rust/src/libsyntax/parse/parser.rs

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use core::prelude::*;

use ast::{ProtoBox, ProtoUniq, RegionTyParamBound, TraitTyParamBound};
use ast::{provided, public, pure_fn, purity, re_static};
use ast::{_mod, add, arg, arm, attribute, bind_by_ref, bind_infer};
use ast::{bind_by_copy, bitand, bitor, bitxor, blk};
use ast::{blk_check_mode, box, by_copy, by_ref, by_val};
use ast::{crate, crate_cfg, decl, decl_item};
use ast::{decl_local, default_blk, deref, div, enum_def, enum_variant_kind};
use ast::{expl, expr, expr_, expr_addr_of, expr_match, expr_again};
use ast::{expr_assert, expr_assign, expr_assign_op, expr_binary, expr_block};
use ast::{expr_break, expr_call, expr_cast, expr_copy, expr_do_body};
use ast::{expr_fail, expr_field, expr_fn, expr_fn_block, expr_if, expr_index};
use ast::{expr_lit, expr_log, expr_loop, expr_loop_body, expr_mac};
use ast::{expr_method_call, expr_paren, expr_path, expr_rec, expr_repeat};
use ast::{expr_ret, expr_swap, expr_struct, expr_tup, expr_unary};
use ast::{expr_vec, expr_vstore, expr_vstore_mut_box};
use ast::{expr_vstore_fixed, expr_vstore_slice, expr_vstore_box};
use ast::{expr_vstore_mut_slice, expr_while, extern_fn, field, fn_decl};
use ast::{expr_vstore_uniq, TyFn, Onceness, Once, Many};
use ast::{foreign_item, foreign_item_const, foreign_item_fn, foreign_mod};
use ast::{ident, impure_fn, infer, inherited, item, item_, item_const};
use ast::{item_const, item_enum, item_fn, item_foreign_mod, item_impl};
use ast::{item_mac, item_mod, item_struct, item_trait, item_ty, lit, lit_};
use ast::{lit_bool, lit_float, lit_float_unsuffixed, lit_int};
use ast::{lit_int_unsuffixed, lit_nil, lit_str, lit_uint, local, m_const};
use ast::{m_imm, m_mutbl, mac_, mac_invoc_tt, matcher, match_nonterminal};
use ast::{match_seq, match_tok, method, mode, module_ns, mt, mul, mutability};
use ast::{named_field, neg, node_id, noreturn, not, pat, pat_box, pat_enum};
use ast::{pat_ident, pat_lit, pat_range, pat_rec, pat_region, pat_struct};
use ast::{pat_tup, pat_uniq, pat_wild, path, private, Proto, ProtoBare};
use ast::{ProtoBorrowed, re_self, re_anon, re_named, region, rem, required};
use ast::{ret_style, return_val, self_ty, shl, shr, stmt, stmt_decl};
use ast::{stmt_expr, stmt_semi, stmt_mac, struct_def, struct_field};
use ast::{struct_immutable, struct_mutable, struct_variant_kind, subtract};
use ast::{sty_box, sty_by_ref, sty_region, sty_static, sty_uniq, sty_value};
use ast::{token_tree, trait_method, trait_ref, tt_delim, tt_seq, tt_tok};
use ast::{tt_nonterminal, tuple_variant_kind, Ty, ty_, ty_bot, ty_box};
use ast::{ty_field, ty_fixed_length_vec, ty_fn, ty_infer, ty_mac, ty_method};
use ast::{ty_nil, ty_param, ty_param_bound, ty_path, ty_ptr, ty_rec, ty_rptr};
use ast::{ty_tup, ty_u32, ty_uniq, ty_vec, type_value_ns, uniq};
use ast::{unnamed_field, unsafe_blk, unsafe_fn, variant, view_item};
use ast::{view_item_, view_item_import, view_item_use};
use ast::{view_path, view_path_glob, view_path_list, view_path_simple};
use ast::{visibility, vstore, vstore_box, vstore_fixed, vstore_slice};
use ast::{vstore_uniq};
use ast;
use ast_util::{spanned, respan, mk_sp, ident_to_path, operator_prec};
use ast_util;
use classify;
use codemap::{span,FssNone, BytePos};
use codemap;
use parse::attr::parser_attr;
use parse::common::{seq_sep_none, token_to_str};
use parse::common::{seq_sep_trailing_disallowed, seq_sep_trailing_allowed};
use parse::lexer::reader;
use parse::obsolete::{ObsoleteClassTraits, ObsoleteModeInFnType};
use parse::obsolete::{ObsoleteLet, ObsoleteFieldTerminator};
use parse::obsolete::{ObsoleteMoveInit, ObsoleteBinaryMove};
use parse::obsolete::{ObsoleteStructCtor, ObsoleteWith, ObsoleteClassMethod};
use parse::obsolete::{ObsoleteSyntax, ObsoleteLowerCaseKindBounds};
use parse::obsolete::{ObsoleteUnsafeBlock};
use parse::prec::{as_prec, token_to_binop};
use parse::token::{can_begin_expr, is_ident, is_ident_or_path};
use parse::token::{is_plain_ident, INTERPOLATED, special_idents};
use parse::token;
use parse::{new_sub_parser_from_file, next_node_id, parse_sess};
use print::pprust::expr_to_str;
use util::interner::Interner;

use core::cmp;
use core::dvec::DVec;
use core::dvec;
use core::either::{Either, Left, Right};
use core::either;
use core::result::Result;
use core::vec::push;
use core::vec;
use std::map::HashMap;

#[deriving_eq]
enum restriction {
    UNRESTRICTED,
    RESTRICT_STMT_EXPR,
    RESTRICT_NO_CALL_EXPRS,
    RESTRICT_NO_BAR_OP,
    RESTRICT_NO_BAR_OR_DOUBLEBAR_OP,
}

//  So that we can distinguish a class dtor from other class members

enum class_contents { dtor_decl(blk, ~[attribute], codemap::span),
                      members(~[@struct_field]) }

type arg_or_capture_item = Either<arg, ()>;
type item_info = (ident, item_, Option<~[attribute]>);

pub enum item_or_view_item {
    iovi_none,
    iovi_item(@item),
    iovi_foreign_item(@foreign_item),
    iovi_view_item(@view_item)
}

enum view_item_parse_mode {
    VIEW_ITEMS_AND_ITEMS_ALLOWED,
    VIEW_ITEMS_AND_FOREIGN_ITEMS_ALLOWED,
    IMPORTS_AND_ITEMS_ALLOWED
}

/* The expr situation is not as complex as I thought it would be.
The important thing is to make sure that lookahead doesn't balk
at INTERPOLATED tokens */
macro_rules! maybe_whole_expr (
    ($p:expr) => ( match copy $p.token {
      INTERPOLATED(token::nt_expr(e)) => {
        $p.bump();
        return e;
      }
      INTERPOLATED(token::nt_path(pt)) => {
        $p.bump();
        return $p.mk_expr($p.span.lo, $p.span.lo,
                       expr_path(pt));
      }
      _ => ()
    })
)

macro_rules! maybe_whole (
    ($p:expr, $constructor:ident) => ( match copy $p.token {
      INTERPOLATED(token::$constructor(ref x)) => { $p.bump(); return (*x); }
      _ => ()
    }) ;
    (deref $p:expr, $constructor:ident) => ( match copy $p.token {
      INTERPOLATED(token::$constructor(x)) => { $p.bump(); return *x; }
      _ => ()
    }) ;
    (Some $p:expr, $constructor:ident) => ( match copy $p.token {
      INTERPOLATED(token::$constructor(x)) => { $p.bump(); return Some(x); }
      _ => ()
    }) ;
    (iovi $p:expr, $constructor:ident) => ( match copy $p.token {
      INTERPOLATED(token::$constructor(x)) => {
        $p.bump();
        return iovi_item(x);
      }
      _ => ()
    }) ;
    (pair_empty $p:expr, $constructor:ident) => ( match copy $p.token {
      INTERPOLATED(token::$constructor(ref x)) => {
        $p.bump(); return (~[], (*x));
      }
      _ => ()
    })

)


pure fn maybe_append(+lhs: ~[attribute], rhs: Option<~[attribute]>)
                  -> ~[attribute] {
    match rhs {
        None => lhs,
        Some(ref attrs) => vec::append(lhs, (*attrs))
    }
}


/* ident is handled by common.rs */

pub fn Parser(sess: parse_sess,
              cfg: ast::crate_cfg,
              +rdr: reader) -> Parser {

    let tok0 = rdr.next_token();
    let span0 = tok0.sp;
    let interner = rdr.interner();

    Parser {
        reader: move rdr,
        interner: move interner,
        sess: sess,
        cfg: cfg,
        token: tok0.tok,
        span: span0,
        last_span: span0,
        buffer: [mut {tok: tok0.tok, sp: span0}, ..4],
        buffer_start: 0,
        buffer_end: 0,
        tokens_consumed: 0u,
        restriction: UNRESTRICTED,
        quote_depth: 0u,
        keywords: token::keyword_table(),
        strict_keywords: token::strict_keyword_table(),
        reserved_keywords: token::reserved_keyword_table(),
        obsolete_set: HashMap(),
        mod_path_stack: ~[],
    }
}

pub struct Parser {
    sess: parse_sess,
    cfg: crate_cfg,
    mut token: token::Token,
    mut span: span,
    mut last_span: span,
    mut buffer: [mut {tok: token::Token, sp: span} * 4],
    mut buffer_start: int,
    mut buffer_end: int,
    mut tokens_consumed: uint,
    mut restriction: restriction,
    mut quote_depth: uint, // not (yet) related to the quasiquoter
    reader: reader,
    interner: @token::ident_interner,
    keywords: HashMap<~str, ()>,
    strict_keywords: HashMap<~str, ()>,
    reserved_keywords: HashMap<~str, ()>,
    /// The set of seen errors about obsolete syntax. Used to suppress
    /// extra detail when the same error is seen twice
    obsolete_set: HashMap<ObsoleteSyntax, ()>,
    /// Used to determine the path to externally loaded source files
    mut mod_path_stack: ~[~str],

    drop {} /* do not copy the parser; its state is tied to outside state */
}

pub impl Parser {
    fn bump() {
        self.last_span = self.span;
        let next = if self.buffer_start == self.buffer_end {
            self.reader.next_token()
        } else {
            let next = self.buffer[self.buffer_start];
            self.buffer_start = (self.buffer_start + 1) & 3;
            next
        };
        self.token = next.tok;
        self.span = next.sp;
        self.tokens_consumed += 1u;
    }
    fn swap(next: token::Token, +lo: BytePos, +hi: BytePos) {
        self.token = next;
        self.span = mk_sp(lo, hi);
    }
    fn buffer_length() -> int {
        if self.buffer_start <= self.buffer_end {
            return self.buffer_end - self.buffer_start;
        }
        return (4 - self.buffer_start) + self.buffer_end;
    }
    fn look_ahead(distance: uint) -> token::Token {
        let dist = distance as int;
        while self.buffer_length() < dist {
            self.buffer[self.buffer_end] = self.reader.next_token();
            self.buffer_end = (self.buffer_end + 1) & 3;
        }
        return copy self.buffer[(self.buffer_start + dist - 1) & 3].tok;
    }
    fn fatal(m: ~str) -> ! {
        self.sess.span_diagnostic.span_fatal(copy self.span, m)
    }
    fn span_fatal(sp: span, m: ~str) -> ! {
        self.sess.span_diagnostic.span_fatal(sp, m)
    }
    fn span_note(sp: span, m: ~str) {
        self.sess.span_diagnostic.span_note(sp, m)
    }
    fn bug(m: ~str) -> ! {
        self.sess.span_diagnostic.span_bug(copy self.span, m)
    }
    fn warn(m: ~str) {
        self.sess.span_diagnostic.span_warn(copy self.span, m)
    }
    fn span_err(sp: span, m: ~str) {
        self.sess.span_diagnostic.span_err(sp, m)
    }
    fn abort_if_errors() {
        self.sess.span_diagnostic.handler().abort_if_errors();
    }
    fn get_id() -> node_id { next_node_id(self.sess) }

    pure fn id_to_str(id: ident) -> @~str { self.sess.interner.get(id) }

    fn token_is_fn_keyword(+tok: token::Token) -> bool {
        self.token_is_keyword(~"pure", tok) ||
            self.token_is_keyword(~"unsafe", tok) ||
            self.token_is_keyword(~"once", tok) ||
            self.token_is_keyword(~"fn", tok) ||
            self.token_is_keyword(~"extern", tok)
    }

    fn parse_ty_fn(pre_proto: Option<ast::Proto>,
                       pre_region_name: Option<ident>) -> ty_
    {
        /*

        (&|~|@) [r/] [pure|unsafe] [once] fn [:K] (S) -> T
        ^~~~~~^ ^~~^ ^~~~~~~~~~~~^ ^~~~~^    ^~~^ ^~^    ^
           |     |     |             |        |    |     |
           |     |     |             |        |    |   Return type
           |     |     |             |        |  Argument types
           |     |     |             |    Environment bounds
           |     |     |          Once-ness (a.k.a., affine)
           |     |   Purity
           | Lifetime bound
        Allocation type

