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};
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::{BlockCheckMode, box};
21 use ast::{Crate, CrateConfig, decl, decl_item};
22 use ast::{decl_local, DefaultBlock, 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_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, expr_for_loop, 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, NodeId, 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::{TypeField, ty_fixed_length_vec, ty_closure, ty_bare_fn};
53 use ast::{ty_infer, TypeMethod};
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, UnsafeBlock, 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;
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, ObsoleteUnsafeExternFn};
88 use parse::obsolete::{ParserObsoleteMethods};
89 use parse::token::{can_begin_expr, get_ident_interner, ident_to_str, is_ident};
90 use parse::token::{is_ident_or_path};
91 use parse::token::{is_plain_ident, INTERPOLATED, keywords, special_idents};
92 use parse::token::{token_to_binop};
94 use parse::{new_sub_parser_from_file, next_node_id, ParseSess};
98 use std::either::Either;
100 use std::hashmap::HashSet;
109 RESTRICT_NO_BAR_OR_DOUBLEBAR_OP,
112 type arg_or_capture_item = Either<arg, ()>;
113 type item_info = (ident, item_, Option<~[Attribute]>);
115 pub enum item_or_view_item {
116 // Indicates a failure to parse any kind of item. The attributes are
118 iovi_none(~[Attribute]),
120 iovi_foreign_item(@foreign_item),
121 iovi_view_item(view_item)
125 enum view_item_parse_mode {
126 VIEW_ITEMS_AND_ITEMS_ALLOWED,
127 FOREIGN_ITEMS_ALLOWED,
128 IMPORTS_AND_ITEMS_ALLOWED
131 /* The expr situation is not as complex as I thought it would be.
132 The important thing is to make sure that lookahead doesn't balk
133 at INTERPOLATED tokens */
134 macro_rules! maybe_whole_expr (
137 // This horrible convolution is brought to you by
138 // @mut, have a terrible day
139 let ret = match *($p).token {
140 INTERPOLATED(token::nt_expr(e)) => {
143 INTERPOLATED(token::nt_path(ref pt)) => {
147 expr_path(/* bad */ (*pt).clone())))
162 macro_rules! maybe_whole (
163 ($p:expr, $constructor:ident) => (
165 let __found__ = match *($p).token {
166 INTERPOLATED(token::$constructor(_)) => {
167 Some(($p).bump_and_get())
172 Some(INTERPOLATED(token::$constructor(x))) => {
179 (deref $p:expr, $constructor:ident) => (
181 let __found__ = match *($p).token {
182 INTERPOLATED(token::$constructor(_)) => {
183 Some(($p).bump_and_get())
188 Some(INTERPOLATED(token::$constructor(x))) => {
195 (Some $p:expr, $constructor:ident) => (
197 let __found__ = match *($p).token {
198 INTERPOLATED(token::$constructor(_)) => {
199 Some(($p).bump_and_get())
204 Some(INTERPOLATED(token::$constructor(x))) => {
205 return Some(x.clone()),
211 (iovi $p:expr, $constructor:ident) => (
213 let __found__ = match *($p).token {
214 INTERPOLATED(token::$constructor(_)) => {
215 Some(($p).bump_and_get())
220 Some(INTERPOLATED(token::$constructor(x))) => {
221 return iovi_item(x.clone())
227 (pair_empty $p:expr, $constructor:ident) => (
229 let __found__ = match *($p).token {
230 INTERPOLATED(token::$constructor(_)) => {
231 Some(($p).bump_and_get())
236 Some(INTERPOLATED(token::$constructor(x))) => {
237 return (~[], x.clone())
246 fn maybe_append(lhs: ~[Attribute], rhs: Option<~[Attribute]>)
250 Some(ref attrs) => vec::append(lhs, (*attrs))
255 struct ParsedItemsAndViewItems {
256 attrs_remaining: ~[Attribute],
257 view_items: ~[view_item],
259 foreign_items: ~[@foreign_item]
262 /* ident is handled by common.rs */
264 pub fn Parser(sess: @mut ParseSess,
265 cfg: ast::CrateConfig,
268 let tok0 = rdr.next_token();
269 let interner = get_ident_interner();
271 let placeholder = TokenAndSpan {
272 tok: token::UNDERSCORE,
281 token: @mut tok0.tok,
283 last_span: @mut span,
290 buffer_start: @mut 0,
292 tokens_consumed: @mut 0,
293 restriction: @mut UNRESTRICTED,
295 obsolete_set: @mut HashSet::new(),
296 mod_path_stack: @mut ~[],
300 // ooh, nasty mutable fields everywhere....
302 sess: @mut ParseSess,
304 // the current token:
305 token: @mut token::Token,
306 // the span of the current token:
308 // the span of the prior token:
309 last_span: @mut span,
310 buffer: @mut [TokenAndSpan, ..4],
311 buffer_start: @mut int,
312 buffer_end: @mut int,
313 tokens_consumed: @mut uint,
314 restriction: @mut restriction,
315 quote_depth: @mut uint, // not (yet) related to the quasiquoter
317 interner: @token::ident_interner,
318 /// The set of seen errors about obsolete syntax. Used to suppress
319 /// extra detail when the same error is seen twice
320 obsolete_set: @mut HashSet<ObsoleteSyntax>,
321 /// Used to determine the path to externally loaded source files
322 mod_path_stack: @mut ~[@str],
326 impl Drop for Parser {
327 /* do not copy the parser; its state is tied to outside state */
332 // convert a token to a string using self's reader
333 pub fn token_to_str(&self, token: &token::Token) -> ~str {
334 token::to_str(get_ident_interner(), token)
337 // convert the current token to a string using self's reader
338 pub fn this_token_to_str(&self) -> ~str {
339 self.token_to_str(self.token)
342 pub fn unexpected_last(&self, t: &token::Token) -> ! {
346 "unexpected token: `%s`",
352 pub fn unexpected(&self) -> ! {
355 "unexpected token: `%s`",
356 self.this_token_to_str()
361 // expect and consume the token t. Signal an error if
362 // the next token is not t.
363 pub fn expect(&self, t: &token::Token) {
364 if *self.token == *t {
369 "expected `%s` but found `%s`",
370 self.token_to_str(t),
371 self.this_token_to_str()
377 pub fn parse_ident(&self) -> ast::ident {
378 self.check_strict_keywords();
379 self.check_reserved_keywords();
381 token::IDENT(i, _) => {
385 token::INTERPOLATED(token::nt_ident(*)) => {
386 self.bug("ident interpolation not converted to real token");
391 "expected ident, found `%s`",
392 self.this_token_to_str()
399 pub fn parse_path_list_ident(&self) -> ast::path_list_ident {
400 let lo = self.span.lo;
401 let ident = self.parse_ident();
402 let hi = self.last_span.hi;
403 spanned(lo, hi, ast::path_list_ident_ { name: ident,
407 // consume token 'tok' if it exists. Returns true if the given
408 // token was present, false otherwise.
409 pub fn eat(&self, tok: &token::Token) -> bool {
410 let is_present = *self.token == *tok;
411 if is_present { self.bump() }
415 pub fn is_keyword(&self, kw: keywords::Keyword) -> bool {
416 token::is_keyword(kw, self.token)
419 // if the next token is the given keyword, eat it and return
420 // true. Otherwise, return false.
421 pub fn eat_keyword(&self, kw: keywords::Keyword) -> bool {
422 let is_kw = match *self.token {
423 token::IDENT(sid, false) => kw.to_ident().name == sid.name,
426 if is_kw { self.bump() }
430 // if the given word is not a keyword, signal an error.
431 // if the next token is not the given word, signal an error.
432 // otherwise, eat it.
433 pub fn expect_keyword(&self, kw: keywords::Keyword) {
434 if !self.eat_keyword(kw) {
437 "expected `%s`, found `%s`",
438 self.id_to_str(kw.to_ident()).to_str(),
439 self.this_token_to_str()
445 // signal an error if the given string is a strict keyword
446 pub fn check_strict_keywords(&self) {
447 if token::is_strict_keyword(self.token) {
448 self.span_err(*self.last_span,
449 fmt!("found `%s` in ident position", self.this_token_to_str()));
453 // signal an error if the current token is a reserved keyword
454 pub fn check_reserved_keywords(&self) {
455 if token::is_reserved_keyword(self.token) {
456 self.fatal(fmt!("`%s` is a reserved keyword", self.this_token_to_str()));
460 // expect and consume a GT. if a >> is seen, replace it
461 // with a single > and continue. If a GT is not seen,
463 pub fn expect_gt(&self) {
465 token::GT => self.bump(),
466 token::BINOP(token::SHR) => self.replace_token(
468 self.span.lo + BytePos(1u),
471 _ => self.fatal(fmt!("expected `%s`, found `%s`",
472 self.token_to_str(&token::GT),
473 self.this_token_to_str()))
477 // parse a sequence bracketed by '<' and '>', stopping
479 pub fn parse_seq_to_before_gt<T>(&self,
480 sep: Option<token::Token>,
481 f: &fn(&Parser) -> T)
483 let mut first = true;
484 let mut v = opt_vec::Empty;
485 while *self.token != token::GT
486 && *self.token != token::BINOP(token::SHR) {
489 if first { first = false; }
490 else { self.expect(t); }
499 pub fn parse_seq_to_gt<T>(&self,
500 sep: Option<token::Token>,
501 f: &fn(&Parser) -> T)
503 let v = self.parse_seq_to_before_gt(sep, f);
508 // parse a sequence, including the closing delimiter. The function
509 // f must consume tokens until reaching the next separator or
511 pub fn parse_seq_to_end<T>(&self,
514 f: &fn(&Parser) -> T)
516 let val = self.parse_seq_to_before_end(ket, sep, f);
521 // parse a sequence, not including the closing delimiter. The function
522 // f must consume tokens until reaching the next separator or
524 pub fn parse_seq_to_before_end<T>(&self,
527 f: &fn(&Parser) -> T)
529 let mut first: bool = true;
530 let mut v: ~[T] = ~[];
531 while *self.token != *ket {
534 if first { first = false; }
535 else { self.expect(t); }
539 if sep.trailing_sep_allowed && *self.token == *ket { break; }
545 // parse a sequence, including the closing delimiter. The function
546 // f must consume tokens until reaching the next separator or
548 pub fn parse_unspanned_seq<T>(&self,
552 f: &fn(&Parser) -> T)
555 let result = self.parse_seq_to_before_end(ket, sep, f);
560 // NB: Do not use this function unless you actually plan to place the
561 // spanned list in the AST.
562 pub fn parse_seq<T>(&self,
566 f: &fn(&Parser) -> T)
568 let lo = self.span.lo;
570 let result = self.parse_seq_to_before_end(ket, sep, f);
571 let hi = self.span.hi;
573 spanned(lo, hi, result)
576 // advance the parser by one token
578 *self.last_span = *self.span;
579 let next = if *self.buffer_start == *self.buffer_end {
580 self.reader.next_token()
582 // Avoid token copies with `util::replace`.
583 let buffer_start = *self.buffer_start as uint;
584 let next_index = (buffer_start + 1) & 3 as uint;
585 *self.buffer_start = next_index as int;
587 let placeholder = TokenAndSpan {
588 tok: token::UNDERSCORE,
591 util::replace(&mut self.buffer[buffer_start], placeholder)
593 *self.span = next.sp;
594 *self.token = next.tok;
595 *self.tokens_consumed += 1u;
598 // Advance the parser by one token and return the bumped token.
599 pub fn bump_and_get(&self) -> token::Token {
600 let old_token = util::replace(self.token, token::UNDERSCORE);
605 // EFFECT: replace the current token and span with the given one
606 pub fn replace_token(&self,
611 *self.span = mk_sp(lo, hi);
613 pub fn buffer_length(&self) -> int {
614 if *self.buffer_start <= *self.buffer_end {
615 return *self.buffer_end - *self.buffer_start;
617 return (4 - *self.buffer_start) + *self.buffer_end;
619 pub fn look_ahead<R>(&self, distance: uint, f: &fn(&token::Token) -> R)
621 let dist = distance as int;
622 while self.buffer_length() < dist {
623 self.buffer[*self.buffer_end] = self.reader.next_token();
624 *self.buffer_end = (*self.buffer_end + 1) & 3;
626 f(&self.buffer[(*self.buffer_start + dist - 1) & 3].tok)
628 pub fn fatal(&self, m: &str) -> ! {
629 self.sess.span_diagnostic.span_fatal(*self.span, m)
631 pub fn span_fatal(&self, sp: span, m: &str) -> ! {
632 self.sess.span_diagnostic.span_fatal(sp, m)
634 pub fn span_note(&self, sp: span, m: &str) {
635 self.sess.span_diagnostic.span_note(sp, m)
637 pub fn bug(&self, m: &str) -> ! {
638 self.sess.span_diagnostic.span_bug(*self.span, m)
640 pub fn warn(&self, m: &str) {
641 self.sess.span_diagnostic.span_warn(*self.span, m)
643 pub fn span_err(&self, sp: span, m: &str) {
644 self.sess.span_diagnostic.span_err(sp, m)
646 pub fn abort_if_errors(&self) {
647 self.sess.span_diagnostic.handler().abort_if_errors();
649 pub fn get_id(&self) -> NodeId { next_node_id(self.sess) }
651 pub fn id_to_str(&self, id: ident) -> @str {
652 get_ident_interner().get(id.name)
655 // is this one of the keywords that signals a closure type?
656 pub fn token_is_closure_keyword(&self, tok: &token::Token) -> bool {
657 token::is_keyword(keywords::Pure, tok) ||
658 token::is_keyword(keywords::Unsafe, tok) ||
659 token::is_keyword(keywords::Once, tok) ||
660 token::is_keyword(keywords::Fn, tok)
663 pub fn token_is_lifetime(&self, tok: &token::Token) -> bool {
665 token::LIFETIME(*) => true,
670 pub fn get_lifetime(&self, tok: &token::Token) -> ast::ident {
672 token::LIFETIME(ref ident) => *ident,
673 _ => self.bug("not a lifetime"),
677 // parse a ty_bare_fun type:
678 pub fn parse_ty_bare_fn(&self) -> ty_ {
681 extern "ABI" [pure|unsafe] fn <'lt> (S) -> T
682 ^~~~^ ^~~~~~~~~~~~^ ^~~~^ ^~^ ^
693 let opt_abis = self.parse_opt_abis();
694 let abis = opt_abis.unwrap_or_default(AbiSet::Rust());
695 let purity = self.parse_unsafety();
696 self.expect_keyword(keywords::Fn);
697 let (decl, lifetimes) = self.parse_ty_fn_decl();
698 return ty_bare_fn(@TyBareFn {
701 lifetimes: lifetimes,
706 // parse a ty_closure type
707 pub fn parse_ty_closure(&self,
709 region: Option<ast::Lifetime>)
713 (&|~|@) ['r] [pure|unsafe] [once] fn [:Bounds] <'lt> (S) -> T
714 ^~~~~~^ ^~~^ ^~~~~~~~~~~~^ ^~~~~^ ^~~~~~~~^ ^~~~^ ^~^ ^
716 | | | | | | | Return type
717 | | | | | | Argument types
719 | | | | Closure bounds
720 | | | Once-ness (a.k.a., affine)
727 // At this point, the allocation type and lifetime bound have been
730 let purity = self.parse_unsafety();
731 let onceness = parse_onceness(self);
732 self.expect_keyword(keywords::Fn);
733 let bounds = self.parse_optional_ty_param_bounds();
735 if self.parse_fn_ty_sigil().is_some() {
736 self.obsolete(*self.span, ObsoletePostFnTySigil);
739 let (decl, lifetimes) = self.parse_ty_fn_decl();
741 return ty_closure(@TyClosure {
748 lifetimes: lifetimes,
751 fn parse_onceness(this: &Parser) -> Onceness {
752 if this.eat_keyword(keywords::Once) {
760 // looks like this should be called parse_unsafety
761 pub fn parse_unsafety(&self) -> purity {
762 if self.eat_keyword(keywords::Pure) {
763 self.obsolete(*self.last_span, ObsoletePurity);
765 } else if self.eat_keyword(keywords::Unsafe) {
772 // parse a function type (following the 'fn')
773 pub fn parse_ty_fn_decl(&self) -> (fn_decl, OptVec<ast::Lifetime>) {
784 let lifetimes = if self.eat(&token::LT) {
785 let lifetimes = self.parse_lifetimes();
792 let inputs = self.parse_unspanned_seq(
795 seq_sep_trailing_disallowed(token::COMMA),
796 |p| p.parse_arg_general(false)
798 let (ret_style, ret_ty) = self.parse_ret_ty();
799 let decl = ast::fn_decl {
807 // parse the methods in a trait declaration
808 pub fn parse_trait_methods(&self) -> ~[trait_method] {
809 do self.parse_unspanned_seq(
814 let attrs = p.parse_outer_attributes();
817 let vis = p.parse_visibility();
818 let pur = p.parse_fn_purity();
819 // NB: at the moment, trait methods are public by default; this
821 let ident = p.parse_ident();
823 let generics = p.parse_generics();
825 let (explicit_self, d) = do self.parse_fn_decl_with_self() |p| {
826 // This is somewhat dubious; We don't want to allow argument
827 // names to be left off if there is a definition...
