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.
15 use ast::{Sigil, BorrowedSigil, ManagedSigil, OwnedSigil};
16 use ast::{CallSugar, NoSugar, DoSugar};
17 use ast::{TyBareFn, TyClosure};
18 use ast::{RegionTyParamBound, TraitTyParamBound};
19 use ast::{provided, public, purity};
20 use ast::{_mod, add, arg, arm, Attribute, bind_by_ref, bind_infer};
21 use ast::{bitand, bitor, bitxor, Block};
22 use ast::{BlockCheckMode, box};
23 use ast::{Crate, CrateConfig, decl, decl_item};
24 use ast::{decl_local, DefaultBlock, deref, div, enum_def, explicit_self};
25 use ast::{expr, expr_, expr_addr_of, expr_match, expr_again};
26 use ast::{expr_assign, expr_assign_op, expr_binary, expr_block};
27 use ast::{expr_break, expr_call, expr_cast, expr_do_body};
28 use ast::{expr_field, expr_fn_block, expr_if, expr_index};
29 use ast::{expr_lit, expr_log, expr_loop, expr_mac};
30 use ast::{expr_method_call, expr_paren, expr_path, expr_repeat};
31 use ast::{expr_ret, expr_self, expr_struct, expr_tup, expr_unary};
32 use ast::{expr_vec, expr_vstore, expr_vstore_mut_box};
33 use ast::{expr_vstore_slice, expr_vstore_box};
34 use ast::{expr_vstore_mut_slice, expr_while, expr_for_loop, extern_fn, Field, fn_decl};
35 use ast::{expr_vstore_uniq, Onceness, Once, Many};
36 use ast::{foreign_item, foreign_item_static, foreign_item_fn, foreign_mod};
37 use ast::{ident, impure_fn, inherited, item, item_, item_static};
38 use ast::{item_enum, item_fn, item_foreign_mod, item_impl};
39 use ast::{item_mac, item_mod, item_struct, item_trait, item_ty, lit, lit_};
40 use ast::{lit_bool, lit_float, lit_float_unsuffixed, lit_int};
41 use ast::{lit_int_unsuffixed, lit_nil, lit_str, lit_uint, Local, m_const};
42 use ast::{m_imm, m_mutbl, mac_, mac_invoc_tt, matcher, match_nonterminal};
43 use ast::{match_seq, match_tok, method, mt, mul, mutability};
44 use ast::{named_field, neg, NodeId, noreturn, not, pat, pat_box, pat_enum};
45 use ast::{pat_ident, pat_lit, pat_range, pat_region, pat_struct};
46 use ast::{pat_tup, pat_uniq, pat_wild, private};
47 use ast::{rem, required};
48 use ast::{ret_style, return_val, shl, shr, stmt, stmt_decl};
49 use ast::{stmt_expr, stmt_semi, stmt_mac, struct_def, struct_field};
50 use ast::{struct_variant_kind, subtract};
51 use ast::{sty_box, sty_region, sty_static, sty_uniq, sty_value};
52 use ast::{token_tree, trait_method, trait_ref, tt_delim, tt_seq, tt_tok};
53 use ast::{tt_nonterminal, tuple_variant_kind, Ty, ty_, ty_bot, ty_box};
54 use ast::{TypeField, ty_fixed_length_vec, ty_closure, ty_bare_fn};
55 use ast::{ty_infer, TypeMethod};
56 use ast::{ty_nil, TyParam, TyParamBound, ty_path, ty_ptr, ty_rptr};
57 use ast::{ty_tup, ty_u32, ty_uniq, ty_vec, uniq};
58 use ast::{unnamed_field, UnsafeBlock, unsafe_fn, view_item};
59 use ast::{view_item_, view_item_extern_mod, view_item_use};
60 use ast::{view_path, view_path_glob, view_path_list, view_path_simple};
63 use ast_util::{as_prec, operator_prec};
65 use codemap::{span, BytePos, spanned, mk_sp};
67 use parse::attr::parser_attr;
69 use parse::common::{SeqSep, seq_sep_none};
70 use parse::common::{seq_sep_trailing_disallowed, seq_sep_trailing_allowed};
71 use parse::lexer::reader;
72 use parse::lexer::TokenAndSpan;
73 use parse::obsolete::{ObsoleteClassTraits};
74 use parse::obsolete::{ObsoleteLet, ObsoleteFieldTerminator};
75 use parse::obsolete::{ObsoleteMoveInit, ObsoleteBinaryMove, ObsoleteSwap};
76 use parse::obsolete::ObsoleteSyntax;
77 use parse::obsolete::{ObsoleteUnsafeBlock, ObsoleteImplSyntax};
78 use parse::obsolete::{ObsoleteMutOwnedPointer};
79 use parse::obsolete::{ObsoleteMutVector, ObsoleteImplVisibility};
80 use parse::obsolete::{ObsoleteRecordType, ObsoleteRecordPattern};
81 use parse::obsolete::{ObsoletePostFnTySigil};
82 use parse::obsolete::{ObsoleteBareFnType, ObsoleteNewtypeEnum};
83 use parse::obsolete::ObsoleteMode;
84 use parse::obsolete::{ObsoleteLifetimeNotation, ObsoleteConstManagedPointer};
85 use parse::obsolete::{ObsoletePurity, ObsoleteStaticMethod};
86 use parse::obsolete::{ObsoleteConstItem, ObsoleteFixedLengthVectorType};
87 use parse::obsolete::{ObsoleteNamedExternModule, ObsoleteMultipleLocalDecl};
88 use parse::obsolete::{ObsoleteMutWithMultipleBindings};
89 use parse::obsolete::{ObsoleteExternVisibility, ObsoleteUnsafeExternFn};
90 use parse::obsolete::{ParserObsoleteMethods, ObsoletePrivVisibility};
91 use parse::token::{can_begin_expr, get_ident_interner, ident_to_str, is_ident};
92 use parse::token::{is_ident_or_path};
93 use parse::token::{is_plain_ident, INTERPOLATED, keywords, special_idents};
94 use parse::token::{token_to_binop};
96 use parse::{new_sub_parser_from_file, next_node_id, ParseSess};
100 use std::either::Either;
102 use std::hashmap::HashSet;
111 RESTRICT_NO_BAR_OR_DOUBLEBAR_OP,
114 type arg_or_capture_item = Either<arg, ()>;
115 type item_info = (ident, item_, Option<~[Attribute]>);
117 pub enum item_or_view_item {
118 // Indicates a failure to parse any kind of item. The attributes are
120 iovi_none(~[Attribute]),
122 iovi_foreign_item(@foreign_item),
123 iovi_view_item(view_item)
127 enum view_item_parse_mode {
128 VIEW_ITEMS_AND_ITEMS_ALLOWED,
129 FOREIGN_ITEMS_ALLOWED,
130 IMPORTS_AND_ITEMS_ALLOWED
133 /* The expr situation is not as complex as I thought it would be.
134 The important thing is to make sure that lookahead doesn't balk
135 at INTERPOLATED tokens */
136 macro_rules! maybe_whole_expr (
139 // This horrible convolution is brought to you by
140 // @mut, have a terrible day
141 let ret = match *($p).token {
142 INTERPOLATED(token::nt_expr(e)) => {
145 INTERPOLATED(token::nt_path(ref pt)) => {
149 expr_path(/* bad */ (*pt).clone())))
164 macro_rules! maybe_whole (
165 ($p:expr, $constructor:ident) => (
167 let __found__ = match *($p).token {
168 INTERPOLATED(token::$constructor(_)) => {
169 Some(($p).bump_and_get())
174 Some(INTERPOLATED(token::$constructor(x))) => {
181 (deref $p:expr, $constructor:ident) => (
183 let __found__ = match *($p).token {
184 INTERPOLATED(token::$constructor(_)) => {
185 Some(($p).bump_and_get())
190 Some(INTERPOLATED(token::$constructor(x))) => {
197 (Some $p:expr, $constructor:ident) => (
199 let __found__ = match *($p).token {
200 INTERPOLATED(token::$constructor(_)) => {
201 Some(($p).bump_and_get())
206 Some(INTERPOLATED(token::$constructor(x))) => {
207 return Some(x.clone()),
213 (iovi $p:expr, $constructor:ident) => (
215 let __found__ = match *($p).token {
216 INTERPOLATED(token::$constructor(_)) => {
217 Some(($p).bump_and_get())
222 Some(INTERPOLATED(token::$constructor(x))) => {
223 return iovi_item(x.clone())
229 (pair_empty $p:expr, $constructor:ident) => (
231 let __found__ = match *($p).token {
232 INTERPOLATED(token::$constructor(_)) => {
233 Some(($p).bump_and_get())
238 Some(INTERPOLATED(token::$constructor(x))) => {
239 return (~[], x.clone())
248 fn maybe_append(lhs: ~[Attribute], rhs: Option<~[Attribute]>)
252 Some(ref attrs) => vec::append(lhs, (*attrs))
257 struct ParsedItemsAndViewItems {
258 attrs_remaining: ~[Attribute],
259 view_items: ~[view_item],
261 foreign_items: ~[@foreign_item]
264 /* ident is handled by common.rs */
266 pub fn Parser(sess: @mut ParseSess,
267 cfg: ast::CrateConfig,
270 let tok0 = rdr.next_token();
271 let interner = get_ident_interner();
273 let placeholder = TokenAndSpan {
274 tok: token::UNDERSCORE,
283 token: @mut tok0.tok,
285 last_span: @mut span,
292 buffer_start: @mut 0,
294 tokens_consumed: @mut 0,
295 restriction: @mut UNRESTRICTED,
297 obsolete_set: @mut HashSet::new(),
298 mod_path_stack: @mut ~[],
302 // ooh, nasty mutable fields everywhere....
304 sess: @mut ParseSess,
306 // the current token:
307 token: @mut token::Token,
308 // the span of the current token:
310 // the span of the prior token:
311 last_span: @mut span,
312 buffer: @mut [TokenAndSpan, ..4],
313 buffer_start: @mut int,
314 buffer_end: @mut int,
315 tokens_consumed: @mut uint,
316 restriction: @mut restriction,
317 quote_depth: @mut uint, // not (yet) related to the quasiquoter
319 interner: @token::ident_interner,
320 /// The set of seen errors about obsolete syntax. Used to suppress
321 /// extra detail when the same error is seen twice
322 obsolete_set: @mut HashSet<ObsoleteSyntax>,
323 /// Used to determine the path to externally loaded source files
324 mod_path_stack: @mut ~[@str],
328 impl Drop for Parser {
329 /* do not copy the parser; its state is tied to outside state */
334 // convert a token to a string using self's reader
335 pub fn token_to_str(&self, token: &token::Token) -> ~str {
336 token::to_str(get_ident_interner(), token)
339 // convert the current token to a string using self's reader
340 pub fn this_token_to_str(&self) -> ~str {
341 self.token_to_str(self.token)
344 pub fn unexpected_last(&self, t: &token::Token) -> ! {
348 "unexpected token: `%s`",
354 pub fn unexpected(&self) -> ! {
357 "unexpected token: `%s`",
358 self.this_token_to_str()
363 // expect and consume the token t. Signal an error if
364 // the next token is not t.
365 pub fn expect(&self, t: &token::Token) {
366 if *self.token == *t {
371 "expected `%s` but found `%s`",
372 self.token_to_str(t),
373 self.this_token_to_str()
379 pub fn parse_ident(&self) -> ast::ident {
380 self.check_strict_keywords();
381 self.check_reserved_keywords();
383 token::IDENT(i, _) => {
387 token::INTERPOLATED(token::nt_ident(*)) => {
388 self.bug("ident interpolation not converted to real token");
393 "expected ident, found `%s`",
394 self.this_token_to_str()
401 pub fn parse_path_list_ident(&self) -> ast::path_list_ident {
402 let lo = self.span.lo;
403 let ident = self.parse_ident();
404 let hi = self.last_span.hi;
405 spanned(lo, hi, ast::path_list_ident_ { name: ident,
409 // consume token 'tok' if it exists. Returns true if the given
410 // token was present, false otherwise.
411 pub fn eat(&self, tok: &token::Token) -> bool {
412 let is_present = *self.token == *tok;
413 if is_present { self.bump() }
417 pub fn is_keyword(&self, kw: keywords::Keyword) -> bool {
418 token::is_keyword(kw, self.token)
421 // if the next token is the given keyword, eat it and return
422 // true. Otherwise, return false.
423 pub fn eat_keyword(&self, kw: keywords::Keyword) -> bool {
424 let is_kw = match *self.token {
425 token::IDENT(sid, false) => kw.to_ident().name == sid.name,
428 if is_kw { self.bump() }
432 // if the given word is not a keyword, signal an error.
433 // if the next token is not the given word, signal an error.
434 // otherwise, eat it.
435 pub fn expect_keyword(&self, kw: keywords::Keyword) {
436 if !self.eat_keyword(kw) {
439 "expected `%s`, found `%s`",
440 self.id_to_str(kw.to_ident()).to_str(),
441 self.this_token_to_str()
447 // signal an error if the given string is a strict keyword
448 pub fn check_strict_keywords(&self) {
449 if token::is_strict_keyword(self.token) {
450 self.span_err(*self.last_span,
451 fmt!("found `%s` in ident position", self.this_token_to_str()));
455 // signal an error if the current token is a reserved keyword
456 pub fn check_reserved_keywords(&self) {
457 if token::is_reserved_keyword(self.token) {
458 self.fatal(fmt!("`%s` is a reserved keyword", self.this_token_to_str()));
462 // expect and consume a GT. if a >> is seen, replace it
463 // with a single > and continue. If a GT is not seen,
465 pub fn expect_gt(&self) {
467 token::GT => self.bump(),
468 token::BINOP(token::SHR) => self.replace_token(
470 self.span.lo + BytePos(1u),
473 _ => self.fatal(fmt!("expected `%s`, found `%s`",
474 self.token_to_str(&token::GT),
475 self.this_token_to_str()))
479 // parse a sequence bracketed by '<' and '>', stopping
481 pub fn parse_seq_to_before_gt<T>(&self,
482 sep: Option<token::Token>,
483 f: &fn(&Parser) -> T)
485 let mut first = true;
486 let mut v = opt_vec::Empty;
487 while *self.token != token::GT
488 && *self.token != token::BINOP(token::SHR) {
491 if first { first = false; }
492 else { self.expect(t); }
501 pub fn parse_seq_to_gt<T>(&self,
502 sep: Option<token::Token>,
503 f: &fn(&Parser) -> T)
505 let v = self.parse_seq_to_before_gt(sep, f);
510 // parse a sequence, including the closing delimiter. The function
511 // f must consume tokens until reaching the next separator or
513 pub fn parse_seq_to_end<T>(&self,
516 f: &fn(&Parser) -> T)
518 let val = self.parse_seq_to_before_end(ket, sep, f);
523 // parse a sequence, not including the closing delimiter. The function
524 // f must consume tokens until reaching the next separator or
526 pub fn parse_seq_to_before_end<T>(&self,
529 f: &fn(&Parser) -> T)
531 let mut first: bool = true;
532 let mut v: ~[T] = ~[];
533 while *self.token != *ket {
536 if first { first = false; }
537 else { self.expect(t); }
541 if sep.trailing_sep_allowed && *self.token == *ket { break; }
547 // parse a sequence, including the closing delimiter. The function
548 // f must consume tokens until reaching the next separator or
550 pub fn parse_unspanned_seq<T>(&self,
554 f: &fn(&Parser) -> T)
557 let result = self.parse_seq_to_before_end(ket, sep, f);
562 // NB: Do not use this function unless you actually plan to place the
563 // spanned list in the AST.
564 pub fn parse_seq<T>(&self,
568 f: &fn(&Parser) -> T)
570 let lo = self.span.lo;
572 let result = self.parse_seq_to_before_end(ket, sep, f);
573 let hi = self.span.hi;
575 spanned(lo, hi, result)
578 // advance the parser by one token
580 *self.last_span = *self.span;
581 let next = if *self.buffer_start == *self.buffer_end {
582 self.reader.next_token()
584 // Avoid token copies with `util::replace`.
585 let buffer_start = *self.buffer_start as uint;
586 let next_index = (buffer_start + 1) & 3 as uint;
587 *self.buffer_start = next_index as int;
589 let placeholder = TokenAndSpan {
590 tok: token::UNDERSCORE,
593 util::replace(&mut self.buffer[buffer_start], placeholder)
595 *self.span = next.sp;
596 *self.token = next.tok;
597 *self.tokens_consumed += 1u;
600 // Advance the parser by one token and return the bumped token.