        */

        // At this point, the allocation type and lifetime bound have been
        // parsed.

        let purity = parse_purity(&self);
        let onceness = parse_onceness(&self);

        let bounds, post_proto;
        if self.eat_keyword(~"extern") {
            self.expect_keyword(~"fn");
            post_proto = Some(ast::ProtoBare);
            bounds = @~[];
        } else {
            self.expect_keyword(~"fn");
            post_proto = self.parse_fn_ty_proto();
            bounds = self.parse_optional_ty_param_bounds();
        };

        let proto = match (pre_proto, post_proto) {
            (None, None) => ast::ProtoBorrowed,
            (Some(p), None) | (None, Some(p)) => p,
            (Some(_), Some(_)) => {
                self.fatal(~"cannot combine prefix and postfix \
                             syntax for closure kind; note that \
                             postfix syntax is obsolete");
            }
        };

        let region = if pre_region_name.is_some() {
            Some(self.region_from_name(pre_region_name))
        } else {
            None
        };

        return ty_fn(@TyFn {
            proto: proto,
            region: region,
            purity: purity,
            onceness: onceness,
            bounds: bounds,
            decl: self.parse_ty_fn_decl()
        });

        fn parse_purity(self: &Parser) -> purity {
            if self.eat_keyword(~"pure") {
                return pure_fn;
            } else if self.eat_keyword(~"unsafe") {
                return unsafe_fn;
            } else {
                return impure_fn;
            }
        }

        fn parse_onceness(self: &Parser) -> Onceness {
            if self.eat_keyword(~"once") {Once} else {Many}
        }
    }


    fn parse_ty_fn_decl() -> fn_decl {
        let inputs = do self.parse_unspanned_seq(
            token::LPAREN, token::RPAREN,
            seq_sep_trailing_disallowed(token::COMMA)) |p| {

            p.parse_arg_general(false)
        };
        let (ret_style, ret_ty) = self.parse_ret_ty();
        ast::fn_decl { inputs: inputs, output: ret_ty, cf: ret_style }
    }

    fn parse_trait_methods() -> ~[trait_method] {
        do self.parse_unspanned_seq(token::LBRACE, token::RBRACE,
                                    seq_sep_none()) |p| {
            let attrs = p.parse_outer_attributes();
            let lo = p.span.lo;
            let is_static = p.parse_staticness();
            let static_sty = spanned(lo, p.span.hi, sty_static);

            let vis = p.parse_visibility();
            let pur = p.parse_fn_purity();
            // NB: at the moment, trait methods are public by default; this
            // could change.
            let ident = p.parse_method_name();

            let tps = p.parse_ty_params();

            let (self_ty, d) = do self.parse_fn_decl_with_self() |p| {
                // This is somewhat dubious; We don't want to allow argument
                // names to be left off if there is a definition...
                either::Left(p.parse_arg_general(false))
            };
            // XXX: Wrong. Shouldn't allow both static and self_ty
            let self_ty = if is_static { static_sty } else { self_ty };

            let hi = p.last_span.hi;
            debug!("parse_trait_methods(): trait method signature ends in \
                    `%s`",
                   token_to_str(p.reader, p.token));
            match p.token {
              token::SEMI => {
                p.bump();
                debug!("parse_trait_methods(): parsing required method");
                // NB: at the moment, visibility annotations on required
                // methods are ignored; this could change.
                required(ty_method {
                    ident: ident,
                    attrs: attrs,
                    purity: pur,
                    decl: d,
                    tps: tps,
                    self_ty: self_ty,
                    id: p.get_id(),
                    span: mk_sp(lo, hi)
                })
              }
              token::LBRACE => {
                debug!("parse_trait_methods(): parsing provided method");
                let (inner_attrs, body) =
                    p.parse_inner_attrs_and_block(true);
                let attrs = vec::append(attrs, inner_attrs);
                provided(@ast::method {
                    ident: ident,
                    attrs: attrs,
                    tps: tps,
                    self_ty: self_ty,
                    purity: pur,
                    decl: d,
                    body: body,
                    id: p.get_id(),
                    span: mk_sp(lo, hi),
                    self_id: p.get_id(),
                    vis: vis,
                })
              }

              _ => { p.fatal(~"expected `;` or `}` but found `" +
                          token_to_str(p.reader, p.token) + ~"`");
                }
            }
        }
    }


    fn parse_mt() -> mt {
        let mutbl = self.parse_mutability();
        let t = self.parse_ty(false);
        mt { ty: t, mutbl: mutbl }
    }

    fn parse_ty_field() -> ty_field {
        let lo = self.span.lo;
        let mutbl = self.parse_mutability();
        let id = self.parse_ident();
        self.expect(token::COLON);
        let ty = self.parse_ty(false);
        spanned(
            lo,
            ty.span.hi,
            ast::ty_field_ {
                ident: id,
                mt: ast::mt { ty: ty, mutbl: mutbl },
            }
        )
    }

    fn parse_ret_ty() -> (ret_style, @Ty) {
        return if self.eat(token::RARROW) {
            let lo = self.span.lo;
            if self.eat(token::NOT) {
                (
                    noreturn,
                    @Ty {
                        id: self.get_id(),
                        node: ty_bot,
                        span: mk_sp(lo, self.last_span.hi)
                    }
                )
            } else {
                (return_val, self.parse_ty(false))
            }
        } else {
            let pos = self.span.lo;
            (
                return_val,
                @Ty {
                    id: self.get_id(),
                    node: ty_nil,
                    span: mk_sp(pos, pos),
                }
            )
        }
    }

    fn region_from_name(s: Option<ident>) -> @region {
        let r = match s {
            Some(id) if id == special_idents::static => ast::re_static,
            Some(id) if id == special_idents::self_ => re_self,
            Some(id) => re_named(id),
            None => re_anon
        };

        @ast::region { id: self.get_id(), node: r }
    }

    // Parses something like "&x"
    fn parse_region() -> @region {
        self.expect(token::BINOP(token::AND));

        match copy self.token {
          token::IDENT(sid, _) => {
            self.bump();
            self.region_from_name(Some(sid))
          }
          _ => {
            self.region_from_name(None)
          }
        }
    }

    fn parse_ty(colons_before_params: bool) -> @Ty {
        maybe_whole!(self, nt_ty);

        let lo = self.span.lo;

        let t = if self.token == token::LPAREN {
            self.bump();
            if self.token == token::RPAREN {
                self.bump();
                ty_nil
            } else {
                let mut ts = ~[self.parse_ty(false)];
                while self.token == token::COMMA {
                    self.bump();
                    ts.push(self.parse_ty(false));
                }
                let t = if vec::len(ts) == 1u { ts[0].node }
                else { ty_tup(ts) };
                self.expect(token::RPAREN);
                t
            }
        } else if self.token == token::AT {
            self.bump();
            self.parse_box_or_uniq_pointee(ast::ProtoBox, ty_box)
        } else if self.token == token::TILDE {
            self.bump();
            self.parse_box_or_uniq_pointee(ast::ProtoUniq, ty_uniq)
        } else if self.token == token::BINOP(token::STAR) {
            self.bump();
            ty_ptr(self.parse_mt())
        } else if self.token == token::LBRACE {
            let elems = self.parse_unspanned_seq(
                token::LBRACE, token::RBRACE,
                seq_sep_trailing_allowed(token::COMMA),
                |p| p.parse_ty_field());
            if vec::len(elems) == 0u {
                self.unexpected_last(token::RBRACE);
            }
            ty_rec(elems)
        } else if self.token == token::LBRACKET {
            self.expect(token::LBRACKET);
            let mt = self.parse_mt();

            // Parse the `* 3` in `[ int * 3 ]`
            let t = match self.maybe_parse_fixed_vstore_with_star() {
                None => ty_vec(mt),
                Some(suffix) => ty_fixed_length_vec(mt, suffix)
            };
            self.expect(token::RBRACKET);
            t
        } else if self.token == token::BINOP(token::AND) {
            self.bump();
            self.parse_borrowed_pointee()
        } else if self.token_is_fn_keyword(self.token) {
            self.parse_ty_fn(None, None)
        } else if self.token == token::MOD_SEP
            || is_ident_or_path(self.token) {
            let path = self.parse_path_with_tps(colons_before_params);
            ty_path(path, self.get_id())
        } else { self.fatal(~"expected type"); };

        let sp = mk_sp(lo, self.last_span.hi);
        @Ty {id: self.get_id(), node: t, span: sp}
    }

    fn parse_box_or_uniq_pointee(
        proto: ast::Proto,
        ctor: &fn(+v: mt) -> ty_) -> ty_
    {
        // @foo/fn() or @fn() are parsed directly as fn types:
        match copy self.token {
            token::IDENT(rname, _) => {
                if self.look_ahead(1u) == token::BINOP(token::SLASH) &&
                    self.token_is_fn_keyword(self.look_ahead(2u))
                {
                    self.bump(); self.bump();
                    return self.parse_ty_fn(Some(proto), Some(rname));
                } else if self.token_is_fn_keyword(self.token) {
                    return self.parse_ty_fn(Some(proto), None);
                }
            }
            _ => {}
        }

        // other things are parsed as @ + a type.  Note that constructs like
        // @[] and @str will be resolved during typeck to slices and so forth,
        // rather than boxed ptrs.  But the special casing of str/vec is not
        // reflected in the AST type.
        let mt = self.parse_mt();
        ctor(mt)
    }

    fn parse_borrowed_pointee() -> ty_ {
        // look for `&foo/` and interpret `foo` as the region name:
        let rname = match copy self.token {
            token::IDENT(sid, _) => {
                if self.look_ahead(1u) == token::BINOP(token::SLASH) {
                    self.bump(); self.bump();
                    Some(sid)
                } else {
                    None
                }
            }
            _ => { None }
        };

        if self.token_is_fn_keyword(self.token) {
            return self.parse_ty_fn(Some(ProtoBorrowed), rname);
        }

        let r = self.region_from_name(rname);
        let mt = self.parse_mt();
        return ty_rptr(r, mt);
    }

    fn parse_arg_mode() -> mode {
        if self.eat(token::BINOP(token::MINUS)) {
            expl(by_copy) // NDM outdated syntax
        } else if self.eat(token::ANDAND) {
            expl(by_ref)
        } else if self.eat(token::BINOP(token::PLUS)) {
            if self.eat(token::BINOP(token::PLUS)) {
                expl(by_val)
            } else {
                expl(by_copy)
            }
        } else {
            infer(self.get_id())
        }
    }

    fn is_named_argument() -> bool {
        let offset = if self.token == token::BINOP(token::AND) {
            1
        } else if self.token == token::BINOP(token::MINUS) {
            1
        } else if self.token == token::ANDAND {
            1
        } else if self.token == token::BINOP(token::PLUS) {
            if self.look_ahead(1) == token::BINOP(token::PLUS) {
                2
            } else {
                1
            }
        } else { 0 };
        if offset == 0 {
            is_plain_ident(self.token)
                && self.look_ahead(1) == token::COLON
        } else {
            is_plain_ident(self.look_ahead(offset))
                && self.look_ahead(offset + 1) == token::COLON
        }
    }

    fn parse_capture_item_or(parse_arg_fn: fn(Parser) -> arg_or_capture_item)
        -> arg_or_capture_item
    {
        if self.eat_keyword(~"move") || self.eat_keyword(~"copy") {
            // XXX outdated syntax now that moves-based-on-type has gone in
            self.parse_ident();
            either::Right(())
        } else {
            parse_arg_fn(self)
        }
    }