828 either::Left(p.parse_arg_general(false))
831 let hi = p.last_span.hi;
832 debug!("parse_trait_methods(): trait method signature ends in \
834 self.this_token_to_str());
838 debug!("parse_trait_methods(): parsing required method");
839 // NB: at the moment, visibility annotations on required
840 // methods are ignored; this could change.
841 required(TypeMethod {
847 explicit_self: explicit_self,
853 debug!("parse_trait_methods(): parsing provided method");
854 let (inner_attrs, body) =
855 p.parse_inner_attrs_and_block();
856 let attrs = vec::append(attrs, inner_attrs);
857 provided(@ast::method {
861 explicit_self: explicit_self,
875 "expected `;` or `}` but found `%s`",
876 self.this_token_to_str()
884 // parse a possibly mutable type
885 pub fn parse_mt(&self) -> mt {
886 let mutbl = self.parse_mutability();
887 let t = ~self.parse_ty(false);
888 mt { ty: t, mutbl: mutbl }
891 // parse [mut/const/imm] ID : TY
892 // now used only by obsolete record syntax parser...
893 pub fn parse_ty_field(&self) -> TypeField {
894 let lo = self.span.lo;
895 let mutbl = self.parse_mutability();
896 let id = self.parse_ident();
897 self.expect(&token::COLON);
898 let ty = ~self.parse_ty(false);
902 mt: ast::mt { ty: ty, mutbl: mutbl },
907 // parse optional return type [ -> TY ] in function decl
908 pub fn parse_ret_ty(&self) -> (ret_style, Ty) {
909 return if self.eat(&token::RARROW) {
910 let lo = self.span.lo;
911 if self.eat(&token::NOT) {
917 span: mk_sp(lo, self.last_span.hi)
921 (return_val, self.parse_ty(false))
924 let pos = self.span.lo;
930 span: mk_sp(pos, pos),
937 // Useless second parameter for compatibility with quasiquote macros.
939 pub fn parse_ty(&self, _: bool) -> Ty {
940 maybe_whole!(self, nt_ty);
942 let lo = self.span.lo;
944 let t = if *self.token == token::LPAREN {
946 if *self.token == token::RPAREN {
950 // (t) is a parenthesized ty
951 // (t,) is the type of a tuple with only one field,
953 let mut ts = ~[self.parse_ty(false)];
954 let mut one_tuple = false;
955 while *self.token == token::COMMA {
957 if *self.token != token::RPAREN {
958 ts.push(self.parse_ty(false));
965 if ts.len() == 1 && !one_tuple {
966 self.expect(&token::RPAREN);
971 self.expect(&token::RPAREN);
974 } else if *self.token == token::AT {
977 self.parse_box_or_uniq_pointee(ManagedSigil, ty_box)
978 } else if *self.token == token::TILDE {
981 self.parse_box_or_uniq_pointee(OwnedSigil, ty_uniq)
982 } else if *self.token == token::BINOP(token::STAR) {
983 // STAR POINTER (bare pointer?)
985 ty_ptr(self.parse_mt())
986 } else if *self.token == token::LBRACE {
987 // STRUCTURAL RECORD (remove?)
988 let elems = self.parse_unspanned_seq(
991 seq_sep_trailing_allowed(token::COMMA),
992 |p| p.parse_ty_field()
994 if elems.len() == 0 {
995 self.unexpected_last(&token::RBRACE);
997 self.obsolete(*self.last_span, ObsoleteRecordType);
999 } else if *self.token == token::LBRACKET {
1001 self.expect(&token::LBRACKET);
1002 let mt = self.parse_mt();
1003 if mt.mutbl == m_mutbl { // `m_const` too after snapshot
1004 self.obsolete(*self.last_span, ObsoleteMutVector);
1007 // Parse the `, ..e` in `[ int, ..e ]`
1008 // where `e` is a const expression
1009 let t = match self.maybe_parse_fixed_vstore() {
1011 Some(suffix) => ty_fixed_length_vec(mt, suffix)
1013 self.expect(&token::RBRACKET);
1015 } else if *self.token == token::BINOP(token::AND) {
1018 self.parse_borrowed_pointee()
1019 } else if self.eat_keyword(keywords::Extern) {
1021 self.parse_ty_bare_fn()
1022 } else if self.token_is_closure_keyword(self.token) {
1024 let result = self.parse_ty_closure(ast::BorrowedSigil, None);
1025 self.obsolete(*self.last_span, ObsoleteBareFnType);
1027 } else if *self.token == token::MOD_SEP
1028 || is_ident_or_path(self.token) {
1030 let (path, bounds) = self.parse_type_path();
1031 ty_path(path, bounds, self.get_id())
1033 self.fatal(fmt!("expected type, found token %?",
1037 let sp = mk_sp(lo, self.last_span.hi);
1038 Ty {id: self.get_id(), node: t, span: sp}
1041 // parse the type following a @ or a ~
1042 pub fn parse_box_or_uniq_pointee(&self,
1044 ctor: &fn(v: mt) -> ty_) -> ty_ {
1045 // @'foo fn() or @foo/fn() or @fn() are parsed directly as fn types:
1047 token::LIFETIME(*) => {
1048 let lifetime = self.parse_lifetime();
1050 return self.parse_ty_closure(sigil, Some(lifetime));
1053 token::IDENT(*) => {
1054 if self.look_ahead(1, |t| *t == token::BINOP(token::SLASH)) &&
1055 self.look_ahead(2, |t|
1056 self.token_is_closure_keyword(t)) {
1057 let lifetime = self.parse_lifetime();
1058 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1059 return self.parse_ty_closure(sigil, Some(lifetime));
1060 } else if self.token_is_closure_keyword(self.token) {
1061 return self.parse_ty_closure(sigil, None);
1067 // other things are parsed as @ + a type. Note that constructs like
1068 // @[] and @str will be resolved during typeck to slices and so forth,
1069 // rather than boxed ptrs. But the special casing of str/vec is not
1070 // reflected in the AST type.
1071 let mt = self.parse_mt();
1073 if mt.mutbl != m_imm && sigil == OwnedSigil {
1074 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
1076 if mt.mutbl == m_const && sigil == ManagedSigil {
1077 self.obsolete(*self.last_span, ObsoleteConstManagedPointer);
1083 pub fn parse_borrowed_pointee(&self) -> ty_ {
1084 // look for `&'lt` or `&'foo ` and interpret `foo` as the region name:
1085 let opt_lifetime = self.parse_opt_lifetime();
1087 if self.token_is_closure_keyword(self.token) {
1088 return self.parse_ty_closure(BorrowedSigil, opt_lifetime);
1091 let mt = self.parse_mt();
1092 return ty_rptr(opt_lifetime, mt);
1095 // parse an optional, obsolete argument mode.
1096 pub fn parse_arg_mode(&self) {
1097 if self.eat(&token::BINOP(token::MINUS)) {
1098 self.obsolete(*self.span, ObsoleteMode);
1099 } else if self.eat(&token::ANDAND) {
1100 self.obsolete(*self.span, ObsoleteMode);
1101 } else if self.eat(&token::BINOP(token::PLUS)) {
1102 if self.eat(&token::BINOP(token::PLUS)) {
1103 self.obsolete(*self.span, ObsoleteMode);
1105 self.obsolete(*self.span, ObsoleteMode);
1112 pub fn is_named_argument(&self) -> bool {
1113 let offset = match *self.token {
1114 token::BINOP(token::AND) => 1,
1115 token::BINOP(token::MINUS) => 1,
1117 token::BINOP(token::PLUS) => {
1118 if self.look_ahead(1, |t| *t == token::BINOP(token::PLUS)) {
1128 is_plain_ident(&*self.token)
1129 && self.look_ahead(1, |t| *t == token::COLON)
1131 self.look_ahead(offset, |t| is_plain_ident(t))
1132 && self.look_ahead(offset + 1, |t| *t == token::COLON)
1136 // This version of parse arg doesn't necessarily require
1137 // identifier names.
1138 pub fn parse_arg_general(&self, require_name: bool) -> arg {
1139 let is_mutbl = self.eat_keyword(keywords::Mut);
1140 let pat = if require_name || self.is_named_argument() {
1141 self.parse_arg_mode();
1142 let pat = self.parse_pat();
1144 if is_mutbl && !ast_util::pat_is_ident(pat) {
1145 self.obsolete(*self.span, ObsoleteMutWithMultipleBindings)
1148 self.expect(&token::COLON);
1151 ast_util::ident_to_pat(self.get_id(),
1153 special_idents::invalid)
1156 let t = self.parse_ty(false);
1166 // parse a single function argument
1167 pub fn parse_arg(&self) -> arg_or_capture_item {
1168 either::Left(self.parse_arg_general(true))
1171 // parse an argument in a lambda header e.g. |arg, arg|
1172 pub fn parse_fn_block_arg(&self) -> arg_or_capture_item {
1173 self.parse_arg_mode();
1174 let is_mutbl = self.eat_keyword(keywords::Mut);
1175 let pat = self.parse_pat();
1176 let t = if self.eat(&token::COLON) {
1177 self.parse_ty(false)
1182 span: mk_sp(self.span.lo, self.span.hi),
1185 either::Left(ast::arg {
1193 pub fn maybe_parse_fixed_vstore(&self) -> Option<@ast::expr> {
1194 if self.eat(&token::BINOP(token::STAR)) {
1195 self.obsolete(*self.last_span, ObsoleteFixedLengthVectorType);
1196 Some(self.parse_expr())
1197 } else if *self.token == token::COMMA &&
1198 self.look_ahead(1, |t| *t == token::DOTDOT) {
1201 Some(self.parse_expr())
1207 // matches token_lit = LIT_INT | ...
1208 pub fn lit_from_token(&self, tok: &token::Token) -> lit_ {
1210 token::LIT_INT(i, it) => lit_int(i, it),
1211 token::LIT_UINT(u, ut) => lit_uint(u, ut),
1212 token::LIT_INT_UNSUFFIXED(i) => lit_int_unsuffixed(i),
1213 token::LIT_FLOAT(s, ft) => lit_float(self.id_to_str(s), ft),
1214 token::LIT_FLOAT_UNSUFFIXED(s) =>
1215 lit_float_unsuffixed(self.id_to_str(s)),
1216 token::LIT_STR(s) => lit_str(self.id_to_str(s)),
1217 token::LPAREN => { self.expect(&token::RPAREN); lit_nil },
1218 _ => { self.unexpected_last(tok); }
1222 // matches lit = true | false | token_lit
1223 pub fn parse_lit(&self) -> lit {
1224 let lo = self.span.lo;
1225 let lit = if self.eat_keyword(keywords::True) {
1227 } else if self.eat_keyword(keywords::False) {
1230 let token = self.bump_and_get();
1231 let lit = self.lit_from_token(&token);
1234 codemap::spanned { node: lit, span: mk_sp(lo, self.last_span.hi) }
1237 // matches '-' lit | lit
1238 pub fn parse_literal_maybe_minus(&self) -> @expr {
1239 let minus_lo = self.span.lo;
1240 let minus_present = self.eat(&token::BINOP(token::MINUS));
1242 let lo = self.span.lo;
1243 let literal = @self.parse_lit();
1244 let hi = self.span.hi;
1245 let expr = self.mk_expr(lo, hi, expr_lit(literal));
1248 let minus_hi = self.span.hi;
1249 self.mk_expr(minus_lo, minus_hi, self.mk_unary(neg, expr))
1255 // parse a path into a vector of idents, whether the path starts
1256 // with ::, and a span.
1257 pub fn parse_path(&self) -> (~[ast::ident],bool,span) {
1258 let lo = self.span.lo;
1259 let is_global = self.eat(&token::MOD_SEP);
1260 let (ids,span{lo:_,hi,expn_info}) = self.parse_path_non_global();
1261 (ids,is_global,span{lo:lo,hi:hi,expn_info:expn_info})
1264 // parse a path beginning with an identifier into a vector of idents and a span
1265 pub fn parse_path_non_global(&self) -> (~[ast::ident],span) {
1266 let lo = self.span.lo;
1268 // must be at least one to begin:
1269 ids.push(self.parse_ident());
1273 let is_ident = do self.look_ahead(1) |t| {
1275 token::IDENT(*) => true,
1281 ids.push(self.parse_ident());
1289 (ids, mk_sp(lo, self.last_span.hi))
1292 // parse a path that doesn't have type parameters attached
1293 pub fn parse_path_without_tps(&self) -> ast::Path {
1294 maybe_whole!(self, nt_path);
1295 let (ids,is_global,sp) = self.parse_path();
1296 ast::Path { span: sp,
1303 pub fn parse_bounded_path_with_tps(&self, colons: bool,
1304 before_tps: Option<&fn()>) -> ast::Path {
1305 debug!("parse_path_with_tps(colons=%b)", colons);
1307 maybe_whole!(self, nt_path);
1308 let lo = self.span.lo;
1309 let path = self.parse_path_without_tps();
1310 if colons && !self.eat(&token::MOD_SEP) {
1314 // If the path might have bounds on it, they should be parsed before
1315 // the parameters, e.g. module::TraitName:B1+B2<T>
1316 before_tps.map_move(|callback| callback());
1318 // Parse the (obsolete) trailing region parameter, if any, which will
1319 // be written "foo/&x"
1321 if *self.token == token::BINOP(token::SLASH)
1322 && self.look_ahead(1, |t| *t == token::BINOP(token::AND))
1324 self.bump(); self.bump();
1325 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1327 token::IDENT(sid, _) => {
1328 let span = self.span;
1330 Some(ast::Lifetime {
1337 self.fatal(fmt!("Expected a lifetime name"));
1345 // Parse any lifetime or type parameters which may appear:
1346 let (lifetimes, tps) = self.parse_generic_values();
1347 let hi = self.span.lo;
1349 let rp = match (&rp_slash, &lifetimes) {
1350 (&Some(_), _) => rp_slash,
1354 } else if v.len() == 1 {
1357 self.fatal(fmt!("Expected at most one \
1358 lifetime name (for now)"));
1364 span: mk_sp(lo, hi),
1371 // parse a path optionally with type parameters. If 'colons'
1372 // is true, then type parameters must be preceded by colons,
1373 // as in a::t::<t1,t2>
1374 pub fn parse_path_with_tps(&self, colons: bool) -> ast::Path {
1375 self.parse_bounded_path_with_tps(colons, None)
1378 // Like the above, but can also parse kind bounds in the case of a
1379 // path to be used as a type that might be a trait.
