -122,7 +122,7 @@ pub enum ast_node {
 }
 
 impl ast_node {
-    pub fn with_attrs<T>(&self, f: &fn(Option<&[Attribute]>) -> T) -> T {
+    pub fn with_attrs<T>(&self, f: |Option<&[Attribute]>| -> T) -> T {
         let attrs = match *self {
             node_item(i, _) => Some(i.attrs.as_slice()),
             node_foreign_item(fi, _, _, _) => Some(fi.attrs.as_slice()),
@@ -480,9 +480,8 @@ pub fn node_id_to_str(map: map, id: NodeId, itr: @ident_interner) -> ~str {
     }
 }
 
-pub fn node_item_query<Result>(items: map, id: NodeId,
-                               query: &fn(@item) -> Result,
-                               error_msg: ~str) -> Result {
+pub fn node_item_query<Result>(items: map, id: NodeId, query: |@item| -> Result, error_msg: ~str)
+                       -> Result {
     match items.find(&id) {
         Some(&node_item(it, _)) => query(it),
         _ => fail!("{}", error_msg)

src/libsyntax/ast_util.rs

@@ -636,7 +636,7 @@ pub fn is_item_impl(item: @ast::item) -> bool {
     }
 }
 
-pub fn walk_pat(pat: @Pat, it: &fn(@Pat) -> bool) -> bool {
+pub fn walk_pat(pat: @Pat, it: |@Pat| -> bool) -> bool {
     if !it(pat) {
         return false;
     }
@@ -665,7 +665,7 @@ pub fn walk_pat(pat: @Pat, it: &fn(@Pat) -> bool) -> bool {
 }
 
 pub trait EachViewItem {
-    fn each_view_item(&self, f: &fn(&ast::view_item) -> bool) -> bool;
+    fn each_view_item(&self, f: |&ast::view_item| -> bool) -> bool;
 }
 
 struct EachViewItemData<'self> {
@@ -679,7 +679,7 @@ fn visit_view_item(&mut self, view_item: &ast::view_item, _: ()) {
 }
 
 impl EachViewItem for ast::Crate {
-    fn each_view_item(&self, f: &fn(&ast::view_item) -> bool) -> bool {
+    fn each_view_item(&self, f: |&ast::view_item| -> bool) -> bool {
         let mut visit = EachViewItemData {
             callback: f,
         };

src/libsyntax/diagnostic.rs

@@ -347,9 +347,11 @@ fn print_macro_backtrace(cm: @codemap::CodeMap, sp: Span) {
     }
 }
 
-pub fn expect<T:Clone>(diag: @mut span_handler,
-                       opt: Option<T>,
-                       msg: &fn() -> ~str) -> T {
+pub fn expect<T:Clone>(
+              diag: @mut span_handler,
+              opt: Option<T>,
+              msg: || -> ~str)
+              -> T {
     match opt {
        Some(ref t) => (*t).clone(),
        None => diag.handler().bug(msg()),

src/libsyntax/ext/base.rs

@@ -559,11 +559,11 @@ pub fn contains_key (&self, key: &K) -> bool {
     // should each_key and each_value operate on shadowed
     // names? I think not.
     // delaying implementing this....
-    pub fn each_key (&self, _f: &fn (&K)->bool) {
+    pub fn each_key (&self, _f: |&K| -> bool) {
         fail!("unimplemented 2013-02-15T10:01");
     }
 
-    pub fn each_value (&self, _f: &fn (&V) -> bool) {
+    pub fn each_value (&self, _f: |&V| -> bool) {
         fail!("unimplemented 2013-02-15T10:02");
     }
 
@@ -601,7 +601,11 @@ pub fn insert (&mut self, key: K, ext: @V) -> bool {
     // ... there are definitely some opportunities for abstraction
     // here that I'm ignoring. (e.g., manufacturing a predicate on
     // the maps in the chain, and using an abstract "find".
-    pub fn insert_into_frame(&mut self, key: K, ext: @V, n: K, pred: &fn(&@V)->bool) {
+    pub fn insert_into_frame(&mut self,
+                             key: K,
+                             ext: @V,
+                             n: K,
+                             pred: |&@V| -> bool) {
         match *self {
             BaseMapChain (~ref mut map) => {
                 if satisfies_pred(map,&n,pred) {
@@ -622,10 +626,12 @@ pub fn insert_into_frame(&mut self, key: K, ext: @V, n: K, pred: &fn(&@V)->bool)
 }
 