601 pub fn bump_and_get(&self) -> token::Token {
602 let old_token = util::replace(self.token, token::UNDERSCORE);
607 // EFFECT: replace the current token and span with the given one
608 pub fn replace_token(&self,
613 *self.span = mk_sp(lo, hi);
615 pub fn buffer_length(&self) -> int {
616 if *self.buffer_start <= *self.buffer_end {
617 return *self.buffer_end - *self.buffer_start;
619 return (4 - *self.buffer_start) + *self.buffer_end;
621 pub fn look_ahead<R>(&self, distance: uint, f: &fn(&token::Token) -> R)
623 let dist = distance as int;
624 while self.buffer_length() < dist {
625 self.buffer[*self.buffer_end] = self.reader.next_token();
626 *self.buffer_end = (*self.buffer_end + 1) & 3;
628 f(&self.buffer[(*self.buffer_start + dist - 1) & 3].tok)
630 pub fn fatal(&self, m: &str) -> ! {
631 self.sess.span_diagnostic.span_fatal(*self.span, m)
633 pub fn span_fatal(&self, sp: span, m: &str) -> ! {
634 self.sess.span_diagnostic.span_fatal(sp, m)
636 pub fn span_note(&self, sp: span, m: &str) {
637 self.sess.span_diagnostic.span_note(sp, m)
639 pub fn bug(&self, m: &str) -> ! {
640 self.sess.span_diagnostic.span_bug(*self.span, m)
642 pub fn warn(&self, m: &str) {
643 self.sess.span_diagnostic.span_warn(*self.span, m)
645 pub fn span_err(&self, sp: span, m: &str) {
646 self.sess.span_diagnostic.span_err(sp, m)
648 pub fn abort_if_errors(&self) {
649 self.sess.span_diagnostic.handler().abort_if_errors();
651 pub fn get_id(&self) -> NodeId { next_node_id(self.sess) }
653 pub fn id_to_str(&self, id: ident) -> @str {
654 get_ident_interner().get(id.name)
657 // is this one of the keywords that signals a closure type?
658 pub fn token_is_closure_keyword(&self, tok: &token::Token) -> bool {
659 token::is_keyword(keywords::Pure, tok) ||
660 token::is_keyword(keywords::Unsafe, tok) ||
661 token::is_keyword(keywords::Once, tok) ||
662 token::is_keyword(keywords::Fn, tok)
665 pub fn token_is_lifetime(&self, tok: &token::Token) -> bool {
667 token::LIFETIME(*) => true,
672 pub fn get_lifetime(&self, tok: &token::Token) -> ast::ident {
674 token::LIFETIME(ref ident) => *ident,
675 _ => self.bug("not a lifetime"),
679 // parse a ty_bare_fun type:
680 pub fn parse_ty_bare_fn(&self) -> ty_ {
683 extern "ABI" [pure|unsafe] fn <'lt> (S) -> T
684 ^~~~^ ^~~~~~~~~~~~^ ^~~~^ ^~^ ^
695 let opt_abis = self.parse_opt_abis();
696 let abis = opt_abis.unwrap_or_default(AbiSet::Rust());
697 let purity = self.parse_unsafety();
698 self.expect_keyword(keywords::Fn);
699 let (decl, lifetimes) = self.parse_ty_fn_decl();
700 return ty_bare_fn(@TyBareFn {
703 lifetimes: lifetimes,
708 // parse a ty_closure type
709 pub fn parse_ty_closure(&self,
711 region: Option<ast::Lifetime>)
715 (&|~|@) ['r] [pure|unsafe] [once] fn [:Bounds] <'lt> (S) -> T
716 ^~~~~~^ ^~~^ ^~~~~~~~~~~~^ ^~~~~^ ^~~~~~~~^ ^~~~^ ^~^ ^
718 | | | | | | | Return type
719 | | | | | | Argument types
721 | | | | Closure bounds
722 | | | Once-ness (a.k.a., affine)
729 // At this point, the allocation type and lifetime bound have been
732 let purity = self.parse_unsafety();
733 let onceness = parse_onceness(self);
734 self.expect_keyword(keywords::Fn);
735 let bounds = self.parse_optional_ty_param_bounds();
737 if self.parse_fn_ty_sigil().is_some() {
738 self.obsolete(*self.span, ObsoletePostFnTySigil);
741 let (decl, lifetimes) = self.parse_ty_fn_decl();
743 return ty_closure(@TyClosure {
750 lifetimes: lifetimes,
753 fn parse_onceness(this: &Parser) -> Onceness {
754 if this.eat_keyword(keywords::Once) {
762 // looks like this should be called parse_unsafety
763 pub fn parse_unsafety(&self) -> purity {
764 if self.eat_keyword(keywords::Pure) {
765 self.obsolete(*self.last_span, ObsoletePurity);
767 } else if self.eat_keyword(keywords::Unsafe) {
774 // parse a function type (following the 'fn')
775 pub fn parse_ty_fn_decl(&self) -> (fn_decl, OptVec<ast::Lifetime>) {
786 let lifetimes = if self.eat(&token::LT) {
787 let lifetimes = self.parse_lifetimes();
794 let inputs = self.parse_unspanned_seq(
797 seq_sep_trailing_disallowed(token::COMMA),
798 |p| p.parse_arg_general(false)
800 let (ret_style, ret_ty) = self.parse_ret_ty();
801 let decl = ast::fn_decl {
809 // parse the methods in a trait declaration
810 pub fn parse_trait_methods(&self) -> ~[trait_method] {
811 do self.parse_unspanned_seq(
816 let attrs = p.parse_outer_attributes();
819 let vis = p.parse_non_priv_visibility();
820 let pur = p.parse_fn_purity();
821 // NB: at the moment, trait methods are public by default; this
823 let ident = p.parse_ident();
825 let generics = p.parse_generics();
827 let (explicit_self, d) = do self.parse_fn_decl_with_self() |p| {
828 // This is somewhat dubious; We don't want to allow argument
829 // names to be left off if there is a definition...
830 either::Left(p.parse_arg_general(false))
833 let hi = p.last_span.hi;
834 debug!("parse_trait_methods(): trait method signature ends in \
836 self.this_token_to_str());
840 debug!("parse_trait_methods(): parsing required method");
841 // NB: at the moment, visibility annotations on required
842 // methods are ignored; this could change.
843 required(TypeMethod {
849 explicit_self: explicit_self,
855 debug!("parse_trait_methods(): parsing provided method");
856 let (inner_attrs, body) =
857 p.parse_inner_attrs_and_block();
858 let attrs = vec::append(attrs, inner_attrs);
859 provided(@ast::method {
863 explicit_self: explicit_self,
877 "expected `;` or `}` but found `%s`",
878 self.this_token_to_str()
886 // parse a possibly mutable type
887 pub fn parse_mt(&self) -> mt {
888 let mutbl = self.parse_mutability();
889 let t = ~self.parse_ty(false);
890 mt { ty: t, mutbl: mutbl }
893 // parse [mut/const/imm] ID : TY
894 // now used only by obsolete record syntax parser...
895 pub fn parse_ty_field(&self) -> TypeField {
896 let lo = self.span.lo;
897 let mutbl = self.parse_mutability();
898 let id = self.parse_ident();
899 self.expect(&token::COLON);
900 let ty = ~self.parse_ty(false);
904 mt: ast::mt { ty: ty, mutbl: mutbl },
909 // parse optional return type [ -> TY ] in function decl
910 pub fn parse_ret_ty(&self) -> (ret_style, Ty) {
911 return if self.eat(&token::RARROW) {
912 let lo = self.span.lo;
913 if self.eat(&token::NOT) {
919 span: mk_sp(lo, self.last_span.hi)
923 (return_val, self.parse_ty(false))
926 let pos = self.span.lo;
932 span: mk_sp(pos, pos),
939 // Useless second parameter for compatibility with quasiquote macros.
941 pub fn parse_ty(&self, _: bool) -> Ty {
942 maybe_whole!(self, nt_ty);
944 let lo = self.span.lo;
946 let t = if *self.token == token::LPAREN {
948 if *self.token == token::RPAREN {
952 // (t) is a parenthesized ty
953 // (t,) is the type of a tuple with only one field,
955 let mut ts = ~[self.parse_ty(false)];
956 let mut one_tuple = false;
957 while *self.token == token::COMMA {
959 if *self.token != token::RPAREN {
960 ts.push(self.parse_ty(false));
967 if ts.len() == 1 && !one_tuple {
968 self.expect(&token::RPAREN);
973 self.expect(&token::RPAREN);
976 } else if *self.token == token::AT {
979 self.parse_box_or_uniq_pointee(ManagedSigil, ty_box)
980 } else if *self.token == token::TILDE {
983 self.parse_box_or_uniq_pointee(OwnedSigil, ty_uniq)
984 } else if *self.token == token::BINOP(token::STAR) {
985 // STAR POINTER (bare pointer?)
987 ty_ptr(self.parse_mt())
988 } else if *self.token == token::LBRACE {
989 // STRUCTURAL RECORD (remove?)
990 let elems = self.parse_unspanned_seq(
993 seq_sep_trailing_allowed(token::COMMA),
994 |p| p.parse_ty_field()
996 if elems.len() == 0 {
997 self.unexpected_last(&token::RBRACE);
999 self.obsolete(*self.last_span, ObsoleteRecordType);
1001 } else if *self.token == token::LBRACKET {
1003 self.expect(&token::LBRACKET);
1004 let mt = self.parse_mt();
1005 if mt.mutbl == m_mutbl { // `m_const` too after snapshot
1006 self.obsolete(*self.last_span, ObsoleteMutVector);
1009 // Parse the `, ..e` in `[ int, ..e ]`
1010 // where `e` is a const expression
1011 let t = match self.maybe_parse_fixed_vstore() {
1013 Some(suffix) => ty_fixed_length_vec(mt, suffix)
1015 self.expect(&token::RBRACKET);
1017 } else if *self.token == token::BINOP(token::AND) {
1020 self.parse_borrowed_pointee()
1021 } else if self.eat_keyword(keywords::Extern) {
1023 self.parse_ty_bare_fn()
1024 } else if self.token_is_closure_keyword(self.token) {
1026 let result = self.parse_ty_closure(ast::BorrowedSigil, None);
1027 self.obsolete(*self.last_span, ObsoleteBareFnType);
1029 } else if *self.token == token::MOD_SEP
1030 || is_ident_or_path(self.token) {
1032 let (path, bounds) = self.parse_type_path();
1033 ty_path(path, bounds, self.get_id())
1035 self.fatal(fmt!("expected type, found token %?",
1039 let sp = mk_sp(lo, self.last_span.hi);
1040 Ty {id: self.get_id(), node: t, span: sp}
1043 // parse the type following a @ or a ~
1044 pub fn parse_box_or_uniq_pointee(&self,
1046 ctor: &fn(v: mt) -> ty_) -> ty_ {
1047 // @'foo fn() or @foo/fn() or @fn() are parsed directly as fn types:
1049 token::LIFETIME(*) => {
1050 let lifetime = self.parse_lifetime();
1052 return self.parse_ty_closure(sigil, Some(lifetime));
1055 token::IDENT(*) => {
1056 if self.look_ahead(1, |t| *t == token::BINOP(token::SLASH)) &&
1057 self.look_ahead(2, |t|
1058 self.token_is_closure_keyword(t)) {
1059 let lifetime = self.parse_lifetime();
1060 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1061 return self.parse_ty_closure(sigil, Some(lifetime));
1062 } else if self.token_is_closure_keyword(self.token) {
1063 return self.parse_ty_closure(sigil, None);
1069 // other things are parsed as @ + a type. Note that constructs like
1070 // @[] and @str will be resolved during typeck to slices and so forth,
1071 // rather than boxed ptrs. But the special casing of str/vec is not
1072 // reflected in the AST type.
1073 let mt = self.parse_mt();
1075 if mt.mutbl != m_imm && sigil == OwnedSigil {
1076 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
1078 if mt.mutbl == m_const && sigil == ManagedSigil {
1079 self.obsolete(*self.last_span, ObsoleteConstManagedPointer);
1085 pub fn parse_borrowed_pointee(&self) -> ty_ {
1086 // look for `&'lt` or `&'foo ` and interpret `foo` as the region name:
1087 let opt_lifetime = self.parse_opt_lifetime();
1089 if self.token_is_closure_keyword(self.token) {
1090 return self.parse_ty_closure(BorrowedSigil, opt_lifetime);
1093 let mt = self.parse_mt();
1094 return ty_rptr(opt_lifetime, mt);
1097 // parse an optional, obsolete argument mode.
1098 pub fn parse_arg_mode(&self) {
1099 if self.eat(&token::BINOP(token::MINUS)) {
1100 self.obsolete(*self.span, ObsoleteMode);
1101 } else if self.eat(&token::ANDAND) {
1102 self.obsolete(*self.span, ObsoleteMode);
1103 } else if self.eat(&token::BINOP(token::PLUS)) {
1104 if self.eat(&token::BINOP(token::PLUS)) {
1105 self.obsolete(*self.span, ObsoleteMode);
1107 self.obsolete(*self.span, ObsoleteMode);
1114 pub fn is_named_argument(&self) -> bool {
1115 let offset = match *self.token {
1116 token::BINOP(token::AND) => 1,
1117 token::BINOP(token::MINUS) => 1,
1119 token::BINOP(token::PLUS) => {
1120 if self.look_ahead(1, |t| *t == token::BINOP(token::PLUS)) {
1130 is_plain_ident(&*self.token)
1131 && self.look_ahead(1, |t| *t == token::COLON)
1133 self.look_ahead(offset, |t| is_plain_ident(t))
1134 && self.look_ahead(offset + 1, |t| *t == token::COLON)
1138 // This version of parse arg doesn't necessarily require
1139 // identifier names.
1140 pub fn parse_arg_general(&self, require_name: bool) -> arg {
1141 let is_mutbl = self.eat_keyword(keywords::Mut);
1142 let pat = if require_name || self.is_named_argument() {
1143 self.parse_arg_mode();
1144 let pat = self.parse_pat();
1146 if is_mutbl && !ast_util::pat_is_ident(pat) {
1147 self.obsolete(*self.span, ObsoleteMutWithMultipleBindings)
1150 self.expect(&token::COLON);
1153 ast_util::ident_to_pat(self.get_id(),
1155 special_idents::invalid)
1158 let t = self.parse_ty(false);
1168 // parse a single function argument
1169 pub fn parse_arg(&self) -> arg_or_capture_item {
1170 either::Left(self.parse_arg_general(true))
1173 // parse an argument in a lambda header e.g. |arg, arg|
1174 pub fn parse_fn_block_arg(&self) -> arg_or_capture_item {
1175 self.parse_arg_mode();
1176 let is_mutbl = self.eat_keyword(keywords::Mut);
1177 let pat = self.parse_pat();
1178 let t = if self.eat(&token::COLON) {
1179 self.parse_ty(false)
1184 span: mk_sp(self.span.lo, self.span.hi),
1187 either::Left(ast::arg {
1195 pub fn maybe_parse_fixed_vstore(&self) -> Option<@ast::expr> {
1196 if self.eat(&token::BINOP(token::STAR)) {
1197 self.obsolete(*self.last_span, ObsoleteFixedLengthVectorType);
1198 Some(self.parse_expr())
1199 } else if *self.token == token::COMMA &&
1200 self.look_ahead(1, |t| *t == token::DOTDOT) {
1203 Some(self.parse_expr())
1209 // matches token_lit = LIT_INT | ...
1210 pub fn lit_from_token(&self, tok: &token::Token) -> lit_ {
1212 token::LIT_INT(i, it) => lit_int(i, it),
1213 token::LIT_UINT(u, ut) => lit_uint(u, ut),
1214 token::LIT_INT_UNSUFFIXED(i) => lit_int_unsuffixed(i),
1215 token::LIT_FLOAT(s, ft) => lit_float(self.id_to_str(s), ft),
1216 token::LIT_FLOAT_UNSUFFIXED(s) =>
1217 lit_float_unsuffixed(self.id_to_str(s)),
1218 token::LIT_STR(s) => lit_str(self.id_to_str(s)),
1219 token::LPAREN => { self.expect(&token::RPAREN); lit_nil },
1220 _ => { self.unexpected_last(tok); }
1224 // matches lit = true | false | token_lit
1225 pub fn parse_lit(&self) -> lit {
1226 let lo = self.span.lo;
1227 let lit = if self.eat_keyword(keywords::True) {
1229 } else if self.eat_keyword(keywords::False) {
1232 let token = self.bump_and_get();
1233 let lit = self.lit_from_token(&token);
1236 codemap::spanned { node: lit, span: mk_sp(lo, self.last_span.hi) }
1239 // matches '-' lit | lit
1240 pub fn parse_literal_maybe_minus(&self) -> @expr {
1241 let minus_lo = self.span.lo;
1242 let minus_present = self.eat(&token::BINOP(token::MINUS));
1244 let lo = self.span.lo;
1245 let literal = @self.parse_lit();
1246 let hi = self.span.hi;
1247 let expr = self.mk_expr(lo, hi, expr_lit(literal));
1250 let minus_hi = self.span.hi;
1251 self.mk_expr(minus_lo, minus_hi, self.mk_unary(neg, expr))
1257 // parse a path into a vector of idents, whether the path starts
1258 // with ::, and a span.