1380 pub fn parse_type_path(&self) -> (ast::Path, Option<OptVec<TyParamBound>>) {
1381 let mut bounds = None;
1382 let path = self.parse_bounded_path_with_tps(false, Some(|| {
1383 // Note: this closure might not even get called in the case of a
1384 // macro-generated path. But that's the macro parser's job.
1385 bounds = self.parse_optional_ty_param_bounds();
1390 /// parses 0 or 1 lifetime
1391 pub fn parse_opt_lifetime(&self) -> Option<ast::Lifetime> {
1393 token::LIFETIME(*) => {
1394 Some(self.parse_lifetime())
1397 // Also accept the (obsolete) syntax `foo/`
1398 token::IDENT(*) => {
1399 if self.look_ahead(1, |t| *t == token::BINOP(token::SLASH)) {
1400 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1401 Some(self.parse_lifetime())
1413 /// Parses a single lifetime
1414 // matches lifetime = ( LIFETIME ) | ( IDENT / )
1415 pub fn parse_lifetime(&self) -> ast::Lifetime {
1417 token::LIFETIME(i) => {
1418 let span = self.span;
1420 return ast::Lifetime {
1427 // Also accept the (obsolete) syntax `foo/`
1428 token::IDENT(i, _) => {
1429 let span = self.span;
1431 self.expect(&token::BINOP(token::SLASH));
1432 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1433 return ast::Lifetime {
1441 self.fatal(fmt!("Expected a lifetime name"));
1446 // matches lifetimes = ( lifetime ) | ( lifetime , lifetimes )
1447 // actually, it matches the empty one too, but putting that in there
1448 // messes up the grammar....
1449 pub fn parse_lifetimes(&self) -> OptVec<ast::Lifetime> {
1452 * Parses zero or more comma separated lifetimes.
1453 * Expects each lifetime to be followed by either
1454 * a comma or `>`. Used when parsing type parameter
1455 * lists, where we expect something like `<'a, 'b, T>`.
1458 let mut res = opt_vec::Empty;
1461 token::LIFETIME(_) => {
1462 res.push(self.parse_lifetime());
1470 token::COMMA => { self.bump();}
1471 token::GT => { return res; }
1472 token::BINOP(token::SHR) => { return res; }
1474 self.fatal(fmt!("expected `,` or `>` after lifetime name, got: %?",
1481 pub fn token_is_mutability(&self, tok: &token::Token) -> bool {
1482 token::is_keyword(keywords::Mut, tok) ||
1483 token::is_keyword(keywords::Const, tok)
1486 // parse mutability declaration (mut/const/imm)
1487 pub fn parse_mutability(&self) -> mutability {
1488 if self.eat_keyword(keywords::Mut) {
1490 } else if self.eat_keyword(keywords::Const) {
1497 // parse ident COLON expr
1498 pub fn parse_field(&self) -> Field {
1499 let lo = self.span.lo;
1500 let i = self.parse_ident();
1501 self.expect(&token::COLON);
1502 let e = self.parse_expr();
1506 span: mk_sp(lo, e.span.hi),
1510 pub fn mk_expr(&self, lo: BytePos, hi: BytePos, node: expr_) -> @expr {
1514 span: mk_sp(lo, hi),
1518 pub fn mk_unary(&self, unop: ast::unop, expr: @expr) -> ast::expr_ {
1519 expr_unary(self.get_id(), unop, expr)
1522 pub fn mk_binary(&self, binop: ast::binop, lhs: @expr, rhs: @expr) -> ast::expr_ {
1523 expr_binary(self.get_id(), binop, lhs, rhs)
1526 pub fn mk_call(&self, f: @expr, args: ~[@expr], sugar: CallSugar) -> ast::expr_ {
1527 expr_call(f, args, sugar)
1530 pub fn mk_method_call(&self,
1535 sugar: CallSugar) -> ast::expr_ {
1536 expr_method_call(self.get_id(), rcvr, ident, tps, args, sugar)
1539 pub fn mk_index(&self, expr: @expr, idx: @expr) -> ast::expr_ {
1540 expr_index(self.get_id(), expr, idx)
1543 pub fn mk_field(&self, expr: @expr, ident: ident, tys: ~[Ty]) -> ast::expr_ {
1544 expr_field(expr, ident, tys)
1547 pub fn mk_assign_op(&self, binop: ast::binop, lhs: @expr, rhs: @expr) -> ast::expr_ {
1548 expr_assign_op(self.get_id(), binop, lhs, rhs)
1551 pub fn mk_mac_expr(&self, lo: BytePos, hi: BytePos, m: mac_) -> @expr {
1554 node: expr_mac(codemap::spanned {node: m, span: mk_sp(lo, hi)}),
1555 span: mk_sp(lo, hi),
1559 pub fn mk_lit_u32(&self, i: u32) -> @expr {
1560 let span = self.span;
1561 let lv_lit = @codemap::spanned {
1562 node: lit_uint(i as u64, ty_u32),
1568 node: expr_lit(lv_lit),
1573 // at the bottom (top?) of the precedence hierarchy,
1574 // parse things like parenthesized exprs,
1575 // macros, return, etc.
1576 pub fn parse_bottom_expr(&self) -> @expr {
1577 maybe_whole_expr!(self);
1579 let lo = self.span.lo;
1580 let mut hi = self.span.hi;
1584 if *self.token == token::LPAREN {
1586 // (e) is parenthesized e
1587 // (e,) is a tuple with only one field, e
1588 let mut trailing_comma = false;
1589 if *self.token == token::RPAREN {
1592 let lit = @spanned(lo, hi, lit_nil);
1593 return self.mk_expr(lo, hi, expr_lit(lit));
1595 let mut es = ~[self.parse_expr()];
1596 while *self.token == token::COMMA {
1598 if *self.token != token::RPAREN {
1599 es.push(self.parse_expr());
1602 trailing_comma = true;
1606 self.expect(&token::RPAREN);
1608 return if es.len() == 1 && !trailing_comma {
1609 self.mk_expr(lo, self.span.hi, expr_paren(es[0]))
1612 self.mk_expr(lo, hi, expr_tup(es))
1614 } else if *self.token == token::LBRACE {
1616 let blk = self.parse_block_tail(lo, DefaultBlock);
1617 return self.mk_expr(blk.span.lo, blk.span.hi,
1619 } else if token::is_bar(&*self.token) {
1620 return self.parse_lambda_expr();
1621 } else if self.eat_keyword(keywords::Self) {
1624 } else if self.eat_keyword(keywords::If) {
1625 return self.parse_if_expr();
1626 } else if self.eat_keyword(keywords::For) {
1627 return self.parse_for_expr();
1628 } else if self.eat_keyword(keywords::Do) {
1629 return self.parse_sugary_call_expr(lo, ~"do", DoSugar,
1631 } else if self.eat_keyword(keywords::While) {
1632 return self.parse_while_expr();
1633 } else if self.token_is_lifetime(&*self.token) {
1634 let lifetime = self.get_lifetime(&*self.token);
1636 self.expect(&token::COLON);
1637 self.expect_keyword(keywords::Loop);
1638 return self.parse_loop_expr(Some(lifetime));
1639 } else if self.eat_keyword(keywords::Loop) {
1640 return self.parse_loop_expr(None);
1641 } else if self.eat_keyword(keywords::Match) {
1642 return self.parse_match_expr();
1643 } else if self.eat_keyword(keywords::Unsafe) {
1644 return self.parse_block_expr(lo, UnsafeBlock);
1645 } else if *self.token == token::LBRACKET {
1647 let mutbl = self.parse_mutability();
1648 if mutbl == m_mutbl || mutbl == m_const {
1649 self.obsolete(*self.last_span, ObsoleteMutVector);
1652 if *self.token == token::RBRACKET {
1655 ex = expr_vec(~[], mutbl);
1658 let first_expr = self.parse_expr();
1659 if *self.token == token::COMMA &&
1660 self.look_ahead(1, |t| *t == token::DOTDOT) {
1661 // Repeating vector syntax: [ 0, ..512 ]
1664 let count = self.parse_expr();
1665 self.expect(&token::RBRACKET);
1666 ex = expr_repeat(first_expr, count, mutbl);
1667 } else if *self.token == token::COMMA {
1668 // Vector with two or more elements.
1670 let remaining_exprs = self.parse_seq_to_end(
1672 seq_sep_trailing_allowed(token::COMMA),
1675 ex = expr_vec(~[first_expr] + remaining_exprs, mutbl);
1677 // Vector with one element.
1678 self.expect(&token::RBRACKET);
1679 ex = expr_vec(~[first_expr], mutbl);
1682 hi = self.last_span.hi;
1683 } else if self.eat_keyword(keywords::__Log) {
1685 self.expect(&token::LPAREN);
1686 let lvl = self.parse_expr();
1687 self.expect(&token::COMMA);
1688 let e = self.parse_expr();
1689 ex = expr_log(lvl, e);
1691 self.expect(&token::RPAREN);
1692 } else if self.eat_keyword(keywords::Return) {
1693 // RETURN expression
1694 if can_begin_expr(&*self.token) {
1695 let e = self.parse_expr();
1697 ex = expr_ret(Some(e));
1698 } else { ex = expr_ret(None); }
1699 } else if self.eat_keyword(keywords::Break) {
1701 if self.token_is_lifetime(&*self.token) {
1702 let lifetime = self.get_lifetime(&*self.token);
1704 ex = expr_break(Some(lifetime));
1706 ex = expr_break(None);
1709 } else if *self.token == token::MOD_SEP ||
1710 is_ident(&*self.token) && !self.is_keyword(keywords::True) &&
1711 !self.is_keyword(keywords::False) {
1712 let pth = self.parse_path_with_tps(true);
1714 // `!`, as an operator, is prefix, so we know this isn't that
1715 if *self.token == token::NOT {
1716 // MACRO INVOCATION expression
1719 token::LPAREN | token::LBRACE => {}
1720 _ => self.fatal("expected open delimiter")
1723 let ket = token::flip_delimiter(&*self.token);
1726 let tts = self.parse_seq_to_end(&ket,
1728 |p| p.parse_token_tree());
1729 let hi = self.span.hi;
1731 return self.mk_mac_expr(lo, hi, mac_invoc_tt(pth, tts));
1732 } else if *self.token == token::LBRACE {
1733 // This might be a struct literal.
1734 if self.looking_at_record_literal() {
1735 // It's a struct literal.
1737 let mut fields = ~[];
1738 let mut base = None;
1740 fields.push(self.parse_field());
1741 while *self.token != token::RBRACE {
1742 if self.try_parse_obsolete_with() {
1746 self.expect(&token::COMMA);
1748 if self.eat(&token::DOTDOT) {
1749 base = Some(self.parse_expr());
1753 if *self.token == token::RBRACE {
1754 // Accept an optional trailing comma.
1757 fields.push(self.parse_field());
1761 self.expect(&token::RBRACE);
1762 ex = expr_struct(pth, fields, base);
1763 return self.mk_expr(lo, hi, ex);
1768 ex = expr_path(pth);
1770 // other literal expression
1771 let lit = self.parse_lit();
1773 ex = expr_lit(@lit);
1776 return self.mk_expr(lo, hi, ex);
1779 // parse a block or unsafe block
1780 pub fn parse_block_expr(&self, lo: BytePos, blk_mode: BlockCheckMode)
1782 self.expect(&token::LBRACE);
1783 let blk = self.parse_block_tail(lo, blk_mode);
1784 return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
1787 // parse a.b or a(13) or a[4] or just a
1788 pub fn parse_dot_or_call_expr(&self) -> @expr {
1789 let b = self.parse_bottom_expr();
1790 self.parse_dot_or_call_expr_with(b)
1793 pub fn parse_dot_or_call_expr_with(&self, e0: @expr) -> @expr {
1799 if self.eat(&token::DOT) {
1801 token::IDENT(i, _) => {
1804 let (_, tys) = if self.eat(&token::MOD_SEP) {
1805 self.expect(&token::LT);
1806 self.parse_generic_values_after_lt()
1808 (opt_vec::Empty, ~[])
1811 // expr.f() method call
1814 let es = self.parse_unspanned_seq(
1817 seq_sep_trailing_disallowed(token::COMMA),
1822 let nd = self.mk_method_call(e, i, tys, es, NoSugar);
1823 e = self.mk_expr(lo, hi, nd);
1826 e = self.mk_expr(lo, hi, self.mk_field(e, i, tys));
1830 _ => self.unexpected()
1834 if self.expr_is_complete(e) { break; }
1838 let es = self.parse_unspanned_seq(
1841 seq_sep_trailing_disallowed(token::COMMA),
1846 let nd = self.mk_call(e, es, NoSugar);
1847 e = self.mk_expr(lo, hi, nd);
1851 token::LBRACKET => {
1853 let ix = self.parse_expr();
1855 self.expect(&token::RBRACKET);
1856 e = self.mk_expr(lo, hi, self.mk_index(e, ix));
1865 // parse an optional separator followed by a kleene-style
1866 // repetition token (+ or *).
1867 pub fn parse_sep_and_zerok(&self) -> (Option<token::Token>, bool) {
1868 fn parse_zerok(parser: &Parser) -> Option<bool> {
1869 match *parser.token {
1870 token::BINOP(token::STAR) | token::BINOP(token::PLUS) => {
1871 let zerok = *parser.token == token::BINOP(token::STAR);
1879 match parse_zerok(self) {
1880 Some(zerok) => return (None, zerok),
1884 let separator = self.bump_and_get();
1885 match parse_zerok(self) {
1886 Some(zerok) => (Some(separator), zerok),
1887 None => self.fatal("expected `*` or `+`")
1891 // parse a single token tree from the input.
1892 pub fn parse_token_tree(&self) -> token_tree {
1893 maybe_whole!(deref self, nt_tt);
1895 // this is the fall-through for the 'match' below.
1896 // invariants: the current token is not a left-delimiter,
1897 // not an EOF, and not the desired right-delimiter (if
1898 // it were, parse_seq_to_before_end would have prevented
1899 // reaching this point.
1900 fn parse_non_delim_tt_tok(p: &Parser) -> token_tree {
1901 maybe_whole!(deref p, nt_tt);
1903 token::RPAREN | token::RBRACE | token::RBRACKET
1907 "incorrect close delimiter: `%s`",
1908 p.this_token_to_str()
1912 /* we ought to allow different depths of unquotation */
1913 token::DOLLAR if *p.quote_depth > 0u => {
1917 if *p.token == token::LPAREN {
1918 let seq = p.parse_seq(
1922 |p| p.parse_token_tree()
1924 let (s, z) = p.parse_sep_and_zerok();
1925 let seq = match seq {
1926 spanned { node, _ } => node,
1929 mk_sp(sp.lo, p.span.hi),
1935 tt_nonterminal(sp, p.parse_ident())
1944 // turn the next token into a tt_tok:
1945 fn parse_any_tt_tok(p: &Parser) -> token_tree{
1946 tt_tok(*p.span, p.bump_and_get())
1951 self.fatal("file ended with unbalanced delimiters");
1953 token::LPAREN | token::LBRACE | token::LBRACKET => {
1954 let close_delim = token::flip_delimiter(&*self.token);
1956 // Parse the open delimiter.
1957 let mut result = ~[parse_any_tt_tok(self)];
1960 self.parse_seq_to_before_end(&close_delim,
1962 |p| p.parse_token_tree());
1963 result.push_all_move(trees);
1965 // Parse the close delimiter.