 // returns true if the binding for 'n' satisfies 'pred' in 'map'
-fn satisfies_pred<K : Eq + Hash + IterBytes,V>(map : &mut HashMap<K,V>,
-                                               n: &K,
-                                               pred: &fn(&V)->bool)
-    -> bool {
+fn satisfies_pred<K:Eq + Hash + IterBytes,
+                  V>(
+                  map: &mut HashMap<K,V>,
+                  n: &K,
+                  pred: |&V| -> bool)
+                  -> bool {
     match map.find(n) {
         Some(ref v) => (pred(*v)),
         None => false
@@ -637,7 +643,8 @@ mod test {
     use super::MapChain;
     use std::hashmap::HashMap;
 
-    #[test] fn testenv () {
+    #[test]
+    fn testenv() {
         let mut a = HashMap::new();
         a.insert (@"abc",@15);
         let m = MapChain::new(~a);

src/libsyntax/ext/deriving/decodable.rs

@@ -124,9 +124,12 @@ fn decodable_substructure(cx: @ExtCtxt, span: Span,
 /// Create a decoder for a single enum variant/struct:
 /// - `outer_pat_ident` is the name of this enum variant/struct
 /// - `getarg` should retrieve the `uint`-th field with name `@str`.
-fn decode_static_fields(cx: @ExtCtxt, outer_span: Span, outer_pat_ident: Ident,
+fn decode_static_fields(cx: @ExtCtxt,
+                        outer_span: Span,
+                        outer_pat_ident: Ident,
                         fields: &StaticFields,
-                        getarg: &fn(Span, @str, uint) -> @Expr) -> @Expr {
+                        getarg: |Span, @str, uint| -> @Expr)
+                        -> @Expr {
     match *fields {
         Unnamed(ref fields) => {
             if fields.is_empty() {

