1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 use ast::{Sigil, BorrowedSigil, ManagedSigil, OwnedSigil};
14 use ast::{CallSugar, NoSugar, DoSugar, ForSugar};
15 use ast::{TyBareFn, TyClosure};
16 use ast::{RegionTyParamBound, TraitTyParamBound};
17 use ast::{provided, public, purity};
18 use ast::{_mod, add, arg, arm, Attribute, bind_by_ref, bind_infer};
19 use ast::{bitand, bitor, bitxor, Block};
20 use ast::{blk_check_mode, box};
21 use ast::{Crate, CrateConfig, decl, decl_item};
22 use ast::{decl_local, default_blk, deref, div, enum_def, explicit_self};
23 use ast::{expr, expr_, expr_addr_of, expr_match, expr_again};
24 use ast::{expr_assign, expr_assign_op, expr_binary, expr_block};
25 use ast::{expr_break, expr_call, expr_cast, expr_do_body};
26 use ast::{expr_field, expr_fn_block, expr_if, expr_index};
27 use ast::{expr_lit, expr_log, expr_loop, expr_loop_body, expr_mac};
28 use ast::{expr_method_call, expr_paren, expr_path, expr_repeat};
29 use ast::{expr_ret, expr_self, expr_struct, expr_tup, expr_unary};
30 use ast::{expr_vec, expr_vstore, expr_vstore_mut_box};
31 use ast::{expr_vstore_slice, expr_vstore_box};
32 use ast::{expr_vstore_mut_slice, expr_while, extern_fn, Field, fn_decl};
33 use ast::{expr_vstore_uniq, Onceness, Once, Many};
34 use ast::{foreign_item, foreign_item_static, foreign_item_fn, foreign_mod};
35 use ast::{ident, impure_fn, inherited, item, item_, item_static};
36 use ast::{item_enum, item_fn, item_foreign_mod, item_impl};
37 use ast::{item_mac, item_mod, item_struct, item_trait, item_ty, lit, lit_};
38 use ast::{lit_bool, lit_float, lit_float_unsuffixed, lit_int};
39 use ast::{lit_int_unsuffixed, lit_nil, lit_str, lit_uint, Local, m_const};
40 use ast::{m_imm, m_mutbl, mac_, mac_invoc_tt, matcher, match_nonterminal};
41 use ast::{match_seq, match_tok, method, mt, mul, mutability};
42 use ast::{named_field, neg, node_id, noreturn, not, pat, pat_box, pat_enum};
43 use ast::{pat_ident, pat_lit, pat_range, pat_region, pat_struct};
44 use ast::{pat_tup, pat_uniq, pat_wild, private};
45 use ast::{rem, required};
46 use ast::{ret_style, return_val, shl, shr, stmt, stmt_decl};
47 use ast::{stmt_expr, stmt_semi, stmt_mac, struct_def, struct_field};
48 use ast::{struct_variant_kind, subtract};
49 use ast::{sty_box, sty_region, sty_static, sty_uniq, sty_value};
50 use ast::{token_tree, trait_method, trait_ref, tt_delim, tt_seq, tt_tok};
51 use ast::{tt_nonterminal, tuple_variant_kind, Ty, ty_, ty_bot, ty_box};
52 use ast::{ty_field, ty_fixed_length_vec, ty_closure, ty_bare_fn};
53 use ast::{ty_infer, ty_method};
54 use ast::{ty_nil, TyParam, TyParamBound, ty_path, ty_ptr, ty_rptr};
55 use ast::{ty_tup, ty_u32, ty_uniq, ty_vec, uniq};
56 use ast::{unnamed_field, unsafe_blk, unsafe_fn, view_item};
57 use ast::{view_item_, view_item_extern_mod, view_item_use};
58 use ast::{view_path, view_path_glob, view_path_list, view_path_simple};
61 use ast_util::{as_prec, operator_prec};
63 use codemap::{span, BytePos, spanned, mk_sp};
65 use parse::attr::parser_attr;
67 use parse::common::{SeqSep, seq_sep_none};
68 use parse::common::{seq_sep_trailing_disallowed, seq_sep_trailing_allowed};
69 use parse::lexer::reader;
70 use parse::lexer::TokenAndSpan;
71 use parse::obsolete::{ObsoleteClassTraits};
72 use parse::obsolete::{ObsoleteLet, ObsoleteFieldTerminator};
73 use parse::obsolete::{ObsoleteMoveInit, ObsoleteBinaryMove, ObsoleteSwap};
74 use parse::obsolete::{ObsoleteSyntax, ObsoleteLowerCaseKindBounds};
75 use parse::obsolete::{ObsoleteUnsafeBlock, ObsoleteImplSyntax};
76 use parse::obsolete::{ObsoleteMutOwnedPointer};
77 use parse::obsolete::{ObsoleteMutVector, ObsoleteImplVisibility};
78 use parse::obsolete::{ObsoleteRecordType, ObsoleteRecordPattern};
79 use parse::obsolete::{ObsoletePostFnTySigil};
80 use parse::obsolete::{ObsoleteBareFnType, ObsoleteNewtypeEnum};
81 use parse::obsolete::ObsoleteMode;
82 use parse::obsolete::{ObsoleteLifetimeNotation, ObsoleteConstManagedPointer};
83 use parse::obsolete::{ObsoletePurity, ObsoleteStaticMethod};
84 use parse::obsolete::{ObsoleteConstItem, ObsoleteFixedLengthVectorType};
85 use parse::obsolete::{ObsoleteNamedExternModule, ObsoleteMultipleLocalDecl};
86 use parse::obsolete::{ObsoleteMutWithMultipleBindings};
87 use parse::obsolete::{ObsoleteExternVisibility, ParserObsoleteMethods};
88 use parse::token::{can_begin_expr, get_ident_interner, ident_to_str, is_ident};
89 use parse::token::{is_ident_or_path};
90 use parse::token::{is_plain_ident, INTERPOLATED, keywords, special_idents};
91 use parse::token::{token_to_binop};
93 use parse::{new_sub_parser_from_file, next_node_id, ParseSess};
97 use std::either::Either;
99 use std::hashmap::HashSet;
108 RESTRICT_NO_BAR_OR_DOUBLEBAR_OP,
111 type arg_or_capture_item = Either<arg, ()>;
112 type item_info = (ident, item_, Option<~[Attribute]>);
114 pub enum item_or_view_item {
115 // Indicates a failure to parse any kind of item. The attributes are
117 iovi_none(~[Attribute]),
119 iovi_foreign_item(@foreign_item),
120 iovi_view_item(view_item)
124 enum view_item_parse_mode {
125 VIEW_ITEMS_AND_ITEMS_ALLOWED,
126 FOREIGN_ITEMS_ALLOWED,
127 IMPORTS_AND_ITEMS_ALLOWED
130 /* The expr situation is not as complex as I thought it would be.
131 The important thing is to make sure that lookahead doesn't balk
132 at INTERPOLATED tokens */
133 macro_rules! maybe_whole_expr (
136 // This horrible convolution is brought to you by
137 // @mut, have a terrible day
138 let ret = match *($p).token {
139 INTERPOLATED(token::nt_expr(e)) => {
142 INTERPOLATED(token::nt_path(ref pt)) => {
146 expr_path(/* bad */ (*pt).clone())))
161 macro_rules! maybe_whole (
162 ($p:expr, $constructor:ident) => (
164 let __found__ = match *($p).token {
165 INTERPOLATED(token::$constructor(_)) => {
166 Some(($p).bump_and_get())
171 Some(INTERPOLATED(token::$constructor(x))) => {
178 (deref $p:expr, $constructor:ident) => (
180 let __found__ = match *($p).token {
181 INTERPOLATED(token::$constructor(_)) => {
182 Some(($p).bump_and_get())
187 Some(INTERPOLATED(token::$constructor(x))) => {
194 (Some $p:expr, $constructor:ident) => (
196 let __found__ = match *($p).token {
197 INTERPOLATED(token::$constructor(_)) => {
198 Some(($p).bump_and_get())
203 Some(INTERPOLATED(token::$constructor(x))) => {
204 return Some(x.clone()),
210 (iovi $p:expr, $constructor:ident) => (
212 let __found__ = match *($p).token {
213 INTERPOLATED(token::$constructor(_)) => {
214 Some(($p).bump_and_get())
219 Some(INTERPOLATED(token::$constructor(x))) => {
220 return iovi_item(x.clone())
226 (pair_empty $p:expr, $constructor:ident) => (
228 let __found__ = match *($p).token {
229 INTERPOLATED(token::$constructor(_)) => {
230 Some(($p).bump_and_get())
235 Some(INTERPOLATED(token::$constructor(x))) => {
236 return (~[], x.clone())
245 fn maybe_append(lhs: ~[Attribute], rhs: Option<~[Attribute]>)
249 Some(ref attrs) => vec::append(lhs, (*attrs))
254 struct ParsedItemsAndViewItems {
255 attrs_remaining: ~[Attribute],
256 view_items: ~[view_item],
258 foreign_items: ~[@foreign_item]
261 /* ident is handled by common.rs */
263 pub fn Parser(sess: @mut ParseSess,
264 cfg: ast::CrateConfig,
267 let tok0 = rdr.next_token();
268 let interner = get_ident_interner();
270 let placeholder = TokenAndSpan {
271 tok: token::UNDERSCORE,
280 token: @mut tok0.tok,
282 last_span: @mut span,
289 buffer_start: @mut 0,
291 tokens_consumed: @mut 0,
292 restriction: @mut UNRESTRICTED,
294 obsolete_set: @mut HashSet::new(),
295 mod_path_stack: @mut ~[],
299 // ooh, nasty mutable fields everywhere....
301 sess: @mut ParseSess,
303 // the current token:
304 token: @mut token::Token,
305 // the span of the current token:
307 // the span of the prior token:
308 last_span: @mut span,
309 buffer: @mut [TokenAndSpan, ..4],
310 buffer_start: @mut int,
311 buffer_end: @mut int,
312 tokens_consumed: @mut uint,
313 restriction: @mut restriction,
314 quote_depth: @mut uint, // not (yet) related to the quasiquoter
316 interner: @token::ident_interner,
317 /// The set of seen errors about obsolete syntax. Used to suppress
318 /// extra detail when the same error is seen twice
319 obsolete_set: @mut HashSet<ObsoleteSyntax>,
320 /// Used to determine the path to externally loaded source files
321 mod_path_stack: @mut ~[@str],
325 impl Drop for Parser {
326 /* do not copy the parser; its state is tied to outside state */
331 // convert a token to a string using self's reader
332 pub fn token_to_str(&self, token: &token::Token) -> ~str {
333 token::to_str(get_ident_interner(), token)
336 // convert the current token to a string using self's reader
337 pub fn this_token_to_str(&self) -> ~str {
338 self.token_to_str(self.token)
341 pub fn unexpected_last(&self, t: &token::Token) -> ! {
345 "unexpected token: `%s`",
351 pub fn unexpected(&self) -> ! {
354 "unexpected token: `%s`",
355 self.this_token_to_str()
360 // expect and consume the token t. Signal an error if
361 // the next token is not t.
362 pub fn expect(&self, t: &token::Token) {
363 if *self.token == *t {
368 "expected `%s` but found `%s`",
369 self.token_to_str(t),
370 self.this_token_to_str()
376 pub fn parse_ident(&self) -> ast::ident {
377 self.check_strict_keywords();
378 self.check_reserved_keywords();
380 token::IDENT(i, _) => {
384 token::INTERPOLATED(token::nt_ident(*)) => {
385 self.bug("ident interpolation not converted to real token");
390 "expected ident, found `%s`",
391 self.this_token_to_str()
398 pub fn parse_path_list_ident(&self) -> ast::path_list_ident {
399 let lo = self.span.lo;
400 let ident = self.parse_ident();
401 let hi = self.last_span.hi;
402 spanned(lo, hi, ast::path_list_ident_ { name: ident,
406 // consume token 'tok' if it exists. Returns true if the given
407 // token was present, false otherwise.
408 pub fn eat(&self, tok: &token::Token) -> bool {
409 let is_present = *self.token == *tok;
410 if is_present { self.bump() }
414 pub fn is_keyword(&self, kw: keywords::Keyword) -> bool {
415 token::is_keyword(kw, self.token)
418 // if the next token is the given keyword, eat it and return
419 // true. Otherwise, return false.
420 pub fn eat_keyword(&self, kw: keywords::Keyword) -> bool {
421 let is_kw = match *self.token {
422 token::IDENT(sid, false) => kw.to_ident().name == sid.name,
425 if is_kw { self.bump() }
429 // if the given word is not a keyword, signal an error.
430 // if the next token is not the given word, signal an error.
431 // otherwise, eat it.
432 pub fn expect_keyword(&self, kw: keywords::Keyword) {
433 if !self.eat_keyword(kw) {
436 "expected `%s`, found `%s`",
437 self.id_to_str(kw.to_ident()).to_str(),
438 self.this_token_to_str()
444 // signal an error if the given string is a strict keyword
445 pub fn check_strict_keywords(&self) {
446 if token::is_strict_keyword(self.token) {
447 self.span_err(*self.last_span,
448 fmt!("found `%s` in ident position", self.this_token_to_str()));
452 // signal an error if the current token is a reserved keyword
453 pub fn check_reserved_keywords(&self) {
454 if token::is_reserved_keyword(self.token) {
455 self.fatal(fmt!("`%s` is a reserved keyword", self.this_token_to_str()));
459 // expect and consume a GT. if a >> is seen, replace it
460 // with a single > and continue. If a GT is not seen,
462 pub fn expect_gt(&self) {
464 token::GT => self.bump(),
465 token::BINOP(token::SHR) => self.replace_token(
467 self.span.lo + BytePos(1u),
470 _ => self.fatal(fmt!("expected `%s`, found `%s`",
471 self.token_to_str(&token::GT),
472 self.this_token_to_str()))
476 // parse a sequence bracketed by '<' and '>', stopping
478 pub fn parse_seq_to_before_gt<T>(&self,
479 sep: Option<token::Token>,
480 f: &fn(&Parser) -> T)
482 let mut first = true;
483 let mut v = opt_vec::Empty;
484 while *self.token != token::GT
485 && *self.token != token::BINOP(token::SHR) {
488 if first { first = false; }
489 else { self.expect(t); }
498 pub fn parse_seq_to_gt<T>(&self,
499 sep: Option<token::Token>,
500 f: &fn(&Parser) -> T)
502 let v = self.parse_seq_to_before_gt(sep, f);
507 // parse a sequence, including the closing delimiter. The function
508 // f must consume tokens until reaching the next separator or
510 pub fn parse_seq_to_end<T>(&self,
513 f: &fn(&Parser) -> T)
515 let val = self.parse_seq_to_before_end(ket, sep, f);
520 // parse a sequence, not including the closing delimiter. The function
521 // f must consume tokens until reaching the next separator or
523 pub fn parse_seq_to_before_end<T>(&self,
526 f: &fn(&Parser) -> T)
528 let mut first: bool = true;
529 let mut v: ~[T] = ~[];
530 while *self.token != *ket {
533 if first { first = false; }
534 else { self.expect(t); }
538 if sep.trailing_sep_allowed && *self.token == *ket { break; }
544 // parse a sequence, including the closing delimiter. The function
545 // f must consume tokens until reaching the next separator or
547 pub fn parse_unspanned_seq<T>(&self,
551 f: &fn(&Parser) -> T)
554 let result = self.parse_seq_to_before_end(ket, sep, f);
559 // NB: Do not use this function unless you actually plan to place the
560 // spanned list in the AST.
561 pub fn parse_seq<T>(&self,
565 f: &fn(&Parser) -> T)
567 let lo = self.span.lo;
569 let result = self.parse_seq_to_before_end(ket, sep, f);
570 let hi = self.span.hi;
572 spanned(lo, hi, result)
575 // advance the parser by one token
577 *self.last_span = *self.span;
578 let next = if *self.buffer_start == *self.buffer_end {
579 self.reader.next_token()
581 // Avoid token copies with `util::replace`.
582 let buffer_start = *self.buffer_start as uint;
583 let next_index = (buffer_start + 1) & 3 as uint;
584 *self.buffer_start = next_index as int;
586 let placeholder = TokenAndSpan {
587 tok: token::UNDERSCORE,
590 util::replace(&mut self.buffer[buffer_start], placeholder)
592 *self.span = next.sp;
593 *self.token = next.tok;
594 *self.tokens_consumed += 1u;
597 // Advance the parser by one token and return the bumped token.