1966 result.push(parse_any_tt_tok(self));
1968 tt_delim(@mut result)
1970 _ => parse_non_delim_tt_tok(self)
1974 // parse a stream of tokens into a list of token_trees,
1976 pub fn parse_all_token_trees(&self) -> ~[token_tree] {
1978 while *self.token != token::EOF {
1979 tts.push(self.parse_token_tree());
1984 pub fn parse_matchers(&self) -> ~[matcher] {
1985 // unification of matchers and token_trees would vastly improve
1986 // the interpolation of matchers
1987 maybe_whole!(self, nt_matchers);
1988 let name_idx = @mut 0u;
1990 token::LBRACE | token::LPAREN | token::LBRACKET => {
1991 let other_delimiter = token::flip_delimiter(self.token);
1993 self.parse_matcher_subseq_upto(name_idx, &other_delimiter)
1995 _ => self.fatal("expected open delimiter")
1999 // This goofy function is necessary to correctly match parens in matchers.
2000 // Otherwise, `$( ( )` would be a valid matcher, and `$( () )` would be
2001 // invalid. It's similar to common::parse_seq.
2002 pub fn parse_matcher_subseq_upto(&self,
2003 name_idx: @mut uint,
2006 let mut ret_val = ~[];
2007 let mut lparens = 0u;
2009 while *self.token != *ket || lparens > 0u {
2010 if *self.token == token::LPAREN { lparens += 1u; }
2011 if *self.token == token::RPAREN { lparens -= 1u; }
2012 ret_val.push(self.parse_matcher(name_idx));
2020 pub fn parse_matcher(&self, name_idx: @mut uint) -> matcher {
2021 let lo = self.span.lo;
2023 let m = if *self.token == token::DOLLAR {
2025 if *self.token == token::LPAREN {
2026 let name_idx_lo = *name_idx;
2028 let ms = self.parse_matcher_subseq_upto(name_idx,
2031 self.fatal("repetition body must be nonempty");
2033 let (sep, zerok) = self.parse_sep_and_zerok();
2034 match_seq(ms, sep, zerok, name_idx_lo, *name_idx)
2036 let bound_to = self.parse_ident();
2037 self.expect(&token::COLON);
2038 let nt_name = self.parse_ident();
2039 let m = match_nonterminal(bound_to, nt_name, *name_idx);
2044 match_tok(self.bump_and_get())
2047 return spanned(lo, self.span.hi, m);
2050 // parse a prefix-operator expr
2051 pub fn parse_prefix_expr(&self) -> @expr {
2052 let lo = self.span.lo;
2059 let e = self.parse_prefix_expr();
2061 ex = self.mk_unary(not, e);
2063 token::BINOP(b) => {
2067 let e = self.parse_prefix_expr();
2069 ex = self.mk_unary(neg, e);
2073 let e = self.parse_prefix_expr();
2075 ex = self.mk_unary(deref, e);
2079 let _lt = self.parse_opt_lifetime();
2080 let m = self.parse_mutability();
2081 let e = self.parse_prefix_expr();
2083 // HACK: turn &[...] into a &-evec
2085 expr_vec(*) | expr_lit(@codemap::spanned {
2086 node: lit_str(_), span: _
2089 expr_vstore(e, expr_vstore_slice)
2091 expr_vec(*) if m == m_mutbl => {
2092 expr_vstore(e, expr_vstore_mut_slice)
2094 _ => expr_addr_of(m, e)
2097 _ => return self.parse_dot_or_call_expr()
2102 let m = self.parse_mutability();
2104 self.obsolete(*self.last_span, ObsoleteConstManagedPointer);
2107 let e = self.parse_prefix_expr();
2109 // HACK: turn @[...] into a @-evec
2111 expr_vec(*) | expr_repeat(*) if m == m_mutbl =>
2112 expr_vstore(e, expr_vstore_mut_box),
2114 expr_lit(@codemap::spanned { node: lit_str(_), span: _}) |
2115 expr_repeat(*) if m == m_imm => expr_vstore(e, expr_vstore_box),
2116 _ => self.mk_unary(box(m), e)
2121 let m = self.parse_mutability();
2123 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
2126 let e = self.parse_prefix_expr();
2128 // HACK: turn ~[...] into a ~-evec
2131 expr_lit(@codemap::spanned { node: lit_str(_), span: _}) |
2132 expr_repeat(*) => expr_vstore(e, expr_vstore_uniq),
2133 _ => self.mk_unary(uniq, e)
2136 _ => return self.parse_dot_or_call_expr()
2138 return self.mk_expr(lo, hi, ex);
2141 // parse an expression of binops
2142 pub fn parse_binops(&self) -> @expr {
2143 self.parse_more_binops(self.parse_prefix_expr(), 0)
2146 // parse an expression of binops of at least min_prec precedence
2147 pub fn parse_more_binops(&self, lhs: @expr, min_prec: uint) -> @expr {
2148 if self.expr_is_complete(lhs) { return lhs; }
2150 // Prevent dynamic borrow errors later on by limiting the
2151 // scope of the borrows.
2153 let token: &token::Token = self.token;
2154 let restriction: &restriction = self.restriction;
2155 match (token, restriction) {
2156 (&token::BINOP(token::OR), &RESTRICT_NO_BAR_OP) => return lhs,
2157 (&token::BINOP(token::OR),
2158 &RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
2159 (&token::OROR, &RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
2164 let cur_opt = token_to_binop(self.token);
2167 let cur_prec = operator_prec(cur_op);
2168 if cur_prec > min_prec {
2170 let expr = self.parse_prefix_expr();
2171 let rhs = self.parse_more_binops(expr, cur_prec);
2172 let bin = self.mk_expr(lhs.span.lo, rhs.span.hi,
2173 self.mk_binary(cur_op, lhs, rhs));
2174 self.parse_more_binops(bin, min_prec)
2180 if as_prec > min_prec && self.eat_keyword(keywords::As) {
2181 let rhs = self.parse_ty(true);
2182 let _as = self.mk_expr(lhs.span.lo,
2184 expr_cast(lhs, rhs));
2185 self.parse_more_binops(_as, min_prec)
2193 // parse an assignment expression....
2194 // actually, this seems to be the main entry point for
2195 // parsing an arbitrary expression.
2196 pub fn parse_assign_expr(&self) -> @expr {
2197 let lo = self.span.lo;
2198 let lhs = self.parse_binops();
2202 let rhs = self.parse_expr();
2203 self.mk_expr(lo, rhs.span.hi, expr_assign(lhs, rhs))
2205 token::BINOPEQ(op) => {
2207 let rhs = self.parse_expr();
2208 let aop = match op {
2210 token::MINUS => subtract,
2212 token::SLASH => div,
2213 token::PERCENT => rem,
2214 token::CARET => bitxor,
2215 token::AND => bitand,
2220 self.mk_expr(lo, rhs.span.hi,
2221 self.mk_assign_op(aop, lhs, rhs))
2224 self.obsolete(*self.span, ObsoleteBinaryMove);
2225 // Bogus value (but it's an error)
2229 self.mk_expr(lo, self.span.hi,
2233 self.obsolete(*self.span, ObsoleteSwap);
2235 // Ignore what we get, this is an error anyway
2237 self.mk_expr(lo, self.span.hi, expr_break(None))
2245 // parse an 'if' expression ('if' token already eaten)
2246 pub fn parse_if_expr(&self) -> @expr {
2247 let lo = self.last_span.lo;
2248 let cond = self.parse_expr();
2249 let thn = self.parse_block();
2250 let mut els: Option<@expr> = None;
2251 let mut hi = thn.span.hi;
2252 if self.eat_keyword(keywords::Else) {
2253 let elexpr = self.parse_else_expr();
2255 hi = elexpr.span.hi;
2257 self.mk_expr(lo, hi, expr_if(cond, thn, els))
2260 // `|args| { ... }` or `{ ...}` like in `do` expressions
2261 pub fn parse_lambda_block_expr(&self) -> @expr {
2262 self.parse_lambda_expr_(
2265 token::BINOP(token::OR) | token::OROR => {
2266 self.parse_fn_block_decl()
2269 // No argument list - `do foo {`
2283 let blk = self.parse_block();
2284 self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk))
2289 pub fn parse_lambda_expr(&self) -> @expr {
2290 self.parse_lambda_expr_(|| self.parse_fn_block_decl(),
2291 || self.parse_expr())
2294 // parse something of the form |args| expr
2295 // this is used both in parsing a lambda expr
2296 // and in parsing a block expr as e.g. in for...
2297 pub fn parse_lambda_expr_(&self,
2298 parse_decl: &fn() -> fn_decl,
2299 parse_body: &fn() -> @expr)
2301 let lo = self.last_span.lo;
2302 let decl = parse_decl();
2303 let body = parse_body();
2304 let fakeblock = ast::Block {
2309 rules: DefaultBlock,
2313 return self.mk_expr(lo, body.span.hi,
2314 expr_fn_block(decl, fakeblock));
2317 pub fn parse_else_expr(&self) -> @expr {
2318 if self.eat_keyword(keywords::If) {
2319 return self.parse_if_expr();
2321 let blk = self.parse_block();
2322 return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
2326 // parse a 'for' .. 'in' expression ('for' token already eaten)
2327 pub fn parse_for_expr(&self) -> @expr {
2328 // Parse: `for <src_pat> in <src_expr> <src_loop_block>`
2330 let lo = self.last_span.lo;
2331 let pat = self.parse_pat();
2332 self.expect_keyword(keywords::In);
2333 let expr = self.parse_expr();
2334 let loop_block = self.parse_block();
2335 let hi = self.span.hi;
2337 self.mk_expr(lo, hi, expr_for_loop(pat, expr, loop_block))
2341 // parse a 'for' or 'do'.
2342 // the 'for' and 'do' expressions parse as calls, but look like
2343 // function calls followed by a closure expression.
2344 pub fn parse_sugary_call_expr(&self, lo: BytePos,
2347 ctor: &fn(v: @expr) -> expr_)
2349 // Parse the callee `foo` in
2352 // etc, or the portion of the call expression before the lambda in
2355 // for foo.bar(a) || {
2356 // Turn on the restriction to stop at | or || so we can parse
2357 // them as the lambda arguments
2358 let e = self.parse_expr_res(RESTRICT_NO_BAR_OR_DOUBLEBAR_OP);
2360 expr_call(f, ref args, NoSugar) => {
2361 let block = self.parse_lambda_block_expr();
2362 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2364 let args = vec::append((*args).clone(), [last_arg]);
2365 self.mk_expr(lo, block.span.hi, expr_call(f, args, sugar))
2367 expr_method_call(_, f, i, ref tps, ref args, NoSugar) => {
2368 let block = self.parse_lambda_block_expr();
2369 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2371 let args = vec::append((*args).clone(), [last_arg]);
2372 self.mk_expr(lo, block.span.hi,
2373 self.mk_method_call(f,
2379 expr_field(f, i, ref tps) => {
2380 let block = self.parse_lambda_block_expr();
2381 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2383 self.mk_expr(lo, block.span.hi,
2384 self.mk_method_call(f,
2390 expr_path(*) | expr_call(*) | expr_method_call(*) |
2392 let block = self.parse_lambda_block_expr();
2393 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2398 self.mk_call(e, ~[last_arg], sugar))
2401 // There may be other types of expressions that can
2402 // represent the callee in `for` and `do` expressions
2403 // but they aren't represented by tests
2404 debug!("sugary call on %?", e.node);
2407 fmt!("`%s` must be followed by a block call", keyword));
2412 pub fn parse_while_expr(&self) -> @expr {
2413 let lo = self.last_span.lo;
2414 let cond = self.parse_expr();
2415 let body = self.parse_block();
2416 let hi = body.span.hi;
2417 return self.mk_expr(lo, hi, expr_while(cond, body));
2420 pub fn parse_loop_expr(&self, opt_ident: Option<ast::ident>) -> @expr {
2421 // loop headers look like 'loop {' or 'loop unsafe {'
2422 let is_loop_header =
2423 *self.token == token::LBRACE
2424 || (is_ident(&*self.token)
2425 && self.look_ahead(1, |t| *t == token::LBRACE));
2428 // This is a loop body
2429 let lo = self.last_span.lo;
2430 let body = self.parse_block();
2431 let hi = body.span.hi;
2432 return self.mk_expr(lo, hi, expr_loop(body, opt_ident));
2434 // This is a 'continue' expression
2435 if opt_ident.is_some() {
2436 self.span_err(*self.last_span,
2437 "a label may not be used with a `loop` expression");
2440 let lo = self.span.lo;
2441 let ex = if self.token_is_lifetime(&*self.token) {
2442 let lifetime = self.get_lifetime(&*self.token);
2444 expr_again(Some(lifetime))
2448 let hi = self.span.hi;
2449 return self.mk_expr(lo, hi, ex);
2453 // For distingishing between record literals and blocks
2454 fn looking_at_record_literal(&self) -> bool {
2455 *self.token == token::LBRACE &&
2456 (self.look_ahead(1, |t| token::is_keyword(keywords::Mut, t)) ||
2457 (self.look_ahead(1, |t| token::is_plain_ident(t)) &&
2458 self.look_ahead(2, |t| *t == token::COLON)))
2461 fn parse_match_expr(&self) -> @expr {
2462 let lo = self.last_span.lo;
2463 let discriminant = self.parse_expr();
2464 self.expect(&token::LBRACE);
2465 let mut arms: ~[arm] = ~[];
2466 while *self.token != token::RBRACE {
2467 let pats = self.parse_pats();
2468 let mut guard = None;
2469 if self.eat_keyword(keywords::If) {
2470 guard = Some(self.parse_expr());
2472 self.expect(&token::FAT_ARROW);
2473 let expr = self.parse_expr_res(RESTRICT_STMT_EXPR);
2476 !classify::expr_is_simple_block(expr)
2477 && *self.token != token::RBRACE;
2480 self.expect(&token::COMMA);
2482 self.eat(&token::COMMA);
2485 let blk = ast::Block {
2490 rules: DefaultBlock,
2494 arms.push(ast::arm { pats: pats, guard: guard, body: blk });
2496 let hi = self.span.hi;
2498 return self.mk_expr(lo, hi, expr_match(discriminant, arms));
2501 // parse an expression
2502 pub fn parse_expr(&self) -> @expr {
2503 return self.parse_expr_res(UNRESTRICTED);
2506 // parse an expression, subject to the given restriction
2507 fn parse_expr_res(&self, r: restriction) -> @expr {
2508 let old = *self.restriction;
2509 *self.restriction = r;
2510 let e = self.parse_assign_expr();
2511 *self.restriction = old;
2515 // parse the RHS of a local variable declaration (e.g. '= 14;')
2516 fn parse_initializer(&self) -> Option<@expr> {
2520 return Some(self.parse_expr());
2523 self.obsolete(*self.span, ObsoleteMoveInit);
2534 // parse patterns, separated by '|' s
2535 fn parse_pats(&self) -> ~[@pat] {
2538 pats.push(self.parse_pat());
2539 if *self.token == token::BINOP(token::OR) { self.bump(); }
2540 else { return pats; }
2544 fn parse_pat_vec_elements(
2546 ) -> (~[@pat], Option<@pat>, ~[@pat]) {
2547 let mut before = ~[];
2548 let mut slice = None;
2549 let mut after = ~[];
2550 let mut first = true;
2551 let mut before_slice = true;
2553 while *self.token != token::RBRACKET {
2554 if first { first = false; }
2555 else { self.expect(&token::COMMA); }
2557 let mut is_slice = false;
2559 if *self.token == token::DOTDOT {
2562 before_slice = false;
2566 let subpat = self.parse_pat();
2569 @ast::pat { node: pat_wild, _ } => (),
2570 @ast::pat { node: pat_ident(_, _, _), _ } => (),
2571 @ast::pat { span, _ } => self.span_fatal(
2572 span, "expected an identifier or `_`"
2575 slice = Some(subpat);
2578 before.push(subpat);
2585 (before, slice, after)
2588 // parse the fields of a struct-like pattern
2589 fn parse_pat_fields(&self) -> (~[ast::field_pat], bool) {
2590 let mut fields = ~[];
2591 let mut etc = false;
2592 let mut first = true;
2593 while *self.token != token::RBRACE {
2594 if first { first = false; }
2595 else { self.expect(&token::COMMA); }
2597 if *self.token == token::UNDERSCORE {
2599 if *self.token != token::RBRACE {
2602 "expected `}`, found `%s`",
2603 self.this_token_to_str()
2611 let lo1 = self.last_span.lo;
2612 let fieldname = self.parse_ident();
2613 let hi1 = self.last_span.lo;
2614 let fieldpath = ast_util::ident_to_path(mk_sp(lo1, hi1),
2617 if *self.token == token::COLON {
2619 subpat = self.parse_pat();
2621 subpat = @ast::pat {
2623 node: pat_ident(bind_infer, fieldpath, None),
2624 span: *self.last_span
2627 fields.push(ast::field_pat { ident: fieldname, pat: subpat });
2629 return (fields, etc);
2633 pub fn parse_pat(&self) -> @pat {
2634 maybe_whole!(self, nt_pat);
2636 let lo = self.span.lo;
2641 token::UNDERSCORE => {
2644 hi = self.last_span.hi;
2654 let sub = self.parse_pat();
2656 // HACK: parse @"..." as a literal of a vstore @str
2657 pat = match sub.node {
2659 node: expr_lit(@codemap::spanned {
2665 node: expr_vstore(e, expr_vstore_box),
2666 span: mk_sp(lo, hi),
2672 hi = self.last_span.hi;
2682 let sub = self.parse_pat();
2684 // HACK: parse ~"..." as a literal of a vstore ~str
2685 pat = match sub.node {
2687 node: expr_lit(@codemap::spanned {
2693 node: expr_vstore(e, expr_vstore_uniq),
2694 span: mk_sp(lo, hi),
2700 hi = self.last_span.hi;
2707 token::BINOP(token::AND) => {
2709 let lo = self.span.lo;
2711 let sub = self.parse_pat();
2713 // HACK: parse &"..." as a literal of a borrowed str
2714 pat = match sub.node {
2716 node: expr_lit(@codemap::spanned {
2717 node: lit_str(_), span: _}), _
2721 node: expr_vstore(e, expr_vstore_slice),
2726 _ => pat_region(sub)
2728 hi = self.last_span.hi;
2737 let (_, _) = self.parse_pat_fields();
2739 self.obsolete(*self.span, ObsoleteRecordPattern);
2741 hi = self.last_span.hi;
2749 // parse (pat,pat,pat,...) as tuple
2751 if *self.token == token::RPAREN {
2754 let lit = @codemap::spanned {
2756 span: mk_sp(lo, hi)};
2757 let expr = self.mk_expr(lo, hi, expr_lit(lit));
2758 pat = pat_lit(expr);
2760 let mut fields = ~[self.parse_pat()];
2761 if self.look_ahead(1, |t| *t != token::RPAREN) {
2762 while *self.token == token::COMMA {
2764 fields.push(self.parse_pat());
2767 if fields.len() == 1 { self.expect(&token::COMMA); }
2768 self.expect(&token::RPAREN);
2769 pat = pat_tup(fields);
2771 hi = self.last_span.hi;
2778 token::LBRACKET => {
2779 // parse [pat,pat,...] as vector pattern
2781 let (before, slice, after) =
2782 self.parse_pat_vec_elements();
2784 self.expect(&token::RBRACKET);
2785 pat = ast::pat_vec(before, slice, after);
2786 hi = self.last_span.hi;
2796 let tok = self.token;
2797 if !is_ident_or_path(tok)
2798 || self.is_keyword(keywords::True)
2799 || self.is_keyword(keywords::False) {
2800 // Parse an expression pattern or exp .. exp.