1259 pub fn parse_path(&self) -> (~[ast::ident],bool,span) {
1260 let lo = self.span.lo;
1261 let is_global = self.eat(&token::MOD_SEP);
1262 let (ids,span{lo:_,hi,expn_info}) = self.parse_path_non_global();
1263 (ids,is_global,span{lo:lo,hi:hi,expn_info:expn_info})
1266 // parse a path beginning with an identifier into a vector of idents and a span
1267 pub fn parse_path_non_global(&self) -> (~[ast::ident],span) {
1268 let lo = self.span.lo;
1270 // must be at least one to begin:
1271 ids.push(self.parse_ident());
1275 let is_ident = do self.look_ahead(1) |t| {
1277 token::IDENT(*) => true,
1283 ids.push(self.parse_ident());
1291 (ids, mk_sp(lo, self.last_span.hi))
1294 // parse a path that doesn't have type parameters attached
1295 pub fn parse_path_without_tps(&self) -> ast::Path {
1296 maybe_whole!(self, nt_path);
1297 let (ids,is_global,sp) = self.parse_path();
1298 ast::Path { span: sp,
1305 pub fn parse_bounded_path_with_tps(&self, colons: bool,
1306 before_tps: Option<&fn()>) -> ast::Path {
1307 debug!("parse_path_with_tps(colons=%b)", colons);
1309 maybe_whole!(self, nt_path);
1310 let lo = self.span.lo;
1311 let path = self.parse_path_without_tps();
1312 if colons && !self.eat(&token::MOD_SEP) {
1316 // If the path might have bounds on it, they should be parsed before
1317 // the parameters, e.g. module::TraitName:B1+B2<T>
1318 before_tps.map_move(|callback| callback());
1320 // Parse the (obsolete) trailing region parameter, if any, which will
1321 // be written "foo/&x"
1323 if *self.token == token::BINOP(token::SLASH)
1324 && self.look_ahead(1, |t| *t == token::BINOP(token::AND))
1326 self.bump(); self.bump();
1327 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1329 token::IDENT(sid, _) => {
1330 let span = self.span;
1332 Some(ast::Lifetime {
1339 self.fatal(fmt!("Expected a lifetime name"));
1347 // Parse any lifetime or type parameters which may appear:
1348 let (lifetimes, tps) = self.parse_generic_values();
1349 let hi = self.span.lo;
1351 let rp = match (&rp_slash, &lifetimes) {
1352 (&Some(_), _) => rp_slash,
1356 } else if v.len() == 1 {
1359 self.fatal(fmt!("Expected at most one \
1360 lifetime name (for now)"));
1366 span: mk_sp(lo, hi),
1373 // parse a path optionally with type parameters. If 'colons'
1374 // is true, then type parameters must be preceded by colons,
1375 // as in a::t::<t1,t2>
1376 pub fn parse_path_with_tps(&self, colons: bool) -> ast::Path {
1377 self.parse_bounded_path_with_tps(colons, None)
1380 // Like the above, but can also parse kind bounds in the case of a
1381 // path to be used as a type that might be a trait.
1382 pub fn parse_type_path(&self) -> (ast::Path, Option<OptVec<TyParamBound>>) {
1383 let mut bounds = None;
1384 let path = self.parse_bounded_path_with_tps(false, Some(|| {
1385 // Note: this closure might not even get called in the case of a
1386 // macro-generated path. But that's the macro parser's job.
1387 bounds = self.parse_optional_ty_param_bounds();
1392 /// parses 0 or 1 lifetime
1393 pub fn parse_opt_lifetime(&self) -> Option<ast::Lifetime> {
1395 token::LIFETIME(*) => {
1396 Some(self.parse_lifetime())
1399 // Also accept the (obsolete) syntax `foo/`
1400 token::IDENT(*) => {
1401 if self.look_ahead(1, |t| *t == token::BINOP(token::SLASH)) {
1402 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1403 Some(self.parse_lifetime())
1415 /// Parses a single lifetime
1416 // matches lifetime = ( LIFETIME ) | ( IDENT / )
1417 pub fn parse_lifetime(&self) -> ast::Lifetime {
1419 token::LIFETIME(i) => {
1420 let span = self.span;
1422 return ast::Lifetime {
1429 // Also accept the (obsolete) syntax `foo/`
1430 token::IDENT(i, _) => {
1431 let span = self.span;
1433 self.expect(&token::BINOP(token::SLASH));
1434 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
1435 return ast::Lifetime {
1443 self.fatal(fmt!("Expected a lifetime name"));
1448 // matches lifetimes = ( lifetime ) | ( lifetime , lifetimes )
1449 // actually, it matches the empty one too, but putting that in there
1450 // messes up the grammar....
1451 pub fn parse_lifetimes(&self) -> OptVec<ast::Lifetime> {
1454 * Parses zero or more comma separated lifetimes.
1455 * Expects each lifetime to be followed by either
1456 * a comma or `>`. Used when parsing type parameter
1457 * lists, where we expect something like `<'a, 'b, T>`.
1460 let mut res = opt_vec::Empty;
1463 token::LIFETIME(_) => {
1464 res.push(self.parse_lifetime());
1472 token::COMMA => { self.bump();}
1473 token::GT => { return res; }
1474 token::BINOP(token::SHR) => { return res; }
1476 self.fatal(fmt!("expected `,` or `>` after lifetime name, got: %?",
1483 pub fn token_is_mutability(&self, tok: &token::Token) -> bool {
1484 token::is_keyword(keywords::Mut, tok) ||
1485 token::is_keyword(keywords::Const, tok)
1488 // parse mutability declaration (mut/const/imm)
1489 pub fn parse_mutability(&self) -> mutability {
1490 if self.eat_keyword(keywords::Mut) {
1492 } else if self.eat_keyword(keywords::Const) {
1499 // parse ident COLON expr
1500 pub fn parse_field(&self) -> Field {
1501 let lo = self.span.lo;
1502 let i = self.parse_ident();
1503 self.expect(&token::COLON);
1504 let e = self.parse_expr();
1508 span: mk_sp(lo, e.span.hi),
1512 pub fn mk_expr(&self, lo: BytePos, hi: BytePos, node: expr_) -> @expr {
1516 span: mk_sp(lo, hi),
1520 pub fn mk_unary(&self, unop: ast::unop, expr: @expr) -> ast::expr_ {
1521 expr_unary(self.get_id(), unop, expr)
1524 pub fn mk_binary(&self, binop: ast::binop, lhs: @expr, rhs: @expr) -> ast::expr_ {
1525 expr_binary(self.get_id(), binop, lhs, rhs)
1528 pub fn mk_call(&self, f: @expr, args: ~[@expr], sugar: CallSugar) -> ast::expr_ {
1529 expr_call(f, args, sugar)
1532 pub fn mk_method_call(&self,
1537 sugar: CallSugar) -> ast::expr_ {
1538 expr_method_call(self.get_id(), rcvr, ident, tps, args, sugar)
1541 pub fn mk_index(&self, expr: @expr, idx: @expr) -> ast::expr_ {
1542 expr_index(self.get_id(), expr, idx)
1545 pub fn mk_field(&self, expr: @expr, ident: ident, tys: ~[Ty]) -> ast::expr_ {
1546 expr_field(expr, ident, tys)
1549 pub fn mk_assign_op(&self, binop: ast::binop, lhs: @expr, rhs: @expr) -> ast::expr_ {
1550 expr_assign_op(self.get_id(), binop, lhs, rhs)
1553 pub fn mk_mac_expr(&self, lo: BytePos, hi: BytePos, m: mac_) -> @expr {
1556 node: expr_mac(codemap::spanned {node: m, span: mk_sp(lo, hi)}),
1557 span: mk_sp(lo, hi),
1561 pub fn mk_lit_u32(&self, i: u32) -> @expr {
1562 let span = self.span;
1563 let lv_lit = @codemap::spanned {
1564 node: lit_uint(i as u64, ty_u32),
1570 node: expr_lit(lv_lit),
1575 // at the bottom (top?) of the precedence hierarchy,
1576 // parse things like parenthesized exprs,
1577 // macros, return, etc.
1578 pub fn parse_bottom_expr(&self) -> @expr {
1579 maybe_whole_expr!(self);
1581 let lo = self.span.lo;
1582 let mut hi = self.span.hi;
1586 if *self.token == token::LPAREN {
1588 // (e) is parenthesized e
1589 // (e,) is a tuple with only one field, e
1590 let mut trailing_comma = false;
1591 if *self.token == token::RPAREN {
1594 let lit = @spanned(lo, hi, lit_nil);
1595 return self.mk_expr(lo, hi, expr_lit(lit));
1597 let mut es = ~[self.parse_expr()];
1598 while *self.token == token::COMMA {
1600 if *self.token != token::RPAREN {
1601 es.push(self.parse_expr());
1604 trailing_comma = true;
1608 self.expect(&token::RPAREN);
1610 return if es.len() == 1 && !trailing_comma {
1611 self.mk_expr(lo, self.span.hi, expr_paren(es[0]))
1614 self.mk_expr(lo, hi, expr_tup(es))
1616 } else if *self.token == token::LBRACE {
1618 let blk = self.parse_block_tail(lo, DefaultBlock);
1619 return self.mk_expr(blk.span.lo, blk.span.hi,
1621 } else if token::is_bar(&*self.token) {
1622 return self.parse_lambda_expr();
1623 } else if self.eat_keyword(keywords::Self) {
1626 } else if self.eat_keyword(keywords::If) {
1627 return self.parse_if_expr();
1628 } else if self.eat_keyword(keywords::For) {
1629 return self.parse_for_expr();
1630 } else if self.eat_keyword(keywords::Do) {
1631 return self.parse_sugary_call_expr(lo, ~"do", DoSugar,
1633 } else if self.eat_keyword(keywords::While) {
1634 return self.parse_while_expr();
1635 } else if self.token_is_lifetime(&*self.token) {
1636 let lifetime = self.get_lifetime(&*self.token);
1638 self.expect(&token::COLON);
1639 self.expect_keyword(keywords::Loop);
1640 return self.parse_loop_expr(Some(lifetime));
1641 } else if self.eat_keyword(keywords::Loop) {
1642 return self.parse_loop_expr(None);
1643 } else if self.eat_keyword(keywords::Match) {
1644 return self.parse_match_expr();
1645 } else if self.eat_keyword(keywords::Unsafe) {
1646 return self.parse_block_expr(lo, UnsafeBlock);
1647 } else if *self.token == token::LBRACKET {
1649 let mutbl = self.parse_mutability();
1650 if mutbl == m_mutbl || mutbl == m_const {
1651 self.obsolete(*self.last_span, ObsoleteMutVector);
1654 if *self.token == token::RBRACKET {
1657 ex = expr_vec(~[], mutbl);
1660 let first_expr = self.parse_expr();
1661 if *self.token == token::COMMA &&
1662 self.look_ahead(1, |t| *t == token::DOTDOT) {
1663 // Repeating vector syntax: [ 0, ..512 ]
1666 let count = self.parse_expr();
1667 self.expect(&token::RBRACKET);
1668 ex = expr_repeat(first_expr, count, mutbl);
1669 } else if *self.token == token::COMMA {
1670 // Vector with two or more elements.
1672 let remaining_exprs = self.parse_seq_to_end(
1674 seq_sep_trailing_allowed(token::COMMA),
1677 ex = expr_vec(~[first_expr] + remaining_exprs, mutbl);
1679 // Vector with one element.
1680 self.expect(&token::RBRACKET);
1681 ex = expr_vec(~[first_expr], mutbl);
1684 hi = self.last_span.hi;
1685 } else if self.eat_keyword(keywords::__Log) {
1687 self.expect(&token::LPAREN);
1688 let lvl = self.parse_expr();
1689 self.expect(&token::COMMA);
1690 let e = self.parse_expr();
1691 ex = expr_log(lvl, e);
1693 self.expect(&token::RPAREN);
1694 } else if self.eat_keyword(keywords::Return) {
1695 // RETURN expression
1696 if can_begin_expr(&*self.token) {
1697 let e = self.parse_expr();
1699 ex = expr_ret(Some(e));
1700 } else { ex = expr_ret(None); }
1701 } else if self.eat_keyword(keywords::Break) {
1703 if self.token_is_lifetime(&*self.token) {
1704 let lifetime = self.get_lifetime(&*self.token);
1706 ex = expr_break(Some(lifetime));
1708 ex = expr_break(None);
1711 } else if *self.token == token::MOD_SEP ||
1712 is_ident(&*self.token) && !self.is_keyword(keywords::True) &&
1713 !self.is_keyword(keywords::False) {
1714 let pth = self.parse_path_with_tps(true);
1716 // `!`, as an operator, is prefix, so we know this isn't that
1717 if *self.token == token::NOT {
1718 // MACRO INVOCATION expression
1721 token::LPAREN | token::LBRACE => {}
1722 _ => self.fatal("expected open delimiter")
1725 let ket = token::flip_delimiter(&*self.token);
1728 let tts = self.parse_seq_to_end(&ket,
1730 |p| p.parse_token_tree());
1731 let hi = self.span.hi;
1733 return self.mk_mac_expr(lo, hi, mac_invoc_tt(pth, tts));
1734 } else if *self.token == token::LBRACE {
1735 // This might be a struct literal.
1736 if self.looking_at_record_literal() {
1737 // It's a struct literal.
1739 let mut fields = ~[];
1740 let mut base = None;
1742 fields.push(self.parse_field());
1743 while *self.token != token::RBRACE {
1744 if self.try_parse_obsolete_with() {
1748 self.expect(&token::COMMA);
1750 if self.eat(&token::DOTDOT) {
1751 base = Some(self.parse_expr());
1755 if *self.token == token::RBRACE {
1756 // Accept an optional trailing comma.
1759 fields.push(self.parse_field());
1763 self.expect(&token::RBRACE);
1764 ex = expr_struct(pth, fields, base);
1765 return self.mk_expr(lo, hi, ex);
1770 ex = expr_path(pth);
1772 // other literal expression
1773 let lit = self.parse_lit();
1775 ex = expr_lit(@lit);
1778 return self.mk_expr(lo, hi, ex);
1781 // parse a block or unsafe block
1782 pub fn parse_block_expr(&self, lo: BytePos, blk_mode: BlockCheckMode)
1784 self.expect(&token::LBRACE);
1785 let blk = self.parse_block_tail(lo, blk_mode);
1786 return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
1789 // parse a.b or a(13) or a[4] or just a
1790 pub fn parse_dot_or_call_expr(&self) -> @expr {
1791 let b = self.parse_bottom_expr();
1792 self.parse_dot_or_call_expr_with(b)
1795 pub fn parse_dot_or_call_expr_with(&self, e0: @expr) -> @expr {
1801 if self.eat(&token::DOT) {
1803 token::IDENT(i, _) => {
1806 let (_, tys) = if self.eat(&token::MOD_SEP) {
1807 self.expect(&token::LT);
1808 self.parse_generic_values_after_lt()
1810 (opt_vec::Empty, ~[])
1813 // expr.f() method call
1816 let es = self.parse_unspanned_seq(
1819 seq_sep_trailing_disallowed(token::COMMA),
1824 let nd = self.mk_method_call(e, i, tys, es, NoSugar);
1825 e = self.mk_expr(lo, hi, nd);
1828 e = self.mk_expr(lo, hi, self.mk_field(e, i, tys));
1832 _ => self.unexpected()
1836 if self.expr_is_complete(e) { break; }
1840 let es = self.parse_unspanned_seq(
1843 seq_sep_trailing_disallowed(token::COMMA),
1848 let nd = self.mk_call(e, es, NoSugar);
1849 e = self.mk_expr(lo, hi, nd);
1853 token::LBRACKET => {
1855 let ix = self.parse_expr();
1857 self.expect(&token::RBRACKET);
1858 e = self.mk_expr(lo, hi, self.mk_index(e, ix));
1867 // parse an optional separator followed by a kleene-style
1868 // repetition token (+ or *).