    // This version of parse arg doesn't necessarily require
    // identifier names.
    fn parse_arg_general(require_name: bool) -> arg {
        let mut m;
        let mut is_mutbl = false;
        let pat = if require_name || self.is_named_argument() {
            m = self.parse_arg_mode();
            is_mutbl = self.eat_keyword(~"mut");
            let pat = self.parse_pat(false);
            self.expect(token::COLON);
            pat
        } else {
            m = infer(self.get_id());
            ast_util::ident_to_pat(self.get_id(),
                                   copy self.last_span,
                                   special_idents::invalid)
        };

        let t = self.parse_ty(false);

        ast::arg { mode: m, is_mutbl: is_mutbl,
                  ty: t, pat: pat, id: self.get_id() }
    }

    fn parse_arg() -> arg_or_capture_item {
        either::Left(self.parse_arg_general(true))
    }

    fn parse_arg_or_capture_item() -> arg_or_capture_item {
        self.parse_capture_item_or(|p| p.parse_arg())
    }

    fn parse_fn_block_arg() -> arg_or_capture_item {
        do self.parse_capture_item_or |p| {
            let m = p.parse_arg_mode();
            let is_mutbl = self.eat_keyword(~"mut");
            let pat = p.parse_pat(false);
            let t = if p.eat(token::COLON) {
                p.parse_ty(false)
            } else {
                @Ty {
                    id: p.get_id(),
                    node: ty_infer,
                    span: mk_sp(p.span.lo, p.span.hi),
                }
            };
            either::Left(ast::arg {
                mode: m,
                is_mutbl: is_mutbl,
                ty: t,
                pat: pat,
                id: p.get_id()
            })
        }
    }

    fn maybe_parse_fixed_vstore_with_star() -> Option<uint> {
        if self.eat(token::BINOP(token::STAR)) {
            match copy self.token {
                token::LIT_INT_UNSUFFIXED(i) if i >= 0i64 => {
                    self.bump();
                    Some(i as uint)
                }
                _ => {
                    self.fatal(
                        fmt!("expected integral vector length \
                              but found `%s`",
                             token_to_str(self.reader, self.token)));
                }
            }
        } else {
            None
        }
    }

    fn lit_from_token(tok: token::Token) -> lit_ {
        match tok {
          token::LIT_INT(i, it) => lit_int(i, it),
          token::LIT_UINT(u, ut) => lit_uint(u, ut),
          token::LIT_INT_UNSUFFIXED(i) => lit_int_unsuffixed(i),
          token::LIT_FLOAT(s, ft) => lit_float(self.id_to_str(s), ft),
          token::LIT_FLOAT_UNSUFFIXED(s) =>
            lit_float_unsuffixed(self.id_to_str(s)),
          token::LIT_STR(s) => lit_str(self.id_to_str(s)),
          token::LPAREN => { self.expect(token::RPAREN); lit_nil },
          _ => { self.unexpected_last(tok); }
        }
    }

    fn parse_lit() -> lit {
        let lo = self.span.lo;
        let lit = if self.eat_keyword(~"true") {
            lit_bool(true)
        } else if self.eat_keyword(~"false") {
            lit_bool(false)
        } else {
            let tok = self.token;
            self.bump();
            self.lit_from_token(tok)
        };
        ast::spanned { node: lit, span: mk_sp(lo, self.last_span.hi) }
    }

    fn parse_path_without_tps() -> @path {
        self.parse_path_without_tps_(|p| p.parse_ident(),
                                     |p| p.parse_ident())
    }

    fn parse_path_without_tps_(
        parse_ident: fn(Parser) -> ident,
        parse_last_ident: fn(Parser) -> ident) -> @path {

        maybe_whole!(self, nt_path);
        let lo = self.span.lo;
        let global = self.eat(token::MOD_SEP);
        let mut ids = ~[];
        loop {
            let is_not_last =
                self.look_ahead(2u) != token::LT
                && self.look_ahead(1u) == token::MOD_SEP;

            if is_not_last {
                ids.push(parse_ident(self));
                self.expect(token::MOD_SEP);
            } else {
                ids.push(parse_last_ident(self));
                break;
            }
        }
        @ast::path { span: mk_sp(lo, self.last_span.hi),
                     global: global,
                     idents: ids,
                     rp: None,
                     types: ~[] }
    }

    fn parse_value_path() -> @path {
        self.parse_path_without_tps_(|p| p.parse_ident(),
                                     |p| p.parse_value_ident())
    }

    fn parse_path_with_tps(colons: bool) -> @path {
        debug!("parse_path_with_tps(colons=%b)", colons);

        maybe_whole!(self, nt_path);
        let lo = self.span.lo;
        let path = self.parse_path_without_tps();
        if colons && !self.eat(token::MOD_SEP) {
            return path;
        }

        // Parse the region parameter, if any, which will
        // be written "foo/&x"
        let rp = {
            // Hack: avoid parsing vstores like /@ and /~.  This is painful
            // because the notation for region bounds and the notation for
            // vstores is... um... the same.  I guess that's my fault.  This
            // is still not ideal as for &str we end up parsing more than we
            // ought to and have to sort it out later.
            if self.token == token::BINOP(token::SLASH)
                && self.look_ahead(1u) == token::BINOP(token::AND) {

                self.expect(token::BINOP(token::SLASH));
                Some(self.parse_region())
            } else {
                None
            }
        };

        // Parse any type parameters which may appear:
        let tps = {
            if self.token == token::LT {
                self.parse_seq_lt_gt(Some(token::COMMA),
                                     |p| p.parse_ty(false))
            } else {
                ast::spanned {node: ~[], span: path.span}
            }
        };

        @ast::path { span: mk_sp(lo, tps.span.hi),
                     rp: rp,
                     types: tps.node,
                     .. *path }
    }

    fn parse_mutability() -> mutability {
        if self.eat_keyword(~"mut") {
            m_mutbl
        } else if self.eat_keyword(~"const") {
            m_const
        } else {
            m_imm
        }
    }

    fn parse_field(sep: token::Token) -> field {
        let lo = self.span.lo;
        let m = self.parse_mutability();
        let i = self.parse_ident();
        self.expect(sep);
        let e = self.parse_expr();
        spanned(lo, e.span.hi, ast::field_ { mutbl: m, ident: i, expr: e })
    }

    fn mk_expr(+lo: BytePos, +hi: BytePos, +node: expr_) -> @expr {
        @expr {
            id: self.get_id(),
            callee_id: self.get_id(),
            node: node,
            span: mk_sp(lo, hi),
        }
    }

    fn mk_mac_expr(+lo: BytePos, +hi: BytePos, m: mac_) -> @expr {
        @expr {
            id: self.get_id(),
            callee_id: self.get_id(),
            node: expr_mac(ast::spanned {node: m, span: mk_sp(lo, hi)}),
            span: mk_sp(lo, hi),
        }
    }

    fn mk_lit_u32(i: u32) -> @expr {
        let span = self.span;
        let lv_lit = @ast::spanned { node: lit_uint(i as u64, ty_u32),
                                     span: span };

        @expr {
            id: self.get_id(),
            callee_id: self.get_id(),
            node: expr_lit(lv_lit),
            span: span,
        }
    }

    fn parse_bottom_expr() -> @expr {
        maybe_whole_expr!(self);
        let lo = self.span.lo;
        let mut hi = self.span.hi;

        let mut ex: expr_;

        if self.token == token::LPAREN {
            self.bump();
            if self.token == token::RPAREN {
                hi = self.span.hi;
                self.bump();
                let lit = @spanned(lo, hi, lit_nil);
                return self.mk_expr(lo, hi, expr_lit(lit));
            }
            let mut es = ~[self.parse_expr()];
            while self.token == token::COMMA {
                self.bump(); es.push(self.parse_expr());
            }
            hi = self.span.hi;
            self.expect(token::RPAREN);

            return if es.len() == 1 {
                self.mk_expr(lo, self.span.hi, expr_paren(es[0]))
            }
            else {
                self.mk_expr(lo, hi, expr_tup(es))
            }
        } else if self.token == token::LBRACE {
            if self.looking_at_record_literal() {
                ex = self.parse_record_literal();
                hi = self.span.hi;
            } else {
                self.bump();
                let blk = self.parse_block_tail(lo, default_blk);
                return self.mk_expr(blk.span.lo, blk.span.hi,
                                     expr_block(blk));
            }
        } else if token::is_bar(self.token) {
            return self.parse_lambda_expr();
        } else if self.eat_keyword(~"if") {
            return self.parse_if_expr();
        } else if self.eat_keyword(~"for") {
            return self.parse_sugary_call_expr(~"for", expr_loop_body);
        } else if self.eat_keyword(~"do") {
            return self.parse_sugary_call_expr(~"do", expr_do_body);
        } else if self.eat_keyword(~"while") {
            return self.parse_while_expr();
        } else if self.eat_keyword(~"loop") {
            return self.parse_loop_expr();
        } else if self.eat_keyword(~"match") {
            return self.parse_match_expr();
        } else if self.eat_keyword(~"fn") {
            let opt_proto = self.parse_fn_ty_proto();
            let proto = match opt_proto {
                None | Some(ast::ProtoBare) => {
                    self.fatal(~"fn expr are deprecated, use fn@")
                }
                Some(p) => { p }
            };
            return self.parse_fn_expr(proto);
        } else if self.eat_keyword(~"unsafe") {
            return self.parse_block_expr(lo, unsafe_blk);
        } else if self.token == token::LBRACKET {
            self.bump();
            let mutbl = self.parse_mutability();
            if self.token == token::RBRACKET {
                // Empty vector.
                self.bump();
                ex = expr_vec(~[], mutbl);
            } else {
                // Nonempty vector.
                let first_expr = self.parse_expr();
                if self.token == token::COMMA &&
                        self.look_ahead(1) == token::DOTDOT {
                    // Repeating vector syntax: [ 0, ..512 ]
                    self.bump();
                    self.bump();
                    let count = self.parse_expr();
                    self.expect(token::RBRACKET);
                    ex = expr_repeat(first_expr, count, mutbl);
                } else if self.token == token::COMMA {
                    // Vector with two or more elements.
                    self.bump();
                    let remaining_exprs =
                        self.parse_seq_to_end(token::RBRACKET,
                            seq_sep_trailing_allowed(token::COMMA),
                            |p| p.parse_expr());
                    ex = expr_vec(~[first_expr] + remaining_exprs, mutbl);
                } else {
                    // Vector with one element.
                    self.expect(token::RBRACKET);
                    ex = expr_vec(~[first_expr], mutbl);
                }
            }
            hi = self.span.hi;
        } else if self.eat_keyword(~"fail") {
            if can_begin_expr(self.token) {
                let e = self.parse_expr();
                hi = e.span.hi;
                ex = expr_fail(Some(e));
            } else { ex = expr_fail(None); }
        } else if self.eat_keyword(~"log") {
            self.expect(token::LPAREN);
            let lvl = self.parse_expr();
            self.expect(token::COMMA);
            let e = self.parse_expr();
            ex = expr_log(ast::log_other, lvl, e);
            hi = self.span.hi;
            self.expect(token::RPAREN);
        } else if self.eat_keyword(~"assert") {
            let e = self.parse_expr();
            ex = expr_assert(e);
            hi = e.span.hi;
        } else if self.eat_keyword(~"return") {
            if can_begin_expr(self.token) {
                let e = self.parse_expr();
                hi = e.span.hi;
                ex = expr_ret(Some(e));
            } else { ex = expr_ret(None); }
        } else if self.eat_keyword(~"break") {
            if is_ident(self.token) {
                ex = expr_break(Some(self.parse_ident()));
            } else {
                ex = expr_break(None);
            }
            hi = self.span.hi;
        } else if self.eat_keyword(~"copy") {
            let e = self.parse_expr();
            ex = expr_copy(e);
            hi = e.span.hi;
        } else if self.eat_keyword(~"move") {
            // XXX move keyword is no longer important, remove after snapshot
            return self.parse_expr();
        } else if self.token == token::MOD_SEP ||
            is_ident(self.token) && !self.is_keyword(~"true") &&
            !self.is_keyword(~"false") {
            let pth = self.parse_path_with_tps(true);

            /* `!`, as an operator, is prefix, so we know this isn't that */
            if self.token == token::NOT {
                self.bump();
                let tts = match self.token {
                  token::LPAREN | token::LBRACE => {
                    let ket = token::flip_delimiter(copy self.token);
                    self.parse_unspanned_seq(copy self.token, ket,
                                             seq_sep_none(),
                                             |p| p.parse_token_tree())
                  }
                  _ => self.fatal(~"expected open delimiter")
                };
                let hi = self.span.hi;

                return self.mk_mac_expr(
                    lo, hi, mac_invoc_tt(pth, tts));
            } else if self.token == token::LBRACE {
                // This might be a struct literal.
                if self.looking_at_record_literal() {
                    // It's a struct literal.
                    self.bump();
                    let mut fields = ~[];
                    let mut base = None;
                    fields.push(self.parse_field(token::COLON));
                    while self.token != token::RBRACE {

                        if self.try_parse_obsolete_with() {
                            break;
                        }

                        self.expect(token::COMMA);

                        if self.eat(token::DOTDOT) {
                            base = Some(self.parse_expr());
                            break;
                        }

                        if self.token == token::RBRACE {
                            // Accept an optional trailing comma.
                            break;
                        }
                        fields.push(self.parse_field(token::COLON));
                    }

                    hi = pth.span.hi;
                    self.expect(token::RBRACE);
                    ex = expr_struct(pth, fields, base);
                    return self.mk_expr(lo, hi, ex);
                }
            }

            hi = pth.span.hi;
            ex = expr_path(pth);
        } else {
            let lit = self.parse_lit();
            hi = lit.span.hi;
            ex = expr_lit(@lit);
        }

        return self.mk_expr(lo, hi, ex);
    }

    fn parse_block_expr(lo: BytePos, blk_mode: blk_check_mode) -> @expr {
        self.expect(token::LBRACE);
        let blk = self.parse_block_tail(lo, blk_mode);
        return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
    }

    fn parse_dot_or_call_expr() -> @expr {
        let b = self.parse_bottom_expr();
        self.parse_dot_or_call_expr_with(b)
    }

    fn permits_call() -> bool {
        return self.restriction != RESTRICT_NO_CALL_EXPRS;
    }

    fn parse_dot_or_call_expr_with(e0: @expr) -> @expr {
        let mut e = e0;
        let lo = e.span.lo;
        let mut hi;
        loop {
            // expr.f
            if self.eat(token::DOT) {
                match copy self.token {
                  token::IDENT(i, _) => {
                    hi = self.span.hi;
                    self.bump();
                    let tys = if self.eat(token::MOD_SEP) {
                        self.expect(token::LT);
                        self.parse_seq_to_gt(Some(token::COMMA),
                                             |p| p.parse_ty(false))
                    } else {
                        ~[]
                    };