2802 // These expressions are limited to literals (possibly
2803 // preceded by unary-minus) or identifiers.
2804 let val = self.parse_literal_maybe_minus();
2805 if self.eat(&token::DOTDOT) {
2806 let end = if is_ident_or_path(tok) {
2807 let path = self.parse_path_with_tps(true);
2808 let hi = self.span.hi;
2809 self.mk_expr(lo, hi, expr_path(path))
2811 self.parse_literal_maybe_minus()
2813 pat = pat_range(val, end);
2817 } else if self.eat_keyword(keywords::Ref) {
2819 let mutbl = self.parse_mutability();
2820 pat = self.parse_pat_ident(bind_by_ref(mutbl));
2822 let can_be_enum_or_struct = do self.look_ahead(1) |t| {
2824 token::LPAREN | token::LBRACKET | token::LT |
2825 token::LBRACE | token::MOD_SEP => true,
2830 if self.look_ahead(1, |t| *t == token::DOTDOT) {
2831 let start = self.parse_expr_res(RESTRICT_NO_BAR_OP);
2832 self.eat(&token::DOTDOT);
2833 let end = self.parse_expr_res(RESTRICT_NO_BAR_OP);
2834 pat = pat_range(start, end);
2835 } else if is_plain_ident(&*self.token) && !can_be_enum_or_struct {
2836 let name = self.parse_path_without_tps();
2838 if self.eat(&token::AT) {
2840 sub = Some(self.parse_pat());
2845 pat = pat_ident(bind_infer, name, sub);
2847 // parse an enum pat
2848 let enum_path = self.parse_path_with_tps(true);
2853 self.parse_pat_fields();
2855 pat = pat_struct(enum_path, fields, etc);
2858 let mut args: ~[@pat] = ~[];
2861 let is_star = do self.look_ahead(1) |t| {
2863 token::BINOP(token::STAR) => true,
2868 // This is a "top constructor only" pat
2871 self.expect(&token::RPAREN);
2872 pat = pat_enum(enum_path, None);
2874 args = self.parse_unspanned_seq(
2877 seq_sep_trailing_disallowed(token::COMMA),
2880 pat = pat_enum(enum_path, Some(args));
2884 if enum_path.idents.len()==1u {
2885 // it could still be either an enum
2886 // or an identifier pattern, resolve
2887 // will sort it out:
2888 pat = pat_ident(bind_infer,
2892 pat = pat_enum(enum_path, Some(args));
2900 hi = self.last_span.hi;
2904 span: mk_sp(lo, hi),
2908 // parse ident or ident @ pat
2909 // used by the copy foo and ref foo patterns to give a good
2910 // error message when parsing mistakes like ref foo(a,b)
2911 fn parse_pat_ident(&self,
2912 binding_mode: ast::binding_mode)
2914 if !is_plain_ident(&*self.token) {
2915 self.span_fatal(*self.last_span,
2916 "expected identifier, found path");
2918 // why a path here, and not just an identifier?
2919 let name = self.parse_path_without_tps();
2920 let sub = if self.eat(&token::AT) {
2921 Some(self.parse_pat())
2926 // just to be friendly, if they write something like
2928 // we end up here with ( as the current token. This shortly
2929 // leads to a parse error. Note that if there is no explicit
2930 // binding mode then we do not end up here, because the lookahead
2931 // will direct us over to parse_enum_variant()
2932 if *self.token == token::LPAREN {
2935 "expected identifier, found enum pattern");
2938 pat_ident(binding_mode, name, sub)
2941 // parse a local variable declaration
2942 fn parse_local(&self, is_mutbl: bool) -> @Local {
2943 let lo = self.span.lo;
2944 let pat = self.parse_pat();
2946 if is_mutbl && !ast_util::pat_is_ident(pat) {
2947 self.obsolete(*self.span, ObsoleteMutWithMultipleBindings)
2953 span: mk_sp(lo, lo),
2955 if self.eat(&token::COLON) { ty = self.parse_ty(false); }
2956 let init = self.parse_initializer();
2963 span: mk_sp(lo, self.last_span.hi),
2967 // parse a "let" stmt
2968 fn parse_let(&self) -> @decl {
2969 let is_mutbl = self.eat_keyword(keywords::Mut);
2970 let lo = self.span.lo;
2971 let local = self.parse_local(is_mutbl);
2972 while self.eat(&token::COMMA) {
2973 let _ = self.parse_local(is_mutbl);
2974 self.obsolete(*self.span, ObsoleteMultipleLocalDecl);
2976 return @spanned(lo, self.last_span.hi, decl_local(local));
2979 // parse a structure field
2980 fn parse_name_and_ty(&self,
2982 attrs: ~[Attribute]) -> @struct_field {
2983 let lo = self.span.lo;
2984 if !is_plain_ident(&*self.token) {
2985 self.fatal("expected ident");
2987 let name = self.parse_ident();
2988 self.expect(&token::COLON);
2989 let ty = self.parse_ty(false);
2990 @spanned(lo, self.last_span.hi, ast::struct_field_ {
2991 kind: named_field(name, pr),
2998 // parse a statement. may include decl.
2999 // precondition: any attributes are parsed already
3000 pub fn parse_stmt(&self, item_attrs: ~[Attribute]) -> @stmt {
3001 maybe_whole!(self, nt_stmt);
3003 fn check_expected_item(p: &Parser, found_attrs: bool) {
3004 // If we have attributes then we should have an item
3006 p.span_err(*p.last_span, "expected item after attributes");
3010 let lo = self.span.lo;
3011 if self.is_keyword(keywords::Let) {
3012 check_expected_item(self, !item_attrs.is_empty());
3013 self.expect_keyword(keywords::Let);
3014 let decl = self.parse_let();
3015 return @spanned(lo, decl.span.hi, stmt_decl(decl, self.get_id()));
3016 } else if is_ident(&*self.token)
3017 && !token::is_any_keyword(self.token)
3018 && self.look_ahead(1, |t| *t == token::NOT) {
3019 // parse a macro invocation. Looks like there's serious
3020 // overlap here; if this clause doesn't catch it (and it
3021 // won't, for brace-delimited macros) it will fall through
3022 // to the macro clause of parse_item_or_view_item. This
3023 // could use some cleanup, it appears to me.
3025 // whoops! I now have a guess: I'm guessing the "parens-only"
3026 // rule here is deliberate, to allow macro users to use parens
3027 // for things that should be parsed as stmt_mac, and braces
3028 // for things that should expand into items. Tricky, and
3029 // somewhat awkward... and probably undocumented. Of course,
3030 // I could just be wrong.
3032 check_expected_item(self, !item_attrs.is_empty());
3034 // Potential trouble: if we allow macros with paths instead of
3035 // idents, we'd need to look ahead past the whole path here...
3036 let pth = self.parse_path_without_tps();
3039 let id = if *self.token == token::LPAREN {
3040 token::special_idents::invalid // no special identifier
3045 let tts = self.parse_unspanned_seq(
3049 |p| p.parse_token_tree()
3051 let hi = self.span.hi;
3053 if id == token::special_idents::invalid {
3054 return @spanned(lo, hi, stmt_mac(
3055 spanned(lo, hi, mac_invoc_tt(pth, tts)), false));
3057 // if it has a special ident, it's definitely an item
3058 return @spanned(lo, hi, stmt_decl(
3059 @spanned(lo, hi, decl_item(
3061 lo, hi, id /*id is good here*/,
3062 item_mac(spanned(lo, hi, mac_invoc_tt(pth, tts))),
3063 inherited, ~[/*no attrs*/]))),
3068 let found_attrs = !item_attrs.is_empty();
3069 match self.parse_item_or_view_item(item_attrs, false) {
3072 let decl = @spanned(lo, hi, decl_item(i));
3073 return @spanned(lo, hi, stmt_decl(decl, self.get_id()));
3075 iovi_view_item(vi) => {
3076 self.span_fatal(vi.span,
3077 "view items must be declared at the top of the block");
3079 iovi_foreign_item(_) => {
3080 self.fatal("foreign items are not allowed here");
3082 iovi_none(_) => { /* fallthrough */ }
3085 check_expected_item(self, found_attrs);
3087 // Remainder are line-expr stmts.
3088 let e = self.parse_expr_res(RESTRICT_STMT_EXPR);
3089 return @spanned(lo, e.span.hi, stmt_expr(e, self.get_id()));
3093 // is this expression a successfully-parsed statement?
3094 fn expr_is_complete(&self, e: @expr) -> bool {
3095 return *self.restriction == RESTRICT_STMT_EXPR &&
3096 !classify::expr_requires_semi_to_be_stmt(e);
3099 // parse a block. No inner attrs are allowed.
3100 pub fn parse_block(&self) -> Block {
3101 maybe_whole!(self, nt_block);
3103 let lo = self.span.lo;
3104 if self.eat_keyword(keywords::Unsafe) {
3105 self.obsolete(*self.span, ObsoleteUnsafeBlock);
3107 self.expect(&token::LBRACE);
3109 return self.parse_block_tail_(lo, DefaultBlock, ~[]);
3112 // parse a block. Inner attrs are allowed.
3113 fn parse_inner_attrs_and_block(&self)
3114 -> (~[Attribute], Block) {
3116 maybe_whole!(pair_empty self, nt_block);
3118 let lo = self.span.lo;
3119 if self.eat_keyword(keywords::Unsafe) {
3120 self.obsolete(*self.span, ObsoleteUnsafeBlock);
3122 self.expect(&token::LBRACE);
3123 let (inner, next) = self.parse_inner_attrs_and_next();
3125 (inner, self.parse_block_tail_(lo, DefaultBlock, next))
3128 // Precondition: already parsed the '{' or '#{'
3129 // I guess that also means "already parsed the 'impure'" if
3130 // necessary, and this should take a qualifier.
3131 // some blocks start with "#{"...
3132 fn parse_block_tail(&self, lo: BytePos, s: BlockCheckMode) -> Block {
3133 self.parse_block_tail_(lo, s, ~[])
3136 // parse the rest of a block expression or function body
3137 fn parse_block_tail_(&self, lo: BytePos, s: BlockCheckMode,
3138 first_item_attrs: ~[Attribute]) -> Block {
3139 let mut stmts = ~[];
3140 let mut expr = None;
3142 // wouldn't it be more uniform to parse view items only, here?
3143 let ParsedItemsAndViewItems {
3144 attrs_remaining: attrs_remaining,
3145 view_items: view_items,
3148 } = self.parse_items_and_view_items(first_item_attrs,
3151 for item in items.iter() {
3152 let decl = @spanned(item.span.lo, item.span.hi, decl_item(*item));
3153 stmts.push(@spanned(item.span.lo, item.span.hi,
3154 stmt_decl(decl, self.get_id())));
3157 let mut attributes_box = attrs_remaining;
3159 while (*self.token != token::RBRACE) {
3160 // parsing items even when they're not allowed lets us give
3161 // better error messages and recover more gracefully.
3162 attributes_box.push_all(self.parse_outer_attributes());
3165 if !attributes_box.is_empty() {
3166 self.span_err(*self.last_span, "expected item after attributes");
3167 attributes_box = ~[];
3169 self.bump(); // empty
3172 // fall through and out.