598 pub fn bump_and_get(&self) -> token::Token {
599 let old_token = util::replace(self.token, token::UNDERSCORE);
604 // EFFECT: replace the current token and span with the given one
605 pub fn replace_token(&self,
610 *self.span = mk_sp(lo, hi);
612 pub fn buffer_length(&self) -> int {
613 if *self.buffer_start <= *self.buffer_end {
614 return *self.buffer_end - *self.buffer_start;
616 return (4 - *self.buffer_start) + *self.buffer_end;
618 pub fn look_ahead<R>(&self, distance: uint, f: &fn(&token::Token) -> R)
620 let dist = distance as int;
621 while self.buffer_length() < dist {
622 self.buffer[*self.buffer_end] = self.reader.next_token();
623 *self.buffer_end = (*self.buffer_end + 1) & 3;
625 f(&self.buffer[(*self.buffer_start + dist - 1) & 3].tok)
627 pub fn fatal(&self, m: &str) -> ! {
628 self.sess.span_diagnostic.span_fatal(*self.span, m)
630 pub fn span_fatal(&self, sp: span, m: &str) -> ! {
631 self.sess.span_diagnostic.span_fatal(sp, m)
633 pub fn span_note(&self, sp: span, m: &str) {
634 self.sess.span_diagnostic.span_note(sp, m)
636 pub fn bug(&self, m: &str) -> ! {
637 self.sess.span_diagnostic.span_bug(*self.span, m)
639 pub fn warn(&self, m: &str) {
640 self.sess.span_diagnostic.span_warn(*self.span, m)
642 pub fn span_err(&self, sp: span, m: &str) {
643 self.sess.span_diagnostic.span_err(sp, m)
645 pub fn abort_if_errors(&self) {
646 self.sess.span_diagnostic.handler().abort_if_errors();
648 pub fn get_id(&self) -> node_id { next_node_id(self.sess) }
650 pub fn id_to_str(&self, id: ident) -> @str {
651 get_ident_interner().get(id.name)
654 // is this one of the keywords that signals a closure type?
655 pub fn token_is_closure_keyword(&self, tok: &token::Token) -> bool {
656 token::is_keyword(keywords::Pure, tok) ||
657 token::is_keyword(keywords::Unsafe, tok) ||
658 token::is_keyword(keywords::Once, tok) ||
659 token::is_keyword(keywords::Fn, tok)
662 pub fn token_is_lifetime(&self, tok: &token::Token) -> bool {
664 token::LIFETIME(*) => true,
669 pub fn get_lifetime(&self, tok: &token::Token) -> ast::ident {
671 token::LIFETIME(ref ident) => *ident,
672 _ => self.bug("not a lifetime"),
676 // parse a ty_bare_fun type:
677 pub fn parse_ty_bare_fn(&self) -> ty_ {
680 extern "ABI" [pure|unsafe] fn <'lt> (S) -> T
681 ^~~~^ ^~~~~~~~~~~~^ ^~~~^ ^~^ ^
692 let opt_abis = self.parse_opt_abis();
693 let abis = opt_abis.get_or_default(AbiSet::Rust());
694 let purity = self.parse_unsafety();
695 self.expect_keyword(keywords::Fn);
696 let (decl, lifetimes) = self.parse_ty_fn_decl();
697 return ty_bare_fn(@TyBareFn {
700 lifetimes: lifetimes,
705 // parse a ty_closure type
706 pub fn parse_ty_closure(&self,
708 region: Option<ast::Lifetime>)
712 (&|~|@) ['r] [pure|unsafe] [once] fn [:Bounds] <'lt> (S) -> T
713 ^~~~~~^ ^~~^ ^~~~~~~~~~~~^ ^~~~~^ ^~~~~~~~^ ^~~~^ ^~^ ^
715 | | | | | | | Return type
716 | | | | | | Argument types
718 | | | | Closure bounds
719 | | | Once-ness (a.k.a., affine)
726 // At this point, the allocation type and lifetime bound have been
729 let purity = self.parse_unsafety();
730 let onceness = parse_onceness(self);
731 self.expect_keyword(keywords::Fn);
732 let bounds = self.parse_optional_ty_param_bounds();
734 if self.parse_fn_ty_sigil().is_some() {
735 self.obsolete(*self.span, ObsoletePostFnTySigil);
738 let (decl, lifetimes) = self.parse_ty_fn_decl();
740 return ty_closure(@TyClosure {
747 lifetimes: lifetimes,
750 fn parse_onceness(this: &Parser) -> Onceness {
751 if this.eat_keyword(keywords::Once) {
759 // looks like this should be called parse_unsafety
760 pub fn parse_unsafety(&self) -> purity {
761 if self.eat_keyword(keywords::Pure) {
762 self.obsolete(*self.last_span, ObsoletePurity);
764 } else if self.eat_keyword(keywords::Unsafe) {
771 // parse a function type (following the 'fn')
772 pub fn parse_ty_fn_decl(&self) -> (fn_decl, OptVec<ast::Lifetime>) {
783 let lifetimes = if self.eat(&token::LT) {
784 let lifetimes = self.parse_lifetimes();
791 let inputs = self.parse_unspanned_seq(
794 seq_sep_trailing_disallowed(token::COMMA),
795 |p| p.parse_arg_general(false)
797 let (ret_style, ret_ty) = self.parse_ret_ty();
798 let decl = ast::fn_decl {
806 // parse the methods in a trait declaration
807 pub fn parse_trait_methods(&self) -> ~[trait_method] {
808 do self.parse_unspanned_seq(
813 let attrs = p.parse_outer_attributes();
816 let vis = p.parse_visibility();
817 let pur = p.parse_fn_purity();
818 // NB: at the moment, trait methods are public by default; this
820 let ident = p.parse_ident();
822 let generics = p.parse_generics();
824 let (explicit_self, d) = do self.parse_fn_decl_with_self() |p| {
825 // This is somewhat dubious; We don't want to allow argument
826 // names to be left off if there is a definition...
827 either::Left(p.parse_arg_general(false))
830 let hi = p.last_span.hi;
831 debug!("parse_trait_methods(): trait method signature ends in \
833 self.this_token_to_str());
837 debug!("parse_trait_methods(): parsing required method");
838 // NB: at the moment, visibility annotations on required
839 // methods are ignored; this could change.
846 explicit_self: explicit_self,
852 debug!("parse_trait_methods(): parsing provided method");
853 let (inner_attrs, body) =
854 p.parse_inner_attrs_and_block();
855 let attrs = vec::append(attrs, inner_attrs);
856 provided(@ast::method {
860 explicit_self: explicit_self,
874 "expected `;` or `}` but found `%s`",
875 self.this_token_to_str()
883 // parse a possibly mutable type
884 pub fn parse_mt(&self) -> mt {
885 let mutbl = self.parse_mutability();
886 let t = ~self.parse_ty(false);
887 mt { ty: t, mutbl: mutbl }
890 // parse [mut/const/imm] ID : TY
891 // now used only by obsolete record syntax parser...
892 pub fn parse_ty_field(&self) -> ty_field {
893 let lo = self.span.lo;
894 let mutbl = self.parse_mutability();
895 let id = self.parse_ident();
896 self.expect(&token::COLON);
897 let ty = ~self.parse_ty(false);
903 mt: ast::mt { ty: ty, mutbl: mutbl },
908 // parse optional return type [ -> TY ] in function decl
909 pub fn parse_ret_ty(&self) -> (ret_style, Ty) {
910 return if self.eat(&token::RARROW) {
911 let lo = self.span.lo;
912 if self.eat(&token::NOT) {
918 span: mk_sp(lo, self.last_span.hi)
922 (return_val, self.parse_ty(false))
925 let pos = self.span.lo;
931 span: mk_sp(pos, pos),
938 // Useless second parameter for compatibility with quasiquote macros.
940 pub fn parse_ty(&self, _: bool) -> Ty {
941 maybe_whole!(self, nt_ty);
943 let lo = self.span.lo;
945 let t = if *self.token == token::LPAREN {
947 if *self.token == token::RPAREN {
951 // (t) is a parenthesized ty
952 // (t,) is the type of a tuple with only one field,
954 let mut ts = ~[self.parse_ty(false)];
955 let mut one_tuple = false;
956 while *self.token == token::COMMA {
958 if *self.token != token::RPAREN {
959 ts.push(self.parse_ty(false));
966 if ts.len() == 1 && !one_tuple {
967 self.expect(&token::RPAREN);
972 self.expect(&token::RPAREN);
975 } else if *self.token == token::AT {
978 self.parse_box_or_uniq_pointee(ManagedSigil, ty_box)
979 } else if *self.token == token::TILDE {
982 self.parse_box_or_uniq_pointee(OwnedSigil, ty_uniq)
983 } else if *self.token == token::BINOP(token::STAR) {
984 // STAR POINTER (bare pointer?)
986 ty_ptr(self.parse_mt())
987 } else if *self.token == token::LBRACE {
988 // STRUCTURAL RECORD (remove?)
989 let elems = self.parse_unspanned_seq(
992 seq_sep_trailing_allowed(token::COMMA),
993 |p| p.parse_ty_field()
995 if elems.len() == 0 {
996 self.unexpected_last(&token::RBRACE);
998 self.obsolete(*self.last_span, ObsoleteRecordType);
1000 } else if *self.token == token::LBRACKET {
1002 self.expect(&token::LBRACKET);
1003 let mt = self.parse_mt();
1004 if mt.mutbl == m_mutbl { // `m_const` too after snapshot
1005 self.obsolete(*self.last_span, ObsoleteMutVector);
1008 // Parse the `, ..e` in `[ int, ..e ]`
1009 // where `e` is a const expression
1010 let t = match self.maybe_parse_fixed_vstore() {
1012 Some(suffix) => ty_fixed_length_vec(mt, suffix)
1014 self.expect(&token::RBRACKET);
1016 } else if *self.token == token::BINOP(token::AND) {
1019 self.parse_borrowed_pointee()
1020 } else if self.eat_keyword(keywords::Extern) {
1022 self.parse_ty_bare_fn()
1023 } else if self.token_is_closure_keyword(self.token) {
1025 let result = self.parse_ty_closure(ast::BorrowedSigil, None);
1026 self.obsolete(*self.last_span, ObsoleteBareFnType);
1028 } else if *self.token == token::MOD_SEP
1029 || is_ident_or_path(self.token) {
1031 let (path, bounds) = self.parse_type_path();
1032 ty_path(path, bounds, self.get_id())
1034 self.fatal(fmt!("expected type, found token %?",
1038 let sp = mk_sp(lo, self.last_span.hi);
1039 Ty {id: self.get_id(), node: t, span: sp}
1042 // parse the type following a @ or a ~
1043 pub fn parse_box_or_uniq_pointee(&self,
1045 ctor: &fn(v: mt) -> ty_) -> ty_ {
1046 // @'foo fn() or @foo/fn() or @fn() are parsed directly as fn types:
1048 token::LIFETIME(*) => {
1049 let lifetime = self.parse_lifetime();
1051 return self.parse_ty_closure(sigil, Some(lifetime));
1054 token::IDENT(*) => {
1055 if self.look_ahead(1, |t| *t == token::BINOP(token::SLASH)) &&
1056 self.look_ahead(2, |t|
1057 self.token_is_closure_keyword(t)) {
1058 let lifetime = self.parse_lifetime();
1059 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1060 return self.parse_ty_closure(sigil, Some(lifetime));
1061 } else if self.token_is_closure_keyword(self.token) {
1062 return self.parse_ty_closure(sigil, None);
1068 // other things are parsed as @ + a type. Note that constructs like
1069 // @[] and @str will be resolved during typeck to slices and so forth,
1070 // rather than boxed ptrs. But the special casing of str/vec is not
1071 // reflected in the AST type.
1072 let mt = self.parse_mt();
1074 if mt.mutbl != m_imm && sigil == OwnedSigil {
1075 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
1077 if mt.mutbl == m_const && sigil == ManagedSigil {
1078 self.obsolete(*self.last_span, ObsoleteConstManagedPointer);
1084 pub fn parse_borrowed_pointee(&self) -> ty_ {
1085 // look for `&'lt` or `&'foo ` and interpret `foo` as the region name:
1086 let opt_lifetime = self.parse_opt_lifetime();
1088 if self.token_is_closure_keyword(self.token) {
1089 return self.parse_ty_closure(BorrowedSigil, opt_lifetime);
1092 let mt = self.parse_mt();
1093 return ty_rptr(opt_lifetime, mt);
1096 // parse an optional, obsolete argument mode.
1097 pub fn parse_arg_mode(&self) {
1098 if self.eat(&token::BINOP(token::MINUS)) {
1099 self.obsolete(*self.span, ObsoleteMode);
1100 } else if self.eat(&token::ANDAND) {
1101 self.obsolete(*self.span, ObsoleteMode);
1102 } else if self.eat(&token::BINOP(token::PLUS)) {
1103 if self.eat(&token::BINOP(token::PLUS)) {
1104 self.obsolete(*self.span, ObsoleteMode);
1106 self.obsolete(*self.span, ObsoleteMode);
1113 pub fn is_named_argument(&self) -> bool {
1114 let offset = match *self.token {
1115 token::BINOP(token::AND) => 1,
1116 token::BINOP(token::MINUS) => 1,
1118 token::BINOP(token::PLUS) => {
1119 if self.look_ahead(1, |t| *t == token::BINOP(token::PLUS)) {
1129 is_plain_ident(&*self.token)
1130 && self.look_ahead(1, |t| *t == token::COLON)
1132 self.look_ahead(offset, |t| is_plain_ident(t))
1133 && self.look_ahead(offset + 1, |t| *t == token::COLON)
1137 // This version of parse arg doesn't necessarily require
1138 // identifier names.
1139 pub fn parse_arg_general(&self, require_name: bool) -> arg {
1140 let is_mutbl = self.eat_keyword(keywords::Mut);
1141 let pat = if require_name || self.is_named_argument() {
1142 self.parse_arg_mode();
1143 let pat = self.parse_pat();
1145 if is_mutbl && !ast_util::pat_is_ident(pat) {
1146 self.obsolete(*self.span, ObsoleteMutWithMultipleBindings)
1149 self.expect(&token::COLON);
1152 ast_util::ident_to_pat(self.get_id(),
1154 special_idents::invalid)
1157 let t = self.parse_ty(false);
1167 // parse a single function argument
1168 pub fn parse_arg(&self) -> arg_or_capture_item {
1169 either::Left(self.parse_arg_general(true))
1172 // parse an argument in a lambda header e.g. |arg, arg|
1173 pub fn parse_fn_block_arg(&self) -> arg_or_capture_item {
1174 self.parse_arg_mode();
1175 let is_mutbl = self.eat_keyword(keywords::Mut);
1176 let pat = self.parse_pat();
1177 let t = if self.eat(&token::COLON) {
1178 self.parse_ty(false)
1183 span: mk_sp(self.span.lo, self.span.hi),
1186 either::Left(ast::arg {
1194 pub fn maybe_parse_fixed_vstore(&self) -> Option<@ast::expr> {
1195 if self.eat(&token::BINOP(token::STAR)) {
1196 self.obsolete(*self.last_span, ObsoleteFixedLengthVectorType);
1197 Some(self.parse_expr())
1198 } else if *self.token == token::COMMA &&
1199 self.look_ahead(1, |t| *t == token::DOTDOT) {
1202 Some(self.parse_expr())
1208 // matches token_lit = LIT_INT | ...