1869 pub fn parse_sep_and_zerok(&self) -> (Option<token::Token>, bool) {
1870 fn parse_zerok(parser: &Parser) -> Option<bool> {
1871 match *parser.token {
1872 token::BINOP(token::STAR) | token::BINOP(token::PLUS) => {
1873 let zerok = *parser.token == token::BINOP(token::STAR);
1881 match parse_zerok(self) {
1882 Some(zerok) => return (None, zerok),
1886 let separator = self.bump_and_get();
1887 match parse_zerok(self) {
1888 Some(zerok) => (Some(separator), zerok),
1889 None => self.fatal("expected `*` or `+`")
1893 // parse a single token tree from the input.
1894 pub fn parse_token_tree(&self) -> token_tree {
1895 maybe_whole!(deref self, nt_tt);
1897 // this is the fall-through for the 'match' below.
1898 // invariants: the current token is not a left-delimiter,
1899 // not an EOF, and not the desired right-delimiter (if
1900 // it were, parse_seq_to_before_end would have prevented
1901 // reaching this point.
1902 fn parse_non_delim_tt_tok(p: &Parser) -> token_tree {
1903 maybe_whole!(deref p, nt_tt);
1905 token::RPAREN | token::RBRACE | token::RBRACKET
1909 "incorrect close delimiter: `%s`",
1910 p.this_token_to_str()
1914 /* we ought to allow different depths of unquotation */
1915 token::DOLLAR if *p.quote_depth > 0u => {
1919 if *p.token == token::LPAREN {
1920 let seq = p.parse_seq(
1924 |p| p.parse_token_tree()
1926 let (s, z) = p.parse_sep_and_zerok();
1927 let seq = match seq {
1928 spanned { node, _ } => node,
1931 mk_sp(sp.lo, p.span.hi),
1937 tt_nonterminal(sp, p.parse_ident())
1946 // turn the next token into a tt_tok:
1947 fn parse_any_tt_tok(p: &Parser) -> token_tree{
1948 tt_tok(*p.span, p.bump_and_get())
1953 self.fatal("file ended with unbalanced delimiters");
1955 token::LPAREN | token::LBRACE | token::LBRACKET => {
1956 let close_delim = token::flip_delimiter(&*self.token);
1958 // Parse the open delimiter.
1959 let mut result = ~[parse_any_tt_tok(self)];
1962 self.parse_seq_to_before_end(&close_delim,
1964 |p| p.parse_token_tree());
1965 result.push_all_move(trees);
1967 // Parse the close delimiter.
1968 result.push(parse_any_tt_tok(self));
1970 tt_delim(@mut result)
1972 _ => parse_non_delim_tt_tok(self)
1976 // parse a stream of tokens into a list of token_trees,
1978 pub fn parse_all_token_trees(&self) -> ~[token_tree] {
1980 while *self.token != token::EOF {
1981 tts.push(self.parse_token_tree());
1986 pub fn parse_matchers(&self) -> ~[matcher] {
1987 // unification of matchers and token_trees would vastly improve
1988 // the interpolation of matchers
1989 maybe_whole!(self, nt_matchers);
1990 let name_idx = @mut 0u;
1992 token::LBRACE | token::LPAREN | token::LBRACKET => {
1993 let other_delimiter = token::flip_delimiter(self.token);
1995 self.parse_matcher_subseq_upto(name_idx, &other_delimiter)
1997 _ => self.fatal("expected open delimiter")
2001 // This goofy function is necessary to correctly match parens in matchers.
2002 // Otherwise, `$( ( )` would be a valid matcher, and `$( () )` would be
2003 // invalid. It's similar to common::parse_seq.
2004 pub fn parse_matcher_subseq_upto(&self,
2005 name_idx: @mut uint,
2008 let mut ret_val = ~[];
2009 let mut lparens = 0u;
2011 while *self.token != *ket || lparens > 0u {
2012 if *self.token == token::LPAREN { lparens += 1u; }
2013 if *self.token == token::RPAREN { lparens -= 1u; }
2014 ret_val.push(self.parse_matcher(name_idx));
2022 pub fn parse_matcher(&self, name_idx: @mut uint) -> matcher {
2023 let lo = self.span.lo;
2025 let m = if *self.token == token::DOLLAR {
2027 if *self.token == token::LPAREN {
2028 let name_idx_lo = *name_idx;
2030 let ms = self.parse_matcher_subseq_upto(name_idx,
2033 self.fatal("repetition body must be nonempty");
2035 let (sep, zerok) = self.parse_sep_and_zerok();
2036 match_seq(ms, sep, zerok, name_idx_lo, *name_idx)
2038 let bound_to = self.parse_ident();
2039 self.expect(&token::COLON);
2040 let nt_name = self.parse_ident();
2041 let m = match_nonterminal(bound_to, nt_name, *name_idx);
2046 match_tok(self.bump_and_get())
2049 return spanned(lo, self.span.hi, m);
2052 // parse a prefix-operator expr
2053 pub fn parse_prefix_expr(&self) -> @expr {
2054 let lo = self.span.lo;
2061 let e = self.parse_prefix_expr();
2063 ex = self.mk_unary(not, e);
2065 token::BINOP(b) => {
2069 let e = self.parse_prefix_expr();
2071 ex = self.mk_unary(neg, e);
2075 let e = self.parse_prefix_expr();
2077 ex = self.mk_unary(deref, e);
2081 let _lt = self.parse_opt_lifetime();
2082 let m = self.parse_mutability();
2083 let e = self.parse_prefix_expr();
2085 // HACK: turn &[...] into a &-evec
2087 expr_vec(*) | expr_lit(@codemap::spanned {
2088 node: lit_str(_), span: _
2091 expr_vstore(e, expr_vstore_slice)
2093 expr_vec(*) if m == m_mutbl => {
2094 expr_vstore(e, expr_vstore_mut_slice)
2096 _ => expr_addr_of(m, e)
2099 _ => return self.parse_dot_or_call_expr()
2104 let m = self.parse_mutability();
2106 self.obsolete(*self.last_span, ObsoleteConstManagedPointer);
2109 let e = self.parse_prefix_expr();
2111 // HACK: turn @[...] into a @-evec
2113 expr_vec(*) | expr_repeat(*) if m == m_mutbl =>
2114 expr_vstore(e, expr_vstore_mut_box),
2116 expr_lit(@codemap::spanned { node: lit_str(_), span: _}) |
2117 expr_repeat(*) if m == m_imm => expr_vstore(e, expr_vstore_box),
2118 _ => self.mk_unary(box(m), e)
2123 let m = self.parse_mutability();
2125 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
2128 let e = self.parse_prefix_expr();
2130 // HACK: turn ~[...] into a ~-evec
2133 expr_lit(@codemap::spanned { node: lit_str(_), span: _}) |
2134 expr_repeat(*) => expr_vstore(e, expr_vstore_uniq),
2135 _ => self.mk_unary(uniq, e)
2138 _ => return self.parse_dot_or_call_expr()
2140 return self.mk_expr(lo, hi, ex);
2143 // parse an expression of binops
2144 pub fn parse_binops(&self) -> @expr {
2145 self.parse_more_binops(self.parse_prefix_expr(), 0)
2148 // parse an expression of binops of at least min_prec precedence
2149 pub fn parse_more_binops(&self, lhs: @expr, min_prec: uint) -> @expr {
2150 if self.expr_is_complete(lhs) { return lhs; }
2152 // Prevent dynamic borrow errors later on by limiting the
2153 // scope of the borrows.
2155 let token: &token::Token = self.token;
2156 let restriction: &restriction = self.restriction;
2157 match (token, restriction) {
2158 (&token::BINOP(token::OR), &RESTRICT_NO_BAR_OP) => return lhs,
2159 (&token::BINOP(token::OR),
2160 &RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
2161 (&token::OROR, &RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
2166 let cur_opt = token_to_binop(self.token);
2169 let cur_prec = operator_prec(cur_op);
2170 if cur_prec > min_prec {
2172 let expr = self.parse_prefix_expr();
2173 let rhs = self.parse_more_binops(expr, cur_prec);
2174 let bin = self.mk_expr(lhs.span.lo, rhs.span.hi,
2175 self.mk_binary(cur_op, lhs, rhs));
2176 self.parse_more_binops(bin, min_prec)
2182 if as_prec > min_prec && self.eat_keyword(keywords::As) {
2183 let rhs = self.parse_ty(true);
2184 let _as = self.mk_expr(lhs.span.lo,
2186 expr_cast(lhs, rhs));
2187 self.parse_more_binops(_as, min_prec)
2195 // parse an assignment expression....
2196 // actually, this seems to be the main entry point for
2197 // parsing an arbitrary expression.
2198 pub fn parse_assign_expr(&self) -> @expr {
2199 let lo = self.span.lo;
2200 let lhs = self.parse_binops();
2204 let rhs = self.parse_expr();
2205 self.mk_expr(lo, rhs.span.hi, expr_assign(lhs, rhs))
2207 token::BINOPEQ(op) => {
2209 let rhs = self.parse_expr();
2210 let aop = match op {
2212 token::MINUS => subtract,
2214 token::SLASH => div,
2215 token::PERCENT => rem,
2216 token::CARET => bitxor,
2217 token::AND => bitand,
2222 self.mk_expr(lo, rhs.span.hi,
2223 self.mk_assign_op(aop, lhs, rhs))
2226 self.obsolete(*self.span, ObsoleteBinaryMove);
2227 // Bogus value (but it's an error)
2231 self.mk_expr(lo, self.span.hi,
2235 self.obsolete(*self.span, ObsoleteSwap);
2237 // Ignore what we get, this is an error anyway
2239 self.mk_expr(lo, self.span.hi, expr_break(None))
2247 // parse an 'if' expression ('if' token already eaten)
2248 pub fn parse_if_expr(&self) -> @expr {
2249 let lo = self.last_span.lo;
2250 let cond = self.parse_expr();
2251 let thn = self.parse_block();
2252 let mut els: Option<@expr> = None;
2253 let mut hi = thn.span.hi;
2254 if self.eat_keyword(keywords::Else) {
2255 let elexpr = self.parse_else_expr();
2257 hi = elexpr.span.hi;
2259 self.mk_expr(lo, hi, expr_if(cond, thn, els))
2262 // `|args| { ... }` or `{ ...}` like in `do` expressions
2263 pub fn parse_lambda_block_expr(&self) -> @expr {
2264 self.parse_lambda_expr_(
2267 token::BINOP(token::OR) | token::OROR => {
2268 self.parse_fn_block_decl()
2271 // No argument list - `do foo {`
2285 let blk = self.parse_block();
2286 self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk))
2291 pub fn parse_lambda_expr(&self) -> @expr {
2292 self.parse_lambda_expr_(|| self.parse_fn_block_decl(),
2293 || self.parse_expr())
2296 // parse something of the form |args| expr
2297 // this is used both in parsing a lambda expr
2298 // and in parsing a block expr as e.g. in for...
2299 pub fn parse_lambda_expr_(&self,
2300 parse_decl: &fn() -> fn_decl,
2301 parse_body: &fn() -> @expr)
2303 let lo = self.last_span.lo;
2304 let decl = parse_decl();
2305 let body = parse_body();
2306 let fakeblock = ast::Block {
2311 rules: DefaultBlock,
2315 return self.mk_expr(lo, body.span.hi,
2316 expr_fn_block(decl, fakeblock));
2319 pub fn parse_else_expr(&self) -> @expr {
2320 if self.eat_keyword(keywords::If) {
2321 return self.parse_if_expr();
2323 let blk = self.parse_block();
2324 return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
2328 // parse a 'for' .. 'in' expression ('for' token already eaten)
2329 pub fn parse_for_expr(&self) -> @expr {
2330 // Parse: `for <src_pat> in <src_expr> <src_loop_block>`
2332 let lo = self.last_span.lo;
2333 let pat = self.parse_pat();
2334 self.expect_keyword(keywords::In);
2335 let expr = self.parse_expr();
2336 let loop_block = self.parse_block();
2337 let hi = self.span.hi;
2339 self.mk_expr(lo, hi, expr_for_loop(pat, expr, loop_block))
2343 // parse a 'for' or 'do'.
2344 // the 'for' and 'do' expressions parse as calls, but look like
2345 // function calls followed by a closure expression.