                    // expr.f() method call
                    match copy self.token {
                        token::LPAREN if self.permits_call() => {
                            let es = self.parse_unspanned_seq(
                                token::LPAREN, token::RPAREN,
                                seq_sep_trailing_disallowed(token::COMMA),
                                |p| p.parse_expr());
                            hi = self.span.hi;

                            let nd = expr_method_call(e, i, tys, es, false);
                            e = self.mk_expr(lo, hi, move nd);
                        }
                        _ => {
                            e = self.mk_expr(lo, hi, expr_field(e, i, tys));
                        }
                    }
                  }
                  _ => self.unexpected()
                }
                loop;
            }
            if self.expr_is_complete(e) { break; }
            match copy self.token {
              // expr(...)
              token::LPAREN if self.permits_call() => {
                let es = self.parse_unspanned_seq(
                    token::LPAREN, token::RPAREN,
                    seq_sep_trailing_disallowed(token::COMMA),
                    |p| p.parse_expr());
                hi = self.span.hi;

                let nd = expr_call(e, es, false);
                e = self.mk_expr(lo, hi, nd);
              }

              // expr[...]
              token::LBRACKET => {
                self.bump();
                let ix = self.parse_expr();
                hi = ix.span.hi;
                self.expect(token::RBRACKET);
                e = self.mk_expr(lo, hi, expr_index(e, ix));
              }

              _ => return e
            }
        }
        return e;
    }

    fn parse_sep_and_zerok() -> (Option<token::Token>, bool) {
        if self.token == token::BINOP(token::STAR)
            || self.token == token::BINOP(token::PLUS) {
            let zerok = self.token == token::BINOP(token::STAR);
            self.bump();
            return (None, zerok);
        } else {
            let sep = self.token;
            self.bump();
            if self.token == token::BINOP(token::STAR)
                || self.token == token::BINOP(token::PLUS) {
                let zerok = self.token == token::BINOP(token::STAR);
                self.bump();
                return (Some(sep), zerok);
            } else {
                self.fatal(~"expected `*` or `+`");
            }
        }
    }

    fn parse_token_tree() -> token_tree {
        maybe_whole!(deref self, nt_tt);

        fn parse_tt_tok(p: Parser, delim_ok: bool) -> token_tree {
            maybe_whole!(deref p, nt_tt);
            match p.token {
              token::RPAREN | token::RBRACE | token::RBRACKET
              if !delim_ok => {
                p.fatal(~"incorrect close delimiter: `"
                           + token_to_str(p.reader, p.token) + ~"`");
              }
              token::EOF => {
                p.fatal(~"file ended in the middle of a macro invocation");
              }
              /* we ought to allow different depths of unquotation */
              token::DOLLAR if p.quote_depth > 0u => {
                p.bump();
                let sp = p.span;

                if p.token == token::LPAREN {
                    let seq = p.parse_seq(token::LPAREN, token::RPAREN,
                                          seq_sep_none(),
                                          |p| p.parse_token_tree());
                    let (s, z) = p.parse_sep_and_zerok();
                    return tt_seq(mk_sp(sp.lo ,p.span.hi), seq.node, s, z);
                } else {
                    return tt_nonterminal(sp, p.parse_ident());
                }
              }
              _ => { /* ok */ }
            }
            let res = tt_tok(p.span, p.token);
            p.bump();
            return res;
        }

        return match self.token {
          token::LPAREN | token::LBRACE | token::LBRACKET => {
              // tjc: ??????
            let ket = token::flip_delimiter(copy self.token);
            tt_delim(vec::append(
                ~[parse_tt_tok(self, true)],
                vec::append(
                    self.parse_seq_to_before_end(
                        ket, seq_sep_none(),
                        |p| p.parse_token_tree()),
                    ~[parse_tt_tok(self, true)])))
          }
          _ => parse_tt_tok(self, false)
        };
    }

    fn parse_all_token_trees() -> ~[token_tree] {
        let tts = DVec();
        while self.token != token::EOF {
            tts.push(self.parse_token_tree());
        }
        tts.get()
    }

    fn parse_matchers() -> ~[matcher] {
        // unification of matchers and token_trees would vastly improve
        // the interpolation of matchers
        maybe_whole!(self, nt_matchers);
        let name_idx = @mut 0u;
        return match self.token {
          token::LBRACE | token::LPAREN | token::LBRACKET => {
            self.parse_matcher_subseq(name_idx, copy self.token,
                                      // tjc: not sure why we need a copy
                                      token::flip_delimiter(copy self.token))
          }
          _ => self.fatal(~"expected open delimiter")
        }
    }


    // This goofy function is necessary to correctly match parens in matchers.
    // Otherwise, `$( ( )` would be a valid matcher, and `$( () )` would be
    // invalid. It's similar to common::parse_seq.
    fn parse_matcher_subseq(name_idx: @mut uint, bra: token::Token,
                            ket: token::Token) -> ~[matcher] {
        let mut ret_val = ~[];
        let mut lparens = 0u;

        self.expect(bra);

        while self.token != ket || lparens > 0u {
            if self.token == token::LPAREN { lparens += 1u; }
            if self.token == token::RPAREN { lparens -= 1u; }
            ret_val.push(self.parse_matcher(name_idx));
        }

        self.bump();

        return ret_val;
    }

    fn parse_matcher(name_idx: @mut uint) -> matcher {
        let lo = self.span.lo;

        let m = if self.token == token::DOLLAR {
            self.bump();
            if self.token == token::LPAREN {
                let name_idx_lo = *name_idx;
                let ms = self.parse_matcher_subseq(name_idx, token::LPAREN,
                                                   token::RPAREN);
                if ms.len() == 0u {
                    self.fatal(~"repetition body must be nonempty");
                }
                let (sep, zerok) = self.parse_sep_and_zerok();
                match_seq(ms, sep, zerok, name_idx_lo, *name_idx)
            } else {
                let bound_to = self.parse_ident();
                self.expect(token::COLON);
                let nt_name = self.parse_ident();
                let m = match_nonterminal(bound_to, nt_name, *name_idx);
                *name_idx += 1u;
                m
            }
        } else {
            let m = match_tok(self.token);
            self.bump();
            m
        };

        return spanned(lo, self.span.hi, m);
    }


    fn parse_prefix_expr() -> @expr {
        let lo = self.span.lo;
        let mut hi;

        let mut ex;
        match copy self.token {
          token::NOT => {
            self.bump();
            let e = self.parse_prefix_expr();
            hi = e.span.hi;
            self.get_id(); // see ast_util::op_expr_callee_id
            ex = expr_unary(not, e);
          }
          token::BINOP(b) => {
            match b {
              token::MINUS => {
                self.bump();
                let e = self.parse_prefix_expr();
                hi = e.span.hi;
                self.get_id(); // see ast_util::op_expr_callee_id
                ex = expr_unary(neg, e);
              }
              token::STAR => {
                self.bump();
                let e = self.parse_prefix_expr();
                hi = e.span.hi;
                ex = expr_unary(deref, e);
              }
              token::AND => {
                self.bump();
                let m = self.parse_mutability();
                let e = self.parse_prefix_expr();
                hi = e.span.hi;
                // HACK: turn &[...] into a &-evec
                ex = match e.node {
                  expr_vec(*) | expr_lit(@ast::spanned {
                    node: lit_str(_), span: _
                  })
                  if m == m_imm => {
                    expr_vstore(e, expr_vstore_slice)
                  }
                  expr_vec(*) if m == m_mutbl => {
                    expr_vstore(e, expr_vstore_mut_slice)
                  }
                  _ => expr_addr_of(m, e)
                };
              }
              _ => return self.parse_dot_or_call_expr()
            }
          }
          token::AT => {
            self.bump();
            let m = self.parse_mutability();
            let e = self.parse_prefix_expr();
            hi = e.span.hi;
            // HACK: turn @[...] into a @-evec
            ex = match e.node {
              expr_vec(*) if m == m_mutbl =>
                expr_vstore(e, expr_vstore_mut_box),
              expr_vec(*) if m == m_imm => expr_vstore(e, expr_vstore_box),
              expr_lit(@ast::spanned {
                  node: lit_str(_), span: _}) if m == m_imm =>
                expr_vstore(e, expr_vstore_box),
              _ => expr_unary(box(m), e)
            };
          }
          token::TILDE => {
            self.bump();
            let m = self.parse_mutability();
            let e = self.parse_prefix_expr();
            hi = e.span.hi;
            // HACK: turn ~[...] into a ~-evec
            ex = match e.node {
              expr_vec(*) | expr_lit(@ast::spanned {
                node: lit_str(_), span: _})
              if m == m_imm => expr_vstore(e, expr_vstore_uniq),
              _ => expr_unary(uniq(m), e)
            };
          }
          _ => return self.parse_dot_or_call_expr()
        }
        return self.mk_expr(lo, hi, ex);
    }


    fn parse_binops() -> @expr {
        return self.parse_more_binops(self.parse_prefix_expr(), 0);
    }

    fn parse_more_binops(lhs: @expr, min_prec: uint) ->
        @expr {
        if self.expr_is_complete(lhs) { return lhs; }
        let peeked = self.token;
        if peeked == token::BINOP(token::OR) &&
            (self.restriction == RESTRICT_NO_BAR_OP ||
             self.restriction == RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) {
            return lhs;
        }
        if peeked == token::OROR &&
            self.restriction == RESTRICT_NO_BAR_OR_DOUBLEBAR_OP {
            return lhs;
        }
        let cur_opt   = token_to_binop(peeked);
        match cur_opt {
          Some(cur_op) => {
            let cur_prec = operator_prec(cur_op);
            if cur_prec > min_prec {
                self.bump();
                let expr = self.parse_prefix_expr();
                let rhs = self.parse_more_binops(expr, cur_prec);
                self.get_id(); // see ast_util::op_expr_callee_id
                let bin = self.mk_expr(lhs.span.lo, rhs.span.hi,
                                        expr_binary(cur_op, lhs, rhs));
                return self.parse_more_binops(bin, min_prec);
            }
          }
          _ => ()
        }
        if as_prec > min_prec && self.eat_keyword(~"as") {
            let rhs = self.parse_ty(true);
            let _as =
                self.mk_expr(lhs.span.lo, rhs.span.hi, expr_cast(lhs, rhs));
            return self.parse_more_binops(_as, min_prec);
        }
        return lhs;
    }

    fn parse_assign_expr() -> @expr {
        let lo = self.span.lo;
        let lhs = self.parse_binops();
        match copy self.token {
          token::EQ => {
            self.bump();
            let rhs = self.parse_expr();
            return self.mk_expr(lo, rhs.span.hi, expr_assign(lhs, rhs));
          }
          token::BINOPEQ(op) => {
            self.bump();
            let rhs = self.parse_expr();
            let mut aop;
            match op {
              token::PLUS => aop = add,
              token::MINUS => aop = subtract,
              token::STAR => aop = mul,
              token::SLASH => aop = div,
              token::PERCENT => aop = rem,
              token::CARET => aop = bitxor,
              token::AND => aop = bitand,
              token::OR => aop = bitor,
              token::SHL => aop = shl,
              token::SHR => aop = shr
            }
            self.get_id(); // see ast_util::op_expr_callee_id
            return self.mk_expr(lo, rhs.span.hi,
                                expr_assign_op(aop, lhs, rhs));
          }
          token::LARROW => {
              self.obsolete(copy self.span, ObsoleteBinaryMove);
              // Bogus value (but it's an error)
              self.bump(); // <-
              self.bump(); // rhs
              self.bump(); // ;
              return self.mk_expr(lo, self.span.hi,
                                  expr_break(None));
          }
          token::DARROW => {
            self.bump();
            let rhs = self.parse_expr();
            return self.mk_expr(lo, rhs.span.hi, expr_swap(lhs, rhs));
          }
          _ => {/* fall through */ }
        }
        return lhs;
    }

    fn parse_if_expr() -> @expr {
        let lo = self.last_span.lo;
        let cond = self.parse_expr();
        let thn = self.parse_block();
        let mut els: Option<@expr> = None;
        let mut hi = thn.span.hi;
        if self.eat_keyword(~"else") {
            let elexpr = self.parse_else_expr();
            els = Some(elexpr);
            hi = elexpr.span.hi;
        }
        let q = {cond: cond, then: thn, els: els, lo: lo, hi: hi};
        return self.mk_expr(q.lo, q.hi, expr_if(q.cond, q.then, q.els));
    }

    fn parse_fn_expr(proto: Proto) -> @expr {
        let lo = self.last_span.lo;