1209 pub fn lit_from_token(&self, tok: &token::Token) -> lit_ {
1211 token::LIT_INT(i, it) => lit_int(i, it),
1212 token::LIT_UINT(u, ut) => lit_uint(u, ut),
1213 token::LIT_INT_UNSUFFIXED(i) => lit_int_unsuffixed(i),
1214 token::LIT_FLOAT(s, ft) => lit_float(self.id_to_str(s), ft),
1215 token::LIT_FLOAT_UNSUFFIXED(s) =>
1216 lit_float_unsuffixed(self.id_to_str(s)),
1217 token::LIT_STR(s) => lit_str(self.id_to_str(s)),
1218 token::LPAREN => { self.expect(&token::RPAREN); lit_nil },
1219 _ => { self.unexpected_last(tok); }
1223 // matches lit = true | false | token_lit
1224 pub fn parse_lit(&self) -> lit {
1225 let lo = self.span.lo;
1226 let lit = if self.eat_keyword(keywords::True) {
1228 } else if self.eat_keyword(keywords::False) {
1231 let token = self.bump_and_get();
1232 let lit = self.lit_from_token(&token);
1235 codemap::spanned { node: lit, span: mk_sp(lo, self.last_span.hi) }
1238 // matches '-' lit | lit
1239 pub fn parse_literal_maybe_minus(&self) -> @expr {
1240 let minus_lo = self.span.lo;
1241 let minus_present = self.eat(&token::BINOP(token::MINUS));
1243 let lo = self.span.lo;
1244 let literal = @self.parse_lit();
1245 let hi = self.span.hi;
1246 let expr = self.mk_expr(lo, hi, expr_lit(literal));
1249 let minus_hi = self.span.hi;
1250 self.mk_expr(minus_lo, minus_hi, self.mk_unary(neg, expr))
1256 // parse a path into a vector of idents, whether the path starts
1257 // with ::, and a span.
1258 pub fn parse_path(&self) -> (~[ast::ident],bool,span) {
1259 let lo = self.span.lo;
1260 let is_global = self.eat(&token::MOD_SEP);
1261 let (ids,span{lo:_,hi,expn_info}) = self.parse_path_non_global();
1262 (ids,is_global,span{lo:lo,hi:hi,expn_info:expn_info})
1265 // parse a path beginning with an identifier into a vector of idents and a span
1266 pub fn parse_path_non_global(&self) -> (~[ast::ident],span) {
1267 let lo = self.span.lo;
1269 // must be at least one to begin:
1270 ids.push(self.parse_ident());
1274 let is_ident = do self.look_ahead(1) |t| {
1276 token::IDENT(*) => true,
1282 ids.push(self.parse_ident());
1290 (ids, mk_sp(lo, self.last_span.hi))
1293 // parse a path that doesn't have type parameters attached
1294 pub fn parse_path_without_tps(&self) -> ast::Path {
1295 maybe_whole!(self, nt_path);
1296 let (ids,is_global,sp) = self.parse_path();
1297 ast::Path { span: sp,
1304 pub fn parse_bounded_path_with_tps(&self, colons: bool,
1305 before_tps: Option<&fn()>) -> ast::Path {
1306 debug!("parse_path_with_tps(colons=%b)", colons);
1308 maybe_whole!(self, nt_path);
1309 let lo = self.span.lo;
1310 let path = self.parse_path_without_tps();
1311 if colons && !self.eat(&token::MOD_SEP) {
1315 // If the path might have bounds on it, they should be parsed before
1316 // the parameters, e.g. module::TraitName:B1+B2<T>
1317 before_tps.map_consume(|callback| callback());
1319 // Parse the (obsolete) trailing region parameter, if any, which will
1320 // be written "foo/&x"
1322 if *self.token == token::BINOP(token::SLASH)
1323 && self.look_ahead(1, |t| *t == token::BINOP(token::AND))
1325 self.bump(); self.bump();
1326 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1328 token::IDENT(sid, _) => {
1329 let span = self.span;
1331 Some(ast::Lifetime {
1338 self.fatal(fmt!("Expected a lifetime name"));
1346 // Parse any lifetime or type parameters which may appear:
1347 let (lifetimes, tps) = self.parse_generic_values();
1348 let hi = self.span.lo;
1350 let rp = match (&rp_slash, &lifetimes) {
1351 (&Some(_), _) => rp_slash,
1355 } else if v.len() == 1 {
1358 self.fatal(fmt!("Expected at most one \
1359 lifetime name (for now)"));
1365 span: mk_sp(lo, hi),
1372 // parse a path optionally with type parameters. If 'colons'
1373 // is true, then type parameters must be preceded by colons,
1374 // as in a::t::<t1,t2>
1375 pub fn parse_path_with_tps(&self, colons: bool) -> ast::Path {
1376 self.parse_bounded_path_with_tps(colons, None)
1379 // Like the above, but can also parse kind bounds in the case of a
1380 // path to be used as a type that might be a trait.
1381 pub fn parse_type_path(&self) -> (ast::Path, Option<OptVec<TyParamBound>>) {
1382 let mut bounds = None;
1383 let path = self.parse_bounded_path_with_tps(false, Some(|| {
1384 // Note: this closure might not even get called in the case of a
1385 // macro-generated path. But that's the macro parser's job.
1386 bounds = self.parse_optional_ty_param_bounds();
1391 /// parses 0 or 1 lifetime
1392 pub fn parse_opt_lifetime(&self) -> Option<ast::Lifetime> {
1394 token::LIFETIME(*) => {
1395 Some(self.parse_lifetime())
1398 // Also accept the (obsolete) syntax `foo/`
1399 token::IDENT(*) => {
1400 if self.look_ahead(1, |t| *t == token::BINOP(token::SLASH)) {
1401 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1402 Some(self.parse_lifetime())
1414 /// Parses a single lifetime
1415 // matches lifetime = ( LIFETIME ) | ( IDENT / )
1416 pub fn parse_lifetime(&self) -> ast::Lifetime {
1418 token::LIFETIME(i) => {
1419 let span = self.span;
1421 return ast::Lifetime {
1428 // Also accept the (obsolete) syntax `foo/`
1429 token::IDENT(i, _) => {
1430 let span = self.span;
1432 self.expect(&token::BINOP(token::SLASH));
1433 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1434 return ast::Lifetime {
1442 self.fatal(fmt!("Expected a lifetime name"));
1447 // matches lifetimes = ( lifetime ) | ( lifetime , lifetimes )
1448 // actually, it matches the empty one too, but putting that in there
1449 // messes up the grammar....
1450 pub fn parse_lifetimes(&self) -> OptVec<ast::Lifetime> {
1453 * Parses zero or more comma separated lifetimes.
1454 * Expects each lifetime to be followed by either
1455 * a comma or `>`. Used when parsing type parameter
1456 * lists, where we expect something like `<'a, 'b, T>`.
1459 let mut res = opt_vec::Empty;
1462 token::LIFETIME(_) => {
1463 res.push(self.parse_lifetime());
1471 token::COMMA => { self.bump();}
1472 token::GT => { return res; }
1473 token::BINOP(token::SHR) => { return res; }
1475 self.fatal(fmt!("expected `,` or `>` after lifetime name, got: %?",
1482 pub fn token_is_mutability(&self, tok: &token::Token) -> bool {
1483 token::is_keyword(keywords::Mut, tok) ||
1484 token::is_keyword(keywords::Const, tok)
1487 // parse mutability declaration (mut/const/imm)
1488 pub fn parse_mutability(&self) -> mutability {
1489 if self.eat_keyword(keywords::Mut) {
1491 } else if self.eat_keyword(keywords::Const) {
1498 // parse ident COLON expr
1499 pub fn parse_field(&self) -> Field {
1500 let lo = self.span.lo;
1501 let i = self.parse_ident();
1502 self.expect(&token::COLON);
1503 let e = self.parse_expr();
1507 span: mk_sp(lo, e.span.hi),
1511 pub fn mk_expr(&self, lo: BytePos, hi: BytePos, node: expr_) -> @expr {
1515 span: mk_sp(lo, hi),
1519 pub fn mk_unary(&self, unop: ast::unop, expr: @expr) -> ast::expr_ {
1520 expr_unary(self.get_id(), unop, expr)
1523 pub fn mk_binary(&self, binop: ast::binop, lhs: @expr, rhs: @expr) -> ast::expr_ {
1524 expr_binary(self.get_id(), binop, lhs, rhs)
1527 pub fn mk_call(&self, f: @expr, args: ~[@expr], sugar: CallSugar) -> ast::expr_ {
1528 expr_call(f, args, sugar)
1531 pub fn mk_method_call(&self,
1536 sugar: CallSugar) -> ast::expr_ {
1537 expr_method_call(self.get_id(), rcvr, ident, tps, args, sugar)
1540 pub fn mk_index(&self, expr: @expr, idx: @expr) -> ast::expr_ {
1541 expr_index(self.get_id(), expr, idx)
1544 pub fn mk_field(&self, expr: @expr, ident: ident, tys: ~[Ty]) -> ast::expr_ {
1545 expr_field(expr, ident, tys)
1548 pub fn mk_assign_op(&self, binop: ast::binop, lhs: @expr, rhs: @expr) -> ast::expr_ {
1549 expr_assign_op(self.get_id(), binop, lhs, rhs)
1552 pub fn mk_mac_expr(&self, lo: BytePos, hi: BytePos, m: mac_) -> @expr {
1555 node: expr_mac(codemap::spanned {node: m, span: mk_sp(lo, hi)}),
1556 span: mk_sp(lo, hi),
1560 pub fn mk_lit_u32(&self, i: u32) -> @expr {
1561 let span = self.span;
1562 let lv_lit = @codemap::spanned {
1563 node: lit_uint(i as u64, ty_u32),
1569 node: expr_lit(lv_lit),
1574 // at the bottom (top?) of the precedence hierarchy,
1575 // parse things like parenthesized exprs,
1576 // macros, return, etc.
1577 pub fn parse_bottom_expr(&self) -> @expr {
1578 maybe_whole_expr!(self);
1580 let lo = self.span.lo;
1581 let mut hi = self.span.hi;
1585 if *self.token == token::LPAREN {
1587 // (e) is parenthesized e
1588 // (e,) is a tuple with only one field, e
1589 let mut trailing_comma = false;
1590 if *self.token == token::RPAREN {
1593 let lit = @spanned(lo, hi, lit_nil);
1594 return self.mk_expr(lo, hi, expr_lit(lit));
1596 let mut es = ~[self.parse_expr()];
1597 while *self.token == token::COMMA {
1599 if *self.token != token::RPAREN {
1600 es.push(self.parse_expr());
1603 trailing_comma = true;
1607 self.expect(&token::RPAREN);
1609 return if es.len() == 1 && !trailing_comma {
1610 self.mk_expr(lo, self.span.hi, expr_paren(es[0]))
1613 self.mk_expr(lo, hi, expr_tup(es))
1615 } else if *self.token == token::LBRACE {
1617 let blk = self.parse_block_tail(lo, default_blk);
1618 return self.mk_expr(blk.span.lo, blk.span.hi,
1620 } else if token::is_bar(&*self.token) {
1621 return self.parse_lambda_expr();
1622 } else if self.eat_keyword(keywords::Self) {
1625 } else if self.eat_keyword(keywords::If) {
1626 return self.parse_if_expr();
1627 } else if self.eat_keyword(keywords::For) {
1628 return self.parse_sugary_call_expr(lo, ~"for", ForSugar,
1630 } else if self.eat_keyword(keywords::Do) {
1631 return self.parse_sugary_call_expr(lo, ~"do", DoSugar,
1633 } else if self.eat_keyword(keywords::While) {
1634 return self.parse_while_expr();
1635 } else if self.token_is_lifetime(&*self.token) {
1636 let lifetime = self.get_lifetime(&*self.token);
1638 self.expect(&token::COLON);
1639 self.expect_keyword(keywords::Loop);
1640 return self.parse_loop_expr(Some(lifetime));
1641 } else if self.eat_keyword(keywords::Loop) {
1642 return self.parse_loop_expr(None);
1643 } else if self.eat_keyword(keywords::Match) {
1644 return self.parse_match_expr();
1645 } else if self.eat_keyword(keywords::Unsafe) {
1646 return self.parse_block_expr(lo, unsafe_blk);
1647 } else if *self.token == token::LBRACKET {
1649 let mutbl = self.parse_mutability();
1650 if mutbl == m_mutbl || mutbl == m_const {
1651 self.obsolete(*self.last_span, ObsoleteMutVector);
1654 if *self.token == token::RBRACKET {
1657 ex = expr_vec(~[], mutbl);
1660 let first_expr = self.parse_expr();
1661 if *self.token == token::COMMA &&
1662 self.look_ahead(1, |t| *t == token::DOTDOT) {
1663 // Repeating vector syntax: [ 0, ..512 ]
1666 let count = self.parse_expr();
1667 self.expect(&token::RBRACKET);
1668 ex = expr_repeat(first_expr, count, mutbl);
1669 } else if *self.token == token::COMMA {
1670 // Vector with two or more elements.
1672 let remaining_exprs = self.parse_seq_to_end(
1674 seq_sep_trailing_allowed(token::COMMA),
1677 ex = expr_vec(~[first_expr] + remaining_exprs, mutbl);
1679 // Vector with one element.
1680 self.expect(&token::RBRACKET);
1681 ex = expr_vec(~[first_expr], mutbl);
1684 hi = self.last_span.hi;
1685 } else if self.eat_keyword(keywords::__Log) {
1687 self.expect(&token::LPAREN);
1688 let lvl = self.parse_expr();
1689 self.expect(&token::COMMA);
1690 let e = self.parse_expr();
1691 ex = expr_log(lvl, e);
1693 self.expect(&token::RPAREN);
1694 } else if self.eat_keyword(keywords::Return) {
1695 // RETURN expression
1696 if can_begin_expr(&*self.token) {
1697 let e = self.parse_expr();
1699 ex = expr_ret(Some(e));
1700 } else { ex = expr_ret(None); }
1701 } else if self.eat_keyword(keywords::Break) {
1703 if self.token_is_lifetime(&*self.token) {
1704 let lifetime = self.get_lifetime(&*self.token);
1706 ex = expr_break(Some(lifetime));
1708 ex = expr_break(None);
1711 } else if *self.token == token::MOD_SEP ||
1712 is_ident(&*self.token) && !self.is_keyword(keywords::True) &&
1713 !self.is_keyword(keywords::False) {
1714 let pth = self.parse_path_with_tps(true);
1716 // `!`, as an operator, is prefix, so we know this isn't that
1717 if *self.token == token::NOT {
1718 // MACRO INVOCATION expression
1721 token::LPAREN | token::LBRACE => {}
1722 _ => self.fatal("expected open delimiter")
1725 let ket = token::flip_delimiter(&*self.token);
1728 let tts = self.parse_seq_to_end(&ket,
1730 |p| p.parse_token_tree());
1731 let hi = self.span.hi;
1733 return self.mk_mac_expr(lo, hi, mac_invoc_tt(pth, tts));
1734 } else if *self.token == token::LBRACE {
1735 // This might be a struct literal.
1736 if self.looking_at_record_literal() {
1737 // It's a struct literal.
1739 let mut fields = ~[];
1740 let mut base = None;
1742 fields.push(self.parse_field());
1743 while *self.token != token::RBRACE {
1744 if self.try_parse_obsolete_with() {
1748 self.expect(&token::COMMA);
1750 if self.eat(&token::DOTDOT) {
1751 base = Some(self.parse_expr());
1755 if *self.token == token::RBRACE {
1756 // Accept an optional trailing comma.
1759 fields.push(self.parse_field());
1763 self.expect(&token::RBRACE);
1764 ex = expr_struct(pth, fields, base);
1765 return self.mk_expr(lo, hi, ex);
1770 ex = expr_path(pth);
1772 // other literal expression
1773 let lit = self.parse_lit();
1775 ex = expr_lit(@lit);
1778 return self.mk_expr(lo, hi, ex);
1781 // parse a block or unsafe block
1782 pub fn parse_block_expr(&self, lo: BytePos, blk_mode: blk_check_mode)
1784 self.expect(&token::LBRACE);
1785 let blk = self.parse_block_tail(lo, blk_mode);
1786 return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
1789 // parse a.b or a(13) or a[4] or just a
1790 pub fn parse_dot_or_call_expr(&self) -> @expr {
1791 let b = self.parse_bottom_expr();
1792 self.parse_dot_or_call_expr_with(b)
1795 pub fn parse_dot_or_call_expr_with(&self, e0: @expr) -> @expr {
1801 if self.eat(&token::DOT) {
1803 token::IDENT(i, _) => {
1806 let (_, tys) = if self.eat(&token::MOD_SEP) {
1807 self.expect(&token::LT);
1808 self.parse_generic_values_after_lt()
1810 (opt_vec::Empty, ~[])
1813 // expr.f() method call
1816 let es = self.parse_unspanned_seq(
1819 seq_sep_trailing_disallowed(token::COMMA),
1824 let nd = self.mk_method_call(e, i, tys, es, NoSugar);
1825 e = self.mk_expr(lo, hi, nd);
1828 e = self.mk_expr(lo, hi, self.mk_field(e, i, tys));
1832 _ => self.unexpected()
1836 if self.expr_is_complete(e) { break; }
1840 let es = self.parse_unspanned_seq(
1843 seq_sep_trailing_disallowed(token::COMMA),
1848 let nd = self.mk_call(e, es, NoSugar);
1849 e = self.mk_expr(lo, hi, nd);
1853 token::LBRACKET => {
1855 let ix = self.parse_expr();
1857 self.expect(&token::RBRACKET);
1858 e = self.mk_expr(lo, hi, self.mk_index(e, ix));
1867 // parse an optional separator followed by a kleene-style
1868 // repetition token (+ or *).