2346 pub fn parse_sugary_call_expr(&self, lo: BytePos,
2349 ctor: &fn(v: @expr) -> expr_)
2351 // Parse the callee `foo` in
2354 // etc, or the portion of the call expression before the lambda in
2357 // for foo.bar(a) || {
2358 // Turn on the restriction to stop at | or || so we can parse
2359 // them as the lambda arguments
2360 let e = self.parse_expr_res(RESTRICT_NO_BAR_OR_DOUBLEBAR_OP);
2362 expr_call(f, ref args, NoSugar) => {
2363 let block = self.parse_lambda_block_expr();
2364 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2366 let args = vec::append((*args).clone(), [last_arg]);
2367 self.mk_expr(lo, block.span.hi, expr_call(f, args, sugar))
2369 expr_method_call(_, f, i, ref tps, ref args, NoSugar) => {
2370 let block = self.parse_lambda_block_expr();
2371 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2373 let args = vec::append((*args).clone(), [last_arg]);
2374 self.mk_expr(lo, block.span.hi,
2375 self.mk_method_call(f,
2381 expr_field(f, i, ref tps) => {
2382 let block = self.parse_lambda_block_expr();
2383 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2385 self.mk_expr(lo, block.span.hi,
2386 self.mk_method_call(f,
2392 expr_path(*) | expr_call(*) | expr_method_call(*) |
2394 let block = self.parse_lambda_block_expr();
2395 let last_arg = self.mk_expr(block.span.lo, block.span.hi,
2400 self.mk_call(e, ~[last_arg], sugar))
2403 // There may be other types of expressions that can
2404 // represent the callee in `for` and `do` expressions
2405 // but they aren't represented by tests
2406 debug!("sugary call on %?", e.node);
2409 fmt!("`%s` must be followed by a block call", keyword));
2414 pub fn parse_while_expr(&self) -> @expr {
2415 let lo = self.last_span.lo;
2416 let cond = self.parse_expr();
2417 let body = self.parse_block();
2418 let hi = body.span.hi;
2419 return self.mk_expr(lo, hi, expr_while(cond, body));
2422 pub fn parse_loop_expr(&self, opt_ident: Option<ast::ident>) -> @expr {
2423 // loop headers look like 'loop {' or 'loop unsafe {'
2424 let is_loop_header =
2425 *self.token == token::LBRACE
2426 || (is_ident(&*self.token)
2427 && self.look_ahead(1, |t| *t == token::LBRACE));
2430 // This is a loop body
2431 let lo = self.last_span.lo;
2432 let body = self.parse_block();
2433 let hi = body.span.hi;
2434 return self.mk_expr(lo, hi, expr_loop(body, opt_ident));
2436 // This is a 'continue' expression
2437 if opt_ident.is_some() {
2438 self.span_err(*self.last_span,
2439 "a label may not be used with a `loop` expression");
2442 let lo = self.span.lo;
2443 let ex = if self.token_is_lifetime(&*self.token) {
2444 let lifetime = self.get_lifetime(&*self.token);
2446 expr_again(Some(lifetime))
2450 let hi = self.span.hi;
2451 return self.mk_expr(lo, hi, ex);
2455 // For distingishing between record literals and blocks
2456 fn looking_at_record_literal(&self) -> bool {
2457 *self.token == token::LBRACE &&
2458 (self.look_ahead(1, |t| token::is_keyword(keywords::Mut, t)) ||
2459 (self.look_ahead(1, |t| token::is_plain_ident(t)) &&
2460 self.look_ahead(2, |t| *t == token::COLON)))
2463 fn parse_match_expr(&self) -> @expr {
2464 let lo = self.last_span.lo;
2465 let discriminant = self.parse_expr();
2466 self.expect(&token::LBRACE);
2467 let mut arms: ~[arm] = ~[];
2468 while *self.token != token::RBRACE {
2469 let pats = self.parse_pats();
2470 let mut guard = None;
2471 if self.eat_keyword(keywords::If) {
2472 guard = Some(self.parse_expr());
2474 self.expect(&token::FAT_ARROW);
2475 let expr = self.parse_expr_res(RESTRICT_STMT_EXPR);
2478 !classify::expr_is_simple_block(expr)
2479 && *self.token != token::RBRACE;
2482 self.expect(&token::COMMA);
2484 self.eat(&token::COMMA);
2487 let blk = ast::Block {
2492 rules: DefaultBlock,
2496 arms.push(ast::arm { pats: pats, guard: guard, body: blk });
2498 let hi = self.span.hi;
2500 return self.mk_expr(lo, hi, expr_match(discriminant, arms));
2503 // parse an expression
2504 pub fn parse_expr(&self) -> @expr {
2505 return self.parse_expr_res(UNRESTRICTED);
2508 // parse an expression, subject to the given restriction
2509 fn parse_expr_res(&self, r: restriction) -> @expr {
2510 let old = *self.restriction;
2511 *self.restriction = r;
2512 let e = self.parse_assign_expr();
2513 *self.restriction = old;
2517 // parse the RHS of a local variable declaration (e.g. '= 14;')
2518 fn parse_initializer(&self) -> Option<@expr> {
2522 return Some(self.parse_expr());
2525 self.obsolete(*self.span, ObsoleteMoveInit);
2536 // parse patterns, separated by '|' s
2537 fn parse_pats(&self) -> ~[@pat] {
2540 pats.push(self.parse_pat());
2541 if *self.token == token::BINOP(token::OR) { self.bump(); }
2542 else { return pats; }
2546 fn parse_pat_vec_elements(
2548 ) -> (~[@pat], Option<@pat>, ~[@pat]) {
2549 let mut before = ~[];
2550 let mut slice = None;
2551 let mut after = ~[];
2552 let mut first = true;
2553 let mut before_slice = true;
2555 while *self.token != token::RBRACKET {
2556 if first { first = false; }
2557 else { self.expect(&token::COMMA); }
2559 let mut is_slice = false;
2561 if *self.token == token::DOTDOT {
2564 before_slice = false;
2568 let subpat = self.parse_pat();
2571 @ast::pat { node: pat_wild, _ } => (),
2572 @ast::pat { node: pat_ident(_, _, _), _ } => (),
2573 @ast::pat { span, _ } => self.span_fatal(
2574 span, "expected an identifier or `_`"
2577 slice = Some(subpat);
2580 before.push(subpat);
2587 (before, slice, after)
2590 // parse the fields of a struct-like pattern
2591 fn parse_pat_fields(&self) -> (~[ast::field_pat], bool) {
2592 let mut fields = ~[];
2593 let mut etc = false;
2594 let mut first = true;
2595 while *self.token != token::RBRACE {
2596 if first { first = false; }
2597 else { self.expect(&token::COMMA); }
2599 if *self.token == token::UNDERSCORE {
2601 if *self.token != token::RBRACE {
2604 "expected `}`, found `%s`",
2605 self.this_token_to_str()
2613 let lo1 = self.last_span.lo;
2614 let fieldname = self.parse_ident();
2615 let hi1 = self.last_span.lo;
2616 let fieldpath = ast_util::ident_to_path(mk_sp(lo1, hi1),
2619 if *self.token == token::COLON {
2621 subpat = self.parse_pat();
2623 subpat = @ast::pat {
2625 node: pat_ident(bind_infer, fieldpath, None),
2626 span: *self.last_span
2629 fields.push(ast::field_pat { ident: fieldname, pat: subpat });
2631 return (fields, etc);
2635 pub fn parse_pat(&self) -> @pat {
2636 maybe_whole!(self, nt_pat);
2638 let lo = self.span.lo;
2643 token::UNDERSCORE => {
2646 hi = self.last_span.hi;
2656 let sub = self.parse_pat();
2658 // HACK: parse @"..." as a literal of a vstore @str
2659 pat = match sub.node {
2661 node: expr_lit(@codemap::spanned {
2667 node: expr_vstore(e, expr_vstore_box),
2668 span: mk_sp(lo, hi),
2674 hi = self.last_span.hi;
2684 let sub = self.parse_pat();
2686 // HACK: parse ~"..." as a literal of a vstore ~str
2687 pat = match sub.node {
2689 node: expr_lit(@codemap::spanned {
2695 node: expr_vstore(e, expr_vstore_uniq),
2696 span: mk_sp(lo, hi),
2702 hi = self.last_span.hi;
2709 token::BINOP(token::AND) => {
2711 let lo = self.span.lo;
2713 let sub = self.parse_pat();
2715 // HACK: parse &"..." as a literal of a borrowed str
2716 pat = match sub.node {
2718 node: expr_lit(@codemap::spanned {
2719 node: lit_str(_), span: _}), _
2723 node: expr_vstore(e, expr_vstore_slice),
2728 _ => pat_region(sub)
2730 hi = self.last_span.hi;
2739 let (_, _) = self.parse_pat_fields();
2741 self.obsolete(*self.span, ObsoleteRecordPattern);
2743 hi = self.last_span.hi;
2751 // parse (pat,pat,pat,...) as tuple
2753 if *self.token == token::RPAREN {
2756 let lit = @codemap::spanned {
2758 span: mk_sp(lo, hi)};
2759 let expr = self.mk_expr(lo, hi, expr_lit(lit));
2760 pat = pat_lit(expr);
2762 let mut fields = ~[self.parse_pat()];
2763 if self.look_ahead(1, |t| *t != token::RPAREN) {
2764 while *self.token == token::COMMA {
2766 fields.push(self.parse_pat());
2769 if fields.len() == 1 { self.expect(&token::COMMA); }
2770 self.expect(&token::RPAREN);
2771 pat = pat_tup(fields);
2773 hi = self.last_span.hi;
2780 token::LBRACKET => {
2781 // parse [pat,pat,...] as vector pattern
2783 let (before, slice, after) =
2784 self.parse_pat_vec_elements();
2786 self.expect(&token::RBRACKET);
2787 pat = ast::pat_vec(before, slice, after);
2788 hi = self.last_span.hi;
2798 let tok = self.token;
2799 if !is_ident_or_path(tok)
2800 || self.is_keyword(keywords::True)
2801 || self.is_keyword(keywords::False) {
2802 // Parse an expression pattern or exp .. exp.
2804 // These expressions are limited to literals (possibly
2805 // preceded by unary-minus) or identifiers.
2806 let val = self.parse_literal_maybe_minus();
2807 if self.eat(&token::DOTDOT) {
2808 let end = if is_ident_or_path(tok) {
2809 let path = self.parse_path_with_tps(true);
2810 let hi = self.span.hi;
2811 self.mk_expr(lo, hi, expr_path(path))
2813 self.parse_literal_maybe_minus()
2815 pat = pat_range(val, end);
2819 } else if self.eat_keyword(keywords::Ref) {
2821 let mutbl = self.parse_mutability();
2822 pat = self.parse_pat_ident(bind_by_ref(mutbl));
2824 let can_be_enum_or_struct = do self.look_ahead(1) |t| {
2826 token::LPAREN | token::LBRACKET | token::LT |
2827 token::LBRACE | token::MOD_SEP => true,
2832 if self.look_ahead(1, |t| *t == token::DOTDOT) {
2833 let start = self.parse_expr_res(RESTRICT_NO_BAR_OP);
2834 self.eat(&token::DOTDOT);
2835 let end = self.parse_expr_res(RESTRICT_NO_BAR_OP);
2836 pat = pat_range(start, end);
2837 } else if is_plain_ident(&*self.token) && !can_be_enum_or_struct {
2838 let name = self.parse_path_without_tps();
2840 if self.eat(&token::AT) {
2842 sub = Some(self.parse_pat());
2847 pat = pat_ident(bind_infer, name, sub);
2849 // parse an enum pat
2850 let enum_path = self.parse_path_with_tps(true);
2855 self.parse_pat_fields();
2857 pat = pat_struct(enum_path, fields, etc);
2860 let mut args: ~[@pat] = ~[];
2863 let is_star = do self.look_ahead(1) |t| {
2865 token::BINOP(token::STAR) => true,
2870 // This is a "top constructor only" pat
2873 self.expect(&token::RPAREN);
2874 pat = pat_enum(enum_path, None);
2876 args = self.parse_unspanned_seq(
2879 seq_sep_trailing_disallowed(token::COMMA),
2882 pat = pat_enum(enum_path, Some(args));
2886 if enum_path.idents.len()==1u {
2887 // it could still be either an enum
2888 // or an identifier pattern, resolve
2889 // will sort it out:
2890 pat = pat_ident(bind_infer,
2894 pat = pat_enum(enum_path, Some(args));
2902 hi = self.last_span.hi;
2906 span: mk_sp(lo, hi),
2910 // parse ident or ident @ pat
2911 // used by the copy foo and ref foo patterns to give a good
2912 // error message when parsing mistakes like ref foo(a,b)
2913 fn parse_pat_ident(&self,
2914 binding_mode: ast::binding_mode)
2916 if !is_plain_ident(&*self.token) {
2917 self.span_fatal(*self.last_span,
2918 "expected identifier, found path");
2920 // why a path here, and not just an identifier?
2921 let name = self.parse_path_without_tps();
2922 let sub = if self.eat(&token::AT) {
2923 Some(self.parse_pat())
2928 // just to be friendly, if they write something like
2930 // we end up here with ( as the current token. This shortly
2931 // leads to a parse error. Note that if there is no explicit
2932 // binding mode then we do not end up here, because the lookahead
2933 // will direct us over to parse_enum_variant()
2934 if *self.token == token::LPAREN {
2937 "expected identifier, found enum pattern");
2940 pat_ident(binding_mode, name, sub)
2943 // parse a local variable declaration
2944 fn parse_local(&self, is_mutbl: bool) -> @Local {
2945 let lo = self.span.lo;
2946 let pat = self.parse_pat();
2948 if is_mutbl && !ast_util::pat_is_ident(pat) {
2949 self.obsolete(*self.span, ObsoleteMutWithMultipleBindings)
2955 span: mk_sp(lo, lo),
2957 if self.eat(&token::COLON) { ty = self.parse_ty(false); }
2958 let init = self.parse_initializer();
2965 span: mk_sp(lo, self.last_span.hi),
2969 // parse a "let" stmt
2970 fn parse_let(&self) -> @decl {
2971 let is_mutbl = self.eat_keyword(keywords::Mut);
2972 let lo = self.span.lo;
2973 let local = self.parse_local(is_mutbl);
2974 while self.eat(&token::COMMA) {
2975 let _ = self.parse_local(is_mutbl);
2976 self.obsolete(*self.span, ObsoleteMultipleLocalDecl);
2978 return @spanned(lo, self.last_span.hi, decl_local(local));
2981 // parse a structure field
2982 fn parse_name_and_ty(&self,
2984 attrs: ~[Attribute]) -> @struct_field {
2985 let lo = self.span.lo;
2986 if !is_plain_ident(&*self.token) {
2987 self.fatal("expected ident");
2989 let name = self.parse_ident();
2990 self.expect(&token::COLON);
2991 let ty = self.parse_ty(false);
2992 @spanned(lo, self.last_span.hi, ast::struct_field_ {
2993 kind: named_field(name, pr),
3000 // parse a statement. may include decl.
3001 // precondition: any attributes are parsed already
3002 pub fn parse_stmt(&self, item_attrs: ~[Attribute]) -> @stmt {
3003 maybe_whole!(self, nt_stmt);
3005 fn check_expected_item(p: &Parser, found_attrs: bool) {
3006 // If we have attributes then we should have an item
3008 p.span_err(*p.last_span, "expected item after attributes");
3012 let lo = self.span.lo;
3013 if self.is_keyword(keywords::Let) {
3014 check_expected_item(self, !item_attrs.is_empty());
3015 self.expect_keyword(keywords::Let);
3016 let decl = self.parse_let();
3017 return @spanned(lo, decl.span.hi, stmt_decl(decl, self.get_id()));
3018 } else if is_ident(&*self.token)
3019 && !token::is_any_keyword(self.token)
3020 && self.look_ahead(1, |t| *t == token::NOT) {
3021 // parse a macro invocation. Looks like there's serious
3022 // overlap here; if this clause doesn't catch it (and it
3023 // won't, for brace-delimited macros) it will fall through
3024 // to the macro clause of parse_item_or_view_item. This
3025 // could use some cleanup, it appears to me.
3027 // whoops! I now have a guess: I'm guessing the "parens-only"
3028 // rule here is deliberate, to allow macro users to use parens
3029 // for things that should be parsed as stmt_mac, and braces
3030 // for things that should expand into items. Tricky, and
3031 // somewhat awkward... and probably undocumented. Of course,
3032 // I could just be wrong.
3034 check_expected_item(self, !item_attrs.is_empty());
3036 // Potential trouble: if we allow macros with paths instead of
3037 // idents, we'd need to look ahead past the whole path here...
3038 let pth = self.parse_path_without_tps();
3041 let id = if *self.token == token::LPAREN {
3042 token::special_idents::invalid // no special identifier
3047 let tts = self.parse_unspanned_seq(
3051 |p| p.parse_token_tree()
3053 let hi = self.span.hi;
3055 if id == token::special_idents::invalid {
3056 return @spanned(lo, hi, stmt_mac(
3057 spanned(lo, hi, mac_invoc_tt(pth, tts)), false));
3059 // if it has a special ident, it's definitely an item
3060 return @spanned(lo, hi, stmt_decl(
3061 @spanned(lo, hi, decl_item(
3063 lo, hi, id /*id is good here*/,
3064 item_mac(spanned(lo, hi, mac_invoc_tt(pth, tts))),
3065 inherited, ~[/*no attrs*/]))),
3070 let found_attrs = !item_attrs.is_empty();
3071 match self.parse_item_or_view_item(item_attrs, false) {
3074 let decl = @spanned(lo, hi, decl_item(i));
3075 return @spanned(lo, hi, stmt_decl(decl, self.get_id()));
3077 iovi_view_item(vi) => {
3078 self.span_fatal(vi.span,
3079 "view items must be declared at the top of the block");
3081 iovi_foreign_item(_) => {
3082 self.fatal("foreign items are not allowed here");
3084 iovi_none(_) => { /* fallthrough */ }
3087 check_expected_item(self, found_attrs);
3089 // Remainder are line-expr stmts.
3090 let e = self.parse_expr_res(RESTRICT_STMT_EXPR);
3091 return @spanned(lo, e.span.hi, stmt_expr(e, self.get_id()));
3095 // is this expression a successfully-parsed statement?
3096 fn expr_is_complete(&self, e: @expr) -> bool {
3097 return *self.restriction == RESTRICT_STMT_EXPR &&
3098 !classify::expr_requires_semi_to_be_stmt(e);
3101 // parse a block. No inner attrs are allowed.
3102 pub fn parse_block(&self) -> Block {
3103 maybe_whole!(self, nt_block);
3105 let lo = self.span.lo;
3106 if self.eat_keyword(keywords::Unsafe) {
3107 self.obsolete(*self.span, ObsoleteUnsafeBlock);
3109 self.expect(&token::LBRACE);
3111 return self.parse_block_tail_(lo, DefaultBlock, ~[]);
3114 // parse a block. Inner attrs are allowed.
3115 fn parse_inner_attrs_and_block(&self)
3116 -> (~[Attribute], Block) {
3118 maybe_whole!(pair_empty self, nt_block);
3120 let lo = self.span.lo;
3121 if self.eat_keyword(keywords::Unsafe) {
3122 self.obsolete(*self.span, ObsoleteUnsafeBlock);
3124 self.expect(&token::LBRACE);
3125 let (inner, next) = self.parse_inner_attrs_and_next();
3127 (inner, self.parse_block_tail_(lo, DefaultBlock, next))
3130 // Precondition: already parsed the '{' or '#{'
3131 // I guess that also means "already parsed the 'impure'" if
3132 // necessary, and this should take a qualifier.
3133 // some blocks start with "#{"...
3134 fn parse_block_tail(&self, lo: BytePos, s: BlockCheckMode) -> Block {
3135 self.parse_block_tail_(lo, s, ~[])
3138 // parse the rest of a block expression or function body
3139 fn parse_block_tail_(&self, lo: BytePos, s: BlockCheckMode,
3140 first_item_attrs: ~[Attribute]) -> Block {
3141 let mut stmts = ~[];
3142 let mut expr = None;
3144 // wouldn't it be more uniform to parse view items only, here?