        // if we want to allow fn expression argument types to be inferred in
        // the future, just have to change parse_arg to parse_fn_block_arg.
        let decl = self.parse_fn_decl(|p| p.parse_arg_or_capture_item());

        let body = self.parse_block();
        return self.mk_expr(lo, body.span.hi,expr_fn(proto, decl, body));
    }

    // `|args| { ... }` like in `do` expressions
    fn parse_lambda_block_expr() -> @expr {
        self.parse_lambda_expr_(
            || {
                match self.token {
                  token::BINOP(token::OR) | token::OROR => {
                    self.parse_fn_block_decl()
                  }
                  _ => {
                    // No argument list - `do foo {`
                      ast::fn_decl {
                          inputs: ~[],
                          output: @Ty {
                              id: self.get_id(),
                              node: ty_infer,
                              span: self.span
                          },
                          cf: return_val
                      }
                  }
                }
            },
            || {
                let blk = self.parse_block();
                self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk))
            })
    }

    // `|args| expr`
    fn parse_lambda_expr() -> @expr {
        self.parse_lambda_expr_(|| self.parse_fn_block_decl(),
                                || self.parse_expr())
    }

    fn parse_lambda_expr_(parse_decl: fn&() -> fn_decl,
                          parse_body: fn&() -> @expr) -> @expr {
        let lo = self.last_span.lo;
        let decl = parse_decl();
        let body = parse_body();
        let fakeblock = ast::blk_ {
            view_items: ~[],
            stmts: ~[],
            expr: Some(body),
            id: self.get_id(),
            rules: default_blk,
        };
        let fakeblock = spanned(body.span.lo, body.span.hi,
                                fakeblock);
        return self.mk_expr(lo, body.span.hi,
                            expr_fn_block(decl, fakeblock));
    }

    fn parse_else_expr() -> @expr {
        if self.eat_keyword(~"if") {
            return self.parse_if_expr();
        } else {
            let blk = self.parse_block();
            return self.mk_expr(blk.span.lo, blk.span.hi, expr_block(blk));
        }
    }

    fn parse_sugary_call_expr(keyword: ~str,
                              ctor: fn(+v: @expr) -> expr_) -> @expr {
        let lo = self.last_span;
        // Parse the callee `foo` in
        //    for foo || {
        //    for foo.bar || {
        // etc, or the portion of the call expression before the lambda in
        //    for foo() || {
        // or
        //    for foo.bar(a) || {
        // Turn on the restriction to stop at | or || so we can parse
        // them as the lambda arguments
        let e = self.parse_expr_res(RESTRICT_NO_BAR_OR_DOUBLEBAR_OP);
        match e.node {
            expr_call(f, args, false) => {
                let block = self.parse_lambda_block_expr();
                let last_arg = self.mk_expr(block.span.lo, block.span.hi,
                                            ctor(block));
                let args = vec::append(args, ~[last_arg]);
                self.mk_expr(lo.lo, block.span.hi, expr_call(f, args, true))
            }
            expr_method_call(f, i, tps, args, false) => {
                let block = self.parse_lambda_block_expr();
                let last_arg = self.mk_expr(block.span.lo, block.span.hi,
                                            ctor(block));
                let args = vec::append(args, ~[last_arg]);
                self.mk_expr(lo.lo, block.span.hi,
                             expr_method_call(f, i, tps, args, true))
            }
            expr_field(f, i, tps) => {
                let block = self.parse_lambda_block_expr();
                let last_arg = self.mk_expr(block.span.lo, block.span.hi,
                                            ctor(block));
                self.mk_expr(lo.lo, block.span.hi,
                             expr_method_call(f, i, tps, ~[last_arg], true))
            }
            expr_path(*) | expr_call(*) | expr_method_call(*) |
                expr_paren(*) => {
                let block = self.parse_lambda_block_expr();
                let last_arg = self.mk_expr(block.span.lo, block.span.hi,
                                            ctor(block));
                self.mk_expr(lo.lo, last_arg.span.hi,
                             expr_call(e, ~[last_arg], true))
            }
            _ => {
                // There may be other types of expressions that can
                // represent the callee in `for` and `do` expressions
                // but they aren't represented by tests
                debug!("sugary call on %?", e.node);
                self.span_fatal(
                    lo, fmt!("`%s` must be followed by a block call",
                             keyword));
            }
        }
    }

    fn parse_while_expr() -> @expr {
        let lo = self.last_span.lo;
        let cond = self.parse_expr();
        let body = self.parse_block_no_value();
        let mut hi = body.span.hi;
        return self.mk_expr(lo, hi, expr_while(cond, body));
    }

    fn parse_loop_expr() -> @expr {
        // loop headers look like 'loop {' or 'loop unsafe {'
        let is_loop_header =
            self.token == token::LBRACE
            || (is_ident(copy self.token)
                && self.look_ahead(1) == token::LBRACE);
        // labeled loop headers look like 'loop foo: {'
        let is_labeled_loop_header =
            is_ident(self.token)
            && !self.is_any_keyword(copy self.token)
            && self.look_ahead(1) == token::COLON;

        if is_loop_header || is_labeled_loop_header {
            // This is a loop body
            let opt_ident;
            if is_labeled_loop_header {
                opt_ident = Some(self.parse_ident());
                self.expect(token::COLON);
            } else {
                opt_ident = None;
            }

            let lo = self.last_span.lo;
            let body = self.parse_block_no_value();
            let mut hi = body.span.hi;
            return self.mk_expr(lo, hi, expr_loop(body, opt_ident));
        } else {
            // This is a 'continue' expression
            let lo = self.span.lo;
            let ex = if is_ident(self.token) {
                expr_again(Some(self.parse_ident()))
            } else {
                expr_again(None)
            };
            let hi = self.span.hi;
            return self.mk_expr(lo, hi, ex);
        }
    }

    // For distingishing between record literals and blocks
    fn looking_at_record_literal() -> bool {
        let lookahead = self.look_ahead(1);
        self.token == token::LBRACE &&
            (self.token_is_keyword(~"mut", lookahead) ||
             (is_plain_ident(lookahead) &&
              self.look_ahead(2) == token::COLON))
    }

    fn parse_record_literal() -> expr_ {
        self.expect(token::LBRACE);
        let mut fields = ~[self.parse_field(token::COLON)];
        let mut base = None;
        while self.token != token::RBRACE {
            if self.token == token::COMMA
                && self.look_ahead(1) == token::DOTDOT {
                self.bump();
                self.bump();
                base = Some(self.parse_expr()); break;
            }

            if self.try_parse_obsolete_with() {
                break;
            }

            self.expect(token::COMMA);
            if self.token == token::RBRACE {
                // record ends by an optional trailing comma
                break;
            }
            fields.push(self.parse_field(token::COLON));
        }
        self.expect(token::RBRACE);
        //self.warn(~"REC");
        return expr_rec(fields, base);
    }

    fn parse_match_expr() -> @expr {
        let lo = self.last_span.lo;
        let discriminant = self.parse_expr();
        self.expect(token::LBRACE);
        let mut arms: ~[arm] = ~[];
        while self.token != token::RBRACE {
            let pats = self.parse_pats();
            let mut guard = None;
            if self.eat_keyword(~"if") { guard = Some(self.parse_expr()); }
            self.expect(token::FAT_ARROW);
            let expr = self.parse_expr_res(RESTRICT_STMT_EXPR);

            let require_comma =
                !classify::expr_is_simple_block(expr)
                && self.token != token::RBRACE;

            if require_comma {
                self.expect(token::COMMA);
            } else {
                self.eat(token::COMMA);
            }

            let blk = ast::spanned {
                node: ast::blk_ {
                    view_items: ~[],
                    stmts: ~[],
                    expr: Some(expr),
                    id: self.get_id(),
                    rules: default_blk,
                },
                span: expr.span,
            };

            arms.push(ast::arm { pats: pats, guard: guard, body: blk });
        }
        let mut hi = self.span.hi;
        self.bump();
        return self.mk_expr(lo, hi, expr_match(discriminant, arms));
    }

    fn parse_expr() -> @expr {
        return self.parse_expr_res(UNRESTRICTED);
    }

    fn parse_expr_res(r: restriction) -> @expr {
        let old = self.restriction;
        self.restriction = r;
        let e = self.parse_assign_expr();
        self.restriction = old;
        return e;
    }

    fn parse_initializer() -> Option<@expr> {
        match self.token {
          token::EQ => {
            self.bump();
            return Some(self.parse_expr());
          }
          token::LARROW => {
              self.obsolete(copy self.span, ObsoleteMoveInit);
              self.bump();
              self.bump();
              return None;
          }
          _ => {
            return None;
          }
        }
    }

    fn parse_pats() -> ~[@pat] {
        let mut pats = ~[];
        loop {
            pats.push(self.parse_pat(true));
            if self.token == token::BINOP(token::OR) { self.bump(); }
            else { return pats; }
        };
    }

    fn parse_pat_vec_elements(refutable: bool) -> (~[@pat], Option<@pat>) {
        let mut elements = ~[];
        let mut tail = None;
        let mut first = true;

        while self.token != token::RBRACKET {
            if first { first = false; }
            else { self.expect(token::COMMA); }

            let mut is_tail = false;
            if self.token == token::DOTDOT {
                self.bump();
                is_tail = true;
            }

            let subpat = self.parse_pat(refutable);
            if is_tail {
                match subpat {
                    @ast::pat { node: pat_wild, _ } => (),
                    @ast::pat { node: pat_ident(_, _, _), _ } => (),
                    @ast::pat { span, _ } => self.span_fatal(
                        span, ~"expected an identifier or `_`"
                    )
                }
                tail = Some(subpat);
                break;
            }

            elements.push(subpat);
        }
        return (elements, tail);
    }

    fn parse_pat_fields(refutable: bool) -> (~[ast::field_pat], bool) {
        let mut fields = ~[];
        let mut etc = false;
        let mut first = true;
        while self.token != token::RBRACE {
            if first { first = false; }
            else { self.expect(token::COMMA); }

            if self.token == token::UNDERSCORE {
                self.bump();
                if self.token != token::RBRACE {
                    self.fatal(~"expected `}`, found `" +
                               token_to_str(self.reader, self.token) +
                               ~"`");
                }
                etc = true;
                break;
            }

            let lo1 = self.last_span.lo;
            let fieldname = if self.look_ahead(1u) == token::COLON {
                self.parse_ident()
            } else {
                self.parse_value_ident()
            };
            let hi1 = self.last_span.lo;
            let fieldpath = ast_util::ident_to_path(mk_sp(lo1, hi1),
                                                    fieldname);
            let mut subpat;
            if self.token == token::COLON {
                self.bump();
                subpat = self.parse_pat(refutable);
            } else {
                subpat = @ast::pat {
                    id: self.get_id(),
                    node: pat_ident(bind_infer, fieldpath, None),
                    span: self.last_span
                };
            }
            fields.push(ast::field_pat { ident: fieldname, pat: subpat });
        }
        return (fields, etc);
    }

    fn parse_pat(refutable: bool) -> @pat {
        maybe_whole!(self, nt_pat);

        let lo = self.span.lo;
        let mut hi = self.span.hi;
        let mut pat;
        match self.token {
          token::UNDERSCORE => { self.bump(); pat = pat_wild; }
          token::AT => {
            self.bump();
            let sub = self.parse_pat(refutable);
            hi = sub.span.hi;
            // HACK: parse @"..." as a literal of a vstore @str
            pat = match sub.node {
              pat_lit(e@@expr {
                node: expr_lit(@ast::spanned {node: lit_str(_), span: _}), _
              }) => {
                let vst = @expr {
                    id: self.get_id(),
                    callee_id: self.get_id(),
                    node: expr_vstore(e, expr_vstore_box),
                    span: mk_sp(lo, hi),
                };
                pat_lit(vst)
              }
              _ => pat_box(sub)
            };
          }
          token::TILDE => {
            self.bump();
            let sub = self.parse_pat(refutable);
            hi = sub.span.hi;
            // HACK: parse ~"..." as a literal of a vstore ~str
            pat = match sub.node {
              pat_lit(e@@expr {
                node: expr_lit(@ast::spanned {node: lit_str(_), span: _}), _
              }) => {
                let vst = @expr {
                    id: self.get_id(),
                    callee_id: self.get_id(),
                    node: expr_vstore(e, expr_vstore_uniq),
                    span: mk_sp(lo, hi),
                };
                pat_lit(vst)
              }
              _ => pat_uniq(sub)
            };