1869 pub fn parse_sep_and_zerok(&self) -> (Option<token::Token>, bool) {
1870 fn parse_zerok(parser: &Parser) -> Option<bool> {
1871 match *parser.token {
1872 token::BINOP(token::STAR) | token::BINOP(token::PLUS) => {
1873 let zerok = *parser.token == token::BINOP(token::STAR);
1881 match parse_zerok(self) {
1882 Some(zerok) => return (None, zerok),
1886 let separator = self.bump_and_get();
1887 match parse_zerok(self) {
1888 Some(zerok) => (Some(separator), zerok),
1889 None => self.fatal("expected `*` or `+`")
1893 // parse a single token tree from the input.
1894 pub fn parse_token_tree(&self) -> token_tree {
1895 maybe_whole!(deref self, nt_tt);
1897 // this is the fall-through for the 'match' below.
1898 // invariants: the current token is not a left-delimiter,
1899 // not an EOF, and not the desired right-delimiter (if
1900 // it were, parse_seq_to_before_end would have prevented
1901 // reaching this point.
1902 fn parse_non_delim_tt_tok(p: &Parser) -> token_tree {
1903 maybe_whole!(deref p, nt_tt);
1905 token::RPAREN | token::RBRACE | token::RBRACKET
1909 "incorrect close delimiter: `%s`",
1910 p.this_token_to_str()
1914 /* we ought to allow different depths of unquotation */
1915 token::DOLLAR if *p.quote_depth > 0u => {
1919 if *p.token == token::LPAREN {
1920 let seq = p.parse_seq(
1924 |p| p.parse_token_tree()
1926 let (s, z) = p.parse_sep_and_zerok();
1927 let seq = match seq {
1928 spanned { node, _ } => node,
1931 mk_sp(sp.lo, p.span.hi),
1937 tt_nonterminal(sp, p.parse_ident())
1946 // turn the next token into a tt_tok:
1947 fn parse_any_tt_tok(p: &Parser) -> token_tree{
1948 tt_tok(*p.span, p.bump_and_get())
1953 self.fatal("file ended with unbalanced delimiters");
1955 token::LPAREN | token::LBRACE | token::LBRACKET => {
1956 let close_delim = token::flip_delimiter(&*self.token);
1958 // Parse the open delimiter.
1959 let mut result = ~[parse_any_tt_tok(self)];
1962 self.parse_seq_to_before_end(&close_delim,
1964 |p| p.parse_token_tree());
1965 result.push_all_move(trees);
1967 // Parse the close delimiter.
1968 result.push(parse_any_tt_tok(self));
1970 tt_delim(@mut result)
1972 _ => parse_non_delim_tt_tok(self)
1976 // parse a stream of tokens into a list of token_trees,
1978 pub fn parse_all_token_trees(&self) -> ~[token_tree] {
1980 while *self.token != token::EOF {
1981 tts.push(self.parse_token_tree());
1986 pub fn parse_matchers(&self) -> ~[matcher] {
1987 // unification of matchers and token_trees would vastly improve
1988 // the interpolation of matchers
1989 maybe_whole!(self, nt_matchers);
1990 let name_idx = @mut 0u;
1992 token::LBRACE | token::LPAREN | token::LBRACKET => {
1993 let other_delimiter = token::flip_delimiter(self.token);
1995 self.parse_matcher_subseq_upto(name_idx, &other_delimiter)
1997 _ => self.fatal("expected open delimiter")
2001 // This goofy function is necessary to correctly match parens in matchers.
2002 // Otherwise, `$( ( )` would be a valid matcher, and `$( () )` would be
2003 // invalid. It's similar to common::parse_seq.
2004 pub fn parse_matcher_subseq_upto(&self,
2005 name_idx: @mut uint,
2008 let mut ret_val = ~[];
2009 let mut lparens = 0u;
2011 while *self.token != *ket || lparens > 0u {
2012 if *self.token == token::LPAREN { lparens += 1u; }
2013 if *self.token == token::RPAREN { lparens -= 1u; }
2014 ret_val.push(self.parse_matcher(name_idx));
2022 pub fn parse_matcher(&self, name_idx: @mut uint) -> matcher {
2023 let lo = self.span.lo;
2025 let m = if *self.token == token::DOLLAR {
2027 if *self.token == token::LPAREN {
2028 let name_idx_lo = *name_idx;
2030 let ms = self.parse_matcher_subseq_upto(name_idx,
2033 self.fatal("repetition body must be nonempty");
2035 let (sep, zerok) = self.parse_sep_and_zerok();
2036 match_seq(ms, sep, zerok, name_idx_lo, *name_idx)
2038 let bound_to = self.parse_ident();
2039 self.expect(&token::COLON);
2040 let nt_name = self.parse_ident();
2041 let m = match_nonterminal(bound_to, nt_name, *name_idx);
2046 match_tok(self.bump_and_get())
2049 return spanned(lo, self.span.hi, m);
2052 // parse a prefix-operator expr
2053 pub fn parse_prefix_expr(&self) -> @expr {
2054 let lo = self.span.lo;
2061 let e = self.parse_prefix_expr();
2063 ex = self.mk_unary(not, e);
2065 token::BINOP(b) => {
2069 let e = self.parse_prefix_expr();
2071 ex = self.mk_unary(neg, e);
2075 let e = self.parse_prefix_expr();
2077 ex = self.mk_unary(deref, e);
2081 let _lt = self.parse_opt_lifetime();
2082 let m = self.parse_mutability();
2083 let e = self.parse_prefix_expr();
2085 // HACK: turn &[...] into a &-evec
2087 expr_vec(*) | expr_lit(@codemap::spanned {
2088 node: lit_str(_), span: _
2091 expr_vstore(e, expr_vstore_slice)
2093 expr_vec(*) if m == m_mutbl => {
2094 expr_vstore(e, expr_vstore_mut_slice)
2096 _ => expr_addr_of(m, e)
2099 _ => return self.parse_dot_or_call_expr()
2104 let m = self.parse_mutability();
2106 self.obsolete(*self.last_span, ObsoleteConstManagedPointer);
2109 let e = self.parse_prefix_expr();
2111 // HACK: turn @[...] into a @-evec
2113 expr_vec(*) | expr_repeat(*) if m == m_mutbl =>
2114 expr_vstore(e, expr_vstore_mut_box),
2116 expr_lit(@codemap::spanned { node: lit_str(_), span: _}) |
2117 expr_repeat(*) if m == m_imm => expr_vstore(e, expr_vstore_box),
2118 _ => self.mk_unary(box(m), e)
2123 let m = self.parse_mutability();
2125 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
2128 let e = self.parse_prefix_expr();
2130 // HACK: turn ~[...] into a ~-evec
2133 expr_lit(@codemap::spanned { node: lit_str(_), span: _}) |
2134 expr_repeat(*) => expr_vstore(e, expr_vstore_uniq),
2135 _ => self.mk_unary(uniq, e)
2138 _ => return self.parse_dot_or_call_expr()
2140 return self.mk_expr(lo, hi, ex);
2143 // parse an expression of binops
2144 pub fn parse_binops(&self) -> @expr {
2145 self.parse_more_binops(self.parse_prefix_expr(), 0)
2148 // parse an expression of binops of at least min_prec precedence
2149 pub fn parse_more_binops(&self, lhs: @expr, min_prec: uint) -> @expr {
2150 if self.expr_is_complete(lhs) { return lhs; }
2152 // Prevent dynamic borrow errors later on by limiting the
2153 // scope of the borrows.
2155 let token: &token::Token = self.token;
2156 let restriction: &restriction = self.restriction;
2157 match (token, restriction) {
2158 (&token::BINOP(token::OR), &RESTRICT_NO_BAR_OP) => return lhs,
2159 (&token::BINOP(token::OR),
2160 &RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
2161 (&token::OROR, &RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
2166 let cur_opt = token_to_binop(self.token);
2169 let cur_prec = operator_prec(cur_op);
2170 if cur_prec > min_prec {
2172 let expr = self.parse_prefix_expr();
2173 let rhs = self.parse_more_binops(expr, cur_prec);
2174 let bin = self.mk_expr(lhs.span.lo, rhs.span.hi,
2175 self.mk_binary(cur_op, lhs, rhs));
2176 self.parse_more_binops(bin, min_prec)
2182 if as_prec > min_prec && self.eat_keyword(keywords::As) {
2183 let rhs = self.parse_ty(true);
2184 let _as = self.mk_expr(lhs.span.lo,
2186 expr_cast(lhs, rhs));
2187 self.parse_more_binops(_as, min_prec)
2195 // parse an assignment expression....
2196 // actually, this seems to be the main entry point for
2197 // parsing an arbitrary expression.
2198 pub fn parse_assign_expr(&self) -> @expr {
2199 let lo = self.span.lo;
2200 let lhs = self.parse_binops();
2204 let rhs = self.parse_expr();
2205 self.mk_expr(lo, rhs.span.hi, expr_assign(lhs, rhs))
2207 token::BINOPEQ(op) => {
2209 let rhs = self.parse_expr();
2210 let aop = match op {
2212 token::MINUS => subtract,
2214 token::SLASH => div,
2215 token::PERCENT => rem,
2216 token::CARET => bitxor,
2217 token::AND => bitand,
2222 self.mk_expr(lo, rhs.span.hi,
2223 self.mk_assign_op(aop, lhs, rhs))
2226 self.obsolete(*self.span, ObsoleteBinaryMove);
2227 // Bogus value (but it's an error)
2231 self.mk_expr(lo, self.span.hi,
2235 self.obsolete(*self.span, ObsoleteSwap);
2237 // Ignore what we get, this is an error anyway
2239 self.mk_expr(lo, self.span.hi, expr_break(None))
2247 // parse an 'if' expression ('if' token already eaten)
2248 pub fn parse_if_expr(&self) -> @expr {
2249 let lo = self.last_span.lo;
2250 let cond = self.parse_expr();
2251 let thn = self.parse_block();
2252 let mut els: Option<@expr> = None;
2253 let mut hi = thn.span.hi;
2254 if self.eat_keyword(keywords::Else) {
2255 let elexpr = self.parse_else_expr();
2257 hi = elexpr.span.hi;
2259 self.mk_expr(lo, hi, expr_if(cond, thn, els))
2262 // `|args| { ... }` or `{ ...}` like in `do` expressions
2263 pub fn parse_lambda_block_expr(&self) -> @expr {
2264 self.parse_lambda_expr_(
2267 token::BINOP(token::OR) | token::OROR => {
2268 self.parse_fn_block_decl()
2271 // No argument list - `do foo {`
2285 let blk = self.parse_block();
2286 self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk))
2291 pub fn parse_lambda_expr(&self) -> @expr {
2292 self.parse_lambda_expr_(|| self.parse_fn_block_decl(),
2293 || self.parse_expr())
2296 // parse something of the form |args| expr
2297 // this is used both in parsing a lambda expr
2298 // and in parsing a block expr as e.g. in for...
2299 pub fn parse_lambda_expr_(&self,
2300 parse_decl: &fn() -> fn_decl,
2301 parse_body: &fn() -> @expr)
2303 let lo = self.last_span.lo;
2304 let decl = parse_decl();
2305 let body = parse_body();
2306 let fakeblock = ast::Block {
2315 return self.mk_expr(lo, body.span.hi,
2316 expr_fn_block(decl, fakeblock));
2319 pub fn parse_else_expr(&self) -> @expr {
2320 if self.eat_keyword(keywords::If) {
2321 return self.parse_if_expr();
2323 let blk = self.parse_block();
2324 return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
2328 // parse a 'for' or 'do'.
2329 // the 'for' and 'do' expressions parse as calls, but look like
2330 // function calls followed by a closure expression.