3145 let ParsedItemsAndViewItems {
3146 attrs_remaining: attrs_remaining,
3147 view_items: view_items,
3150 } = self.parse_items_and_view_items(first_item_attrs,
3153 for item in items.iter() {
3154 let decl = @spanned(item.span.lo, item.span.hi, decl_item(*item));
3155 stmts.push(@spanned(item.span.lo, item.span.hi,
3156 stmt_decl(decl, self.get_id())));
3159 let mut attributes_box = attrs_remaining;
3161 while (*self.token != token::RBRACE) {
3162 // parsing items even when they're not allowed lets us give
3163 // better error messages and recover more gracefully.
3164 attributes_box.push_all(self.parse_outer_attributes());
3167 if !attributes_box.is_empty() {
3168 self.span_err(*self.last_span, "expected item after attributes");
3169 attributes_box = ~[];
3171 self.bump(); // empty
3174 // fall through and out.
3177 let stmt = self.parse_stmt(attributes_box);
3178 attributes_box = ~[];
3180 stmt_expr(e, stmt_id) => {
3181 // expression without semicolon
3193 if classify::stmt_ends_with_semi(stmt) {
3196 "expected `;` or `}` after \
3197 expression but found `%s`",
3198 self.token_to_str(t)
3208 stmts.push(@codemap::spanned {
3209 node: stmt_semi(e, stmt_id),
3214 stmt_mac(ref m, _) => {
3215 // statement macro; might be an expr
3222 // if a block ends in `m!(arg)` without
3223 // a `;`, it must be an expr
3226 self.mk_mac_expr(stmt.span.lo,
3238 stmts.push(@codemap::spanned {
3239 node: stmt_mac((*m).clone(), true),
3244 _ => { // all other kinds of statements:
3247 if classify::stmt_ends_with_semi(stmt) {
3248 self.expect(&token::SEMI);
3256 if !attributes_box.is_empty() {
3257 self.span_err(*self.last_span, "expected item after attributes");
3260 let hi = self.span.hi;
3263 view_items: view_items,
3268 span: mk_sp(lo, hi),
3272 fn parse_optional_purity(&self) -> ast::purity {
3273 if self.eat_keyword(keywords::Pure) {
3274 self.obsolete(*self.last_span, ObsoletePurity);
3276 } else if self.eat_keyword(keywords::Unsafe) {
3283 fn parse_optional_onceness(&self) -> ast::Onceness {
3284 if self.eat_keyword(keywords::Once) { ast::Once } else { ast::Many }
3287 // matches optbounds = ( ( : ( boundseq )? )? )
3288 // where boundseq = ( bound + boundseq ) | bound
3289 // and bound = 'static | ty
3290 // Returns "None" if there's no colon (e.g. "T");
3291 // Returns "Some(Empty)" if there's a colon but nothing after (e.g. "T:")
3292 // Returns "Some(stuff)" otherwise (e.g. "T:stuff").
3293 // NB: The None/Some distinction is important for issue #7264.
3294 fn parse_optional_ty_param_bounds(&self) -> Option<OptVec<TyParamBound>> {
3295 if !self.eat(&token::COLON) {
3299 let mut result = opt_vec::Empty;
3302 token::LIFETIME(lifetime) => {
3303 if "static" == self.id_to_str(lifetime) {
3304 result.push(RegionTyParamBound);
3306 self.span_err(*self.span,
3307 "`'static` is the only permissible region bound here");
3311 token::MOD_SEP | token::IDENT(*) => {
3312 let tref = self.parse_trait_ref();
3313 result.push(TraitTyParamBound(tref));
3318 if !self.eat(&token::BINOP(token::PLUS)) {
3323 return Some(result);
3326 // matches typaram = IDENT optbounds
3327 fn parse_ty_param(&self) -> TyParam {
3328 let ident = self.parse_ident();
3329 let opt_bounds = self.parse_optional_ty_param_bounds();
3330 // For typarams we don't care about the difference b/w "<T>" and "<T:>".
3331 let bounds = opt_bounds.unwrap_or_default(opt_vec::Empty);
3332 ast::TyParam { ident: ident, id: self.get_id(), bounds: bounds }
3335 // parse a set of optional generic type parameter declarations
3336 // matches generics = ( ) | ( < > ) | ( < typaramseq ( , )? > ) | ( < lifetimes ( , )? > )
3337 // | ( < lifetimes , typaramseq ( , )? > )
3338 // where typaramseq = ( typaram ) | ( typaram , typaramseq )
3339 pub fn parse_generics(&self) -> ast::Generics {
3340 if self.eat(&token::LT) {
3341 let lifetimes = self.parse_lifetimes();
3342 let ty_params = self.parse_seq_to_gt(
3344 |p| p.parse_ty_param());
3345 ast::Generics { lifetimes: lifetimes, ty_params: ty_params }
3347 ast_util::empty_generics()
3351 // parse a generic use site
3352 fn parse_generic_values(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
3353 if !self.eat(&token::LT) {
3354 (opt_vec::Empty, ~[])
3356 self.parse_generic_values_after_lt()
3360 fn parse_generic_values_after_lt(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
3361 let lifetimes = self.parse_lifetimes();
3362 let result = self.parse_seq_to_gt(
3364 |p| p.parse_ty(false));
3365 (lifetimes, opt_vec::take_vec(result))
3368 // parse the argument list and result type of a function declaration
3369 pub fn parse_fn_decl(&self) -> fn_decl {
3370 let args_or_capture_items: ~[arg_or_capture_item] =
3371 self.parse_unspanned_seq(
3374 seq_sep_trailing_disallowed(token::COMMA),
3378 let inputs = either::lefts(args_or_capture_items);
3380 let (ret_style, ret_ty) = self.parse_ret_ty();
3388 fn is_self_ident(&self) -> bool {
3389 *self.token == token::IDENT(special_idents::self_, false)
3392 fn expect_self_ident(&self) {
3393 if !self.is_self_ident() {
3396 "expected `self` but found `%s`",
3397 self.this_token_to_str()
3404 // parse the argument list and result type of a function
3405 // that may have a self type.
3406 fn parse_fn_decl_with_self(
3409 &fn(&Parser) -> arg_or_capture_item
3410 ) -> (explicit_self, fn_decl) {
3411 fn maybe_parse_explicit_self(
3412 cnstr: &fn(v: mutability) -> ast::explicit_self_,
3414 ) -> ast::explicit_self_ {
3415 // We need to make sure it isn't a mode or a type
3416 if p.look_ahead(1, |t| token::is_keyword(keywords::Self, t)) ||
3417 ((p.look_ahead(1, |t| token::is_keyword(keywords::Const, t)) ||
3418 p.look_ahead(1, |t| token::is_keyword(keywords::Mut, t))) &&
3419 p.look_ahead(2, |t| token::is_keyword(keywords::Self, t))) {
3422 let mutability = p.parse_mutability();
3423 p.expect_self_ident();
3430 fn maybe_parse_borrowed_explicit_self(this: &Parser) -> ast::explicit_self_ {
3431 // The following things are possible to see here:
3436 // fn(&'lt mut self)
3438 // We already know that the current token is `&`.
3440 if this.look_ahead(1, |t| token::is_keyword(keywords::Self, t)) {
3442 this.expect_self_ident();
3443 sty_region(None, m_imm)
3444 } else if this.look_ahead(1, |t| this.token_is_mutability(t)) &&
3446 |t| token::is_keyword(keywords::Self,
3449 let mutability = this.parse_mutability();
3450 this.expect_self_ident();
3451 sty_region(None, mutability)
3452 } else if this.look_ahead(1, |t| this.token_is_lifetime(t)) &&
3454 |t| token::is_keyword(keywords::Self,
3457 let lifetime = this.parse_lifetime();
3458 this.expect_self_ident();
3459 sty_region(Some(lifetime), m_imm)
3460 } else if this.look_ahead(1, |t| this.token_is_lifetime(t)) &&
3461 this.look_ahead(2, |t| this.token_is_mutability(t)) &&
3462 this.look_ahead(3, |t| token::is_keyword(keywords::Self,
3465 let lifetime = this.parse_lifetime();
3466 let mutability = this.parse_mutability();
3467 this.expect_self_ident();
3468 sty_region(Some(lifetime), mutability)
3474 self.expect(&token::LPAREN);
3476 // A bit of complexity and lookahead is needed here in order to be
3477 // backwards compatible.
3478 let lo = self.span.lo;
3479 let explicit_self = match *self.token {
3480 token::BINOP(token::AND) => {
3481 maybe_parse_borrowed_explicit_self(self)
3484 maybe_parse_explicit_self(sty_box, self)
3487 maybe_parse_explicit_self(|mutability| {
3488 if mutability != m_imm {
3489 self.obsolete(*self.last_span, ObsoleteMutOwnedPointer);
3494 token::IDENT(*) if self.is_self_ident() => {
3503 // If we parsed a self type, expect a comma before the argument list.
3504 let args_or_capture_items;
3505 if explicit_self != sty_static {
3509 let sep = seq_sep_trailing_disallowed(token::COMMA);
3510 args_or_capture_items = self.parse_seq_to_before_end(
3517 args_or_capture_items = ~[];
3522 "expected `,` or `)`, found `%s`",
3523 self.this_token_to_str()
3529 let sep = seq_sep_trailing_disallowed(token::COMMA);
3530 args_or_capture_items = self.parse_seq_to_before_end(
3537 self.expect(&token::RPAREN);
3539 let hi = self.span.hi;
3541 let inputs = either::lefts(args_or_capture_items);
3542 let (ret_style, ret_ty) = self.parse_ret_ty();
3544 let fn_decl = ast::fn_decl {
3550 (spanned(lo, hi, explicit_self), fn_decl)
3553 // parse the |arg, arg| header on a lambda
3554 fn parse_fn_block_decl(&self) -> fn_decl {
3555 let inputs_captures = {
3556 if self.eat(&token::OROR) {
3559 self.parse_unspanned_seq(
3560 &token::BINOP(token::OR),
3561 &token::BINOP(token::OR),
3562 seq_sep_trailing_disallowed(token::COMMA),
3563 |p| p.parse_fn_block_arg()
3567 let output = if self.eat(&token::RARROW) {
3568 self.parse_ty(false)
3570 Ty { id: self.get_id(), node: ty_infer, span: *self.span }
3574 inputs: either::lefts(inputs_captures),
3580 // parse the name and optional generic types of a function header.
3581 fn parse_fn_header(&self) -> (ident, ast::Generics) {
3582 let id = self.parse_ident();
3583 let generics = self.parse_generics();
3587 fn mk_item(&self, lo: BytePos, hi: BytePos, ident: ident,
3588 node: item_, vis: visibility,
3589 attrs: ~[Attribute]) -> @item {
3590 @ast::item { ident: ident,
3595 span: mk_sp(lo, hi) }
3598 // parse an item-position function declaration.
3599 fn parse_item_fn(&self, purity: purity, abis: AbiSet) -> item_info {
3600 let (ident, generics) = self.parse_fn_header();
3601 let decl = self.parse_fn_decl();
3602 let (inner_attrs, body) = self.parse_inner_attrs_and_block();
3604 item_fn(decl, purity, abis, generics, body),
3608 // parse a method in a trait impl
3609 fn parse_method(&self) -> @method {
3610 let attrs = self.parse_outer_attributes();
3611 let lo = self.span.lo;
3613 let visa = self.parse_non_priv_visibility();
3614 let pur = self.parse_fn_purity();
3615 let ident = self.parse_ident();
3616 let generics = self.parse_generics();
3617 let (explicit_self, decl) = do self.parse_fn_decl_with_self() |p| {
3621 let (inner_attrs, body) = self.parse_inner_attrs_and_block();
3622 let hi = body.span.hi;
3623 let attrs = vec::append(attrs, inner_attrs);
3628 explicit_self: explicit_self,
3633 span: mk_sp(lo, hi),
3634 self_id: self.get_id(),
3639 // parse trait Foo { ... }
3640 fn parse_item_trait(&self) -> item_info {
3641 let ident = self.parse_ident();
3642 self.parse_region_param();
3643 let tps = self.parse_generics();
3645 // Parse traits, if necessary.
3647 if *self.token == token::COLON {
3649 traits = self.parse_trait_ref_list(&token::LBRACE);
3654 let meths = self.parse_trait_methods();
3655 (ident, item_trait(tps, traits, meths), None)
3658 // Parses two variants (with the region/type params always optional):
3659 // impl<T> Foo { ... }
3660 // impl<T> ToStr for ~[T] { ... }
3661 fn parse_item_impl(&self, visibility: ast::visibility) -> item_info {
3662 // First, parse type parameters if necessary.
3663 let generics = self.parse_generics();
3665 // This is a new-style impl declaration.
3667 let ident = special_idents::clownshoes_extensions;
3669 // Special case: if the next identifier that follows is '(', don't
3670 // allow this to be parsed as a trait.
3671 let could_be_trait = *self.token != token::LPAREN;
3674 let mut ty = self.parse_ty(false);
3676 // Parse traits, if necessary.
3677 let opt_trait = if could_be_trait && self.eat_keyword(keywords::For) {
3678 // New-style trait. Reinterpret the type as a trait.
3679 let opt_trait_ref = match ty.node {
3680 ty_path(ref path, None, node_id) => {
3682 path: /* bad */ (*path).clone(),
3687 self.span_err(ty.span,
3688 "bounded traits are only valid in type position");
3692 self.span_err(ty.span, "not a trait");
3697 ty = self.parse_ty(false);
3699 } else if self.eat(&token::COLON) {
3700 self.obsolete(*self.span, ObsoleteImplSyntax);
3701 Some(self.parse_trait_ref())
3706 // Do not allow visibility to be specified.
3707 if visibility != ast::inherited {
3708 self.obsolete(*self.span, ObsoleteImplVisibility);
3711 let mut meths = ~[];
3712 if !self.eat(&token::SEMI) {
3713 self.expect(&token::LBRACE);
3714 while !self.eat(&token::RBRACE) {
3715 meths.push(self.parse_method());
3719 (ident, item_impl(generics, opt_trait, ty, meths), None)
3722 // parse a::B<~str,int>
3723 fn parse_trait_ref(&self) -> trait_ref {
3725 path: self.parse_path_with_tps(false),
3726 ref_id: self.get_id(),
3730 // parse B + C<~str,int> + D
3731 fn parse_trait_ref_list(&self, ket: &token::Token) -> ~[trait_ref] {
3732 self.parse_seq_to_before_end(
3734 seq_sep_trailing_disallowed(token::BINOP(token::PLUS)),
3735 |p| p.parse_trait_ref()
3739 // parse struct Foo { ... }
3740 fn parse_item_struct(&self) -> item_info {
3741 let class_name = self.parse_ident();
3742 self.parse_region_param();
3743 let generics = self.parse_generics();
3744 if self.eat(&token::COLON) {
3745 self.obsolete(*self.span, ObsoleteClassTraits);
3746 let _ = self.parse_trait_ref_list(&token::LBRACE);
3749 let mut fields: ~[@struct_field];
3752 if self.eat(&token::LBRACE) {
3753 // It's a record-like struct.
3754 is_tuple_like = false;
3756 while *self.token != token::RBRACE {
3757 let r = self.parse_struct_decl_field();
3758 for struct_field in r.iter() {
3759 fields.push(*struct_field)
3762 if fields.len() == 0 {
3763 self.fatal(fmt!("Unit-like struct should be written as `struct %s;`",
3764 get_ident_interner().get(class_name.name)));
3767 } else if *self.token == token::LPAREN {
3768 // It's a tuple-like struct.
3769 is_tuple_like = true;
3770 fields = do self.parse_unspanned_seq(
3773 seq_sep_trailing_allowed(token::COMMA)
3775 let attrs = self.parse_outer_attributes();
3777 let struct_field_ = ast::struct_field_ {
3778 kind: unnamed_field,
3780 ty: p.parse_ty(false),
3783 @spanned(lo, p.span.hi, struct_field_)
3785 self.expect(&token::SEMI);
3786 } else if self.eat(&token::SEMI) {
3787 // It's a unit-like struct.
3788 is_tuple_like = true;
3793 "expected `{`, `(`, or `;` after struct name \
3795 self.this_token_to_str()
3800 let _ = self.get_id(); // XXX: Workaround for crazy bug.