3175 let stmt = self.parse_stmt(attributes_box);
3176 attributes_box = ~[];
3178 stmt_expr(e, stmt_id) => {
3179 // expression without semicolon
3191 if classify::stmt_ends_with_semi(stmt) {
3194 "expected `;` or `}` after \
3195 expression but found `%s`",
3196 self.token_to_str(t)
3206 stmts.push(@codemap::spanned {
3207 node: stmt_semi(e, stmt_id),
3212 stmt_mac(ref m, _) => {
3213 // statement macro; might be an expr
3220 // if a block ends in `m!(arg)` without
3221 // a `;`, it must be an expr
3224 self.mk_mac_expr(stmt.span.lo,
3236 stmts.push(@codemap::spanned {
3237 node: stmt_mac((*m).clone(), true),
3242 _ => { // all other kinds of statements:
3245 if classify::stmt_ends_with_semi(stmt) {
3246 self.expect(&token::SEMI);
3254 if !attributes_box.is_empty() {
3255 self.span_err(*self.last_span, "expected item after attributes");
3258 let hi = self.span.hi;
3261 view_items: view_items,
3266 span: mk_sp(lo, hi),
3270 fn parse_optional_purity(&self) -> ast::purity {
3271 if self.eat_keyword(keywords::Pure) {
3272 self.obsolete(*self.last_span, ObsoletePurity);
3274 } else if self.eat_keyword(keywords::Unsafe) {
3281 fn parse_optional_onceness(&self) -> ast::Onceness {
3282 if self.eat_keyword(keywords::Once) { ast::Once } else { ast::Many }
3285 // matches optbounds = ( ( : ( boundseq )? )? )
3286 // where boundseq = ( bound + boundseq ) | bound
3287 // and bound = 'static | ty
3288 // Returns "None" if there's no colon (e.g. "T");
3289 // Returns "Some(Empty)" if there's a colon but nothing after (e.g. "T:")
3290 // Returns "Some(stuff)" otherwise (e.g. "T:stuff").
3291 // NB: The None/Some distinction is important for issue #7264.
3292 fn parse_optional_ty_param_bounds(&self) -> Option<OptVec<TyParamBound>> {
3293 if !self.eat(&token::COLON) {
3297 let mut result = opt_vec::Empty;
3300 token::LIFETIME(lifetime) => {
3301 if "static" == self.id_to_str(lifetime) {
3302 result.push(RegionTyParamBound);
3304 self.span_err(*self.span,
3305 "`'static` is the only permissible region bound here");
3309 token::MOD_SEP | token::IDENT(*) => {
3310 let tref = self.parse_trait_ref();
3311 result.push(TraitTyParamBound(tref));
3316 if !self.eat(&token::BINOP(token::PLUS)) {
3321 return Some(result);
3324 // matches typaram = IDENT optbounds
3325 fn parse_ty_param(&self) -> TyParam {
3326 let ident = self.parse_ident();
3327 let opt_bounds = self.parse_optional_ty_param_bounds();
3328 // For typarams we don't care about the difference b/w "<T>" and "<T:>".
3329 let bounds = opt_bounds.unwrap_or_default(opt_vec::Empty);
3330 ast::TyParam { ident: ident, id: self.get_id(), bounds: bounds }
3333 // parse a set of optional generic type parameter declarations
3334 // matches generics = ( ) | ( < > ) | ( < typaramseq ( , )? > ) | ( < lifetimes ( , )? > )
3335 // | ( < lifetimes , typaramseq ( , )? > )
3336 // where typaramseq = ( typaram ) | ( typaram , typaramseq )
3337 pub fn parse_generics(&self) -> ast::Generics {
3338 if self.eat(&token::LT) {
3339 let lifetimes = self.parse_lifetimes();
3340 let ty_params = self.parse_seq_to_gt(
3342 |p| p.parse_ty_param());
3343 ast::Generics { lifetimes: lifetimes, ty_params: ty_params }
3345 ast_util::empty_generics()
3349 // parse a generic use site
3350 fn parse_generic_values(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
3351 if !self.eat(&token::LT) {
3352 (opt_vec::Empty, ~[])
3354 self.parse_generic_values_after_lt()
3358 fn parse_generic_values_after_lt(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
3359 let lifetimes = self.parse_lifetimes();
3360 let result = self.parse_seq_to_gt(
3362 |p| p.parse_ty(false));
3363 (lifetimes, opt_vec::take_vec(result))
3366 // parse the argument list and result type of a function declaration
3367 pub fn parse_fn_decl(&self) -> fn_decl {
3368 let args_or_capture_items: ~[arg_or_capture_item] =
3369 self.parse_unspanned_seq(
3372 seq_sep_trailing_disallowed(token::COMMA),
3376 let inputs = either::lefts(args_or_capture_items);
3378 let (ret_style, ret_ty) = self.parse_ret_ty();
3386 fn is_self_ident(&self) -> bool {
3387 *self.token == token::IDENT(special_idents::self_, false)
3390 fn expect_self_ident(&self) {
3391 if !self.is_self_ident() {
3394 "expected `self` but found `%s`",
3395 self.this_token_to_str()
3402 // parse the argument list and result type of a function
3403 // that may have a self type.
3404 fn parse_fn_decl_with_self(
3407 &fn(&Parser) -> arg_or_capture_item
3408 ) -> (explicit_self, fn_decl) {
3409 fn maybe_parse_explicit_self(
3410 cnstr: &fn(v: mutability) -> ast::explicit_self_,
3412 ) -> ast::explicit_self_ {
3413 // We need to make sure it isn't a mode or a type
3414 if p.look_ahead(1, |t| token::is_keyword(keywords::Self, t)) ||
3415 ((p.look_ahead(1, |t| token::is_keyword(keywords::Const, t)) ||
3416 p.look_ahead(1, |t| token::is_keyword(keywords::Mut, t))) &&
3417 p.look_ahead(2, |t| token::is_keyword(keywords::Self, t))) {
3420 let mutability = p.parse_mutability();
3421 p.expect_self_ident();
3428 fn maybe_parse_borrowed_explicit_self(this: &Parser) -> ast::explicit_self_ {
3429 // The following things are possible to see here:
3434 // fn(&'lt mut self)
3436 // We already know that the current token is `&`.
3438 if this.look_ahead(1, |t| token::is_keyword(keywords::Self, t)) {
3440 this.expect_self_ident();
3441 sty_region(None, m_imm)
3442 } else if this.look_ahead(1, |t| this.token_is_mutability(t)) &&
3444 |t| token::is_keyword(keywords::Self,
3447 let mutability = this.parse_mutability();
3448 this.expect_self_ident();
3449 sty_region(None, mutability)
3450 } else if this.look_ahead(1, |t| this.token_is_lifetime(t)) &&
3452 |t| token::is_keyword(keywords::Self,
3455 let lifetime = this.parse_lifetime();
3456 this.expect_self_ident();
3457 sty_region(Some(lifetime), m_imm)
3458 } else if this.look_ahead(1, |t| this.token_is_lifetime(t)) &&
3459 this.look_ahead(2, |t| this.token_is_mutability(t)) &&
3460 this.look_ahead(3, |t| token::is_keyword(keywords::Self,
3463 let lifetime = this.parse_lifetime();
3464 let mutability = this.parse_mutability();
3465 this.expect_self_ident();
3466 sty_region(Some(lifetime), mutability)
3472 self.expect(&token::LPAREN);
3474 // A bit of complexity and lookahead is needed here in order to be
3475 // backwards compatible.
3476 let lo = self.span.lo;
3477 let explicit_self = match *self.token {
3478 token::BINOP(token::AND) => {
3479 maybe_parse_borrowed_explicit_self(self)
3482 maybe_parse_explicit_self(sty_box, self)
3485 maybe_parse_explicit_self(|mutability| {
3486 if mutability != m_imm {
3487 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
3492 token::IDENT(*) if self.is_self_ident() => {
3501 // If we parsed a self type, expect a comma before the argument list.
3502 let args_or_capture_items;
3503 if explicit_self != sty_static {
3507 let sep = seq_sep_trailing_disallowed(token::COMMA);
3508 args_or_capture_items = self.parse_seq_to_before_end(
3515 args_or_capture_items = ~[];
3520 "expected `,` or `)`, found `%s`",
3521 self.this_token_to_str()
3527 let sep = seq_sep_trailing_disallowed(token::COMMA);
3528 args_or_capture_items = self.parse_seq_to_before_end(
3535 self.expect(&token::RPAREN);
3537 let hi = self.span.hi;
3539 let inputs = either::lefts(args_or_capture_items);
3540 let (ret_style, ret_ty) = self.parse_ret_ty();
3542 let fn_decl = ast::fn_decl {
3548 (spanned(lo, hi, explicit_self), fn_decl)
3551 // parse the |arg, arg| header on a lambda
3552 fn parse_fn_block_decl(&self) -> fn_decl {
3553 let inputs_captures = {
3554 if self.eat(&token::OROR) {
3557 self.parse_unspanned_seq(
3558 &token::BINOP(token::OR),
3559 &token::BINOP(token::OR),
3560 seq_sep_trailing_disallowed(token::COMMA),
3561 |p| p.parse_fn_block_arg()
3565 let output = if self.eat(&token::RARROW) {
3566 self.parse_ty(false)
3568 Ty { id: self.get_id(), node: ty_infer, span: *self.span }
3572 inputs: either::lefts(inputs_captures),
3578 // parse the name and optional generic types of a function header.
3579 fn parse_fn_header(&self) -> (ident, ast::Generics) {
3580 let id = self.parse_ident();
3581 let generics = self.parse_generics();
3585 fn mk_item(&self, lo: BytePos, hi: BytePos, ident: ident,
3586 node: item_, vis: visibility,
3587 attrs: ~[Attribute]) -> @item {
3588 @ast::item { ident: ident,
3593 span: mk_sp(lo, hi) }
3596 // parse an item-position function declaration.
3597 fn parse_item_fn(&self, purity: purity, abis: AbiSet) -> item_info {
3598 let (ident, generics) = self.parse_fn_header();
3599 let decl = self.parse_fn_decl();
3600 let (inner_attrs, body) = self.parse_inner_attrs_and_block();
3602 item_fn(decl, purity, abis, generics, body),
3606 // parse a method in a trait impl
3607 fn parse_method(&self) -> @method {
3608 let attrs = self.parse_outer_attributes();
3609 let lo = self.span.lo;
3611 let visa = self.parse_visibility();
3612 let pur = self.parse_fn_purity();
3613 let ident = self.parse_ident();
3614 let generics = self.parse_generics();
3615 let (explicit_self, decl) = do self.parse_fn_decl_with_self() |p| {
3619 let (inner_attrs, body) = self.parse_inner_attrs_and_block();
3620 let hi = body.span.hi;
3621 let attrs = vec::append(attrs, inner_attrs);
3626 explicit_self: explicit_self,
3631 span: mk_sp(lo, hi),
3632 self_id: self.get_id(),
3637 // parse trait Foo { ... }
3638 fn parse_item_trait(&self) -> item_info {
3639 let ident = self.parse_ident();
3640 self.parse_region_param();
3641 let tps = self.parse_generics();
3643 // Parse traits, if necessary.
3645 if *self.token == token::COLON {
3647 traits = self.parse_trait_ref_list(&token::LBRACE);
3652 let meths = self.parse_trait_methods();
3653 (ident, item_trait(tps, traits, meths), None)
3656 // Parses two variants (with the region/type params always optional):
3657 // impl<T> Foo { ... }
3658 // impl<T> ToStr for ~[T] { ... }
3659 fn parse_item_impl(&self, visibility: ast::visibility) -> item_info {
3660 // First, parse type parameters if necessary.
3661 let generics = self.parse_generics();
3663 // This is a new-style impl declaration.
3665 let ident = special_idents::clownshoes_extensions;
3667 // Special case: if the next identifier that follows is '(', don't
3668 // allow this to be parsed as a trait.
3669 let could_be_trait = *self.token != token::LPAREN;
3672 let mut ty = self.parse_ty(false);
3674 // Parse traits, if necessary.
3675 let opt_trait = if could_be_trait && self.eat_keyword(keywords::For) {
3676 // New-style trait. Reinterpret the type as a trait.
3677 let opt_trait_ref = match ty.node {
3678 ty_path(ref path, None, node_id) => {
3680 path: /* bad */ (*path).clone(),
3685 self.span_err(ty.span,
3686 "bounded traits are only valid in type position");
3690 self.span_err(ty.span, "not a trait");
3695 ty = self.parse_ty(false);
3697 } else if self.eat(&token::COLON) {
3698 self.obsolete(*self.span, ObsoleteImplSyntax);
3699 Some(self.parse_trait_ref())
3704 // Do not allow visibility to be specified.
3705 if visibility != ast::inherited {
3706 self.obsolete(*self.span, ObsoleteImplVisibility);
3709 let mut meths = ~[];
3710 if !self.eat(&token::SEMI) {
3711 self.expect(&token::LBRACE);
3712 while !self.eat(&token::RBRACE) {
3713 meths.push(self.parse_method());
3717 (ident, item_impl(generics, opt_trait, ty, meths), None)
3720 // parse a::B<~str,int>
3721 fn parse_trait_ref(&self) -> trait_ref {
3723 path: self.parse_path_with_tps(false),
3724 ref_id: self.get_id(),
3728 // parse B + C<~str,int> + D
3729 fn parse_trait_ref_list(&self, ket: &token::Token) -> ~[trait_ref] {
3730 self.parse_seq_to_before_end(
3732 seq_sep_trailing_disallowed(token::BINOP(token::PLUS)),
3733 |p| p.parse_trait_ref()
3737 // parse struct Foo { ... }
3738 fn parse_item_struct(&self) -> item_info {
3739 let class_name = self.parse_ident();
3740 self.parse_region_param();
3741 let generics = self.parse_generics();
3742 if self.eat(&token::COLON) {
3743 self.obsolete(*self.span, ObsoleteClassTraits);
3744 let _ = self.parse_trait_ref_list(&token::LBRACE);
3747 let mut fields: ~[@struct_field];
3750 if self.eat(&token::LBRACE) {
3751 // It's a record-like struct.
3752 is_tuple_like = false;
3754 while *self.token != token::RBRACE {
3755 let r = self.parse_struct_decl_field();
3756 for struct_field in r.iter() {
3757 fields.push(*struct_field)
3760 if fields.len() == 0 {
3761 self.fatal(fmt!("Unit-like struct should be written as `struct %s;`",
3762 get_ident_interner().get(class_name.name)));
3765 } else if *self.token == token::LPAREN {
3766 // It's a tuple-like struct.
3767 is_tuple_like = true;
3768 fields = do self.parse_unspanned_seq(
3771 seq_sep_trailing_allowed(token::COMMA)
3773 let attrs = self.parse_outer_attributes();
3775 let struct_field_ = ast::struct_field_ {
3776 kind: unnamed_field,
3778 ty: p.parse_ty(false),
3781 @spanned(lo, p.span.hi, struct_field_)
3783 self.expect(&token::SEMI);
3784 } else if self.eat(&token::SEMI) {
3785 // It's a unit-like struct.
3786 is_tuple_like = true;
3791 "expected `{`, `(`, or `;` after struct name \
3793 self.this_token_to_str()
3798 let _ = self.get_id(); // XXX: Workaround for crazy bug.