          }
          token::BINOP(token::AND) => {
              let lo = self.span.lo;
              self.bump();
              let sub = self.parse_pat(refutable);
              hi = sub.span.hi;
              // HACK: parse &"..." as a literal of a borrowed str
              pat = match sub.node {
                  pat_lit(e@@expr {
                      node: expr_lit(@ast::spanned {
                            node: lit_str(_), span: _}), _
                  }) => {
                      let vst = @expr {
                          id: self.get_id(),
                          callee_id: self.get_id(),
                          node: expr_vstore(e, expr_vstore_slice),
                          span: mk_sp(lo, hi)
                      };
                      pat_lit(vst)
                  }
              _ => pat_region(sub)
              };
          }
          token::LBRACE => {
            self.bump();
            let (fields, etc) = self.parse_pat_fields(refutable);
            hi = self.span.hi;
            self.bump();
            pat = pat_rec(fields, etc);
          }
          token::LPAREN => {
            self.bump();
            if self.token == token::RPAREN {
                hi = self.span.hi;
                self.bump();
                let lit = @ast::spanned {node: lit_nil, span: mk_sp(lo, hi)};
                let expr = self.mk_expr(lo, hi, expr_lit(lit));
                pat = pat_lit(expr);
            } else {
                let mut fields = ~[self.parse_pat(refutable)];
                while self.token == token::COMMA {
                    self.bump();
                    fields.push(self.parse_pat(refutable));
                }
                if vec::len(fields) == 1u { self.expect(token::COMMA); }
                hi = self.span.hi;
                self.expect(token::RPAREN);
                pat = pat_tup(fields);
            }
          }
          token::LBRACKET => {
            self.bump();
            let (elements, tail) = self.parse_pat_vec_elements(refutable);
            hi = self.span.hi;
            self.expect(token::RBRACKET);
            pat = ast::pat_vec(elements, tail);
          }
          copy tok => {
            if !is_ident_or_path(tok)
                || self.is_keyword(~"true")
                || self.is_keyword(~"false")
            {
                let val = self.parse_expr_res(RESTRICT_NO_BAR_OP);
                if self.eat(token::DOTDOT) {
                    let end = self.parse_expr_res(RESTRICT_NO_BAR_OP);
                    pat = pat_range(val, end);
                } else {
                    pat = pat_lit(val);
                }
            } else if self.eat_keyword(~"ref") {
                let mutbl = self.parse_mutability();
                pat = self.parse_pat_ident(refutable, bind_by_ref(mutbl));
            } else if self.eat_keyword(~"copy") {
                pat = self.parse_pat_ident(refutable, bind_by_copy);
            } else {
                if self.eat_keyword(~"move") {
                    /* XXX---remove move keyword */
                }

                // XXX---refutable match bindings should work same as let
                let binding_mode =
                    if refutable {bind_infer} else {bind_by_copy};

                let cannot_be_enum_or_struct;
                match self.look_ahead(1) {
                    token::LPAREN | token::LBRACKET | token::LT |
                    token::LBRACE | token::MOD_SEP =>
                        cannot_be_enum_or_struct = false,
                    _ =>
                        cannot_be_enum_or_struct = true
                }

                if is_plain_ident(self.token) && cannot_be_enum_or_struct {
                    let name = self.parse_value_path();
                    let sub;
                    if self.eat(token::AT) {
                        sub = Some(self.parse_pat(refutable));
                    } else {
                        sub = None;
                    };
                    pat = pat_ident(binding_mode, name, sub);
                } else {
                    let enum_path = self.parse_path_with_tps(true);
                    match self.token {
                        token::LBRACE => {
                            self.bump();
                            let (fields, etc) =
                                self.parse_pat_fields(refutable);
                            self.bump();
                            pat = pat_struct(enum_path, fields, etc);
                        }
                        _ => {
                            let mut args: ~[@pat] = ~[];
                            let mut star_pat = false;
                            match self.token {
                              token::LPAREN => match self.look_ahead(1u) {
                                token::BINOP(token::STAR) => {
                                    // This is a "top constructor only" pat
                                      self.bump(); self.bump();
                                      star_pat = true;
                                      self.expect(token::RPAREN);
                                  }
                                _ => {
                                    args = self.parse_unspanned_seq(
                                        token::LPAREN, token::RPAREN,
                                        seq_sep_trailing_disallowed
                                            (token::COMMA),
                                        |p| p.parse_pat(refutable));
                                  }
                              },
                              _ => ()
                            }
                            // at this point, we're not sure whether it's a
                            // enum or a bind
                            if star_pat {
                                pat = pat_enum(enum_path, None);
                            }
                            else if vec::is_empty(args) &&
                                vec::len(enum_path.idents) == 1u {
                                pat = pat_ident(binding_mode,
                                                enum_path,
                                                None);
                            }
                            else {
                                pat = pat_enum(enum_path, Some(args));
                            }
                        }
                    }
                }
            }
            hi = self.span.hi;
          }
        }
        @ast::pat { id: self.get_id(), node: pat, span: mk_sp(lo, hi) }
    }

    fn parse_pat_ident(refutable: bool,
                       binding_mode: ast::binding_mode) -> ast::pat_ {
        if !is_plain_ident(self.token) {
            self.span_fatal(
                copy self.last_span,
                ~"expected identifier, found path");
        }
        let name = self.parse_value_path();
        let sub = if self.eat(token::AT) {
            Some(self.parse_pat(refutable))
        } else { None };

        // just to be friendly, if they write something like
        //   ref Some(i)
        // we end up here with ( as the current token.  This shortly
        // leads to a parse error.  Note that if there is no explicit
        // binding mode then we do not end up here, because the lookahead
        // will direct us over to parse_enum_variant()
        if self.token == token::LPAREN {
            self.span_fatal(
                copy self.last_span,
                ~"expected identifier, found enum pattern");
        }

        pat_ident(binding_mode, name, sub)
    }

    fn parse_local(is_mutbl: bool,
                   allow_init: bool) -> @local {
        let lo = self.span.lo;
        let pat = self.parse_pat(false);
        let mut ty = @Ty {
            id: self.get_id(),
            node: ty_infer,
            span: mk_sp(lo, lo),
        };
        if self.eat(token::COLON) { ty = self.parse_ty(false); }
        let init = if allow_init { self.parse_initializer() } else { None };
        @spanned(
            lo,
            self.last_span.hi,
            ast::local_ {
                is_mutbl: is_mutbl,
                ty: ty,
                pat: pat,
                init: init,
                id: self.get_id(),
            }
        )
    }

    fn parse_let() -> @decl {
        let is_mutbl = self.eat_keyword(~"mut");
        let lo = self.span.lo;
        let mut locals = ~[self.parse_local(is_mutbl, true)];
        while self.eat(token::COMMA) {
            locals.push(self.parse_local(is_mutbl, true));
        }
        return @spanned(lo, self.last_span.hi, decl_local(locals));
    }

    /* assumes "let" token has already been consumed */
    fn parse_instance_var(pr: visibility) -> @struct_field {
        let mut is_mutbl = struct_immutable;
        let lo = self.span.lo;
        if self.eat_keyword(~"mut") {
            is_mutbl = struct_mutable;
        }
        if !is_plain_ident(self.token) {
            self.fatal(~"expected ident");
        }
        let name = self.parse_ident();
        self.expect(token::COLON);
        let ty = self.parse_ty(false);
        @spanned(lo, self.last_span.hi, ast::struct_field_ {
            kind: named_field(name, is_mutbl, pr),
            id: self.get_id(),
            ty: ty
        })
    }

    fn parse_stmt(+first_item_attrs: ~[attribute]) -> @stmt {
        maybe_whole!(self, nt_stmt);

        fn check_expected_item(p: Parser, current_attrs: ~[attribute]) {
            // If we have attributes then we should have an item
            if !current_attrs.is_empty() {
                p.fatal(~"expected item after attrs");
            }
        }

        let lo = self.span.lo;
        if self.is_keyword(~"let") {
            check_expected_item(self, first_item_attrs);
            self.expect_keyword(~"let");
            let decl = self.parse_let();
            return @spanned(lo, decl.span.hi, stmt_decl(decl, self.get_id()));
        } else if is_ident(self.token)
            && !self.is_any_keyword(copy self.token)
            && self.look_ahead(1) == token::NOT {

            check_expected_item(self, first_item_attrs);

            // Potential trouble: if we allow macros with paths instead of
            // idents, we'd need to look ahead past the whole path here...
            let pth = self.parse_value_path();
            self.bump();

            let id = if self.token == token::LPAREN {
                token::special_idents::invalid // no special identifier
            } else {
                self.parse_ident()
            };

            let tts = self.parse_unspanned_seq(
                token::LPAREN, token::RPAREN, seq_sep_none(),
                |p| p.parse_token_tree());
            let hi = self.span.hi;

            if id == token::special_idents::invalid {
                return @spanned(lo, hi, stmt_mac(
                    spanned(lo, hi, mac_invoc_tt(pth, tts)), false));
            } else {
                // if it has a special ident, it's definitely an item
                return @spanned(lo, hi, stmt_decl(
                    @spanned(lo, hi, decl_item(
                        self.mk_item(
                            lo, hi, id /*id is good here*/,
                            item_mac(spanned(lo, hi, mac_invoc_tt(pth, tts))),
                            inherited, ~[/*no attrs*/]))),
                    self.get_id()));
            }

        } else {
            let item_attrs = vec::append(first_item_attrs,
                                         self.parse_outer_attributes());

            match self.parse_item_or_view_item(item_attrs,
                                               true, false, false) {
              iovi_item(i) => {
                let mut hi = i.span.hi;
                let decl = @spanned(lo, hi, decl_item(i));
                return @spanned(lo, hi, stmt_decl(decl, self.get_id()));
              }
              iovi_view_item(vi) => {
                self.span_fatal(vi.span, ~"view items must be declared at \
                                           the top of the block");
              }
              iovi_foreign_item(_) => {
                  self.fatal(~"foreign items are not allowed here");
              }
              iovi_none() => { /* fallthrough */ }
            }

            check_expected_item(self, item_attrs);

            // Remainder are line-expr stmts.
            let e = self.parse_expr_res(RESTRICT_STMT_EXPR);
            return @spanned(lo, e.span.hi, stmt_expr(e, self.get_id()));
        }
    }

    fn expr_is_complete(e: @expr) -> bool {
        return self.restriction == RESTRICT_STMT_EXPR &&
            !classify::expr_requires_semi_to_be_stmt(e);
    }

    fn parse_block() -> blk {
        let (attrs, blk) = self.parse_inner_attrs_and_block(false);
        assert vec::is_empty(attrs);
        return blk;
    }

    fn parse_inner_attrs_and_block(parse_attrs: bool)
        -> (~[attribute], blk) {

        maybe_whole!(pair_empty self, nt_block);

        fn maybe_parse_inner_attrs_and_next(p: Parser, parse_attrs: bool) ->
            {inner: ~[attribute], next: ~[attribute]} {
            if parse_attrs {
                p.parse_inner_attrs_and_next()
            } else {
                {inner: ~[], next: ~[]}
            }
        }

        let lo = self.span.lo;
        if self.eat_keyword(~"unsafe") {
            self.obsolete(copy self.span, ObsoleteUnsafeBlock);
        }
        self.expect(token::LBRACE);
        let {inner: move inner, next: move next} =
            maybe_parse_inner_attrs_and_next(self, parse_attrs);
        return (inner, self.parse_block_tail_(lo, default_blk, next));
    }

    fn parse_block_no_value() -> blk {
        // We parse blocks that cannot have a value the same as any other
        // block; the type checker will make sure that the tail expression (if
        // any) has unit type.
        return self.parse_block();
    }

    // Precondition: already parsed the '{' or '#{'
    // I guess that also means "already parsed the 'impure'" if
    // necessary, and this should take a qualifier.
    // some blocks start with "#{"...
    fn parse_block_tail(lo: BytePos, s: blk_check_mode) -> blk {
        self.parse_block_tail_(lo, s, ~[])
    }

    fn parse_block_tail_(lo: BytePos, s: blk_check_mode,
                         +first_item_attrs: ~[attribute]) -> blk {
        let mut stmts = ~[];
        let mut expr = None;

        let {attrs_remaining: move attrs_remaining,
             view_items: move view_items,
             items: items, _} =
            self.parse_items_and_view_items(first_item_attrs,
                                            IMPORTS_AND_ITEMS_ALLOWED, false);

        for items.each |item| {
            let decl = @spanned(item.span.lo, item.span.hi, decl_item(*item));
            stmts.push(@spanned(item.span.lo, item.span.hi,
                                stmt_decl(decl, self.get_id())));
        }

        let mut initial_attrs = attrs_remaining;

        if self.token == token::RBRACE && !vec::is_empty(initial_attrs) {
            self.fatal(~"expected item");
        }

        while self.token != token::RBRACE {
            match self.token {
                token::SEMI => {
                    self.bump(); // empty
                }
                _ => {
                    let stmt = self.parse_stmt(initial_attrs);
                    initial_attrs = ~[];
                    match stmt.node {
                        stmt_expr(e, stmt_id) => {
                            // Expression without semicolon
                            match self.token {
                                token::SEMI => {
                                    self.bump();
                                    stmts.push(@ast::spanned {
                                        node: stmt_semi(e, stmt_id),
                                        .. *stmt});
                                }
                                token::RBRACE => {
                                    expr = Some(e);
                                }
                                copy t => {
                                    if classify::stmt_ends_with_semi(*stmt) {
                                        self.fatal(
                                            ~"expected `;` or `}` after \
                                              expression but found `"
                                            + token_to_str(self.reader, t)
                                            + ~"`");
                                    }
                                    stmts.push(stmt);
                                }
                            }
                        }