src/libsyntax/ext/deriving/generic.rs

@@ -1064,14 +1064,13 @@ fn create_enum_variant_pattern(cx: @ExtCtxt,
 left-to-right (`true`) or right-to-left (`false`).
 */
 pub fn cs_fold(use_foldl: bool,
-               f: &fn(@ExtCtxt, Span,
-                      old: @Expr,
-                      self_f: @Expr,
-                      other_fs: &[@Expr]) -> @Expr,
+               f: |@ExtCtxt, Span, @Expr, @Expr, &[@Expr]| -> @Expr,
                base: @Expr,
                enum_nonmatch_f: EnumNonMatchFunc,
-               cx: @ExtCtxt, trait_span: Span,
-               substructure: &Substructure) -> @Expr {
+               cx: @ExtCtxt,
+               trait_span: Span,
+               substructure: &Substructure)
+               -> @Expr {
     match *substructure.fields {
         EnumMatching(_, _, ref all_fields) | Struct(ref all_fields) => {
             if use_foldl {
@@ -1104,10 +1103,12 @@ pub fn cs_fold(use_foldl: bool,
 ~~~
 */
 #[inline]
-pub fn cs_same_method(f: &fn(@ExtCtxt, Span, ~[@Expr]) -> @Expr,
+pub fn cs_same_method(f: |@ExtCtxt, Span, ~[@Expr]| -> @Expr,
                       enum_nonmatch_f: EnumNonMatchFunc,
-                      cx: @ExtCtxt, trait_span: Span,
-                      substructure: &Substructure) -> @Expr {
+                      cx: @ExtCtxt,
+                      trait_span: Span,
+                      substructure: &Substructure)
+                      -> @Expr {
     match *substructure.fields {
         EnumMatching(_, _, ref all_fields) | Struct(ref all_fields) => {
             // call self_n.method(other_1_n, other_2_n, ...)
@@ -1136,11 +1137,13 @@ pub fn cs_same_method(f: &fn(@ExtCtxt, Span, ~[@Expr]) -> @Expr,
 */
 #[inline]
 pub fn cs_same_method_fold(use_foldl: bool,
-                           f: &fn(@ExtCtxt, Span, @Expr, @Expr) -> @Expr,
+                           f: |@ExtCtxt, Span, @Expr, @Expr| -> @Expr,
                            base: @Expr,
                            enum_nonmatch_f: EnumNonMatchFunc,
-                           cx: @ExtCtxt, trait_span: Span,
-                           substructure: &Substructure) -> @Expr {
+                           cx: @ExtCtxt,
+                           trait_span: Span,
+                           substructure: &Substructure)
+                           -> @Expr {
     cs_same_method(
         |cx, span, vals| {
             if use_foldl {

src/libsyntax/ext/deriving/rand.rs

@@ -128,10 +128,12 @@ fn rand_substructure(cx: @ExtCtxt, span: Span, substr: &Substructure) -> @Expr {
         _ => cx.bug("Non-static method in `deriving(Rand)`")
     };
 
-    fn rand_thing(cx: @ExtCtxt, span: Span,
+    fn rand_thing(cx: @ExtCtxt,
+                  span: Span,
                   ctor_ident: Ident,
                   summary: &StaticFields,
-                  rand_call: &fn(Span) -> @Expr) -> @Expr {
+                  rand_call: |Span| -> @Expr)
+                  -> @Expr {
         match *summary {
             Unnamed(ref fields) => {
                 if fields.is_empty() {

src/libsyntax/fold.rs

@@ -381,7 +381,7 @@ fn fold_mac(&self, macro: &mac) -> mac {
         }
     }
 
-    fn map_exprs(&self, f: &fn(@Expr) -> @Expr, es: &[@Expr]) -> ~[@Expr] {
+    fn map_exprs(&self, f: |@Expr| -> @Expr, es: &[@Expr]) -> ~[@Expr] {
         es.map(|x| f(*x))
     }
 

src/libsyntax/opt_vec.rs

@@ -50,14 +50,14 @@ pub fn push(&mut self, t: T) {
         *self = Vec(~[t]);
     }
 
-    pub fn map<U>(&self, op: &fn(&T) -> U) -> OptVec<U> {
+    pub fn map<U>(&self, op: |&T| -> U) -> OptVec<U> {
         match *self {
             Empty => Empty,
             Vec(ref v) => Vec(v.map(op))
         }
     }
 
-    pub fn map_move<U>(self, op: &fn(T) -> U) -> OptVec<U> {
+    pub fn map_move<U>(self, op: |T| -> U) -> OptVec<U> {
         match self {
             Empty => Empty,
             Vec(v) => Vec(v.move_iter().map(op).collect())
@@ -91,11 +91,11 @@ pub fn iter<'r>(&'r self) -> OptVecIterator<'r, T> {
     }
 
     #[inline]
-    pub fn map_to_vec<B>(&self, op: &fn(&T) -> B) -> ~[B] {
+    pub fn map_to_vec<B>(&self, op: |&T| -> B) -> ~[B] {
         self.iter().map(op).collect()
     }
 
-    pub fn mapi_to_vec<B>(&self, op: &fn(uint, &T) -> B) -> ~[B] {
+    pub fn mapi_to_vec<B>(&self, op: |uint, &T| -> B) -> ~[B] {
         let mut index = 0;