3799 let new_id = self.get_id();
3801 item_struct(@ast::struct_def {
3803 ctor_id: if is_tuple_like { Some(new_id) } else { None }
3808 fn token_is_pound_or_doc_comment(&self, tok: token::Token) -> bool {
3810 token::POUND | token::DOC_COMMENT(_) => true,
3815 // parse a structure field declaration
3816 pub fn parse_single_struct_field(&self,
3818 attrs: ~[Attribute])
3820 if self.eat_obsolete_ident("let") {
3821 self.obsolete(*self.last_span, ObsoleteLet);
3824 let a_var = self.parse_name_and_ty(vis, attrs);
3827 self.obsolete(*self.span, ObsoleteFieldTerminator);
3835 self.span_fatal(*self.span,
3836 fmt!("expected `,`, or '}' but found `%s`",
3837 self.this_token_to_str()));
3843 // parse an element of a struct definition
3844 fn parse_struct_decl_field(&self) -> ~[@struct_field] {
3846 let attrs = self.parse_outer_attributes();
3848 if self.try_parse_obsolete_priv_section(attrs) {
3852 if self.eat_keyword(keywords::Priv) {
3853 return ~[self.parse_single_struct_field(private, attrs)]
3856 if self.eat_keyword(keywords::Pub) {
3857 return ~[self.parse_single_struct_field(public, attrs)];
3860 if self.try_parse_obsolete_struct_ctor() {
3864 return ~[self.parse_single_struct_field(inherited, attrs)];
3867 // parse visiility: PUB, PRIV, or nothing
3868 fn parse_visibility(&self) -> visibility {
3869 if self.eat_keyword(keywords::Pub) { public }
3870 else if self.eat_keyword(keywords::Priv) { private }
3874 fn parse_staticness(&self) -> bool {
3875 if self.eat_keyword(keywords::Static) {
3876 self.obsolete(*self.last_span, ObsoleteStaticMethod);
3883 // given a termination token and a vector of already-parsed
3884 // attributes (of length 0 or 1), parse all of the items in a module
3885 fn parse_mod_items(&self,
3887 first_item_attrs: ~[Attribute])
3889 // parse all of the items up to closing or an attribute.
3890 // view items are legal here.
3891 let ParsedItemsAndViewItems {
3892 attrs_remaining: attrs_remaining,
3893 view_items: view_items,
3894 items: starting_items,
3896 } = self.parse_items_and_view_items(first_item_attrs, true, true);
3897 let mut items: ~[@item] = starting_items;
3898 let attrs_remaining_len = attrs_remaining.len();
3900 // don't think this other loop is even necessary....
3902 let mut first = true;
3903 while *self.token != term {
3904 let mut attrs = self.parse_outer_attributes();
3906 attrs = attrs_remaining + attrs;
3909 debug!("parse_mod_items: parse_item_or_view_item(attrs=%?)",
3911 match self.parse_item_or_view_item(attrs,
3912 true /* macros allowed */) {
3913 iovi_item(item) => items.push(item),
3914 iovi_view_item(view_item) => {
3915 self.span_fatal(view_item.span,
3916 "view items must be declared at the top of \
3920 self.fatal(fmt!("expected item but found `%s`",
3921 self.this_token_to_str()));
3926 if first && attrs_remaining_len > 0u {
3927 // We parsed attributes for the first item but didn't find it
3928 self.span_err(*self.last_span, "expected item after attributes");
3931 ast::_mod { view_items: view_items, items: items }
3934 fn parse_item_const(&self) -> item_info {
3935 let m = if self.eat_keyword(keywords::Mut) {m_mutbl} else {m_imm};
3936 let id = self.parse_ident();
3937 self.expect(&token::COLON);
3938 let ty = self.parse_ty(false);
3939 self.expect(&token::EQ);
3940 let e = self.parse_expr();
3941 self.expect(&token::SEMI);
3942 (id, item_static(ty, m, e), None)
3945 // parse a `mod <foo> { ... }` or `mod <foo>;` item
3946 fn parse_item_mod(&self, outer_attrs: &[Attribute]) -> item_info {
3947 let id_span = *self.span;
3948 let id = self.parse_ident();
3949 if *self.token == token::SEMI {
3951 // This mod is in an external file. Let's go get it!
3952 let (m, attrs) = self.eval_src_mod(id, outer_attrs, id_span);
3953 (id, m, Some(attrs))
3955 self.push_mod_path(id, outer_attrs);
3956 self.expect(&token::LBRACE);
3957 let (inner, next) = self.parse_inner_attrs_and_next();
3958 let m = self.parse_mod_items(token::RBRACE, next);
3959 self.expect(&token::RBRACE);
3960 self.pop_mod_path();
3961 (id, item_mod(m), Some(inner))
3965 fn push_mod_path(&self, id: ident, attrs: &[Attribute]) {
3966 let default_path = token::interner_get(id.name);
3967 let file_path = match ::attr::first_attr_value_str_by_name(attrs,
3970 None => default_path
3972 self.mod_path_stack.push(file_path)
3975 fn pop_mod_path(&self) {
3976 self.mod_path_stack.pop();
3979 // read a module from a source file.
3980 fn eval_src_mod(&self,
3982 outer_attrs: &[ast::Attribute],
3984 -> (ast::item_, ~[ast::Attribute]) {
3985 let prefix = Path(self.sess.cm.span_to_filename(*self.span));
3986 let prefix = prefix.dir_path();
3987 let mod_path_stack = &*self.mod_path_stack;
3988 let mod_path = Path(".").push_many(*mod_path_stack);
3989 let dir_path = prefix.push_many(mod_path.components);
3990 let file_path = match ::attr::first_attr_value_str_by_name(
3991 outer_attrs, "path") {
3994 if !path.is_absolute {
4001 let mod_name = token::interner_get(id.name).to_owned();
4002 let default_path_str = mod_name + ".rs";
4003 let secondary_path_str = mod_name + "/mod.rs";
4004 let default_path = dir_path.push(default_path_str);
4005 let secondary_path = dir_path.push(secondary_path_str);
4006 let default_exists = default_path.exists();
4007 let secondary_exists = secondary_path.exists();
4008 match (default_exists, secondary_exists) {
4009 (true, false) => default_path,
4010 (false, true) => secondary_path,
4012 self.span_fatal(id_sp, fmt!("file not found for module `%s`", mod_name));
4015 self.span_fatal(id_sp,
4016 fmt!("file for module `%s` found at both %s and %s",
4017 mod_name, default_path_str, secondary_path_str));
4023 self.eval_src_mod_from_path(file_path,
4024 outer_attrs.to_owned(),
4028 fn eval_src_mod_from_path(&self,
4030 outer_attrs: ~[ast::Attribute],
4031 id_sp: span) -> (ast::item_, ~[ast::Attribute]) {
4032 let full_path = path.normalize();
4034 let maybe_i = do self.sess.included_mod_stack.iter().position |p| { *p == full_path };
4037 let stack = &self.sess.included_mod_stack;
4038 let mut err = ~"circular modules: ";
4039 for p in stack.slice(i, stack.len()).iter() {
4040 err.push_str(p.to_str());
4041 err.push_str(" -> ");
4043 err.push_str(full_path.to_str());
4044 self.span_fatal(id_sp, err);
4048 self.sess.included_mod_stack.push(full_path.clone());
4051 new_sub_parser_from_file(self.sess,
4055 let (inner, next) = p0.parse_inner_attrs_and_next();
4056 let mod_attrs = vec::append(outer_attrs, inner);
4057 let first_item_outer_attrs = next;
4058 let m0 = p0.parse_mod_items(token::EOF, first_item_outer_attrs);
4059 self.sess.included_mod_stack.pop();
4060 return (ast::item_mod(m0), mod_attrs);
4063 // parse a function declaration from a foreign module
4064 fn parse_item_foreign_fn(&self, attrs: ~[Attribute]) -> @foreign_item {
4065 let lo = self.span.lo;
4066 let vis = self.parse_visibility();
4068 // Parse obsolete purity.
4069 let purity = self.parse_fn_purity();
4070 if purity != impure_fn {
4071 self.obsolete(*self.last_span, ObsoleteUnsafeExternFn);
4074 let (ident, generics) = self.parse_fn_header();
4075 let decl = self.parse_fn_decl();
4076 let hi = self.span.hi;
4077 self.expect(&token::SEMI);
4078 @ast::foreign_item { ident: ident,
4080 node: foreign_item_fn(decl, generics),
4082 span: mk_sp(lo, hi),
4086 // parse a const definition from a foreign module
4087 fn parse_item_foreign_const(&self, vis: ast::visibility,
4088 attrs: ~[Attribute]) -> @foreign_item {
4089 let lo = self.span.lo;
4091 // XXX: Obsolete; remove after snap.
4092 if self.eat_keyword(keywords::Const) {
4093 self.obsolete(*self.last_span, ObsoleteConstItem);
4095 self.expect_keyword(keywords::Static);
4097 let mutbl = self.eat_keyword(keywords::Mut);
4099 let ident = self.parse_ident();
4100 self.expect(&token::COLON);
4101 let ty = self.parse_ty(false);
4102 let hi = self.span.hi;
4103 self.expect(&token::SEMI);
4104 @ast::foreign_item { ident: ident,
4106 node: foreign_item_static(ty, mutbl),
4108 span: mk_sp(lo, hi),
4112 // parse safe/unsafe and fn
4113 fn parse_fn_purity(&self) -> purity {
4114 if self.eat_keyword(keywords::Fn) { impure_fn }
4115 else if self.eat_keyword(keywords::Pure) {
4116 self.obsolete(*self.last_span, ObsoletePurity);
4117 self.expect_keyword(keywords::Fn);
4118 // NB: We parse this as impure for bootstrapping purposes.
4120 } else if self.eat_keyword(keywords::Unsafe) {
4121 self.expect_keyword(keywords::Fn);
4124 else { self.unexpected(); }
4128 // at this point, this is essentially a wrapper for
4129 // parse_foreign_items.
4130 fn parse_foreign_mod_items(&self,
4131 sort: ast::foreign_mod_sort,
4133 first_item_attrs: ~[Attribute])
4135 let ParsedItemsAndViewItems {
4136 attrs_remaining: attrs_remaining,
4137 view_items: view_items,
4139 foreign_items: foreign_items
4140 } = self.parse_foreign_items(first_item_attrs, true);
4141 if (! attrs_remaining.is_empty()) {
4142 self.span_err(*self.last_span,
4143 "expected item after attributes");
4145 assert!(*self.token == token::RBRACE);
4149 view_items: view_items,
4150 items: foreign_items
4154 // parse extern foo; or extern mod foo { ... } or extern { ... }
4155 fn parse_item_foreign_mod(&self,
4157 opt_abis: Option<AbiSet>,
4158 visibility: visibility,
4159 attrs: ~[Attribute],
4160 items_allowed: bool)
4161 -> item_or_view_item {
4162 let mut must_be_named_mod = false;
4163 if self.is_keyword(keywords::Mod) {
4164 must_be_named_mod = true;
4165 self.expect_keyword(keywords::Mod);
4166 } else if *self.token != token::LBRACE {
4167 self.span_fatal(*self.span,
4168 fmt!("expected `{` or `mod` but found `%s`",
4169 self.this_token_to_str()));
4172 let (sort, ident) = match *self.token {
4173 token::IDENT(*) => (ast::named, self.parse_ident()),
4175 if must_be_named_mod {
4176 self.span_fatal(*self.span,
4177 fmt!("expected foreign module name but \
4179 self.this_token_to_str()));
4183 special_idents::clownshoes_foreign_mod)
4187 // extern mod foo { ... } or extern { ... }
4188 if items_allowed && self.eat(&token::LBRACE) {
4189 // `extern mod foo { ... }` is obsolete.
4190 if sort == ast::named {
4191 self.obsolete(*self.last_span, ObsoleteNamedExternModule);
4194 // Do not allow visibility to be specified.
4195 if visibility != ast::inherited {
4196 self.obsolete(*self.last_span, ObsoleteExternVisibility);
4199 let abis = opt_abis.unwrap_or_default(AbiSet::C());
4201 let (inner, next) = self.parse_inner_attrs_and_next();
4202 let m = self.parse_foreign_mod_items(sort, abis, next);
4203 self.expect(&token::RBRACE);
4205 return iovi_item(self.mk_item(lo,
4208 item_foreign_mod(m),
4210 maybe_append(attrs, Some(inner))));
4213 if opt_abis.is_some() {
4214 self.span_err(*self.span, "an ABI may not be specified here");
4218 let metadata = self.parse_optional_meta();
4219 self.expect(&token::SEMI);
4220 iovi_view_item(ast::view_item {
4221 node: view_item_extern_mod(ident, metadata, self.get_id()),
4224 span: mk_sp(lo, self.last_span.hi)
4228 // parse type Foo = Bar;
4229 fn parse_item_type(&self) -> item_info {
4230 let ident = self.parse_ident();
4231 self.parse_region_param();
4232 let tps = self.parse_generics();
4233 self.expect(&token::EQ);
4234 let ty = self.parse_ty(false);
4235 self.expect(&token::SEMI);
4236 (ident, item_ty(ty, tps), None)
4239 // parse obsolete region parameter
4240 fn parse_region_param(&self) {
4241 if self.eat(&token::BINOP(token::SLASH)) {
4242 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
4243 self.expect(&token::BINOP(token::AND));
4247 // parse a structure-like enum variant definition
4248 // this should probably be renamed or refactored...
4249 fn parse_struct_def(&self) -> @struct_def {
4250 let mut fields: ~[@struct_field] = ~[];
4251 while *self.token != token::RBRACE {
4252 let r = self.parse_struct_decl_field();
4253 for struct_field in r.iter() {
4254 fields.push(*struct_field);
4259 return @ast::struct_def {
4265 // parse the part of an "enum" decl following the '{'
4266 fn parse_enum_def(&self, _generics: &ast::Generics) -> enum_def {
4267 let mut variants = ~[];
4268 let mut all_nullary = true;
4269 let mut have_disr = false;
4270 while *self.token != token::RBRACE {
4271 let variant_attrs = self.parse_outer_attributes();
4272 let vlo = self.span.lo;
4274 let vis = self.parse_visibility();
4279 let mut disr_expr = None;
4280 ident = self.parse_ident();
4281 if self.eat(&token::LBRACE) {
4282 // Parse a struct variant.
4283 all_nullary = false;
4284 kind = struct_variant_kind(self.parse_struct_def());
4285 } else if *self.token == token::LPAREN {
4286 all_nullary = false;
4287 let arg_tys = self.parse_unspanned_seq(
4290 seq_sep_trailing_disallowed(token::COMMA),
4291 |p| p.parse_ty(false)
4293 for ty in arg_tys.consume_iter() {
4294 args.push(ast::variant_arg {
4299 kind = tuple_variant_kind(args);
4300 } else if self.eat(&token::EQ) {
4302 disr_expr = Some(self.parse_expr());
4303 kind = tuple_variant_kind(args);
4305 kind = tuple_variant_kind(~[]);
4308 let vr = ast::variant_ {
4310 attrs: variant_attrs,
4313 disr_expr: disr_expr,
4316 variants.push(spanned(vlo, self.last_span.hi, vr));
4318 if !self.eat(&token::COMMA) { break; }
4320 self.expect(&token::RBRACE);
4321 if (have_disr && !all_nullary) {
4322 self.fatal("discriminator values can only be used with a c-like \
4326 ast::enum_def { variants: variants }
4329 // parse an "enum" declaration
4330 fn parse_item_enum(&self) -> item_info {
4331 let id = self.parse_ident();
4332 self.parse_region_param();
4333 let generics = self.parse_generics();
4335 if *self.token == token::EQ {
4338 let ty = self.parse_ty(false);
4339 self.expect(&token::SEMI);
4340 let variant = spanned(ty.span.lo, ty.span.hi, ast::variant_ {
4343 kind: tuple_variant_kind(
4344 ~[ast::variant_arg {ty: ty, id: self.get_id()}]
4351 self.obsolete(*self.last_span, ObsoleteNewtypeEnum);
4356 ast::enum_def { variants: ~[variant] },
4362 self.expect(&token::LBRACE);
4364 let enum_definition = self.parse_enum_def(&generics);
4365 (id, item_enum(enum_definition, generics), None)
4368 fn parse_fn_ty_sigil(&self) -> Option<Sigil> {
4378 token::BINOP(token::AND) => {
4388 fn fn_expr_lookahead(&self, tok: &token::Token) -> bool {
4390 token::LPAREN | token::AT | token::TILDE | token::BINOP(_) => true,
4395 // parse a string as an ABI spec on an extern type or module
4396 fn parse_opt_abis(&self) -> Option<AbiSet> {
4398 token::LIT_STR(s) => {
4400 let the_string = ident_to_str(&s);
4401 let mut abis = AbiSet::empty();
4402 for word in the_string.word_iter() {
4403 match abi::lookup(word) {
4405 if abis.contains(abi) {
4408 fmt!("ABI `%s` appears twice",
4418 fmt!("illegal ABI: \
4419 expected one of [%s], \
4421 abi::all_names().connect(", "),
4435 // parse one of the items or view items allowed by the
4436 // flags; on failure, return iovi_none.