2331 pub fn parse_sugary_call_expr(&self, lo: BytePos,
2334 ctor: &fn(v: @expr) -> expr_)
2336 // Parse the callee `foo` in
2339 // etc, or the portion of the call expression before the lambda in
2342 // for foo.bar(a) || {
2343 // Turn on the restriction to stop at | or || so we can parse
2344 // them as the lambda arguments
2345 let e = self.parse_expr_res(RESTRICT_NO_BAR_OR_DOUBLEBAR_OP);
2347 expr_call(f, ref args, NoSugar) => {
2348 let block = self.parse_lambda_block_expr();
2349 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2351 let args = vec::append((*args).clone(), [last_arg]);
2352 self.mk_expr(lo, block.span.hi, expr_call(f, args, sugar))
2354 expr_method_call(_, f, i, ref tps, ref args, NoSugar) => {
2355 let block = self.parse_lambda_block_expr();
2356 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2358 let args = vec::append((*args).clone(), [last_arg]);
2359 self.mk_expr(lo, block.span.hi,
2360 self.mk_method_call(f,
2366 expr_field(f, i, ref tps) => {
2367 let block = self.parse_lambda_block_expr();
2368 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2370 self.mk_expr(lo, block.span.hi,
2371 self.mk_method_call(f,
2377 expr_path(*) | expr_call(*) | expr_method_call(*) |
2379 let block = self.parse_lambda_block_expr();
2380 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2385 self.mk_call(e, ~[last_arg], sugar))
2388 // There may be other types of expressions that can
2389 // represent the callee in `for` and `do` expressions
2390 // but they aren't represented by tests
2391 debug!("sugary call on %?", e.node);
2394 fmt!("`%s` must be followed by a block call", keyword));
2399 pub fn parse_while_expr(&self) -> @expr {
2400 let lo = self.last_span.lo;
2401 let cond = self.parse_expr();
2402 let body = self.parse_block();
2403 let hi = body.span.hi;
2404 return self.mk_expr(lo, hi, expr_while(cond, body));
2407 pub fn parse_loop_expr(&self, opt_ident: Option<ast::ident>) -> @expr {
2408 // loop headers look like 'loop {' or 'loop unsafe {'
2409 let is_loop_header =
2410 *self.token == token::LBRACE
2411 || (is_ident(&*self.token)
2412 && self.look_ahead(1, |t| *t == token::LBRACE));
2415 // This is a loop body
2416 let lo = self.last_span.lo;
2417 let body = self.parse_block();
2418 let hi = body.span.hi;
2419 return self.mk_expr(lo, hi, expr_loop(body, opt_ident));
2421 // This is a 'continue' expression
2422 if opt_ident.is_some() {
2423 self.span_err(*self.last_span,
2424 "a label may not be used with a `loop` expression");
2427 let lo = self.span.lo;
2428 let ex = if self.token_is_lifetime(&*self.token) {
2429 let lifetime = self.get_lifetime(&*self.token);
2431 expr_again(Some(lifetime))
2435 let hi = self.span.hi;
2436 return self.mk_expr(lo, hi, ex);
2440 // For distingishing between record literals and blocks
2441 fn looking_at_record_literal(&self) -> bool {
2442 *self.token == token::LBRACE &&
2443 (self.look_ahead(1, |t| token::is_keyword(keywords::Mut, t)) ||
2444 (self.look_ahead(1, |t| token::is_plain_ident(t)) &&
2445 self.look_ahead(2, |t| *t == token::COLON)))
2448 fn parse_match_expr(&self) -> @expr {
2449 let lo = self.last_span.lo;
2450 let discriminant = self.parse_expr();
2451 self.expect(&token::LBRACE);
2452 let mut arms: ~[arm] = ~[];
2453 while *self.token != token::RBRACE {
2454 let pats = self.parse_pats();
2455 let mut guard = None;
2456 if self.eat_keyword(keywords::If) {
2457 guard = Some(self.parse_expr());
2459 self.expect(&token::FAT_ARROW);
2460 let expr = self.parse_expr_res(RESTRICT_STMT_EXPR);
2463 !classify::expr_is_simple_block(expr)
2464 && *self.token != token::RBRACE;
2467 self.expect(&token::COMMA);
2469 self.eat(&token::COMMA);
2472 let blk = ast::Block {
2481 arms.push(ast::arm { pats: pats, guard: guard, body: blk });
2483 let hi = self.span.hi;
2485 return self.mk_expr(lo, hi, expr_match(discriminant, arms));
2488 // parse an expression
2489 pub fn parse_expr(&self) -> @expr {
2490 return self.parse_expr_res(UNRESTRICTED);
2493 // parse an expression, subject to the given restriction
2494 fn parse_expr_res(&self, r: restriction) -> @expr {
2495 let old = *self.restriction;
2496 *self.restriction = r;
2497 let e = self.parse_assign_expr();
2498 *self.restriction = old;
2502 // parse the RHS of a local variable declaration (e.g. '= 14;')
2503 fn parse_initializer(&self) -> Option<@expr> {
2507 return Some(self.parse_expr());
2510 self.obsolete(*self.span, ObsoleteMoveInit);
2521 // parse patterns, separated by '|' s
2522 fn parse_pats(&self) -> ~[@pat] {
2525 pats.push(self.parse_pat());
2526 if *self.token == token::BINOP(token::OR) { self.bump(); }
2527 else { return pats; }
2531 fn parse_pat_vec_elements(
2533 ) -> (~[@pat], Option<@pat>, ~[@pat]) {
2534 let mut before = ~[];
2535 let mut slice = None;
2536 let mut after = ~[];
2537 let mut first = true;
2538 let mut before_slice = true;
2540 while *self.token != token::RBRACKET {
2541 if first { first = false; }
2542 else { self.expect(&token::COMMA); }
2544 let mut is_slice = false;
2546 if *self.token == token::DOTDOT {
2549 before_slice = false;
2553 let subpat = self.parse_pat();
2556 @ast::pat { node: pat_wild, _ } => (),
2557 @ast::pat { node: pat_ident(_, _, _), _ } => (),
2558 @ast::pat { span, _ } => self.span_fatal(
2559 span, "expected an identifier or `_`"
2562 slice = Some(subpat);
2565 before.push(subpat);
2572 (before, slice, after)
2575 // parse the fields of a struct-like pattern
2576 fn parse_pat_fields(&self) -> (~[ast::field_pat], bool) {
2577 let mut fields = ~[];
2578 let mut etc = false;
2579 let mut first = true;
2580 while *self.token != token::RBRACE {
2581 if first { first = false; }
2582 else { self.expect(&token::COMMA); }
2584 if *self.token == token::UNDERSCORE {
2586 if *self.token != token::RBRACE {
2589 "expected `}`, found `%s`",
2590 self.this_token_to_str()
2598 let lo1 = self.last_span.lo;
2599 let fieldname = self.parse_ident();
2600 let hi1 = self.last_span.lo;
2601 let fieldpath = ast_util::ident_to_path(mk_sp(lo1, hi1),
2604 if *self.token == token::COLON {
2606 subpat = self.parse_pat();
2608 subpat = @ast::pat {
2610 node: pat_ident(bind_infer, fieldpath, None),
2611 span: *self.last_span
2614 fields.push(ast::field_pat { ident: fieldname, pat: subpat });
2616 return (fields, etc);
2620 pub fn parse_pat(&self) -> @pat {
2621 maybe_whole!(self, nt_pat);
2623 let lo = self.span.lo;
2628 token::UNDERSCORE => {
2631 hi = self.last_span.hi;
2641 let sub = self.parse_pat();
2643 // HACK: parse @"..." as a literal of a vstore @str
2644 pat = match sub.node {
2646 node: expr_lit(@codemap::spanned {
2652 node: expr_vstore(e, expr_vstore_box),
2653 span: mk_sp(lo, hi),
2659 hi = self.last_span.hi;
2669 let sub = self.parse_pat();
2671 // HACK: parse ~"..." as a literal of a vstore ~str
2672 pat = match sub.node {
2674 node: expr_lit(@codemap::spanned {
2680 node: expr_vstore(e, expr_vstore_uniq),
2681 span: mk_sp(lo, hi),
2687 hi = self.last_span.hi;
2694 token::BINOP(token::AND) => {
2696 let lo = self.span.lo;
2698 let sub = self.parse_pat();
2700 // HACK: parse &"..." as a literal of a borrowed str
2701 pat = match sub.node {
2703 node: expr_lit(@codemap::spanned {
2704 node: lit_str(_), span: _}), _
2708 node: expr_vstore(e, expr_vstore_slice),
2713 _ => pat_region(sub)
2715 hi = self.last_span.hi;
2724 let (_, _) = self.parse_pat_fields();
2726 self.obsolete(*self.span, ObsoleteRecordPattern);
2728 hi = self.last_span.hi;
2736 // parse (pat,pat,pat,...) as tuple
2738 if *self.token == token::RPAREN {
2741 let lit = @codemap::spanned {
2743 span: mk_sp(lo, hi)};
2744 let expr = self.mk_expr(lo, hi, expr_lit(lit));
2745 pat = pat_lit(expr);
2747 let mut fields = ~[self.parse_pat()];
2748 if self.look_ahead(1, |t| *t != token::RPAREN) {
2749 while *self.token == token::COMMA {
2751 fields.push(self.parse_pat());
2754 if fields.len() == 1 { self.expect(&token::COMMA); }
2755 self.expect(&token::RPAREN);
2756 pat = pat_tup(fields);
2758 hi = self.last_span.hi;
2765 token::LBRACKET => {
2766 // parse [pat,pat,...] as vector pattern
2768 let (before, slice, after) =
2769 self.parse_pat_vec_elements();
2771 self.expect(&token::RBRACKET);
2772 pat = ast::pat_vec(before, slice, after);
2773 hi = self.last_span.hi;
2783 let tok = self.token;
2784 if !is_ident_or_path(tok)
2785 || self.is_keyword(keywords::True)
2786 || self.is_keyword(keywords::False) {
2787 // Parse an expression pattern or exp .. exp.
2789 // These expressions are limited to literals (possibly
2790 // preceded by unary-minus) or identifiers.
2791 let val = self.parse_literal_maybe_minus();
2792 if self.eat(&token::DOTDOT) {
2793 let end = if is_ident_or_path(tok) {
2794 let path = self.parse_path_with_tps(true);
2795 let hi = self.span.hi;
2796 self.mk_expr(lo, hi, expr_path(path))
2798 self.parse_literal_maybe_minus()
2800 pat = pat_range(val, end);
2804 } else if self.eat_keyword(keywords::Ref) {
2806 let mutbl = self.parse_mutability();
2807 pat = self.parse_pat_ident(bind_by_ref(mutbl));
2809 let can_be_enum_or_struct = do self.look_ahead(1) |t| {
2811 token::LPAREN | token::LBRACKET | token::LT |
2812 token::LBRACE | token::MOD_SEP => true,
2817 if self.look_ahead(1, |t| *t == token::DOTDOT) {
2818 let start = self.parse_expr_res(RESTRICT_NO_BAR_OP);
2819 self.eat(&token::DOTDOT);
2820 let end = self.parse_expr_res(RESTRICT_NO_BAR_OP);
2821 pat = pat_range(start, end);
2822 } else if is_plain_ident(&*self.token) && !can_be_enum_or_struct {
2823 let name = self.parse_path_without_tps();
2825 if self.eat(&token::AT) {
2827 sub = Some(self.parse_pat());
2832 pat = pat_ident(bind_infer, name, sub);
2834 // parse an enum pat
2835 let enum_path = self.parse_path_with_tps(true);
2840 self.parse_pat_fields();
2842 pat = pat_struct(enum_path, fields, etc);
2845 let mut args: ~[@pat] = ~[];
2848 let is_star = do self.look_ahead(1) |t| {
2850 token::BINOP(token::STAR) => true,
2855 // This is a "top constructor only" pat
2858 self.expect(&token::RPAREN);
2859 pat = pat_enum(enum_path, None);
2861 args = self.parse_unspanned_seq(
2864 seq_sep_trailing_disallowed(token::COMMA),
2867 pat = pat_enum(enum_path, Some(args));
2871 if enum_path.idents.len()==1u {
2872 // it could still be either an enum
2873 // or an identifier pattern, resolve
2874 // will sort it out:
2875 pat = pat_ident(bind_infer,
2879 pat = pat_enum(enum_path, Some(args));
2887 hi = self.last_span.hi;
2891 span: mk_sp(lo, hi),
2895 // parse ident or ident @ pat
2896 // used by the copy foo and ref foo patterns to give a good
2897 // error message when parsing mistakes like ref foo(a,b)
2898 fn parse_pat_ident(&self,
2899 binding_mode: ast::binding_mode)
2901 if !is_plain_ident(&*self.token) {
2902 self.span_fatal(*self.last_span,
2903 "expected identifier, found path");
2905 // why a path here, and not just an identifier?
2906 let name = self.parse_path_without_tps();
2907 let sub = if self.eat(&token::AT) {
2908 Some(self.parse_pat())
2913 // just to be friendly, if they write something like
2915 // we end up here with ( as the current token. This shortly
2916 // leads to a parse error. Note that if there is no explicit
2917 // binding mode then we do not end up here, because the lookahead
2918 // will direct us over to parse_enum_variant()
2919 if *self.token == token::LPAREN {
2922 "expected identifier, found enum pattern");
2925 pat_ident(binding_mode, name, sub)
2928 // parse a local variable declaration
2929 fn parse_local(&self, is_mutbl: bool) -> @Local {
2930 let lo = self.span.lo;
2931 let pat = self.parse_pat();
2933 if is_mutbl && !ast_util::pat_is_ident(pat) {
2934 self.obsolete(*self.span, ObsoleteMutWithMultipleBindings)
2940 span: mk_sp(lo, lo),
2942 if self.eat(&token::COLON) { ty = self.parse_ty(false); }
2943 let init = self.parse_initializer();
2950 span: mk_sp(lo, self.last_span.hi),
2954 // parse a "let" stmt
2955 fn parse_let(&self) -> @decl {
2956 let is_mutbl = self.eat_keyword(keywords::Mut);
2957 let lo = self.span.lo;
2958 let local = self.parse_local(is_mutbl);
2959 while self.eat(&token::COMMA) {
2960 let _ = self.parse_local(is_mutbl);
2961 self.obsolete(*self.span, ObsoleteMultipleLocalDecl);
2963 return @spanned(lo, self.last_span.hi, decl_local(local));
2966 // parse a structure field
2967 fn parse_name_and_ty(&self,
2969 attrs: ~[Attribute]) -> @struct_field {
2970 let lo = self.span.lo;
2971 if !is_plain_ident(&*self.token) {
2972 self.fatal("expected ident");
2974 let name = self.parse_ident();
2975 self.expect(&token::COLON);
2976 let ty = self.parse_ty(false);
2977 @spanned(lo, self.last_span.hi, ast::struct_field_ {
2978 kind: named_field(name, pr),
2985 // parse a statement. may include decl.
2986 // precondition: any attributes are parsed already
2987 pub fn parse_stmt(&self, item_attrs: ~[Attribute]) -> @stmt {
2988 maybe_whole!(self, nt_stmt);
2990 fn check_expected_item(p: &Parser, found_attrs: bool) {
2991 // If we have attributes then we should have an item
2993 p.span_err(*p.last_span, "expected item after attributes");
2997 let lo = self.span.lo;
2998 if self.is_keyword(keywords::Let) {
2999 check_expected_item(self, !item_attrs.is_empty());
3000 self.expect_keyword(keywords::Let);
3001 let decl = self.parse_let();
3002 return @spanned(lo, decl.span.hi, stmt_decl(decl, self.get_id()));
3003 } else if is_ident(&*self.token)
3004 && !token::is_any_keyword(self.token)
3005 && self.look_ahead(1, |t| *t == token::NOT) {
3006 // parse a macro invocation. Looks like there's serious
3007 // overlap here; if this clause doesn't catch it (and it
3008 // won't, for brace-delimited macros) it will fall through
3009 // to the macro clause of parse_item_or_view_item. This
3010 // could use some cleanup, it appears to me.
3012 // whoops! I now have a guess: I'm guessing the "parens-only"
3013 // rule here is deliberate, to allow macro users to use parens
3014 // for things that should be parsed as stmt_mac, and braces
3015 // for things that should expand into items. Tricky, and
3016 // somewhat awkward... and probably undocumented. Of course,
3017 // I could just be wrong.
3019 check_expected_item(self, !item_attrs.is_empty());
3021 // Potential trouble: if we allow macros with paths instead of
3022 // idents, we'd need to look ahead past the whole path here...
3023 let pth = self.parse_path_without_tps();
3026 let id = if *self.token == token::LPAREN {
3027 token::special_idents::invalid // no special identifier
3032 let tts = self.parse_unspanned_seq(
3036 |p| p.parse_token_tree()
3038 let hi = self.span.hi;
3040 if id == token::special_idents::invalid {
3041 return @spanned(lo, hi, stmt_mac(
3042 spanned(lo, hi, mac_invoc_tt(pth, tts)), false));
3044 // if it has a special ident, it's definitely an item
3045 return @spanned(lo, hi, stmt_decl(
3046 @spanned(lo, hi, decl_item(
3048 lo, hi, id /*id is good here*/,
3049 item_mac(spanned(lo, hi, mac_invoc_tt(pth, tts))),
3050 inherited, ~[/*no attrs*/]))),
3055 let found_attrs = !item_attrs.is_empty();
3056 match self.parse_item_or_view_item(item_attrs, false) {
3059 let decl = @spanned(lo, hi, decl_item(i));
3060 return @spanned(lo, hi, stmt_decl(decl, self.get_id()));
3062 iovi_view_item(vi) => {
3063 self.span_fatal(vi.span,
3064 "view items must be declared at the top of the block");
3066 iovi_foreign_item(_) => {
3067 self.fatal("foreign items are not allowed here");
3069 iovi_none(_) => { /* fallthrough */ }
3072 check_expected_item(self, found_attrs);
3074 // Remainder are line-expr stmts.
3075 let e = self.parse_expr_res(RESTRICT_STMT_EXPR);
3076 return @spanned(lo, e.span.hi, stmt_expr(e, self.get_id()));
3080 // is this expression a successfully-parsed statement?
3081 fn expr_is_complete(&self, e: @expr) -> bool {
3082 return *self.restriction == RESTRICT_STMT_EXPR &&
3083 !classify::expr_requires_semi_to_be_stmt(e);
3086 // parse a block. No inner attrs are allowed.
3087 pub fn parse_block(&self) -> Block {
3088 maybe_whole!(self, nt_block);
3090 let lo = self.span.lo;
3091 if self.eat_keyword(keywords::Unsafe) {
3092 self.obsolete(*self.span, ObsoleteUnsafeBlock);
3094 self.expect(&token::LBRACE);
3096 return self.parse_block_tail_(lo, default_blk, ~[]);
3099 // parse a block. Inner attrs are allowed.
3100 fn parse_inner_attrs_and_block(&self)
3101 -> (~[Attribute], Block) {
3103 maybe_whole!(pair_empty self, nt_block);
3105 let lo = self.span.lo;
3106 if self.eat_keyword(keywords::Unsafe) {
3107 self.obsolete(*self.span, ObsoleteUnsafeBlock);
3109 self.expect(&token::LBRACE);
3110 let (inner, next) = self.parse_inner_attrs_and_next();
3112 (inner, self.parse_block_tail_(lo, default_blk, next))
3115 // Precondition: already parsed the '{' or '#{'
3116 // I guess that also means "already parsed the 'impure'" if
3117 // necessary, and this should take a qualifier.
3118 // some blocks start with "#{"...
3119 fn parse_block_tail(&self, lo: BytePos, s: blk_check_mode) -> Block {
3120 self.parse_block_tail_(lo, s, ~[])
3123 // parse the rest of a block expression or function body
3124 fn parse_block_tail_(&self, lo: BytePos, s: blk_check_mode,
3125 first_item_attrs: ~[Attribute]) -> Block {
3126 let mut stmts = ~[];
3127 let mut expr = None;
3129 // wouldn't it be more uniform to parse view items only, here?