         self.map_to_vec(|a| {
             let i = index;

src/libsyntax/parse/lexer.rs

@@ -216,16 +216,22 @@ fn byte_offset(rdr: &StringReader, pos: BytePos) -> BytePos {
 /// Calls `f` with a string slice of the source text spanning from `start`
 /// up to but excluding `rdr.last_pos`, meaning the slice does not include
 /// the character `rdr.curr`.
-pub fn with_str_from<T>(rdr: @mut StringReader, start: BytePos, f: &fn(s: &str) -> T) -> T {
+pub fn with_str_from<T>(
+                     rdr: @mut StringReader,
+                     start: BytePos,
+                     f: |s: &str| -> T)
+                     -> T {
     with_str_from_to(rdr, start, rdr.last_pos, f)
 }
 
 /// Calls `f` with astring slice of the source text spanning from `start`
 /// up to but excluding `end`.
-fn with_str_from_to<T>(rdr: @mut StringReader,
-                       start: BytePos,
-                       end: BytePos,
-                       f: &fn(s: &str) -> T) -> T {
+fn with_str_from_to<T>(
+                    rdr: @mut StringReader,
+                    start: BytePos,
+                    end: BytePos,
+                    f: |s: &str| -> T)
+                    -> T {
     f(rdr.src.slice(
             byte_offset(rdr, start).to_uint(),
             byte_offset(rdr, end).to_uint()))

src/libsyntax/parse/mod.rs

@@ -177,19 +177,14 @@ pub fn parse_tts_from_source_str(
 // consumed all of the input before returning the function's
 // result.
 pub fn parse_from_source_str<T>(
-    f: &fn(&Parser) -> T,
-    name: @str, ss: codemap::FileSubstr,
-    source: @str,
-    cfg: ast::CrateConfig,
-    sess: @mut ParseSess
-) -> T {
-    let p = new_parser_from_source_substr(
-        sess,
-        cfg,
-        name,
-        ss,
-        source
-    );
+                             f: |&Parser| -> T,
+                             name: @str,
+                             ss: codemap::FileSubstr,
+                             source: @str,
+                             cfg: ast::CrateConfig,
+                             sess: @mut ParseSess)
+                             -> T {
+    let p = new_parser_from_source_substr(sess, cfg, name, ss, source);
     let r = f(&p);
     if !p.reader.is_eof() {
         p.reader.fatal(~"expected end-of-string");

src/libsyntax/parse/obsolete.rs

@@ -82,7 +82,7 @@ fn obsolete(&self, sp: Span, kind: ObsoleteSyntax) {
             ),
             ObsoleteBareFnType => (
                 "bare function type",
-                "use `&fn` or `extern fn` instead"
+                "use `|A| -> B` or `extern fn(A) -> B` instead"
             ),
             ObsoleteNamedExternModule => (
                 "named external module",

src/libsyntax/parse/parser.rs

@@ -581,10 +581,8 @@ fn expect_or(&self) {
     }
 
     // Parse a sequence bracketed by `|` and `|`, stopping before the `|`.
-    fn parse_seq_to_before_or<T>(&self,
-                                 sep: &token::Token,
-                                 f: &fn(&Parser) -> T)
-                                 -> ~[T] {
+    fn parse_seq_to_before_or<T>(&self, sep: &token::Token, f: |&Parser| -> T)
+                              -> ~[T] {
         let mut first = true;
         let mut vector = ~[];
         while *self.token != token::BINOP(token::OR) &&
@@ -619,10 +617,11 @@ pub fn expect_gt(&self) {
 
     // parse a sequence bracketed by '<' and '>', stopping
     // before the '>'.
-    pub fn parse_seq_to_before_gt<T>(&self,
-                                     sep: Option<token::Token>,
-                                     f: &fn(&Parser) -> T)
-                                     -> OptVec<T> {
+    pub fn parse_seq_to_before_gt<T>(
+                                  &self,
+                                  sep: Option<token::Token>,
+                                  f: |&Parser| -> T)
+                                  -> OptVec<T> {
         let mut first = true;
         let mut v = opt_vec::Empty;
         while *self.token != token::GT
@@ -639,10 +638,11 @@ pub fn parse_seq_to_before_gt<T>(&self,
         return v;
     }
 
-    pub fn parse_seq_to_gt<T>(&self,
-                              sep: Option<token::Token>,
-                              f: &fn(&Parser) -> T)
-                              -> OptVec<T> {
+    pub fn parse_seq_to_gt<T>(