                        stmt_mac(ref m, _) => {
                            // Statement macro; might be an expr
                            match self.token {
                                token::SEMI => {
                                    self.bump();
                                    stmts.push(@ast::spanned {
                                        node: stmt_mac((*m), true),
                                        .. *stmt});
                                }
                                token::RBRACE => {
                                    // if a block ends in `m!(arg)` without
                                    // a `;`, it must be an expr
                                    expr = Some(
                                        self.mk_mac_expr(stmt.span.lo,
                                                         stmt.span.hi,
                                                         (*m).node));
                                }
                                _ => { stmts.push(stmt); }
                            }
                        }

                        _ => { // All other kinds of statements:
                            stmts.push(stmt);

                            if classify::stmt_ends_with_semi(*stmt) {
                                self.expect(token::SEMI);
                            }
                        }
                    }
                }
            }
        }
        let mut hi = self.span.hi;
        self.bump();
        let bloc = ast::blk_ {
            view_items: view_items,
            stmts: stmts,
            expr: expr,
            id: self.get_id(),
            rules: s,
        };
        spanned(lo, hi, bloc)
    }

    fn mk_ty_path(i: ident) -> @Ty {
        @Ty {
            id: self.get_id(),
            node: ty_path(
                ident_to_path(copy self.last_span, i),
                self.get_id()),
            span: self.last_span,
        }
    }

    fn parse_optional_purity() -> ast::purity {
        if self.eat_keyword(~"pure") {
            ast::pure_fn
        } else if self.eat_keyword(~"unsafe") {
            ast::unsafe_fn
        } else {
            ast::impure_fn
        }
    }

    fn parse_optional_onceness() -> ast::Onceness {
        if self.eat_keyword(~"once") { ast::Once } else { ast::Many }
    }

    fn parse_optional_ty_param_bounds() -> @~[ty_param_bound] {
        let mut bounds = ~[];
        if self.eat(token::COLON) {
            loop {
                if self.eat(token::BINOP(token::AND)) {
                    if self.eat_keyword(~"static") {
                        bounds.push(RegionTyParamBound);
                    } else {
                        self.span_err(copy self.span,
                                      ~"`&static` is the only permissible \
                                        region bound here");
                    }
                } else if is_ident(self.token) {
                    let maybe_bound = match self.token {
                      token::IDENT(copy sid, _) => {
                        match *self.id_to_str(sid) {

                          ~"send"
                          | ~"copy"
                          | ~"const"
                          | ~"owned" => {
                            self.obsolete(copy self.span,
                                          ObsoleteLowerCaseKindBounds);
                            // Bogus value, but doesn't matter, since
                            // is an error
                            Some(TraitTyParamBound(self.mk_ty_path(sid)))
                          }

                          _ => None
                        }
                      }
                      _ => fail
                    };

                    match maybe_bound {
                        Some(bound) => {
                            self.bump();
                            bounds.push(bound);
                        }
                        None => {
                            let ty = self.parse_ty(false);
                            bounds.push(TraitTyParamBound(ty));
                        }
                    }
                } else {
                    break;
                }

                if self.eat(token::BINOP(token::PLUS)) {
                    // Should be `break;` but that isn't backwards compatible.
                }
            }
        }
        return @move bounds;
    }

    fn parse_ty_param() -> ty_param {
        let ident = self.parse_ident();
        let bounds = self.parse_optional_ty_param_bounds();
        ast::ty_param { ident: ident, id: self.get_id(), bounds: bounds }
    }

    fn parse_ty_params() -> ~[ty_param] {
        if self.eat(token::LT) {
            self.parse_seq_to_gt(Some(token::COMMA), |p| p.parse_ty_param())
        } else { ~[] }
    }

    fn parse_fn_decl(parse_arg_fn: fn(Parser) -> arg_or_capture_item)
        -> fn_decl
    {
        let args_or_capture_items: ~[arg_or_capture_item] =
            self.parse_unspanned_seq(
                token::LPAREN, token::RPAREN,
                seq_sep_trailing_disallowed(token::COMMA), parse_arg_fn);

        let inputs = either::lefts(args_or_capture_items);

        let (ret_style, ret_ty) = self.parse_ret_ty();
        ast::fn_decl {
            inputs: inputs,
            output: ret_ty,
            cf: ret_style,
        }
    }

    fn is_self_ident() -> bool {
        match self.token {
          token::IDENT(id, false) if id == special_idents::self_
            => true,
          _ => false
        }
    }

    fn expect_self_ident() {
        if !self.is_self_ident() {
            self.fatal(fmt!("expected `self` but found `%s`",
                            token_to_str(self.reader, self.token)));
        }
        self.bump();
    }

    fn parse_fn_decl_with_self(parse_arg_fn:
                               fn(Parser) -> arg_or_capture_item)
                            -> (self_ty, fn_decl) {

        fn maybe_parse_self_ty(cnstr: fn(+v: mutability) -> ast::self_ty_,
                               p: Parser) -> ast::self_ty_ {
            // We need to make sure it isn't a mode or a type
            if p.token_is_keyword(~"self", p.look_ahead(1)) ||
                ((p.token_is_keyword(~"const", p.look_ahead(1)) ||
                  p.token_is_keyword(~"mut", p.look_ahead(1))) &&
                 p.token_is_keyword(~"self", p.look_ahead(2))) {

                p.bump();
                let mutability = p.parse_mutability();
                p.expect_self_ident();
                cnstr(mutability)
            } else {
                sty_by_ref
            }
        }

        self.expect(token::LPAREN);

        // A bit of complexity and lookahead is needed here in order to to be
        // backwards compatible.
        let lo = self.span.lo;
        let self_ty = match copy self.token {
          token::BINOP(token::AND) => {
            maybe_parse_self_ty(sty_region, self)
          }
          token::AT => {
            maybe_parse_self_ty(sty_box, self)
          }
          token::TILDE => {
            maybe_parse_self_ty(sty_uniq, self)
          }
          token::IDENT(*) if self.is_self_ident() => {
            self.bump();
            sty_value
          }
          _ => {
            sty_by_ref
          }
        };

        // If we parsed a self type, expect a comma before the argument list.
        let args_or_capture_items;
        if self_ty != sty_by_ref {
            match copy self.token {
                token::COMMA => {
                    self.bump();
                    let sep = seq_sep_trailing_disallowed(token::COMMA);
                    args_or_capture_items =
                        self.parse_seq_to_before_end(token::RPAREN,
                                                     sep,
                                                     parse_arg_fn);
                }
                token::RPAREN => {
                    args_or_capture_items = ~[];
                }
                _ => {
                    self.fatal(~"expected `,` or `)`, found `" +
                               token_to_str(self.reader, self.token) + ~"`");
                }
            }
        } else {
            let sep = seq_sep_trailing_disallowed(token::COMMA);
            args_or_capture_items =
                self.parse_seq_to_before_end(token::RPAREN,
                                             sep,
                                             parse_arg_fn);
        }

        self.expect(token::RPAREN);

        let hi = self.span.hi;

        let inputs = either::lefts(args_or_capture_items);
        let (ret_style, ret_ty) = self.parse_ret_ty();

        let fn_decl = ast::fn_decl {
            inputs: inputs,
            output: ret_ty,
            cf: ret_style
        };

        (spanned(lo, hi, self_ty), fn_decl)
    }

    fn parse_fn_block_decl() -> fn_decl {
        let inputs_captures = {
            if self.eat(token::OROR) {
                ~[]
            } else {
                self.parse_unspanned_seq(
                    token::BINOP(token::OR), token::BINOP(token::OR),
                    seq_sep_trailing_disallowed(token::COMMA),
                    |p| p.parse_fn_block_arg())
            }
        };
        let output = if self.eat(token::RARROW) {
            self.parse_ty(false)
        } else {
            @Ty { id: self.get_id(), node: ty_infer, span: self.span }
        };

        ast::fn_decl {
            inputs: either::lefts(inputs_captures),
            output: output,
            cf: return_val,
        }
    }

    fn parse_fn_header() -> {ident: ident, tps: ~[ty_param]} {
        let id = self.parse_value_ident();
        let ty_params = self.parse_ty_params();
        return {ident: id, tps: ty_params};
    }

    fn mk_item(+lo: BytePos, +hi: BytePos, +ident: ident,
               +node: item_, vis: visibility,
               +attrs: ~[attribute]) -> @item {
        @ast::item { ident: ident,
                     attrs: attrs,
                     id: self.get_id(),
                     node: node,
                     vis: vis,
                     span: mk_sp(lo, hi) }
    }

    fn parse_item_fn(purity: purity) -> item_info {
        let t = self.parse_fn_header();
        let decl = self.parse_fn_decl(|p| p.parse_arg());
        let (inner_attrs, body) = self.parse_inner_attrs_and_block(true);
        (t.ident, item_fn(decl, purity, t.tps, body), Some(inner_attrs))
    }

    fn parse_method_name() -> ident {
        self.parse_value_ident()
    }

    fn parse_method() -> @method {
        let attrs = self.parse_outer_attributes();
        let lo = self.span.lo;

        let is_static = self.parse_staticness();
        let static_sty = spanned(lo, self.span.hi, sty_static);

        let visa = self.parse_visibility();
        let pur = self.parse_fn_purity();
        let ident = self.parse_method_name();
        let tps = self.parse_ty_params();
        let (self_ty, decl) = do self.parse_fn_decl_with_self() |p| {
            p.parse_arg()
        };
        // XXX: interaction between staticness, self_ty is broken now
        let self_ty = if is_static { static_sty} else { self_ty };

        let (inner_attrs, body) = self.parse_inner_attrs_and_block(true);
        let attrs = vec::append(attrs, inner_attrs);
        @ast::method {
            ident: ident,
            attrs: attrs,
            tps: tps,
            self_ty: self_ty,
            purity: pur,
            decl: decl,
            body: body,
            id: self.get_id(),
            span: mk_sp(lo, body.span.hi),
            self_id: self.get_id(),
            vis: visa,
        }
    }

    fn parse_item_trait() -> item_info {
        let ident = self.parse_ident();
        self.parse_region_param();
        let tps = self.parse_ty_params();

        // Parse traits, if necessary.
        let traits;
        if self.token == token::COLON {
            self.bump();
            traits = self.parse_trait_ref_list(token::LBRACE);
        } else {
            traits = ~[];
        }

        let meths = self.parse_trait_methods();
        (ident, item_trait(tps, traits, meths), None)
    }

    // Parses two variants (with the region/type params always optional):
    //    impl<T> ~[T] : to_str { ... }
    //    impl<T> to_str for ~[T] { ... }
    fn parse_item_impl() -> item_info {
        fn wrap_path(p: Parser, pt: @path) -> @Ty {
            @Ty {
                id: p.get_id(),
                node: ty_path(pt, p.get_id()),
                span: pt.span,
            }
        }

        // First, parse type parameters if necessary.
        let mut tps;
        if self.token == token::LT {
            tps = self.parse_ty_params();
        } else {
            tps = ~[];
        }

        // This is a new-style impl declaration.
        // XXX: clownshoes
        let ident = special_idents::clownshoes_extensions;

        // Parse the type. (If this is `impl trait for type`, however, this
        // actually parses the trait.)
        let mut ty = self.parse_ty(false);

        // Parse traits, if necessary.
        let opt_trait = if self.token == token::COLON {
            // Old-style trait.
            self.bump();
            Some(self.parse_trait_ref())
        } else if self.eat_keyword(~"for") {
            // New-style trait. Reinterpret the type as a trait.
            let opt_trait_ref = match ty.node {
                ty_path(path, node_id) => {
                    Some(@trait_ref {
                        path: path,
                        ref_id: node_id
                    })
                }
                _ => {
                    self.span_err(copy self.span, ~"not a trait");
                    None
                }
            };

            ty = self.parse_ty(false);
            opt_trait_ref
        } else {
            None
        };

        let mut meths = ~[];
        if !self.eat(token::SEMI) {
            self.expect(token::LBRACE);
            while !self.eat(token::RBRACE) {
                meths.push(self.parse_method());
            }
        }

        (ident, item_impl(tps, opt_trait, ty, meths), None)
    }

    // Instantiates ident <i> with references to <typarams> as arguments.
    // Used to create a path that refers to a class which will be defined as
    // the return type of the ctor function.
    fn ident_to_path_tys(i: ident,
                         typarams: ~[ty_param]) -> @path {
        let s = self.last_span;