4437 // NB: this function no longer parses the items inside an
4439 fn parse_item_or_view_item(&self,
4440 attrs: ~[Attribute],
4441 macros_allowed: bool)
4442 -> item_or_view_item {
4443 maybe_whole!(iovi self, nt_item);
4444 let lo = self.span.lo;
4446 let visibility = self.parse_visibility();
4448 // must be a view item:
4449 if self.eat_keyword(keywords::Use) {
4450 // USE ITEM (iovi_view_item)
4451 let view_item = self.parse_use();
4452 self.expect(&token::SEMI);
4453 return iovi_view_item(ast::view_item {
4457 span: mk_sp(lo, self.last_span.hi)
4460 // either a view item or an item:
4461 if self.eat_keyword(keywords::Extern) {
4462 let opt_abis = self.parse_opt_abis();
4464 if self.eat_keyword(keywords::Fn) {
4465 // EXTERN FUNCTION ITEM
4466 let abis = opt_abis.unwrap_or_default(AbiSet::C());
4467 let (ident, item_, extra_attrs) =
4468 self.parse_item_fn(extern_fn, abis);
4469 return iovi_item(self.mk_item(lo, self.last_span.hi, ident,
4474 // EXTERN MODULE ITEM (iovi_view_item)
4475 return self.parse_item_foreign_mod(lo, opt_abis, visibility, attrs,
4479 // the rest are all guaranteed to be items:
4480 if (self.is_keyword(keywords::Const) ||
4481 (self.is_keyword(keywords::Static) &&
4482 self.look_ahead(1, |t| !token::is_keyword(keywords::Fn, t)))) {
4483 // CONST / STATIC ITEM
4484 if self.is_keyword(keywords::Const) {
4485 self.obsolete(*self.span, ObsoleteConstItem);
4488 let (ident, item_, extra_attrs) = self.parse_item_const();
4489 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4491 maybe_append(attrs, extra_attrs)));
4493 if self.is_keyword(keywords::Fn) &&
4494 self.look_ahead(1, |f| !self.fn_expr_lookahead(f)) {
4497 let (ident, item_, extra_attrs) =
4498 self.parse_item_fn(impure_fn, AbiSet::Rust());
4499 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4501 maybe_append(attrs, extra_attrs)));
4503 if self.eat_keyword(keywords::Pure) {
4504 // PURE FUNCTION ITEM (obsolete)
4505 self.obsolete(*self.last_span, ObsoletePurity);
4506 self.expect_keyword(keywords::Fn);
4507 let (ident, item_, extra_attrs) =
4508 self.parse_item_fn(impure_fn, AbiSet::Rust());
4509 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4511 maybe_append(attrs, extra_attrs)));
4513 if self.is_keyword(keywords::Unsafe)
4514 && self.look_ahead(1u, |t| *t != token::LBRACE) {
4515 // UNSAFE FUNCTION ITEM
4517 self.expect_keyword(keywords::Fn);
4518 let (ident, item_, extra_attrs) =
4519 self.parse_item_fn(unsafe_fn, AbiSet::Rust());
4520 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4522 maybe_append(attrs, extra_attrs)));
4524 if self.eat_keyword(keywords::Mod) {
4526 let (ident, item_, extra_attrs) = self.parse_item_mod(attrs);
4527 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4529 maybe_append(attrs, extra_attrs)));
4531 if self.eat_keyword(keywords::Type) {
4533 let (ident, item_, extra_attrs) = self.parse_item_type();
4534 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4536 maybe_append(attrs, extra_attrs)));
4538 if self.eat_keyword(keywords::Enum) {
4540 let (ident, item_, extra_attrs) = self.parse_item_enum();
4541 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4543 maybe_append(attrs, extra_attrs)));
4545 if self.eat_keyword(keywords::Trait) {
4547 let (ident, item_, extra_attrs) = self.parse_item_trait();
4548 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4550 maybe_append(attrs, extra_attrs)));
4552 if self.eat_keyword(keywords::Impl) {
4554 let (ident, item_, extra_attrs) =
4555 self.parse_item_impl(visibility);
4556 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4558 maybe_append(attrs, extra_attrs)));
4560 if self.eat_keyword(keywords::Struct) {
4562 let (ident, item_, extra_attrs) = self.parse_item_struct();
4563 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4565 maybe_append(attrs, extra_attrs)));
4567 self.parse_macro_use_or_failure(attrs,macros_allowed,lo,visibility)
4570 // parse a foreign item; on failure, return iovi_none.
4571 fn parse_foreign_item(&self,
4572 attrs: ~[Attribute],
4573 macros_allowed: bool)
4574 -> item_or_view_item {
4575 maybe_whole!(iovi self, nt_item);
4576 let lo = self.span.lo;
4578 let visibility = self.parse_visibility();
4580 if (self.is_keyword(keywords::Const) || self.is_keyword(keywords::Static)) {
4581 // FOREIGN CONST ITEM
4582 let item = self.parse_item_foreign_const(visibility, attrs);
4583 return iovi_foreign_item(item);
4585 if (self.is_keyword(keywords::Fn) || self.is_keyword(keywords::Pure) ||
4586 self.is_keyword(keywords::Unsafe)) {
4587 // FOREIGN FUNCTION ITEM
4588 let item = self.parse_item_foreign_fn(attrs);
4589 return iovi_foreign_item(item);
4591 self.parse_macro_use_or_failure(attrs,macros_allowed,lo,visibility)
4594 // this is the fall-through for parsing items.
4595 fn parse_macro_use_or_failure(
4597 attrs: ~[Attribute],
4598 macros_allowed: bool,
4600 visibility : visibility
4601 ) -> item_or_view_item {
4602 if macros_allowed && !token::is_any_keyword(self.token)
4603 && self.look_ahead(1, |t| *t == token::NOT)
4604 && (self.look_ahead(2, |t| is_plain_ident(t))
4605 || self.look_ahead(2, |t| *t == token::LPAREN)
4606 || self.look_ahead(2, |t| *t == token::LBRACE)) {
4607 // MACRO INVOCATION ITEM
4608 if attrs.len() > 0 {
4609 self.fatal("attrs on macros are not yet supported");
4613 let pth = self.parse_path_without_tps();
4614 self.expect(&token::NOT);
4616 // a 'special' identifier (like what `macro_rules!` uses)
4617 // is optional. We should eventually unify invoc syntax
4619 let id = if is_plain_ident(&*self.token) {
4622 token::special_idents::invalid // no special identifier
4624 // eat a matched-delimiter token tree:
4625 let tts = match *self.token {
4626 token::LPAREN | token::LBRACE => {
4627 let ket = token::flip_delimiter(&*self.token);
4629 self.parse_seq_to_end(&ket,
4631 |p| p.parse_token_tree())
4633 _ => self.fatal("expected open delimiter")
4635 // single-variant-enum... :
4636 let m = ast::mac_invoc_tt(pth, tts);
4637 let m: ast::mac = codemap::spanned { node: m,
4638 span: mk_sp(self.span.lo,
4640 let item_ = item_mac(m);
4641 return iovi_item(self.mk_item(lo, self.last_span.hi, id, item_,
4642 visibility, attrs));
4645 // FAILURE TO PARSE ITEM
4646 if visibility != inherited {
4647 let mut s = ~"unmatched visibility `";
4648 if visibility == public {
4654 self.span_fatal(*self.last_span, s);
4656 return iovi_none(attrs);
4659 pub fn parse_item(&self, attrs: ~[Attribute]) -> Option<@ast::item> {
4660 match self.parse_item_or_view_item(attrs, true) {
4661 iovi_none(_) => None,
4662 iovi_view_item(_) =>
4663 self.fatal("view items are not allowed here"),
4664 iovi_foreign_item(_) =>
4665 self.fatal("foreign items are not allowed here"),
4666 iovi_item(item) => Some(item)
4670 // parse, e.g., "use a::b::{z,y}"
4671 fn parse_use(&self) -> view_item_ {
4672 return view_item_use(self.parse_view_paths());
4676 // matches view_path : MOD? IDENT EQ non_global_path
4677 // | MOD? non_global_path MOD_SEP LBRACE RBRACE
4678 // | MOD? non_global_path MOD_SEP LBRACE ident_seq RBRACE
4679 // | MOD? non_global_path MOD_SEP STAR
4680 // | MOD? non_global_path
4681 fn parse_view_path(&self) -> @view_path {
4682 let lo = self.span.lo;
4684 let first_ident = self.parse_ident();
4685 let mut path = ~[first_ident];
4686 debug!("parsed view_path: %s", self.id_to_str(first_ident));
4691 path = ~[self.parse_ident()];
4692 while *self.token == token::MOD_SEP {
4694 let id = self.parse_ident();
4697 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4702 return @spanned(lo, self.span.hi,
4703 view_path_simple(first_ident,
4709 // foo::bar or foo::{a,b,c} or foo::*
4710 while *self.token == token::MOD_SEP {
4714 token::IDENT(i, _) => {
4719 // foo::bar::{a,b,c}
4721 let idents = self.parse_unspanned_seq(
4724 seq_sep_trailing_allowed(token::COMMA),
4725 |p| p.parse_path_list_ident()
4727 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4732 return @spanned(lo, self.span.hi,
4733 view_path_list(path, idents, self.get_id()));
4737 token::BINOP(token::STAR) => {
4739 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4744 return @spanned(lo, self.span.hi,
4745 view_path_glob(path, self.get_id()));
4754 let last = path[path.len() - 1u];
4755 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4762 view_path_simple(last, path, self.get_id()));
4765 // matches view_paths = view_path | view_path , view_paths
4766 fn parse_view_paths(&self) -> ~[@view_path] {
4767 let mut vp = ~[self.parse_view_path()];
4768 while *self.token == token::COMMA {
4770 vp.push(self.parse_view_path());
4775 fn is_view_item(&self) -> bool {
4776 if !self.is_keyword(keywords::Pub) && !self.is_keyword(keywords::Priv) {
4777 token::is_keyword(keywords::Use, self.token)
4778 || (token::is_keyword(keywords::Extern, self.token) &&
4780 |t| token::is_keyword(keywords::Mod, t)))
4782 self.look_ahead(1, |t| token::is_keyword(keywords::Use, t))
4783 || (self.look_ahead(1,
4784 |t| token::is_keyword(keywords::Extern,
4787 |t| token::is_keyword(keywords::Mod, t)))
4791 // parse a view item.
4794 attrs: ~[Attribute],
4797 let lo = self.span.lo;
4798 let node = if self.eat_keyword(keywords::Use) {
4800 } else if self.eat_keyword(keywords::Extern) {
4801 self.expect_keyword(keywords::Mod);
4802 let ident = self.parse_ident();
4803 let metadata = self.parse_optional_meta();
4804 view_item_extern_mod(ident, metadata, self.get_id())
4806 self.bug("expected view item");
4808 self.expect(&token::SEMI);
4809 ast::view_item { node: node,
4812 span: mk_sp(lo, self.last_span.hi) }
4815 // Parses a sequence of items. Stops when it finds program
4816 // text that can't be parsed as an item
4817 // - mod_items uses extern_mod_allowed = true
4818 // - block_tail_ uses extern_mod_allowed = false
4819 fn parse_items_and_view_items(&self,
4820 first_item_attrs: ~[Attribute],
4821 mut extern_mod_allowed: bool,
4822 macros_allowed: bool)
4823 -> ParsedItemsAndViewItems {
4824 let mut attrs = vec::append(first_item_attrs,
4825 self.parse_outer_attributes());
4826 // First, parse view items.
4827 let mut view_items : ~[ast::view_item] = ~[];
4828 let mut items = ~[];
4830 // I think this code would probably read better as a single
4831 // loop with a mutable three-state-variable (for extern mods,
4832 // view items, and regular items) ... except that because
4833 // of macros, I'd like to delay that entire check until later.
4835 match self.parse_item_or_view_item(attrs, macros_allowed) {
4836 iovi_none(attrs) => {
4837 return ParsedItemsAndViewItems {
4838 attrs_remaining: attrs,
4839 view_items: view_items,
4844 iovi_view_item(view_item) => {
4845 match view_item.node {
4846 view_item_use(*) => {
4847 // `extern mod` must precede `use`.
4848 extern_mod_allowed = false;
4850 view_item_extern_mod(*)
4851 if !extern_mod_allowed => {
4852 self.span_err(view_item.span,
4853 "\"extern mod\" declarations are not allowed here");
4855 view_item_extern_mod(*) => {}
4857 view_items.push(view_item);
4859 iovi_item(item) => {
4861 attrs = self.parse_outer_attributes();
4864 iovi_foreign_item(_) => {
4868 attrs = self.parse_outer_attributes();
4871 // Next, parse items.
4873 match self.parse_item_or_view_item(attrs, macros_allowed) {
4874 iovi_none(returned_attrs) => {
4875 attrs = returned_attrs;
4878 iovi_view_item(view_item) => {
4879 attrs = self.parse_outer_attributes();
4880 self.span_err(view_item.span,
4881 "`use` and `extern mod` declarations must precede items");
4883 iovi_item(item) => {
4884 attrs = self.parse_outer_attributes();
4887 iovi_foreign_item(_) => {
4893 ParsedItemsAndViewItems {
4894 attrs_remaining: attrs,
4895 view_items: view_items,
4901 // Parses a sequence of foreign items. Stops when it finds program
4902 // text that can't be parsed as an item
4903 fn parse_foreign_items(&self, first_item_attrs: ~[Attribute],
4904 macros_allowed: bool)
4905 -> ParsedItemsAndViewItems {
4906 let mut attrs = vec::append(first_item_attrs,
4907 self.parse_outer_attributes());
4908 let mut foreign_items = ~[];
4910 match self.parse_foreign_item(attrs, macros_allowed) {
4911 iovi_none(returned_attrs) => {
4912 if *self.token == token::RBRACE {
4913 attrs = returned_attrs;
4918 iovi_view_item(view_item) => {
4919 // I think this can't occur:
4920 self.span_err(view_item.span,
4921 "`use` and `extern mod` declarations must precede items");
4923 iovi_item(item) => {
4924 // FIXME #5668: this will occur for a macro invocation:
4925 self.span_fatal(item.span, "macros cannot expand to foreign items");
4927 iovi_foreign_item(foreign_item) => {
4928 foreign_items.push(foreign_item);
4931 attrs = self.parse_outer_attributes();
4934 ParsedItemsAndViewItems {
4935 attrs_remaining: attrs,
4938 foreign_items: foreign_items
4942 // Parses a source module as a crate. This is the main
4943 // entry point for the parser.
4944 pub fn parse_crate_mod(&self) -> @Crate {
4945 let lo = self.span.lo;
4946 // parse the crate's inner attrs, maybe (oops) one
4947 // of the attrs of an item:
4948 let (inner, next) = self.parse_inner_attrs_and_next();
4949 let first_item_outer_attrs = next;
4950 // parse the items inside the crate:
4951 let m = self.parse_mod_items(token::EOF, first_item_outer_attrs);
4956 config: self.cfg.clone(),
4957 span: mk_sp(lo, self.span.lo)
4961 pub fn parse_str(&self) -> @str {
4963 token::LIT_STR(s) => {
4967 _ => self.fatal("expected string literal")