3130 let ParsedItemsAndViewItems {
3131 attrs_remaining: attrs_remaining,
3132 view_items: view_items,
3135 } = self.parse_items_and_view_items(first_item_attrs,
3138 for items.iter().advance |item| {
3139 let decl = @spanned(item.span.lo, item.span.hi, decl_item(*item));
3140 stmts.push(@spanned(item.span.lo, item.span.hi,
3141 stmt_decl(decl, self.get_id())));
3144 let mut attributes_box = attrs_remaining;
3146 while (*self.token != token::RBRACE) {
3147 // parsing items even when they're not allowed lets us give
3148 // better error messages and recover more gracefully.
3149 attributes_box.push_all(self.parse_outer_attributes());
3152 if !attributes_box.is_empty() {
3153 self.span_err(*self.last_span, "expected item after attributes");
3154 attributes_box = ~[];
3156 self.bump(); // empty
3159 // fall through and out.
3162 let stmt = self.parse_stmt(attributes_box);
3163 attributes_box = ~[];
3165 stmt_expr(e, stmt_id) => {
3166 // expression without semicolon
3178 if classify::stmt_ends_with_semi(stmt) {
3181 "expected `;` or `}` after \
3182 expression but found `%s`",
3183 self.token_to_str(t)
3193 stmts.push(@codemap::spanned {
3194 node: stmt_semi(e, stmt_id),
3199 stmt_mac(ref m, _) => {
3200 // statement macro; might be an expr
3207 // if a block ends in `m!(arg)` without
3208 // a `;`, it must be an expr
3211 self.mk_mac_expr(stmt.span.lo,
3223 stmts.push(@codemap::spanned {
3224 node: stmt_mac((*m).clone(), true),
3229 _ => { // all other kinds of statements:
3232 if classify::stmt_ends_with_semi(stmt) {
3233 self.expect(&token::SEMI);
3241 if !attributes_box.is_empty() {
3242 self.span_err(*self.last_span, "expected item after attributes");
3245 let hi = self.span.hi;
3248 view_items: view_items,
3253 span: mk_sp(lo, hi),
3257 fn parse_optional_purity(&self) -> ast::purity {
3258 if self.eat_keyword(keywords::Pure) {
3259 self.obsolete(*self.last_span, ObsoletePurity);
3261 } else if self.eat_keyword(keywords::Unsafe) {
3268 fn parse_optional_onceness(&self) -> ast::Onceness {
3269 if self.eat_keyword(keywords::Once) { ast::Once } else { ast::Many }
3272 // matches optbounds = ( ( : ( boundseq )? )? )
3273 // where boundseq = ( bound + boundseq ) | bound
3274 // and bound = 'static | ty
3275 // Returns "None" if there's no colon (e.g. "T");
3276 // Returns "Some(Empty)" if there's a colon but nothing after (e.g. "T:")
3277 // Returns "Some(stuff)" otherwise (e.g. "T:stuff").
3278 // NB: The None/Some distinction is important for issue #7264.
3279 fn parse_optional_ty_param_bounds(&self) -> Option<OptVec<TyParamBound>> {
3280 if !self.eat(&token::COLON) {
3284 let mut result = opt_vec::Empty;
3287 token::LIFETIME(lifetime) => {
3288 if "static" == self.id_to_str(lifetime) {
3289 result.push(RegionTyParamBound);
3291 self.span_err(*self.span,
3292 "`'static` is the only permissible region bound here");
3296 token::MOD_SEP | token::IDENT(*) => {
3297 let obsolete_bound = match *self.token {
3298 token::MOD_SEP => false,
3299 token::IDENT(sid, _) => {
3300 match self.id_to_str(sid).as_slice() {
3307 ObsoleteLowerCaseKindBounds);
3317 if !obsolete_bound {
3318 let tref = self.parse_trait_ref();
3319 result.push(TraitTyParamBound(tref));
3325 if !self.eat(&token::BINOP(token::PLUS)) {
3330 return Some(result);
3333 // matches typaram = IDENT optbounds
3334 fn parse_ty_param(&self) -> TyParam {
3335 let ident = self.parse_ident();
3336 let opt_bounds = self.parse_optional_ty_param_bounds();
3337 // For typarams we don't care about the difference b/w "<T>" and "<T:>".
3338 let bounds = opt_bounds.get_or_default(opt_vec::Empty);
3339 ast::TyParam { ident: ident, id: self.get_id(), bounds: bounds }
3342 // parse a set of optional generic type parameter declarations
3343 // matches generics = ( ) | ( < > ) | ( < typaramseq ( , )? > ) | ( < lifetimes ( , )? > )
3344 // | ( < lifetimes , typaramseq ( , )? > )
3345 // where typaramseq = ( typaram ) | ( typaram , typaramseq )
3346 pub fn parse_generics(&self) -> ast::Generics {
3347 if self.eat(&token::LT) {
3348 let lifetimes = self.parse_lifetimes();
3349 let ty_params = self.parse_seq_to_gt(
3351 |p| p.parse_ty_param());
3352 ast::Generics { lifetimes: lifetimes, ty_params: ty_params }
3354 ast_util::empty_generics()
3358 // parse a generic use site
3359 fn parse_generic_values(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
3360 if !self.eat(&token::LT) {
3361 (opt_vec::Empty, ~[])
3363 self.parse_generic_values_after_lt()
3367 fn parse_generic_values_after_lt(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
3368 let lifetimes = self.parse_lifetimes();
3369 let result = self.parse_seq_to_gt(
3371 |p| p.parse_ty(false));
3372 (lifetimes, opt_vec::take_vec(result))
3375 // parse the argument list and result type of a function declaration
3376 pub fn parse_fn_decl(&self) -> fn_decl {
3377 let args_or_capture_items: ~[arg_or_capture_item] =
3378 self.parse_unspanned_seq(
3381 seq_sep_trailing_disallowed(token::COMMA),
3385 let inputs = either::lefts(args_or_capture_items);
3387 let (ret_style, ret_ty) = self.parse_ret_ty();
3395 fn is_self_ident(&self) -> bool {
3396 *self.token == token::IDENT(special_idents::self_, false)
3399 fn expect_self_ident(&self) {
3400 if !self.is_self_ident() {
3403 "expected `self` but found `%s`",
3404 self.this_token_to_str()
3411 // parse the argument list and result type of a function
3412 // that may have a self type.
3413 fn parse_fn_decl_with_self(
3416 &fn(&Parser) -> arg_or_capture_item
3417 ) -> (explicit_self, fn_decl) {
3418 fn maybe_parse_explicit_self(
3419 cnstr: &fn(v: mutability) -> ast::explicit_self_,
3421 ) -> ast::explicit_self_ {
3422 // We need to make sure it isn't a mode or a type
3423 if p.look_ahead(1, |t| token::is_keyword(keywords::Self, t)) ||
3424 ((p.look_ahead(1, |t| token::is_keyword(keywords::Const, t)) ||
3425 p.look_ahead(1, |t| token::is_keyword(keywords::Mut, t))) &&
3426 p.look_ahead(2, |t| token::is_keyword(keywords::Self, t))) {
3429 let mutability = p.parse_mutability();
3430 p.expect_self_ident();
3437 fn maybe_parse_borrowed_explicit_self(this: &Parser) -> ast::explicit_self_ {
3438 // The following things are possible to see here:
3443 // fn(&'lt mut self)
3445 // We already know that the current token is `&`.
3447 if this.look_ahead(1, |t| token::is_keyword(keywords::Self, t)) {
3449 this.expect_self_ident();
3450 sty_region(None, m_imm)
3451 } else if this.look_ahead(1, |t| this.token_is_mutability(t)) &&
3453 |t| token::is_keyword(keywords::Self,
3456 let mutability = this.parse_mutability();
3457 this.expect_self_ident();
3458 sty_region(None, mutability)
3459 } else if this.look_ahead(1, |t| this.token_is_lifetime(t)) &&
3461 |t| token::is_keyword(keywords::Self,
3464 let lifetime = this.parse_lifetime();
3465 this.expect_self_ident();
3466 sty_region(Some(lifetime), m_imm)
3467 } else if this.look_ahead(1, |t| this.token_is_lifetime(t)) &&
3468 this.look_ahead(2, |t| this.token_is_mutability(t)) &&
3469 this.look_ahead(3, |t| token::is_keyword(keywords::Self,
3472 let lifetime = this.parse_lifetime();
3473 let mutability = this.parse_mutability();
3474 this.expect_self_ident();
3475 sty_region(Some(lifetime), mutability)
3481 self.expect(&token::LPAREN);
3483 // A bit of complexity and lookahead is needed here in order to be
3484 // backwards compatible.
3485 let lo = self.span.lo;
3486 let explicit_self = match *self.token {
3487 token::BINOP(token::AND) => {
3488 maybe_parse_borrowed_explicit_self(self)
3491 maybe_parse_explicit_self(sty_box, self)
3494 maybe_parse_explicit_self(|mutability| {
3495 if mutability != m_imm {
3496 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
3501 token::IDENT(*) if self.is_self_ident() => {
3510 // If we parsed a self type, expect a comma before the argument list.
3511 let args_or_capture_items;
3512 if explicit_self != sty_static {
3516 let sep = seq_sep_trailing_disallowed(token::COMMA);
3517 args_or_capture_items = self.parse_seq_to_before_end(
3524 args_or_capture_items = ~[];
3529 "expected `,` or `)`, found `%s`",
3530 self.this_token_to_str()
3536 let sep = seq_sep_trailing_disallowed(token::COMMA);
3537 args_or_capture_items = self.parse_seq_to_before_end(
3544 self.expect(&token::RPAREN);
3546 let hi = self.span.hi;
3548 let inputs = either::lefts(args_or_capture_items);
3549 let (ret_style, ret_ty) = self.parse_ret_ty();
3551 let fn_decl = ast::fn_decl {
3557 (spanned(lo, hi, explicit_self), fn_decl)
3560 // parse the |arg, arg| header on a lambda
3561 fn parse_fn_block_decl(&self) -> fn_decl {
3562 let inputs_captures = {
3563 if self.eat(&token::OROR) {
3566 self.parse_unspanned_seq(
3567 &token::BINOP(token::OR),
3568 &token::BINOP(token::OR),
3569 seq_sep_trailing_disallowed(token::COMMA),
3570 |p| p.parse_fn_block_arg()
3574 let output = if self.eat(&token::RARROW) {
3575 self.parse_ty(false)
3577 Ty { id: self.get_id(), node: ty_infer, span: *self.span }
3581 inputs: either::lefts(inputs_captures),
3587 // parse the name and optional generic types of a function header.
3588 fn parse_fn_header(&self) -> (ident, ast::Generics) {
3589 let id = self.parse_ident();
3590 let generics = self.parse_generics();
3594 fn mk_item(&self, lo: BytePos, hi: BytePos, ident: ident,
3595 node: item_, vis: visibility,
3596 attrs: ~[Attribute]) -> @item {
3597 @ast::item { ident: ident,
3602 span: mk_sp(lo, hi) }
3605 // parse an item-position function declaration.
3606 fn parse_item_fn(&self, purity: purity, abis: AbiSet) -> item_info {
3607 let (ident, generics) = self.parse_fn_header();
3608 let decl = self.parse_fn_decl();
3609 let (inner_attrs, body) = self.parse_inner_attrs_and_block();
3611 item_fn(decl, purity, abis, generics, body),
3615 // parse a method in a trait impl
3616 fn parse_method(&self) -> @method {
3617 let attrs = self.parse_outer_attributes();
3618 let lo = self.span.lo;
3620 let visa = self.parse_visibility();
3621 let pur = self.parse_fn_purity();
3622 let ident = self.parse_ident();
3623 let generics = self.parse_generics();
3624 let (explicit_self, decl) = do self.parse_fn_decl_with_self() |p| {
3628 let (inner_attrs, body) = self.parse_inner_attrs_and_block();
3629 let hi = body.span.hi;
3630 let attrs = vec::append(attrs, inner_attrs);
3635 explicit_self: explicit_self,
3640 span: mk_sp(lo, hi),
3641 self_id: self.get_id(),
3646 // parse trait Foo { ... }
3647 fn parse_item_trait(&self) -> item_info {
3648 let ident = self.parse_ident();
3649 self.parse_region_param();
3650 let tps = self.parse_generics();
3652 // Parse traits, if necessary.
3654 if *self.token == token::COLON {
3656 traits = self.parse_trait_ref_list(&token::LBRACE);
3661 let meths = self.parse_trait_methods();
3662 (ident, item_trait(tps, traits, meths), None)
3665 // Parses two variants (with the region/type params always optional):
3666 // impl<T> Foo { ... }
3667 // impl<T> ToStr for ~[T] { ... }
3668 fn parse_item_impl(&self, visibility: ast::visibility) -> item_info {
3669 // First, parse type parameters if necessary.
3670 let generics = self.parse_generics();
3672 // This is a new-style impl declaration.
3674 let ident = special_idents::clownshoes_extensions;
3676 // Special case: if the next identifier that follows is '(', don't
3677 // allow this to be parsed as a trait.
3678 let could_be_trait = *self.token != token::LPAREN;
3681 let mut ty = self.parse_ty(false);
3683 // Parse traits, if necessary.
3684 let opt_trait = if could_be_trait && self.eat_keyword(keywords::For) {
3685 // New-style trait. Reinterpret the type as a trait.
3686 let opt_trait_ref = match ty.node {
3687 ty_path(ref path, None, node_id) => {
3689 path: /* bad */ (*path).clone(),
3694 self.span_err(ty.span,
3695 "bounded traits are only valid in type position");
3699 self.span_err(ty.span, "not a trait");
3704 ty = self.parse_ty(false);
3706 } else if self.eat(&token::COLON) {
3707 self.obsolete(*self.span, ObsoleteImplSyntax);
3708 Some(self.parse_trait_ref())
3713 // Do not allow visibility to be specified.
3714 if visibility != ast::inherited {
3715 self.obsolete(*self.span, ObsoleteImplVisibility);
3718 let mut meths = ~[];
3719 if !self.eat(&token::SEMI) {
3720 self.expect(&token::LBRACE);
3721 while !self.eat(&token::RBRACE) {
3722 meths.push(self.parse_method());
3726 (ident, item_impl(generics, opt_trait, ty, meths), None)
3729 // parse a::B<~str,int>
3730 fn parse_trait_ref(&self) -> trait_ref {
3732 path: self.parse_path_with_tps(false),
3733 ref_id: self.get_id(),
3737 // parse B + C<~str,int> + D
3738 fn parse_trait_ref_list(&self, ket: &token::Token) -> ~[trait_ref] {
3739 self.parse_seq_to_before_end(
3741 seq_sep_trailing_disallowed(token::BINOP(token::PLUS)),
3742 |p| p.parse_trait_ref()
3746 // parse struct Foo { ... }
3747 fn parse_item_struct(&self) -> item_info {
3748 let class_name = self.parse_ident();
3749 self.parse_region_param();
3750 let generics = self.parse_generics();
3751 if self.eat(&token::COLON) {
3752 self.obsolete(*self.span, ObsoleteClassTraits);
3753 let _ = self.parse_trait_ref_list(&token::LBRACE);
3756 let mut fields: ~[@struct_field];
3759 if self.eat(&token::LBRACE) {
3760 // It's a record-like struct.
3761 is_tuple_like = false;
3763 while *self.token != token::RBRACE {
3764 let r = self.parse_struct_decl_field();
3765 for r.iter().advance |struct_field| {
3766 fields.push(*struct_field)
3769 if fields.len() == 0 {
3770 self.fatal(fmt!("Unit-like struct should be written as `struct %s;`",
3771 get_ident_interner().get(class_name.name)));
3774 } else if *self.token == token::LPAREN {
3775 // It's a tuple-like struct.
3776 is_tuple_like = true;
3777 fields = do self.parse_unspanned_seq(
3780 seq_sep_trailing_allowed(token::COMMA)
3782 let attrs = self.parse_outer_attributes();
3784 let struct_field_ = ast::struct_field_ {
3785 kind: unnamed_field,
3787 ty: p.parse_ty(false),
3790 @spanned(lo, p.span.hi, struct_field_)
3792 self.expect(&token::SEMI);
3793 } else if self.eat(&token::SEMI) {
3794 // It's a unit-like struct.