3801 let new_id = self.get_id();
3803 item_struct(@ast::struct_def {
3805 ctor_id: if is_tuple_like { Some(new_id) } else { None }
3810 fn token_is_pound_or_doc_comment(&self, tok: token::Token) -> bool {
3812 token::POUND | token::DOC_COMMENT(_) => true,
3817 // parse a structure field declaration
3818 pub fn parse_single_struct_field(&self,
3820 attrs: ~[Attribute])
3822 if self.eat_obsolete_ident("let") {
3823 self.obsolete(*self.last_span, ObsoleteLet);
3826 let a_var = self.parse_name_and_ty(vis, attrs);
3829 self.obsolete(*self.span, ObsoleteFieldTerminator);
3837 self.span_fatal(*self.span,
3838 fmt!("expected `,`, or '}' but found `%s`",
3839 self.this_token_to_str()));
3845 // parse an element of a struct definition
3846 fn parse_struct_decl_field(&self) -> ~[@struct_field] {
3848 let attrs = self.parse_outer_attributes();
3850 if self.try_parse_obsolete_priv_section(attrs) {
3854 if self.eat_keyword(keywords::Priv) {
3855 return ~[self.parse_single_struct_field(private, attrs)]
3858 if self.eat_keyword(keywords::Pub) {
3859 return ~[self.parse_single_struct_field(public, attrs)];
3862 if self.try_parse_obsolete_struct_ctor() {
3866 return ~[self.parse_single_struct_field(inherited, attrs)];
3869 // parse visiility: PUB, PRIV, or nothing
3870 fn parse_visibility(&self) -> visibility {
3871 if self.eat_keyword(keywords::Pub) { public }
3872 else if self.eat_keyword(keywords::Priv) { private }
3876 // parse visibility, but emits an obsolete error if it's private
3877 fn parse_non_priv_visibility(&self) -> visibility {
3878 match self.parse_visibility() {
3880 inherited => inherited,
3882 self.obsolete(*self.last_span, ObsoletePrivVisibility);
3888 fn parse_staticness(&self) -> bool {
3889 if self.eat_keyword(keywords::Static) {
3890 self.obsolete(*self.last_span, ObsoleteStaticMethod);
3897 // given a termination token and a vector of already-parsed
3898 // attributes (of length 0 or 1), parse all of the items in a module
3899 fn parse_mod_items(&self,
3901 first_item_attrs: ~[Attribute])
3903 // parse all of the items up to closing or an attribute.
3904 // view items are legal here.
3905 let ParsedItemsAndViewItems {
3906 attrs_remaining: attrs_remaining,
3907 view_items: view_items,
3908 items: starting_items,
3910 } = self.parse_items_and_view_items(first_item_attrs, true, true);
3911 let mut items: ~[@item] = starting_items;
3912 let attrs_remaining_len = attrs_remaining.len();
3914 // don't think this other loop is even necessary....
3916 let mut first = true;
3917 while *self.token != term {
3918 let mut attrs = self.parse_outer_attributes();
3920 attrs = attrs_remaining + attrs;
3923 debug!("parse_mod_items: parse_item_or_view_item(attrs=%?)",
3925 match self.parse_item_or_view_item(attrs,
3926 true /* macros allowed */) {
3927 iovi_item(item) => items.push(item),
3928 iovi_view_item(view_item) => {
3929 self.span_fatal(view_item.span,
3930 "view items must be declared at the top of \
3934 self.fatal(fmt!("expected item but found `%s`",
3935 self.this_token_to_str()));
3940 if first && attrs_remaining_len > 0u {
3941 // We parsed attributes for the first item but didn't find it
3942 self.span_err(*self.last_span, "expected item after attributes");
3945 ast::_mod { view_items: view_items, items: items }
3948 fn parse_item_const(&self) -> item_info {
3949 let m = if self.eat_keyword(keywords::Mut) {m_mutbl} else {m_imm};
3950 let id = self.parse_ident();
3951 self.expect(&token::COLON);
3952 let ty = self.parse_ty(false);
3953 self.expect(&token::EQ);
3954 let e = self.parse_expr();
3955 self.expect(&token::SEMI);
3956 (id, item_static(ty, m, e), None)
3959 // parse a `mod <foo> { ... }` or `mod <foo>;` item
3960 fn parse_item_mod(&self, outer_attrs: &[Attribute]) -> item_info {
3961 let id_span = *self.span;
3962 let id = self.parse_ident();
3963 if *self.token == token::SEMI {
3965 // This mod is in an external file. Let's go get it!
3966 let (m, attrs) = self.eval_src_mod(id, outer_attrs, id_span);
3967 (id, m, Some(attrs))
3969 self.push_mod_path(id, outer_attrs);
3970 self.expect(&token::LBRACE);
3971 let (inner, next) = self.parse_inner_attrs_and_next();
3972 let m = self.parse_mod_items(token::RBRACE, next);
3973 self.expect(&token::RBRACE);
3974 self.pop_mod_path();
3975 (id, item_mod(m), Some(inner))
3979 fn push_mod_path(&self, id: ident, attrs: &[Attribute]) {
3980 let default_path = token::interner_get(id.name);
3981 let file_path = match ::attr::first_attr_value_str_by_name(attrs,
3984 None => default_path
3986 self.mod_path_stack.push(file_path)
3989 fn pop_mod_path(&self) {
3990 self.mod_path_stack.pop();
3993 // read a module from a source file.
3994 fn eval_src_mod(&self,
3996 outer_attrs: &[ast::Attribute],
3998 -> (ast::item_, ~[ast::Attribute]) {
3999 let prefix = Path(self.sess.cm.span_to_filename(*self.span));
4000 let prefix = prefix.dir_path();
4001 let mod_path_stack = &*self.mod_path_stack;
4002 let mod_path = Path(".").push_many(*mod_path_stack);
4003 let dir_path = prefix.push_many(mod_path.components);
4004 let file_path = match ::attr::first_attr_value_str_by_name(
4005 outer_attrs, "path") {
4008 if !path.is_absolute {
4015 let mod_name = token::interner_get(id.name).to_owned();
4016 let default_path_str = mod_name + ".rs";
4017 let secondary_path_str = mod_name + "/mod.rs";
4018 let default_path = dir_path.push(default_path_str);
4019 let secondary_path = dir_path.push(secondary_path_str);
4020 let default_exists = default_path.exists();
4021 let secondary_exists = secondary_path.exists();
4022 match (default_exists, secondary_exists) {
4023 (true, false) => default_path,
4024 (false, true) => secondary_path,
4026 self.span_fatal(id_sp, fmt!("file not found for module `%s`", mod_name));
4029 self.span_fatal(id_sp,
4030 fmt!("file for module `%s` found at both %s and %s",
4031 mod_name, default_path_str, secondary_path_str));
4037 self.eval_src_mod_from_path(file_path,
4038 outer_attrs.to_owned(),
4042 fn eval_src_mod_from_path(&self,
4044 outer_attrs: ~[ast::Attribute],
4045 id_sp: span) -> (ast::item_, ~[ast::Attribute]) {
4046 let full_path = path.normalize();
4048 let maybe_i = do self.sess.included_mod_stack.iter().position |p| { *p == full_path };
4051 let stack = &self.sess.included_mod_stack;
4052 let mut err = ~"circular modules: ";
4053 for p in stack.slice(i, stack.len()).iter() {
4054 err.push_str(p.to_str());
4055 err.push_str(" -> ");
4057 err.push_str(full_path.to_str());
4058 self.span_fatal(id_sp, err);
4062 self.sess.included_mod_stack.push(full_path.clone());
4065 new_sub_parser_from_file(self.sess,
4069 let (inner, next) = p0.parse_inner_attrs_and_next();
4070 let mod_attrs = vec::append(outer_attrs, inner);
4071 let first_item_outer_attrs = next;
4072 let m0 = p0.parse_mod_items(token::EOF, first_item_outer_attrs);
4073 self.sess.included_mod_stack.pop();
4074 return (ast::item_mod(m0), mod_attrs);
4077 // parse a function declaration from a foreign module
4078 fn parse_item_foreign_fn(&self, attrs: ~[Attribute]) -> @foreign_item {
4079 let lo = self.span.lo;
4080 let vis = self.parse_non_priv_visibility();
4082 // Parse obsolete purity.
4083 let purity = self.parse_fn_purity();
4084 if purity != impure_fn {
4085 self.obsolete(*self.last_span, ObsoleteUnsafeExternFn);
4088 let (ident, generics) = self.parse_fn_header();
4089 let decl = self.parse_fn_decl();
4090 let hi = self.span.hi;
4091 self.expect(&token::SEMI);
4092 @ast::foreign_item { ident: ident,
4094 node: foreign_item_fn(decl, generics),
4096 span: mk_sp(lo, hi),
4100 // parse a const definition from a foreign module
4101 fn parse_item_foreign_const(&self, vis: ast::visibility,
4102 attrs: ~[Attribute]) -> @foreign_item {
4103 let lo = self.span.lo;
4105 // XXX: Obsolete; remove after snap.
4106 if self.eat_keyword(keywords::Const) {
4107 self.obsolete(*self.last_span, ObsoleteConstItem);
4109 self.expect_keyword(keywords::Static);
4111 let mutbl = self.eat_keyword(keywords::Mut);
4113 let ident = self.parse_ident();
4114 self.expect(&token::COLON);
4115 let ty = self.parse_ty(false);
4116 let hi = self.span.hi;
4117 self.expect(&token::SEMI);
4118 @ast::foreign_item { ident: ident,
4120 node: foreign_item_static(ty, mutbl),
4122 span: mk_sp(lo, hi),
4126 // parse safe/unsafe and fn
4127 fn parse_fn_purity(&self) -> purity {
4128 if self.eat_keyword(keywords::Fn) { impure_fn }
4129 else if self.eat_keyword(keywords::Pure) {
4130 self.obsolete(*self.last_span, ObsoletePurity);
4131 self.expect_keyword(keywords::Fn);
4132 // NB: We parse this as impure for bootstrapping purposes.
4134 } else if self.eat_keyword(keywords::Unsafe) {
4135 self.expect_keyword(keywords::Fn);
4138 else { self.unexpected(); }
4142 // at this point, this is essentially a wrapper for
4143 // parse_foreign_items.
4144 fn parse_foreign_mod_items(&self,
4145 sort: ast::foreign_mod_sort,
4147 first_item_attrs: ~[Attribute])
4149 let ParsedItemsAndViewItems {
4150 attrs_remaining: attrs_remaining,
4151 view_items: view_items,
4153 foreign_items: foreign_items
4154 } = self.parse_foreign_items(first_item_attrs, true);
4155 if (! attrs_remaining.is_empty()) {
4156 self.span_err(*self.last_span,
4157 "expected item after attributes");
4159 assert!(*self.token == token::RBRACE);
4163 view_items: view_items,
4164 items: foreign_items
4168 // parse extern foo; or extern mod foo { ... } or extern { ... }
4169 fn parse_item_foreign_mod(&self,
4171 opt_abis: Option<AbiSet>,
4172 visibility: visibility,
4173 attrs: ~[Attribute],
4174 items_allowed: bool)
4175 -> item_or_view_item {
4176 let mut must_be_named_mod = false;
4177 if self.is_keyword(keywords::Mod) {
4178 must_be_named_mod = true;
4179 self.expect_keyword(keywords::Mod);
4180 } else if *self.token != token::LBRACE {
4181 self.span_fatal(*self.span,
4182 fmt!("expected `{` or `mod` but found `%s`",
4183 self.this_token_to_str()));
4186 let (sort, maybe_path, ident) = match *self.token {
4187 token::IDENT(*) => {
4188 let the_ident = self.parse_ident();
4189 let path = if *self.token == token::EQ {
4191 Some(self.parse_str())
4194 (ast::named, path, the_ident)
4197 if must_be_named_mod {
4198 self.span_fatal(*self.span,
4199 fmt!("expected foreign module name but \
4201 self.this_token_to_str()));
4204 (ast::anonymous, None,
4205 special_idents::clownshoes_foreign_mod)
4209 // extern mod foo { ... } or extern { ... }
4210 if items_allowed && self.eat(&token::LBRACE) {
4211 // `extern mod foo { ... }` is obsolete.
4212 if sort == ast::named {
4213 self.obsolete(*self.last_span, ObsoleteNamedExternModule);
4216 // Do not allow visibility to be specified.
4217 if visibility != ast::inherited {
4218 self.obsolete(*self.last_span, ObsoleteExternVisibility);
4221 let abis = opt_abis.unwrap_or_default(AbiSet::C());
4223 let (inner, next) = self.parse_inner_attrs_and_next();
4224 let m = self.parse_foreign_mod_items(sort, abis, next);
4225 self.expect(&token::RBRACE);
4227 return iovi_item(self.mk_item(lo,
4230 item_foreign_mod(m),
4232 maybe_append(attrs, Some(inner))));
4235 if opt_abis.is_some() {
4236 self.span_err(*self.span, "an ABI may not be specified here");
4240 let metadata = self.parse_optional_meta();
4241 self.expect(&token::SEMI);
4242 iovi_view_item(ast::view_item {
4243 node: view_item_extern_mod(ident, maybe_path, metadata, self.get_id()),
4246 span: mk_sp(lo, self.last_span.hi)
4250 // parse type Foo = Bar;
4251 fn parse_item_type(&self) -> item_info {
4252 let ident = self.parse_ident();
4253 self.parse_region_param();
4254 let tps = self.parse_generics();
4255 self.expect(&token::EQ);
4256 let ty = self.parse_ty(false);
4257 self.expect(&token::SEMI);
4258 (ident, item_ty(ty, tps), None)
4261 // parse obsolete region parameter
4262 fn parse_region_param(&self) {
4263 if self.eat(&token::BINOP(token::SLASH)) {
4264 self.obsolete(*self.last_span, ObsoleteLifetimeNotation);
4265 self.expect(&token::BINOP(token::AND));
4269 // parse a structure-like enum variant definition
4270 // this should probably be renamed or refactored...
4271 fn parse_struct_def(&self) -> @struct_def {
4272 let mut fields: ~[@struct_field] = ~[];
4273 while *self.token != token::RBRACE {
4274 let r = self.parse_struct_decl_field();
4275 for struct_field in r.iter() {
4276 fields.push(*struct_field);
4281 return @ast::struct_def {
4287 // parse the part of an "enum" decl following the '{'
4288 fn parse_enum_def(&self, _generics: &ast::Generics) -> enum_def {
4289 let mut variants = ~[];
4290 let mut all_nullary = true;
4291 let mut have_disr = false;
4292 while *self.token != token::RBRACE {
4293 let variant_attrs = self.parse_outer_attributes();
4294 let vlo = self.span.lo;
4296 let vis = self.parse_visibility();
4301 let mut disr_expr = None;
4302 ident = self.parse_ident();
4303 if self.eat(&token::LBRACE) {
4304 // Parse a struct variant.
4305 all_nullary = false;
4306 kind = struct_variant_kind(self.parse_struct_def());
4307 } else if *self.token == token::LPAREN {
4308 all_nullary = false;
4309 let arg_tys = self.parse_unspanned_seq(
4312 seq_sep_trailing_disallowed(token::COMMA),
4313 |p| p.parse_ty(false)
4315 for ty in arg_tys.move_iter() {
4316 args.push(ast::variant_arg {
4321 kind = tuple_variant_kind(args);
4322 } else if self.eat(&token::EQ) {
4324 disr_expr = Some(self.parse_expr());
4325 kind = tuple_variant_kind(args);
4327 kind = tuple_variant_kind(~[]);
4330 let vr = ast::variant_ {
4332 attrs: variant_attrs,
4335 disr_expr: disr_expr,
4338 variants.push(spanned(vlo, self.last_span.hi, vr));
4340 if !self.eat(&token::COMMA) { break; }
4342 self.expect(&token::RBRACE);
4343 if (have_disr && !all_nullary) {
4344 self.fatal("discriminator values can only be used with a c-like \
4348 ast::enum_def { variants: variants }
4351 // parse an "enum" declaration
4352 fn parse_item_enum(&self) -> item_info {
4353 let id = self.parse_ident();
4354 self.parse_region_param();
4355 let generics = self.parse_generics();
4357 if *self.token == token::EQ {
4360 let ty = self.parse_ty(false);
4361 self.expect(&token::SEMI);
4362 let variant = spanned(ty.span.lo, ty.span.hi, ast::variant_ {
4365 kind: tuple_variant_kind(
4366 ~[ast::variant_arg {ty: ty, id: self.get_id()}]
4373 self.obsolete(*self.last_span, ObsoleteNewtypeEnum);
4378 ast::enum_def { variants: ~[variant] },
4384 self.expect(&token::LBRACE);
4386 let enum_definition = self.parse_enum_def(&generics);
4387 (id, item_enum(enum_definition, generics), None)
4390 fn parse_fn_ty_sigil(&self) -> Option<Sigil> {
4400 token::BINOP(token::AND) => {
4410 fn fn_expr_lookahead(&self, tok: &token::Token) -> bool {
4412 token::LPAREN | token::AT | token::TILDE | token::BINOP(_) => true,
4417 // parse a string as an ABI spec on an extern type or module
4418 fn parse_opt_abis(&self) -> Option<AbiSet> {
4420 token::LIT_STR(s) => {
4422 let the_string = ident_to_str(&s);
4423 let mut abis = AbiSet::empty();
4424 for word in the_string.word_iter() {
4425 match abi::lookup(word) {
4427 if abis.contains(abi) {
4430 fmt!("ABI `%s` appears twice",
4440 fmt!("illegal ABI: \
4441 expected one of [%s], \
4443 abi::all_names().connect(", "),
4457 // parse one of the items or view items allowed by the
4458 // flags; on failure, return iovi_none.