+                           &self,
+                           sep: Option<token::Token>,
+                           f: |&Parser| -> T)
+                           -> OptVec<T> {
         let v = self.parse_seq_to_before_gt(sep, f);
         self.expect_gt();
         return v;
@@ -651,11 +651,12 @@ pub fn parse_seq_to_gt<T>(&self,
     // parse a sequence, including the closing delimiter. The function
     // f must consume tokens until reaching the next separator or
     // closing bracket.
-    pub fn parse_seq_to_end<T>(&self,
-                               ket: &token::Token,
-                               sep: SeqSep,
-                               f: &fn(&Parser) -> T)
-                               -> ~[T] {
+    pub fn parse_seq_to_end<T>(
+                            &self,
+                            ket: &token::Token,
+                            sep: SeqSep,
+                            f: |&Parser| -> T)
+                            -> ~[T] {
         let val = self.parse_seq_to_before_end(ket, sep, f);
         self.bump();
         val
@@ -664,11 +665,12 @@ pub fn parse_seq_to_end<T>(&self,
     // parse a sequence, not including the closing delimiter. The function
     // f must consume tokens until reaching the next separator or
     // closing bracket.
-    pub fn parse_seq_to_before_end<T>(&self,
-                                      ket: &token::Token,
-                                      sep: SeqSep,
-                                      f: &fn(&Parser) -> T)
-                                      -> ~[T] {
+    pub fn parse_seq_to_before_end<T>(
+                                   &self,
+                                   ket: &token::Token,
+                                   sep: SeqSep,
+                                   f: |&Parser| -> T)
+                                   -> ~[T] {
         let mut first: bool = true;
         let mut v: ~[T] = ~[];
         while *self.token != *ket {
@@ -688,12 +690,13 @@ pub fn parse_seq_to_before_end<T>(&self,
     // parse a sequence, including the closing delimiter. The function
     // f must consume tokens until reaching the next separator or
     // closing bracket.
-    pub fn parse_unspanned_seq<T>(&self,
-                                  bra: &token::Token,
-                                  ket: &token::Token,
-                                  sep: SeqSep,
-                                  f: &fn(&Parser) -> T)
-                                  -> ~[T] {
+    pub fn parse_unspanned_seq<T>(
+                               &self,
+                               bra: &token::Token,
+                               ket: &token::Token,
+                               sep: SeqSep,
+                               f: |&Parser| -> T)
+                               -> ~[T] {
         self.expect(bra);
         let result = self.parse_seq_to_before_end(ket, sep, f);
         self.bump();
@@ -702,12 +705,13 @@ pub fn parse_unspanned_seq<T>(&self,
 
     // NB: Do not use this function unless you actually plan to place the
     // spanned list in the AST.
-    pub fn parse_seq<T>(&self,
-                        bra: &token::Token,
-                        ket: &token::Token,
-                        sep: SeqSep,
-                        f: &fn(&Parser) -> T)
-                        -> Spanned<~[T]> {
+    pub fn parse_seq<T>(
+                     &self,
+                     bra: &token::Token,
+                     ket: &token::Token,
+                     sep: SeqSep,
+                     f: |&Parser| -> T)
+                     -> Spanned<~[T]> {
         let lo = self.span.lo;
         self.expect(bra);
         let result = self.parse_seq_to_before_end(ket, sep, f);
@@ -765,8 +769,8 @@ pub fn buffer_length(&self) -> int {
         }
         return (4 - *self.buffer_start) + *self.buffer_end;
     }
-    pub fn look_ahead<R>(&self, distance: uint, f: &fn(&token::Token) -> R)
-                         -> R {
+    pub fn look_ahead<R>(&self, distance: uint, f: |&token::Token| -> R)
+                      -> R {
         let dist = distance as int;
         while self.buffer_length() < dist {
             self.buffer[*self.buffer_end] = self.reader.next_token();
@@ -1272,7 +1276,8 @@ pub fn parse_ty(&self, _: bool) -> Ty {
     // parse the type following a @ or a ~