3795 is_tuple_like = true;
3800 "expected `{`, `(`, or `;` after struct name \
3802 self.this_token_to_str()
3807 let _ = self.get_id(); // XXX: Workaround for crazy bug.
3808 let new_id = self.get_id();
3810 item_struct(@ast::struct_def {
3812 ctor_id: if is_tuple_like { Some(new_id) } else { None }
3817 fn token_is_pound_or_doc_comment(&self, tok: token::Token) -> bool {
3819 token::POUND | token::DOC_COMMENT(_) => true,
3824 // parse a structure field declaration
3825 pub fn parse_single_struct_field(&self,
3827 attrs: ~[Attribute])
3829 if self.eat_obsolete_ident("let") {
3830 self.obsolete(*self.last_span, ObsoleteLet);
3833 let a_var = self.parse_name_and_ty(vis, attrs);
3836 self.obsolete(*self.span, ObsoleteFieldTerminator);
3844 self.span_fatal(*self.span,
3845 fmt!("expected `,`, or '}' but found `%s`",
3846 self.this_token_to_str()));
3852 // parse an element of a struct definition
3853 fn parse_struct_decl_field(&self) -> ~[@struct_field] {
3855 let attrs = self.parse_outer_attributes();
3857 if self.try_parse_obsolete_priv_section(attrs) {
3861 if self.eat_keyword(keywords::Priv) {
3862 return ~[self.parse_single_struct_field(private, attrs)]
3865 if self.eat_keyword(keywords::Pub) {
3866 return ~[self.parse_single_struct_field(public, attrs)];
3869 if self.try_parse_obsolete_struct_ctor() {
3873 return ~[self.parse_single_struct_field(inherited, attrs)];
3876 // parse visiility: PUB, PRIV, or nothing
3877 fn parse_visibility(&self) -> visibility {
3878 if self.eat_keyword(keywords::Pub) { public }
3879 else if self.eat_keyword(keywords::Priv) { private }
3883 fn parse_staticness(&self) -> bool {
3884 if self.eat_keyword(keywords::Static) {
3885 self.obsolete(*self.last_span, ObsoleteStaticMethod);
3892 // given a termination token and a vector of already-parsed
3893 // attributes (of length 0 or 1), parse all of the items in a module
3894 fn parse_mod_items(&self,
3896 first_item_attrs: ~[Attribute])
3898 // parse all of the items up to closing or an attribute.
3899 // view items are legal here.
3900 let ParsedItemsAndViewItems {
3901 attrs_remaining: attrs_remaining,
3902 view_items: view_items,
3903 items: starting_items,
3905 } = self.parse_items_and_view_items(first_item_attrs, true, true);
3906 let mut items: ~[@item] = starting_items;
3907 let attrs_remaining_len = attrs_remaining.len();
3909 // don't think this other loop is even necessary....
3911 let mut first = true;
3912 while *self.token != term {
3913 let mut attrs = self.parse_outer_attributes();
3915 attrs = attrs_remaining + attrs;
3918 debug!("parse_mod_items: parse_item_or_view_item(attrs=%?)",
3920 match self.parse_item_or_view_item(attrs,
3921 true /* macros allowed */) {
3922 iovi_item(item) => items.push(item),
3923 iovi_view_item(view_item) => {
3924 self.span_fatal(view_item.span,
3925 "view items must be declared at the top of \
3929 self.fatal(fmt!("expected item but found `%s`",
3930 self.this_token_to_str()));
3935 if first && attrs_remaining_len > 0u {
3936 // We parsed attributes for the first item but didn't find it
3937 self.span_err(*self.last_span, "expected item after attributes");
3940 ast::_mod { view_items: view_items, items: items }
3943 fn parse_item_const(&self) -> item_info {
3944 let m = if self.eat_keyword(keywords::Mut) {m_mutbl} else {m_imm};
3945 let id = self.parse_ident();
3946 self.expect(&token::COLON);
3947 let ty = self.parse_ty(false);
3948 self.expect(&token::EQ);
3949 let e = self.parse_expr();
3950 self.expect(&token::SEMI);
3951 (id, item_static(ty, m, e), None)
3954 // parse a `mod <foo> { ... }` or `mod <foo>;` item
3955 fn parse_item_mod(&self, outer_attrs: &[Attribute]) -> item_info {
3956 let id_span = *self.span;
3957 let id = self.parse_ident();
3958 if *self.token == token::SEMI {
3960 // This mod is in an external file. Let's go get it!
3961 let (m, attrs) = self.eval_src_mod(id, outer_attrs, id_span);
3962 (id, m, Some(attrs))
3964 self.push_mod_path(id, outer_attrs);
3965 self.expect(&token::LBRACE);
3966 let (inner, next) = self.parse_inner_attrs_and_next();
3967 let m = self.parse_mod_items(token::RBRACE, next);
3968 self.expect(&token::RBRACE);
3969 self.pop_mod_path();
3970 (id, item_mod(m), Some(inner))
3974 fn push_mod_path(&self, id: ident, attrs: &[Attribute]) {
3975 let default_path = token::interner_get(id.name);
3976 let file_path = match ::attr::first_attr_value_str_by_name(attrs,
3979 None => default_path
3981 self.mod_path_stack.push(file_path)
3984 fn pop_mod_path(&self) {
3985 self.mod_path_stack.pop();
3988 // read a module from a source file.
3989 fn eval_src_mod(&self,
3991 outer_attrs: &[ast::Attribute],
3993 -> (ast::item_, ~[ast::Attribute]) {
3994 let prefix = Path(self.sess.cm.span_to_filename(*self.span));
3995 let prefix = prefix.dir_path();
3996 let mod_path_stack = &*self.mod_path_stack;
3997 let mod_path = Path(".").push_many(*mod_path_stack);
3998 let dir_path = prefix.push_many(mod_path.components);
3999 let file_path = match ::attr::first_attr_value_str_by_name(
4000 outer_attrs, "path") {
4003 if !path.is_absolute {
4010 let mod_name = token::interner_get(id.name).to_owned();
4011 let default_path_str = mod_name + ".rs";
4012 let secondary_path_str = mod_name + "/mod.rs";
4013 let default_path = dir_path.push(default_path_str);
4014 let secondary_path = dir_path.push(secondary_path_str);
4015 let default_exists = default_path.exists();
4016 let secondary_exists = secondary_path.exists();
4017 match (default_exists, secondary_exists) {
4018 (true, false) => default_path,
4019 (false, true) => secondary_path,
4021 self.span_fatal(id_sp, fmt!("file not found for module `%s`", mod_name));
4024 self.span_fatal(id_sp,
4025 fmt!("file for module `%s` found at both %s and %s",
4026 mod_name, default_path_str, secondary_path_str));
4032 self.eval_src_mod_from_path(file_path,
4033 outer_attrs.to_owned(),
4037 fn eval_src_mod_from_path(&self,
4039 outer_attrs: ~[ast::Attribute],
4040 id_sp: span) -> (ast::item_, ~[ast::Attribute]) {
4041 let full_path = path.normalize();
4043 let maybe_i = do self.sess.included_mod_stack.iter().position |p| { *p == full_path };
4046 let stack = &self.sess.included_mod_stack;
4047 let mut err = ~"circular modules: ";
4048 for stack.slice(i, stack.len()).iter().advance |p| {
4049 err.push_str(p.to_str());
4050 err.push_str(" -> ");
4052 err.push_str(full_path.to_str());
4053 self.span_fatal(id_sp, err);
4057 self.sess.included_mod_stack.push(full_path.clone());
4060 new_sub_parser_from_file(self.sess,
4064 let (inner, next) = p0.parse_inner_attrs_and_next();
4065 let mod_attrs = vec::append(outer_attrs, inner);
4066 let first_item_outer_attrs = next;
4067 let m0 = p0.parse_mod_items(token::EOF, first_item_outer_attrs);
4068 self.sess.included_mod_stack.pop();
4069 return (ast::item_mod(m0), mod_attrs);
4072 // parse a function declaration from a foreign module
4073 fn parse_item_foreign_fn(&self, attrs: ~[Attribute]) -> @foreign_item {
4074 let lo = self.span.lo;
4075 let vis = self.parse_visibility();
4076 let purity = self.parse_fn_purity();
4077 let (ident, generics) = self.parse_fn_header();
4078 let decl = self.parse_fn_decl();
4079 let hi = self.span.hi;
4080 self.expect(&token::SEMI);
4081 @ast::foreign_item { ident: ident,
4083 node: foreign_item_fn(decl, purity, generics),
4085 span: mk_sp(lo, hi),
4089 // parse a const definition from a foreign module
4090 fn parse_item_foreign_const(&self, vis: ast::visibility,
4091 attrs: ~[Attribute]) -> @foreign_item {
4092 let lo = self.span.lo;
4094 // XXX: Obsolete; remove after snap.
4095 if self.eat_keyword(keywords::Const) {
4096 self.obsolete(*self.last_span, ObsoleteConstItem);
4098 self.expect_keyword(keywords::Static);
4100 let mutbl = self.eat_keyword(keywords::Mut);
4102 let ident = self.parse_ident();
4103 self.expect(&token::COLON);
4104 let ty = self.parse_ty(false);
4105 let hi = self.span.hi;
4106 self.expect(&token::SEMI);
4107 @ast::foreign_item { ident: ident,
4109 node: foreign_item_static(ty, mutbl),
4111 span: mk_sp(lo, hi),
4115 // parse safe/unsafe and fn
4116 fn parse_fn_purity(&self) -> purity {
4117 if self.eat_keyword(keywords::Fn) { impure_fn }
4118 else if self.eat_keyword(keywords::Pure) {
4119 self.obsolete(*self.last_span, ObsoletePurity);
4120 self.expect_keyword(keywords::Fn);
4121 // NB: We parse this as impure for bootstrapping purposes.
4123 } else if self.eat_keyword(keywords::Unsafe) {
4124 self.expect_keyword(keywords::Fn);
4127 else { self.unexpected(); }
4131 // at this point, this is essentially a wrapper for
4132 // parse_foreign_items.
4133 fn parse_foreign_mod_items(&self,
4134 sort: ast::foreign_mod_sort,
4136 first_item_attrs: ~[Attribute])
4138 let ParsedItemsAndViewItems {
4139 attrs_remaining: attrs_remaining,
4140 view_items: view_items,
4142 foreign_items: foreign_items
4143 } = self.parse_foreign_items(first_item_attrs, true);
4144 if (! attrs_remaining.is_empty()) {
4145 self.span_err(*self.last_span,
4146 "expected item after attributes");
4148 assert!(*self.token == token::RBRACE);
4152 view_items: view_items,
4153 items: foreign_items
4157 // parse extern foo; or extern mod foo { ... } or extern { ... }
4158 fn parse_item_foreign_mod(&self,
4160 opt_abis: Option<AbiSet>,
4161 visibility: visibility,
4162 attrs: ~[Attribute],
4163 items_allowed: bool)
4164 -> item_or_view_item {
4165 let mut must_be_named_mod = false;
4166 if self.is_keyword(keywords::Mod) {
4167 must_be_named_mod = true;
4168 self.expect_keyword(keywords::Mod);
4169 } else if *self.token != token::LBRACE {
4170 self.span_fatal(*self.span,
4171 fmt!("expected `{` or `mod` but found `%s`",
4172 self.this_token_to_str()));
4175 let (sort, ident) = match *self.token {
4176 token::IDENT(*) => (ast::named, self.parse_ident()),
4178 if must_be_named_mod {
4179 self.span_fatal(*self.span,
4180 fmt!("expected foreign module name but \
4182 self.this_token_to_str()));
4186 special_idents::clownshoes_foreign_mod)
4190 // extern mod foo { ... } or extern { ... }
4191 if items_allowed && self.eat(&token::LBRACE) {
4192 // `extern mod foo { ... }` is obsolete.
4193 if sort == ast::named {
4194 self.obsolete(*self.last_span, ObsoleteNamedExternModule);
4197 // Do not allow visibility to be specified.
4198 if visibility != ast::inherited {
4199 self.obsolete(*self.span, ObsoleteExternVisibility);
4202 let abis = opt_abis.get_or_default(AbiSet::C());
4204 let (inner, next) = self.parse_inner_attrs_and_next();
4205 let m = self.parse_foreign_mod_items(sort, abis, next);
4206 self.expect(&token::RBRACE);
4208 return iovi_item(self.mk_item(lo,
4211 item_foreign_mod(m),
4213 maybe_append(attrs, Some(inner))));
4216 if opt_abis.is_some() {
4217 self.span_err(*self.span, "an ABI may not be specified here");
4221 let metadata = self.parse_optional_meta();
4222 self.expect(&token::SEMI);
4223 iovi_view_item(ast::view_item {
4224 node: view_item_extern_mod(ident, metadata, self.get_id()),
4227 span: mk_sp(lo, self.last_span.hi)
4231 // parse type Foo = Bar;
4232 fn parse_item_type(&self) -> item_info {
4233 let ident = self.parse_ident();
4234 self.parse_region_param();
4235 let tps = self.parse_generics();
4236 self.expect(&token::EQ);
4237 let ty = self.parse_ty(false);
4238 self.expect(&token::SEMI);
4239 (ident, item_ty(ty, tps), None)
4242 // parse obsolete region parameter
4243 fn parse_region_param(&self) {
4244 if self.eat(&token::BINOP(token::SLASH)) {
4245 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
4246 self.expect(&token::BINOP(token::AND));
4250 // parse a structure-like enum variant definition
4251 // this should probably be renamed or refactored...
4252 fn parse_struct_def(&self) -> @struct_def {
4253 let mut fields: ~[@struct_field] = ~[];
4254 while *self.token != token::RBRACE {
4255 let r = self.parse_struct_decl_field();
4256 for r.iter().advance |struct_field| {
4257 fields.push(*struct_field);
4262 return @ast::struct_def {
4268 // parse the part of an "enum" decl following the '{'
4269 fn parse_enum_def(&self, _generics: &ast::Generics) -> enum_def {
4270 let mut variants = ~[];
4271 let mut all_nullary = true;
4272 let mut have_disr = false;
4273 while *self.token != token::RBRACE {
4274 let variant_attrs = self.parse_outer_attributes();
4275 let vlo = self.span.lo;
4277 let vis = self.parse_visibility();
4282 let mut disr_expr = None;
4283 ident = self.parse_ident();
4284 if self.eat(&token::LBRACE) {
4285 // Parse a struct variant.
4286 all_nullary = false;
4287 kind = struct_variant_kind(self.parse_struct_def());
4288 } else if *self.token == token::LPAREN {
4289 all_nullary = false;
4290 let arg_tys = self.parse_unspanned_seq(
4293 seq_sep_trailing_disallowed(token::COMMA),
4294 |p| p.parse_ty(false)
4296 for arg_tys.consume_iter().advance |ty| {
4297 args.push(ast::variant_arg {
4302 kind = tuple_variant_kind(args);
4303 } else if self.eat(&token::EQ) {
4305 disr_expr = Some(self.parse_expr());
4306 kind = tuple_variant_kind(args);
4308 kind = tuple_variant_kind(~[]);
4311 let vr = ast::variant_ {
4313 attrs: variant_attrs,
4316 disr_expr: disr_expr,
4319 variants.push(spanned(vlo, self.last_span.hi, vr));
4321 if !self.eat(&token::COMMA) { break; }
4323 self.expect(&token::RBRACE);
4324 if (have_disr && !all_nullary) {
4325 self.fatal("discriminator values can only be used with a c-like \
4329 ast::enum_def { variants: variants }
4332 // parse an "enum" declaration
4333 fn parse_item_enum(&self) -> item_info {
4334 let id = self.parse_ident();
4335 self.parse_region_param();
4336 let generics = self.parse_generics();
4338 if *self.token == token::EQ {
4341 let ty = self.parse_ty(false);
4342 self.expect(&token::SEMI);
4343 let variant = spanned(ty.span.lo, ty.span.hi, ast::variant_ {
4346 kind: tuple_variant_kind(
4347 ~[ast::variant_arg {ty: ty, id: self.get_id()}]
4354 self.obsolete(*self.last_span, ObsoleteNewtypeEnum);
4359 ast::enum_def { variants: ~[variant] },
4365 self.expect(&token::LBRACE);
4367 let enum_definition = self.parse_enum_def(&generics);
4368 (id, item_enum(enum_definition, generics), None)
4371 fn parse_fn_ty_sigil(&self) -> Option<Sigil> {
4381 token::BINOP(token::AND) => {
4391 fn fn_expr_lookahead(&self, tok: &token::Token) -> bool {
4393 token::LPAREN | token::AT | token::TILDE | token::BINOP(_) => true,
4398 // parse a string as an ABI spec on an extern type or module
4399 fn parse_opt_abis(&self) -> Option<AbiSet> {
4401 token::LIT_STR(s) => {
4403 let the_string = ident_to_str(&s);
4404 let mut abis = AbiSet::empty();
4405 for the_string.word_iter().advance |word| {
4406 match abi::lookup(word) {
4408 if abis.contains(abi) {
4411 fmt!("ABI `%s` appears twice",
4421 fmt!("illegal ABI: \
4422 expected one of [%s], \
4424 abi::all_names().connect(", "),
4438 // parse one of the items or view items allowed by the
4439 // flags; on failure, return iovi_none.