4459 // NB: this function no longer parses the items inside an
4461 fn parse_item_or_view_item(&self,
4462 attrs: ~[Attribute],
4463 macros_allowed: bool)
4464 -> item_or_view_item {
4466 INTERPOLATED(token::nt_item(item)) => {
4468 let new_attrs = vec::append(attrs, item.attrs);
4469 return iovi_item(@ast::item {
4471 ..(*item).clone()});
4476 let lo = self.span.lo;
4478 let visibility = self.parse_non_priv_visibility();
4480 // must be a view item:
4481 if self.eat_keyword(keywords::Use) {
4482 // USE ITEM (iovi_view_item)
4483 let view_item = self.parse_use();
4484 self.expect(&token::SEMI);
4485 return iovi_view_item(ast::view_item {
4489 span: mk_sp(lo, self.last_span.hi)
4492 // either a view item or an item:
4493 if self.eat_keyword(keywords::Extern) {
4494 let opt_abis = self.parse_opt_abis();
4496 if self.eat_keyword(keywords::Fn) {
4497 // EXTERN FUNCTION ITEM
4498 let abis = opt_abis.unwrap_or_default(AbiSet::C());
4499 let (ident, item_, extra_attrs) =
4500 self.parse_item_fn(extern_fn, abis);
4501 return iovi_item(self.mk_item(lo, self.last_span.hi, ident,
4506 // EXTERN MODULE ITEM (iovi_view_item)
4507 return self.parse_item_foreign_mod(lo, opt_abis, visibility, attrs,
4511 // the rest are all guaranteed to be items:
4512 if (self.is_keyword(keywords::Const) ||
4513 (self.is_keyword(keywords::Static) &&
4514 self.look_ahead(1, |t| !token::is_keyword(keywords::Fn, t)))) {
4515 // CONST / STATIC ITEM
4516 if self.is_keyword(keywords::Const) {
4517 self.obsolete(*self.span, ObsoleteConstItem);
4520 let (ident, item_, extra_attrs) = self.parse_item_const();
4521 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4523 maybe_append(attrs, extra_attrs)));
4525 if self.is_keyword(keywords::Fn) &&
4526 self.look_ahead(1, |f| !self.fn_expr_lookahead(f)) {
4529 let (ident, item_, extra_attrs) =
4530 self.parse_item_fn(impure_fn, AbiSet::Rust());
4531 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4533 maybe_append(attrs, extra_attrs)));
4535 if self.eat_keyword(keywords::Pure) {
4536 // PURE FUNCTION ITEM (obsolete)
4537 self.obsolete(*self.last_span, ObsoletePurity);
4538 self.expect_keyword(keywords::Fn);
4539 let (ident, item_, extra_attrs) =
4540 self.parse_item_fn(impure_fn, AbiSet::Rust());
4541 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4543 maybe_append(attrs, extra_attrs)));
4545 if self.is_keyword(keywords::Unsafe)
4546 && self.look_ahead(1u, |t| *t != token::LBRACE) {
4547 // UNSAFE FUNCTION ITEM
4549 self.expect_keyword(keywords::Fn);
4550 let (ident, item_, extra_attrs) =
4551 self.parse_item_fn(unsafe_fn, AbiSet::Rust());
4552 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4554 maybe_append(attrs, extra_attrs)));
4556 if self.eat_keyword(keywords::Mod) {
4558 let (ident, item_, extra_attrs) = self.parse_item_mod(attrs);
4559 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4561 maybe_append(attrs, extra_attrs)));
4563 if self.eat_keyword(keywords::Type) {
4565 let (ident, item_, extra_attrs) = self.parse_item_type();
4566 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4568 maybe_append(attrs, extra_attrs)));
4570 if self.eat_keyword(keywords::Enum) {
4572 let (ident, item_, extra_attrs) = self.parse_item_enum();
4573 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4575 maybe_append(attrs, extra_attrs)));
4577 if self.eat_keyword(keywords::Trait) {
4579 let (ident, item_, extra_attrs) = self.parse_item_trait();
4580 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4582 maybe_append(attrs, extra_attrs)));
4584 if self.eat_keyword(keywords::Impl) {
4586 let (ident, item_, extra_attrs) =
4587 self.parse_item_impl(visibility);
4588 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4590 maybe_append(attrs, extra_attrs)));
4592 if self.eat_keyword(keywords::Struct) {
4594 let (ident, item_, extra_attrs) = self.parse_item_struct();
4595 return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
4597 maybe_append(attrs, extra_attrs)));
4599 self.parse_macro_use_or_failure(attrs,macros_allowed,lo,visibility)
4602 // parse a foreign item; on failure, return iovi_none.
4603 fn parse_foreign_item(&self,
4604 attrs: ~[Attribute],
4605 macros_allowed: bool)
4606 -> item_or_view_item {
4607 maybe_whole!(iovi self, nt_item);
4608 let lo = self.span.lo;
4610 let visibility = self.parse_non_priv_visibility();
4612 if (self.is_keyword(keywords::Const) || self.is_keyword(keywords::Static)) {
4613 // FOREIGN CONST ITEM
4614 let item = self.parse_item_foreign_const(visibility, attrs);
4615 return iovi_foreign_item(item);
4617 if (self.is_keyword(keywords::Fn) || self.is_keyword(keywords::Pure) ||
4618 self.is_keyword(keywords::Unsafe)) {
4619 // FOREIGN FUNCTION ITEM
4620 let item = self.parse_item_foreign_fn(attrs);
4621 return iovi_foreign_item(item);
4623 self.parse_macro_use_or_failure(attrs,macros_allowed,lo,visibility)
4626 // this is the fall-through for parsing items.
4627 fn parse_macro_use_or_failure(
4629 attrs: ~[Attribute],
4630 macros_allowed: bool,
4632 visibility : visibility
4633 ) -> item_or_view_item {
4634 if macros_allowed && !token::is_any_keyword(self.token)
4635 && self.look_ahead(1, |t| *t == token::NOT)
4636 && (self.look_ahead(2, |t| is_plain_ident(t))
4637 || self.look_ahead(2, |t| *t == token::LPAREN)
4638 || self.look_ahead(2, |t| *t == token::LBRACE)) {
4639 // MACRO INVOCATION ITEM
4640 if attrs.len() > 0 {
4641 self.fatal("attrs on macros are not yet supported");
4645 let pth = self.parse_path_without_tps();
4646 self.expect(&token::NOT);
4648 // a 'special' identifier (like what `macro_rules!` uses)
4649 // is optional. We should eventually unify invoc syntax
4651 let id = if is_plain_ident(&*self.token) {
4654 token::special_idents::invalid // no special identifier
4656 // eat a matched-delimiter token tree:
4657 let tts = match *self.token {
4658 token::LPAREN | token::LBRACE => {
4659 let ket = token::flip_delimiter(&*self.token);
4661 self.parse_seq_to_end(&ket,
4663 |p| p.parse_token_tree())
4665 _ => self.fatal("expected open delimiter")
4667 // single-variant-enum... :
4668 let m = ast::mac_invoc_tt(pth, tts);
4669 let m: ast::mac = codemap::spanned { node: m,
4670 span: mk_sp(self.span.lo,
4672 let item_ = item_mac(m);
4673 return iovi_item(self.mk_item(lo, self.last_span.hi, id, item_,
4674 visibility, attrs));
4677 // FAILURE TO PARSE ITEM
4678 if visibility != inherited {
4679 let mut s = ~"unmatched visibility `";
4680 if visibility == public {
4686 self.span_fatal(*self.last_span, s);
4688 return iovi_none(attrs);
4691 pub fn parse_item(&self, attrs: ~[Attribute]) -> Option<@ast::item> {
4692 match self.parse_item_or_view_item(attrs, true) {
4693 iovi_none(_) => None,
4694 iovi_view_item(_) =>
4695 self.fatal("view items are not allowed here"),
4696 iovi_foreign_item(_) =>
4697 self.fatal("foreign items are not allowed here"),
4698 iovi_item(item) => Some(item)
4702 // parse, e.g., "use a::b::{z,y}"
4703 fn parse_use(&self) -> view_item_ {
4704 return view_item_use(self.parse_view_paths());
4708 // matches view_path : MOD? IDENT EQ non_global_path
4709 // | MOD? non_global_path MOD_SEP LBRACE RBRACE
4710 // | MOD? non_global_path MOD_SEP LBRACE ident_seq RBRACE
4711 // | MOD? non_global_path MOD_SEP STAR
4712 // | MOD? non_global_path
4713 fn parse_view_path(&self) -> @view_path {
4714 let lo = self.span.lo;
4716 let first_ident = self.parse_ident();
4717 let mut path = ~[first_ident];
4718 debug!("parsed view_path: %s", self.id_to_str(first_ident));
4723 path = ~[self.parse_ident()];
4724 while *self.token == token::MOD_SEP {
4726 let id = self.parse_ident();
4729 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4734 return @spanned(lo, self.span.hi,
4735 view_path_simple(first_ident,
4741 // foo::bar or foo::{a,b,c} or foo::*
4742 while *self.token == token::MOD_SEP {
4746 token::IDENT(i, _) => {
4751 // foo::bar::{a,b,c}
4753 let idents = self.parse_unspanned_seq(
4756 seq_sep_trailing_allowed(token::COMMA),
4757 |p| p.parse_path_list_ident()
4759 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4764 return @spanned(lo, self.span.hi,
4765 view_path_list(path, idents, self.get_id()));
4769 token::BINOP(token::STAR) => {
4771 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4776 return @spanned(lo, self.span.hi,
4777 view_path_glob(path, self.get_id()));
4786 let last = path[path.len() - 1u];
4787 let path = ast::Path { span: mk_sp(lo, self.span.hi),
4794 view_path_simple(last, path, self.get_id()));
4797 // matches view_paths = view_path | view_path , view_paths
4798 fn parse_view_paths(&self) -> ~[@view_path] {
4799 let mut vp = ~[self.parse_view_path()];
4800 while *self.token == token::COMMA {
4802 vp.push(self.parse_view_path());
4807 fn is_view_item(&self) -> bool {
4808 if !self.is_keyword(keywords::Pub) && !self.is_keyword(keywords::Priv) {
4809 token::is_keyword(keywords::Use, self.token)
4810 || (token::is_keyword(keywords::Extern, self.token) &&
4812 |t| token::is_keyword(keywords::Mod, t)))
4814 self.look_ahead(1, |t| token::is_keyword(keywords::Use, t))
4815 || (self.look_ahead(1,
4816 |t| token::is_keyword(keywords::Extern,
4819 |t| token::is_keyword(keywords::Mod, t)))
4823 // parse a view item.
4826 attrs: ~[Attribute],
4829 let lo = self.span.lo;
4830 let node = if self.eat_keyword(keywords::Use) {
4832 } else if self.eat_keyword(keywords::Extern) {
4833 self.expect_keyword(keywords::Mod);
4834 let ident = self.parse_ident();
4835 let path = if *self.token == token::EQ {
4837 Some(self.parse_str())
4840 let metadata = self.parse_optional_meta();
4841 view_item_extern_mod(ident, path, metadata, self.get_id())
4843 self.bug("expected view item");
4845 self.expect(&token::SEMI);
4846 ast::view_item { node: node,
4849 span: mk_sp(lo, self.last_span.hi) }
4852 // Parses a sequence of items. Stops when it finds program
4853 // text that can't be parsed as an item
4854 // - mod_items uses extern_mod_allowed = true
4855 // - block_tail_ uses extern_mod_allowed = false
4856 fn parse_items_and_view_items(&self,
4857 first_item_attrs: ~[Attribute],
4858 mut extern_mod_allowed: bool,
4859 macros_allowed: bool)
4860 -> ParsedItemsAndViewItems {
4861 let mut attrs = vec::append(first_item_attrs,
4862 self.parse_outer_attributes());
4863 // First, parse view items.
4864 let mut view_items : ~[ast::view_item] = ~[];
4865 let mut items = ~[];
4867 // I think this code would probably read better as a single
4868 // loop with a mutable three-state-variable (for extern mods,
4869 // view items, and regular items) ... except that because
4870 // of macros, I'd like to delay that entire check until later.
4872 match self.parse_item_or_view_item(attrs, macros_allowed) {
4873 iovi_none(attrs) => {
4874 return ParsedItemsAndViewItems {
4875 attrs_remaining: attrs,
4876 view_items: view_items,
4881 iovi_view_item(view_item) => {
4882 match view_item.node {
4883 view_item_use(*) => {
4884 // `extern mod` must precede `use`.
4885 extern_mod_allowed = false;
4887 view_item_extern_mod(*)
4888 if !extern_mod_allowed => {
4889 self.span_err(view_item.span,
4890 "\"extern mod\" declarations are not allowed here");
4892 view_item_extern_mod(*) => {}
4894 view_items.push(view_item);
4896 iovi_item(item) => {
4898 attrs = self.parse_outer_attributes();
4901 iovi_foreign_item(_) => {
4905 attrs = self.parse_outer_attributes();
4908 // Next, parse items.
4910 match self.parse_item_or_view_item(attrs, macros_allowed) {
4911 iovi_none(returned_attrs) => {
4912 attrs = returned_attrs;
4915 iovi_view_item(view_item) => {
4916 attrs = self.parse_outer_attributes();
4917 self.span_err(view_item.span,
4918 "`use` and `extern mod` declarations must precede items");
4920 iovi_item(item) => {
4921 attrs = self.parse_outer_attributes();
4924 iovi_foreign_item(_) => {
4930 ParsedItemsAndViewItems {
4931 attrs_remaining: attrs,
4932 view_items: view_items,
4938 // Parses a sequence of foreign items. Stops when it finds program
4939 // text that can't be parsed as an item
4940 fn parse_foreign_items(&self, first_item_attrs: ~[Attribute],
4941 macros_allowed: bool)
4942 -> ParsedItemsAndViewItems {
4943 let mut attrs = vec::append(first_item_attrs,
4944 self.parse_outer_attributes());
4945 let mut foreign_items = ~[];
4947 match self.parse_foreign_item(attrs, macros_allowed) {
4948 iovi_none(returned_attrs) => {
4949 if *self.token == token::RBRACE {
4950 attrs = returned_attrs;
4955 iovi_view_item(view_item) => {
4956 // I think this can't occur:
4957 self.span_err(view_item.span,
4958 "`use` and `extern mod` declarations must precede items");
4960 iovi_item(item) => {
4961 // FIXME #5668: this will occur for a macro invocation:
4962 self.span_fatal(item.span, "macros cannot expand to foreign items");
4964 iovi_foreign_item(foreign_item) => {
4965 foreign_items.push(foreign_item);
4968 attrs = self.parse_outer_attributes();
4971 ParsedItemsAndViewItems {
4972 attrs_remaining: attrs,
4975 foreign_items: foreign_items
4979 // Parses a source module as a crate. This is the main
4980 // entry point for the parser.
4981 pub fn parse_crate_mod(&self) -> @Crate {
4982 let lo = self.span.lo;
4983 // parse the crate's inner attrs, maybe (oops) one
4984 // of the attrs of an item:
4985 let (inner, next) = self.parse_inner_attrs_and_next();
4986 let first_item_outer_attrs = next;
4987 // parse the items inside the crate:
4988 let m = self.parse_mod_items(token::EOF, first_item_outer_attrs);
4993 config: self.cfg.clone(),
4994 span: mk_sp(lo, self.span.lo)
4998 pub fn parse_str(&self) -> @str {
5000 token::LIT_STR(s) => {
5004 _ => self.fatal("expected string literal")