     pub fn parse_box_or_uniq_pointee(&self,
                                      sigil: ast::Sigil,
-                                     ctor: &fn(v: mt) -> ty_) -> ty_ {
+                                     ctor: |v: mt| -> ty_)
+                                     -> ty_ {
         // ~'foo fn() or ~fn() are parsed directly as obsolete fn types:
         match *self.token {
             token::LIFETIME(*) => {
@@ -2467,8 +2472,8 @@ pub fn parse_lambda_expr(&self) -> @Expr {
     // this is used both in parsing a lambda expr
     // and in parsing a block expr as e.g. in for...
     pub fn parse_lambda_expr_(&self,
-                              parse_decl: &fn() -> fn_decl,
-                              parse_body: &fn() -> @Expr)
+                              parse_decl: || -> fn_decl,
+                              parse_body: || -> @Expr)
                               -> @Expr {
         let lo = self.last_span.lo;
         let decl = parse_decl();
@@ -2513,10 +2518,11 @@ pub fn parse_for_expr(&self, opt_ident: Option<ast::Ident>) -> @Expr {
     // parse a 'for' or 'do'.
     // the 'for' and 'do' expressions parse as calls, but look like
     // function calls followed by a closure expression.
-    pub fn parse_sugary_call_expr(&self, lo: BytePos,
+    pub fn parse_sugary_call_expr(&self,
+                                  lo: BytePos,
                                   keyword: ~str,
                                   sugar: CallSugar,
-                                  ctor: &fn(v: @Expr) -> Expr_)
+                                  ctor: |v: @Expr| -> Expr_)
                                   -> @Expr {
         // Parse the callee `foo` in
         //    for foo || {
@@ -3611,11 +3617,12 @@ fn expect_self_ident(&self) {
 
     // parse the argument list and result type of a function
     // that may have a self type.
-    fn parse_fn_decl_with_self(&self, parse_arg_fn: &fn(&Parser) -> arg)
-        -> (explicit_self, fn_decl) {
-
-        fn maybe_parse_explicit_self(cnstr: &fn(v: Mutability) -> ast::explicit_self_,
-                                     p: &Parser) -> ast::explicit_self_ {
+    fn parse_fn_decl_with_self(&self, parse_arg_fn: |&Parser| -> arg)
+                               -> (explicit_self, fn_decl) {
+        fn maybe_parse_explicit_self(cnstr: |v: Mutability| ->
+                                        ast::explicit_self_,
+                                     p: &Parser)
+                                     -> ast::explicit_self_ {
             // We need to make sure it isn't a type
             if p.look_ahead(1, |t| token::is_keyword(keywords::Self, t)) ||
                 ((p.look_ahead(1, |t| token::is_keyword(keywords::Const, t)) ||

src/libsyntax/print/pprust.rs

@@ -331,7 +331,7 @@ pub fn synth_comment(s: @ps, text: ~str) {
     word(s.s, "*/");
 }
 
-pub fn commasep<T>(s: @ps, b: breaks, elts: &[T], op: &fn(@ps, &T)) {
+pub fn commasep<T>(s: @ps, b: breaks, elts: &[T], op: |@ps, &T|) {
     box(s, 0u, b);
     let mut first = true;
     for elt in elts.iter() {
@@ -342,8 +342,12 @@ pub fn commasep<T>(s: @ps, b: breaks, elts: &[T], op: &fn(@ps, &T)) {
 }
 
 
-pub fn commasep_cmnt<T>(s: @ps, b: breaks, elts: &[T], op: &fn(@ps, &T),
-                               get_span: &fn(&T) -> codemap::Span) {
+pub fn commasep_cmnt<T>(
+                     s: @ps,
+                     b: breaks,
+                     elts: &[T],
+                     op: |@ps, &T|,
+                     get_span: |&T| -> codemap::Span) {
     box(s, 0u, b);
     let len = elts.len();
     let mut i = 0u;
@@ -2289,7 +2293,7 @@ pub fn print_string(s: @ps, st: &str, style: ast::StrStyle) {
     word(s.s, st);
 }
 
-pub fn to_str<T>(t: &T, f: &fn(@ps, &T), intr: @ident_interner) -> ~str {
+pub fn to_str<T>(t: &T, f: |@ps, &T|, intr: @ident_interner) -> ~str {
     let wr = @mut MemWriter::new();
     let s = rust_printer(wr as @mut io::Writer, intr);
     f(s, t);

src/libsyntax/util/parser_testing.rs

@@ -39,7 +39,7 @@ pub fn string_to_parser(source_str: @str) -> Parser {
     p
 }
 
-fn with_error_checking_parse<T>(s: @str, f: &fn(&mut Parser) -> T) -> T {
+fn with_error_checking_parse<T>(s: @str, f: |&mut Parser| -> T) -> T {
     let mut p = string_to_parser(s);
     let x = f(&mut p);
     p.abort_if_errors();