4440 // NB: this function no longer parses the items inside an
4442 fn parse_item_or_view_item(&self,
4443 attrs: ~[Attribute],
4444 macros_allowed: bool)
4445 -> item_or_view_item {
4446 maybe_whole!(iovi self, nt_item);
4447 let lo = self.span.lo;
4449 let visibility = self.parse_visibility();
4451 // must be a view item:
4452 if self.eat_keyword(keywords::Use) {
4453 // USE ITEM (iovi_view_item)
4454 let view_item = self.parse_use();
4455 self.expect(&token::SEMI);
4456 return iovi_view_item(ast::view_item {
4460 span: mk_sp(lo, self.last_span.hi)
4463 // either a view item or an item:
4464 if self.eat_keyword(keywords::Extern) {
4465 let opt_abis = self.parse_opt_abis();
4467 if self.eat_keyword(keywords::Fn) {
4468 // EXTERN FUNCTION ITEM
4469 let abis = opt_abis.get_or_default(AbiSet::C());
4470 let (ident, item_, extra_attrs) =
4471 self.parse_item_fn(extern_fn, abis);
4472 return iovi_item(self.mk_item(lo, self.last_span.hi, ident,
4477 // EXTERN MODULE ITEM (iovi_view_item)
4478 return self.parse_item_foreign_mod(lo, opt_abis, visibility, attrs,
4482 // the rest are all guaranteed to be items:
4483 if (self.is_keyword(keywords::Const) ||
4484 (self.is_keyword(keywords::Static) &&
4485 self.look_ahead(1, |t| !token::is_keyword(keywords::Fn, t)))) {
4486 // CONST / STATIC ITEM
4487 if self.is_keyword(keywords::Const) {
4488 self.obsolete(*self.span, ObsoleteConstItem);
4491 let (ident, item_, extra_attrs) = self.parse_item_const();
4492 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4494 maybe_append(attrs, extra_attrs)));
4496 if self.is_keyword(keywords::Fn) &&
4497 self.look_ahead(1, |f| !self.fn_expr_lookahead(f)) {
4500 let (ident, item_, extra_attrs) =
4501 self.parse_item_fn(impure_fn, AbiSet::Rust());
4502 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4504 maybe_append(attrs, extra_attrs)));
4506 if self.eat_keyword(keywords::Pure) {
4507 // PURE FUNCTION ITEM (obsolete)
4508 self.obsolete(*self.last_span, ObsoletePurity);
4509 self.expect_keyword(keywords::Fn);
4510 let (ident, item_, extra_attrs) =
4511 self.parse_item_fn(impure_fn, AbiSet::Rust());
4512 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4514 maybe_append(attrs, extra_attrs)));
4516 if self.is_keyword(keywords::Unsafe)
4517 && self.look_ahead(1u, |t| *t != token::LBRACE) {
4518 // UNSAFE FUNCTION ITEM
4520 self.expect_keyword(keywords::Fn);
4521 let (ident, item_, extra_attrs) =
4522 self.parse_item_fn(unsafe_fn, AbiSet::Rust());
4523 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4525 maybe_append(attrs, extra_attrs)));
4527 if self.eat_keyword(keywords::Mod) {
4529 let (ident, item_, extra_attrs) = self.parse_item_mod(attrs);
4530 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4532 maybe_append(attrs, extra_attrs)));
4534 if self.eat_keyword(keywords::Type) {
4536 let (ident, item_, extra_attrs) = self.parse_item_type();
4537 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4539 maybe_append(attrs, extra_attrs)));
4541 if self.eat_keyword(keywords::Enum) {
4543 let (ident, item_, extra_attrs) = self.parse_item_enum();
4544 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4546 maybe_append(attrs, extra_attrs)));
4548 if self.eat_keyword(keywords::Trait) {
4550 let (ident, item_, extra_attrs) = self.parse_item_trait();
4551 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4553 maybe_append(attrs, extra_attrs)));
4555 if self.eat_keyword(keywords::Impl) {
4557 let (ident, item_, extra_attrs) =
4558 self.parse_item_impl(visibility);
4559 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4561 maybe_append(attrs, extra_attrs)));
4563 if self.eat_keyword(keywords::Struct) {
4565 let (ident, item_, extra_attrs) = self.parse_item_struct();
4566 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4568 maybe_append(attrs, extra_attrs)));
4570 self.parse_macro_use_or_failure(attrs,macros_allowed,lo,visibility)
4573 // parse a foreign item; on failure, return iovi_none.
4574 fn parse_foreign_item(&self,
4575 attrs: ~[Attribute],
4576 macros_allowed: bool)
4577 -> item_or_view_item {
4578 maybe_whole!(iovi self, nt_item);
4579 let lo = self.span.lo;
4581 let visibility = self.parse_visibility();
4583 if (self.is_keyword(keywords::Const) || self.is_keyword(keywords::Static)) {
4584 // FOREIGN CONST ITEM
4585 let item = self.parse_item_foreign_const(visibility, attrs);
4586 return iovi_foreign_item(item);
4588 if (self.is_keyword(keywords::Fn) || self.is_keyword(keywords::Pure) ||
4589 self.is_keyword(keywords::Unsafe)) {
4590 // FOREIGN FUNCTION ITEM
4591 let item = self.parse_item_foreign_fn(attrs);
4592 return iovi_foreign_item(item);
4594 self.parse_macro_use_or_failure(attrs,macros_allowed,lo,visibility)
4597 // this is the fall-through for parsing items.
4598 fn parse_macro_use_or_failure(
4600 attrs: ~[Attribute],
4601 macros_allowed: bool,
4603 visibility : visibility
4604 ) -> item_or_view_item {
4605 if macros_allowed && !token::is_any_keyword(self.token)
4606 && self.look_ahead(1, |t| *t == token::NOT)
4607 && (self.look_ahead(2, |t| is_plain_ident(t))
4608 || self.look_ahead(2, |t| *t == token::LPAREN)
4609 || self.look_ahead(2, |t| *t == token::LBRACE)) {
4610 // MACRO INVOCATION ITEM
4611 if attrs.len() > 0 {
4612 self.fatal("attrs on macros are not yet supported");
4616 let pth = self.parse_path_without_tps();
4617 self.expect(&token::NOT);
4619 // a 'special' identifier (like what `macro_rules!` uses)
4620 // is optional. We should eventually unify invoc syntax
4622 let id = if is_plain_ident(&*self.token) {
4625 token::special_idents::invalid // no special identifier
4627 // eat a matched-delimiter token tree:
4628 let tts = match *self.token {
4629 token::LPAREN | token::LBRACE => {
4630 let ket = token::flip_delimiter(&*self.token);
4632 self.parse_seq_to_end(&ket,
4634 |p| p.parse_token_tree())
4636 _ => self.fatal("expected open delimiter")
4638 // single-variant-enum... :
4639 let m = ast::mac_invoc_tt(pth, tts);
4640 let m: ast::mac = codemap::spanned { node: m,
4641 span: mk_sp(self.span.lo,
4643 let item_ = item_mac(m);
4644 return iovi_item(self.mk_item(lo, self.last_span.hi, id, item_,
4645 visibility, attrs));
4648 // FAILURE TO PARSE ITEM
4649 if visibility != inherited {
4650 let mut s = ~"unmatched visibility `";
4651 if visibility == public {
4657 self.span_fatal(*self.last_span, s);
4659 return iovi_none(attrs);
4662 pub fn parse_item(&self, attrs: ~[Attribute]) -> Option<@ast::item> {
4663 match self.parse_item_or_view_item(attrs, true) {
4664 iovi_none(_) => None,
4665 iovi_view_item(_) =>
4666 self.fatal("view items are not allowed here"),
4667 iovi_foreign_item(_) =>
4668 self.fatal("foreign items are not allowed here"),
4669 iovi_item(item) => Some(item)
4673 // parse, e.g., "use a::b::{z,y}"
4674 fn parse_use(&self) -> view_item_ {
4675 return view_item_use(self.parse_view_paths());
4679 // matches view_path : MOD? IDENT EQ non_global_path
4680 // | MOD? non_global_path MOD_SEP LBRACE RBRACE
4681 // | MOD? non_global_path MOD_SEP LBRACE ident_seq RBRACE
4682 // | MOD? non_global_path MOD_SEP STAR
4683 // | MOD? non_global_path
4684 fn parse_view_path(&self) -> @view_path {
4685 let lo = self.span.lo;
4687 let first_ident = self.parse_ident();
4688 let mut path = ~[first_ident];
4689 debug!("parsed view_path: %s", self.id_to_str(first_ident));
4694 path = ~[self.parse_ident()];
4695 while *self.token == token::MOD_SEP {
4697 let id = self.parse_ident();
4700 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4705 return @spanned(lo, self.span.hi,
4706 view_path_simple(first_ident,
4712 // foo::bar or foo::{a,b,c} or foo::*
4713 while *self.token == token::MOD_SEP {
4717 token::IDENT(i, _) => {
4722 // foo::bar::{a,b,c}
4724 let idents = self.parse_unspanned_seq(
4727 seq_sep_trailing_allowed(token::COMMA),
4728 |p| p.parse_path_list_ident()
4730 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4735 return @spanned(lo, self.span.hi,
4736 view_path_list(path, idents, self.get_id()));
4740 token::BINOP(token::STAR) => {
4742 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4747 return @spanned(lo, self.span.hi,
4748 view_path_glob(path, self.get_id()));
4757 let last = path[path.len() - 1u];
4758 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4765 view_path_simple(last, path, self.get_id()));
4768 // matches view_paths = view_path | view_path , view_paths
4769 fn parse_view_paths(&self) -> ~[@view_path] {
4770 let mut vp = ~[self.parse_view_path()];
4771 while *self.token == token::COMMA {
4773 vp.push(self.parse_view_path());
4778 fn is_view_item(&self) -> bool {
4779 if !self.is_keyword(keywords::Pub) && !self.is_keyword(keywords::Priv) {
4780 token::is_keyword(keywords::Use, self.token)
4781 || (token::is_keyword(keywords::Extern, self.token) &&
4783 |t| token::is_keyword(keywords::Mod, t)))
4785 self.look_ahead(1, |t| token::is_keyword(keywords::Use, t))
4786 || (self.look_ahead(1,
4787 |t| token::is_keyword(keywords::Extern,
4790 |t| token::is_keyword(keywords::Mod, t)))
4794 // parse a view item.
4797 attrs: ~[Attribute],
4800 let lo = self.span.lo;
4801 let node = if self.eat_keyword(keywords::Use) {
4803 } else if self.eat_keyword(keywords::Extern) {
4804 self.expect_keyword(keywords::Mod);
4805 let ident = self.parse_ident();
4806 let metadata = self.parse_optional_meta();
4807 view_item_extern_mod(ident, metadata, self.get_id())
4809 self.bug("expected view item");
4811 self.expect(&token::SEMI);
4812 ast::view_item { node: node,
4815 span: mk_sp(lo, self.last_span.hi) }
4818 // Parses a sequence of items. Stops when it finds program
4819 // text that can't be parsed as an item
4820 // - mod_items uses extern_mod_allowed = true
4821 // - block_tail_ uses extern_mod_allowed = false
4822 fn parse_items_and_view_items(&self,
4823 first_item_attrs: ~[Attribute],
4824 mut extern_mod_allowed: bool,
4825 macros_allowed: bool)
4826 -> ParsedItemsAndViewItems {
4827 let mut attrs = vec::append(first_item_attrs,
4828 self.parse_outer_attributes());
4829 // First, parse view items.
4830 let mut view_items : ~[ast::view_item] = ~[];
4831 let mut items = ~[];
4833 // I think this code would probably read better as a single
4834 // loop with a mutable three-state-variable (for extern mods,
4835 // view items, and regular items) ... except that because
4836 // of macros, I'd like to delay that entire check until later.
4838 match self.parse_item_or_view_item(attrs, macros_allowed) {
4839 iovi_none(attrs) => {
4840 return ParsedItemsAndViewItems {
4841 attrs_remaining: attrs,
4842 view_items: view_items,
4847 iovi_view_item(view_item) => {
4848 match view_item.node {
4849 view_item_use(*) => {
4850 // `extern mod` must precede `use`.
4851 extern_mod_allowed = false;
4853 view_item_extern_mod(*)
4854 if !extern_mod_allowed => {
4855 self.span_err(view_item.span,
4856 "\"extern mod\" declarations are not allowed here");
4858 view_item_extern_mod(*) => {}
4860 view_items.push(view_item);
4862 iovi_item(item) => {
4864 attrs = self.parse_outer_attributes();
4867 iovi_foreign_item(_) => {
4871 attrs = self.parse_outer_attributes();
4874 // Next, parse items.
4876 match self.parse_item_or_view_item(attrs, macros_allowed) {
4877 iovi_none(returned_attrs) => {
4878 attrs = returned_attrs;
4881 iovi_view_item(view_item) => {
4882 attrs = self.parse_outer_attributes();
4883 self.span_err(view_item.span,
4884 "`use` and `extern mod` declarations must precede items");
4886 iovi_item(item) => {
4887 attrs = self.parse_outer_attributes();
4890 iovi_foreign_item(_) => {
4896 ParsedItemsAndViewItems {
4897 attrs_remaining: attrs,
4898 view_items: view_items,
4904 // Parses a sequence of foreign items. Stops when it finds program
4905 // text that can't be parsed as an item
4906 fn parse_foreign_items(&self, first_item_attrs: ~[Attribute],
4907 macros_allowed: bool)
4908 -> ParsedItemsAndViewItems {
4909 let mut attrs = vec::append(first_item_attrs,
4910 self.parse_outer_attributes());
4911 let mut foreign_items = ~[];
4913 match self.parse_foreign_item(attrs, macros_allowed) {
4914 iovi_none(returned_attrs) => {
4915 if *self.token == token::RBRACE {
4916 attrs = returned_attrs;
4921 iovi_view_item(view_item) => {
4922 // I think this can't occur:
4923 self.span_err(view_item.span,
4924 "`use` and `extern mod` declarations must precede items");
4926 iovi_item(item) => {
4927 // FIXME #5668: this will occur for a macro invocation:
4928 self.span_fatal(item.span, "macros cannot expand to foreign items");
4930 iovi_foreign_item(foreign_item) => {
4931 foreign_items.push(foreign_item);
4934 attrs = self.parse_outer_attributes();
4937 ParsedItemsAndViewItems {
4938 attrs_remaining: attrs,
4941 foreign_items: foreign_items
4945 // Parses a source module as a crate. This is the main
4946 // entry point for the parser.
4947 pub fn parse_crate_mod(&self) -> @Crate {
4948 let lo = self.span.lo;
4949 // parse the crate's inner attrs, maybe (oops) one
4950 // of the attrs of an item:
4951 let (inner, next) = self.parse_inner_attrs_and_next();
4952 let first_item_outer_attrs = next;
4953 // parse the items inside the crate:
4954 let m = self.parse_mod_items(token::EOF, first_item_outer_attrs);
4959 config: self.cfg.clone(),
4960 span: mk_sp(lo, self.span.lo)
4964 pub fn parse_str(&self) -> @str {
4966 token::LIT_STR(s) => {
4970 _ => self.fatal("expected string literal")