        @ast::path {
             span: s,
             global: false,
             idents: ~[i],
             rp: None,
             types: do typarams.map |tp| {
                @Ty {
                    id: self.get_id(),
                    node: ty_path(ident_to_path(s, tp.ident), self.get_id()),
                    span: s
                }
            }
         }
    }

    fn ident_to_path(i: ident) -> @path {
        @ast::path { span: self.last_span,
                     global: false,
                     idents: ~[i],
                     rp: None,
                     types: ~[] }
    }

    fn parse_trait_ref() -> @trait_ref {
        @ast::trait_ref {
            path: self.parse_path_with_tps(false),
            ref_id: self.get_id(),
        }
    }

    fn parse_trait_ref_list(ket: token::Token) -> ~[@trait_ref] {
        self.parse_seq_to_before_end(
            ket, seq_sep_none(),
            |p| p.parse_trait_ref())
    }

    fn parse_item_struct() -> item_info {
        let class_name = self.parse_value_ident();
        self.parse_region_param();
        let ty_params = self.parse_ty_params();
        if self.eat(token::COLON) {
            self.obsolete(copy self.span, ObsoleteClassTraits);
            let _ = self.parse_trait_ref_list(token::LBRACE);
        }

        let mut fields: ~[@struct_field];
        let mut the_dtor: Option<(blk, ~[attribute], codemap::span)> = None;
        let is_tuple_like;

        if self.eat(token::LBRACE) {
            // It's a record-like struct.
            is_tuple_like = false;
            fields = ~[];
            while self.token != token::RBRACE {
                match self.parse_class_item() {
                  dtor_decl(ref blk, ref attrs, s) => {
                      match the_dtor {
                        Some((_, _, s_first)) => {
                          self.span_note(s, fmt!("Duplicate destructor \
                                     declaration for class %s",
                                     *self.interner.get(class_name)));
                          self.span_fatal(copy s_first, ~"First destructor \
                                                          declared here");
                        }
                        None => {
                          the_dtor = Some(((*blk), (*attrs), s));
                        }
                      }
                  }
                  members(mms) => {
                    for mms.each |struct_field| {
                        fields.push(*struct_field)
                    }
                  }
                }
            }
            self.bump();
        } else if self.token == token::LPAREN {
            // It's a tuple-like struct.
            is_tuple_like = true;
            fields = do self.parse_unspanned_seq(token::LPAREN, token::RPAREN,
                                                 seq_sep_trailing_allowed
                                                    (token::COMMA)) |p| {
                let lo = p.span.lo;
                let struct_field_ = ast::struct_field_ {
                    kind: unnamed_field,
                    id: self.get_id(),
                    ty: p.parse_ty(false)
                };
                @spanned(lo, p.span.hi, struct_field_)
            };
            self.expect(token::SEMI);
        } else if self.eat(token::SEMI) {
            // It's a unit-like struct.
            is_tuple_like = true;
            fields = ~[];
        } else {
            self.fatal(fmt!("expected `{`, `(`, or `;` after struct name \
                             but found `%s`",
                            token_to_str(self.reader, self.token)));
        }

        let actual_dtor = do the_dtor.map |dtor| {
            let (d_body, d_attrs, d_s) = *dtor;
            ast::spanned { node: ast::struct_dtor_ { id: self.get_id(),
                                                     attrs: d_attrs,
                                                     self_id: self.get_id(),
                                                     body: d_body},
                       span: d_s}};
        let _ = self.get_id();  // XXX: Workaround for crazy bug.
        let new_id = self.get_id();
        (class_name,
         item_struct(@ast::struct_def {
             fields: fields,
             dtor: actual_dtor,
             ctor_id: if is_tuple_like { Some(new_id) } else { None }
         }, ty_params),
         None)
    }

    fn token_is_pound_or_doc_comment(++tok: token::Token) -> bool {
        match tok {
            token::POUND | token::DOC_COMMENT(_) => true,
            _ => false
        }
    }

    fn parse_single_class_item(vis: visibility) -> @struct_field {
        let obsolete_let = self.eat_obsolete_ident("let");
        if obsolete_let { self.obsolete(copy self.last_span, ObsoleteLet) }

        let parse_obsolete_method =
            !((obsolete_let || self.is_keyword(~"mut") ||
               !self.is_any_keyword(copy self.token))
              && !self.token_is_pound_or_doc_comment(copy self.token));

        if !parse_obsolete_method {
            let a_var = self.parse_instance_var(vis);
            match self.token {
              token::SEMI => {
                self.obsolete(copy self.span, ObsoleteFieldTerminator);
                self.bump();
              }
              token::COMMA => {
                self.bump();
              }
              token::RBRACE => {}
              _ => {
                self.span_fatal(copy self.span,
                                fmt!("expected `;`, `,`, or '}' but \
                                      found `%s`",
                                     token_to_str(self.reader,
                                                  self.token)));
              }
            }
            a_var
        } else {
            self.obsolete(copy self.span, ObsoleteClassMethod);
            self.parse_method();
            // bogus value
            @spanned(
                self.span.lo,
                self.span.hi,
                ast::struct_field_ {
                    kind: unnamed_field,
                    id: self.get_id(),
                    ty: @ast::Ty {
                        id: self.get_id(),
                        node: ty_nil,
                        span: copy self.span,
                    }
                }
            )
        }
    }

    fn parse_dtor(attrs: ~[attribute]) -> class_contents {
        let lo = self.last_span.lo;
        let body = self.parse_block();
        dtor_decl(body, attrs, mk_sp(lo, self.last_span.hi))
    }

    fn parse_class_item() -> class_contents {

        if self.try_parse_obsolete_priv_section() {
            return members(~[]);
        }

        if self.eat_keyword(~"priv") {
            return members(~[self.parse_single_class_item(private)])
        }

        if self.eat_keyword(~"pub") {
           return members(~[self.parse_single_class_item(public)]);
        }

        let attrs = self.parse_outer_attributes();

        if self.try_parse_obsolete_struct_ctor() {
            return members(~[]);
        }

        if self.eat_keyword(~"drop") {
           return self.parse_dtor(attrs);
        }
        else {
           return members(~[self.parse_single_class_item(inherited)]);
        }
    }

    fn parse_visibility() -> visibility {
        if self.eat_keyword(~"pub") { public }
        else if self.eat_keyword(~"priv") { private }
        else { inherited }
    }
    fn parse_staticness() -> bool {
        self.eat_keyword(~"static")
    }

    fn parse_mod_items(term: token::Token,
                       +first_item_attrs: ~[attribute]) -> _mod {
        // Shouldn't be any view items since we've already parsed an item attr
        let {attrs_remaining: move attrs_remaining,
             view_items: move view_items,
             items: starting_items, _} =
            self.parse_items_and_view_items(first_item_attrs,
                                            VIEW_ITEMS_AND_ITEMS_ALLOWED,
                                            true);
        let mut items: ~[@item] = move starting_items;

        let mut first = true;
        while self.token != term {
            let mut attrs = self.parse_outer_attributes();
            if first {
                attrs = vec::append(attrs_remaining, attrs);
                first = false;
            }
            debug!("parse_mod_items: parse_item_or_view_item(attrs=%?)",
                   attrs);
            match self.parse_item_or_view_item(attrs, true, false, true) {
              iovi_item(item) => items.push(item),
              iovi_view_item(view_item) => {
                self.span_fatal(view_item.span, ~"view items must be \
                                                  declared at the top of the \
                                                  module");
              }
              _ => {
                self.fatal(~"expected item but found `" +
                           token_to_str(self.reader, self.token) + ~"`");
              }
            }
            debug!("parse_mod_items: attrs=%?", attrs);
        }

        if first && attrs_remaining.len() > 0u {
            // We parsed attributes for the first item but didn't find it
            self.fatal(~"expected item");
        }

        ast::_mod { view_items: view_items, items: items }
    }

    fn parse_item_const() -> item_info {
        let id = self.parse_value_ident();
        self.expect(token::COLON);
        let ty = self.parse_ty(false);
        self.expect(token::EQ);
        let e = self.parse_expr();
        self.expect(token::SEMI);
        (id, item_const(ty, e), None)
    }

    fn parse_item_mod(outer_attrs: ~[ast::attribute]) -> item_info {
        let id_span = self.span;
        let id = self.parse_ident();
        let info_ = if self.token == token::SEMI {
            self.bump();
            // This mod is in an external file. Let's go get it!
            let (m, attrs) = self.eval_src_mod(id, outer_attrs, id_span);
            (id, m, Some(move attrs))
        } else {
            self.push_mod_path(id, outer_attrs);
            self.expect(token::LBRACE);
            let inner_attrs = self.parse_inner_attrs_and_next();
            let m = self.parse_mod_items(token::RBRACE, inner_attrs.next);
            self.expect(token::RBRACE);
            self.pop_mod_path();
            (id, item_mod(m), Some(inner_attrs.inner))
        };

        // XXX: Transitionary hack to do the template work inside core
        // (int-template, iter-trait). If there's a 'merge' attribute
        // on the mod, then we'll go and suck in another file and merge
        // its contents
        match ::attr::first_attr_value_str_by_name(outer_attrs, ~"merge") {
            Some(ref path) => {
                let prefix = Path(
                    self.sess.cm.span_to_filename(copy self.span));
                let prefix = prefix.dir_path();
                let path = Path((*path));
                let (new_mod_item, new_attrs) = self.eval_src_mod_from_path(
                    prefix, path, ~[], id_span);

                let (main_id, main_mod_item, main_attrs) = info_;
                let main_attrs = main_attrs.get();

                let (main_mod, new_mod) =
                    match (main_mod_item, new_mod_item) {
                    (item_mod(m), item_mod(n)) => (m, n),
                    _ => self.bug(~"parsed mod item should be mod")
                };
                let merged_mod = ast::_mod {
                    view_items: main_mod.view_items + new_mod.view_items,
                    items: main_mod.items + new_mod.items
                };

                let merged_attrs = main_attrs + new_attrs;
                (main_id, item_mod(merged_mod), Some(merged_attrs))
            }
            None => info_
        }
    }

    fn push_mod_path(id: ident, attrs: ~[ast::attribute]) {
        let default_path = self.sess.interner.get(id);
        let file_path = match ::attr::first_attr_value_str_by_name(
            attrs, ~"path") {

            Some(ref d) => (*d),
            None => copy *default_path
        };
        self.mod_path_stack.push(file_path)
    }

    fn pop_mod_path() {
        self.mod_path_stack.pop();
    }

    fn eval_src_mod(id: ast::ident,
                    outer_attrs: ~[ast::attribute],
                    id_sp: span) -> (ast::item_, ~[ast::attribute]) {

        let prefix = Path(self.sess.cm.span_to_filename(copy self.span));
        let prefix = prefix.dir_path();
        let mod_path = Path(".").push_many(self.mod_path_stack);
        let default_path = self.sess.interner.get(id) + ~".rs";
        let file_path = match ::attr::first_attr_value_str_by_name(
            outer_attrs, ~"path") {
            Some(ref d) => {
                let path = Path(*d);
                if !path.is_absolute {
                    mod_path.push(*d)
                } else {
                    path
                }
            }
            None => mod_path.push(default_path)
        };

        self.eval_src_mod_from_path(prefix, file_path,
                                    outer_attrs, id_sp)
    }

    fn eval_src_mod_from_path(prefix: Path, path: Path,
                              outer_attrs: ~[ast::attribute],
                              id_sp: span
                             ) -> (ast::item_, ~[ast::attribute]) {

        let full_path = if path.is_absolute {
            path
        } else {
            prefix.push_many(path.components)
        };
        let full_path = full_path.normalize();
        let p0 =
            new_sub_parser_from_file(self.sess, self.cfg,
                                     &full_path, id_sp);
        let inner_attrs = p0.parse_inner_attrs_and_next();
        let mod_attrs = vec::append(outer_attrs, inner_attrs.inner);
        let first_item_outer_attrs = inner_attrs.next;
        let m0 = p0.parse_mod_items(token::EOF, first_item_outer_attrs);
        return (ast::item_mod(m0), mod_attrs);

        fn cdir_path_opt(default: ~str, attrs: ~[ast::attribute]) -> ~str {
            match ::attr::first_attr_value_str_by_name(attrs, ~"path") {
                Some(ref d) => (*d),
                None => default
            }
        }
    }

    fn parse_item_foreign_fn( +attrs: ~[attribute]) -> @foreign_item {
        let lo = self.span.lo;
        let vis = self.parse_visibility();
        let purity = self.parse_fn_purity();
        let t = self.parse_fn_header();
        let decl = self.parse_fn_decl(|p| p.parse_arg());
        let mut hi = self.span.hi;
        self.expect(token::SEMI);
        @ast::foreign_item { ident: t.ident,
                             attrs: attrs,
                             node: foreign_item_fn(decl, purity, t.tps),
                             id: self.get_id(),
                             span: mk_sp(lo, hi),
                             vis: vis }
    }

    fn parse_item_foreign_const(vis: ast::visibility,
                                +attrs: ~[attribute]) -> @foreign_item {
        let lo = self.span.lo;
        self.expect_keyword(~"const");
        let ident = self.parse_ident();
        self.expect(token::COLON);
        let ty = self.parse_ty(false);
        let hi = self.span.hi;
        self.expect(token::SEMI);
        @ast::foreign_item { ident: ident,
                             attrs: attrs,
                             node: foreign_item_const(ty),
                             id: self.get_id(),
                             span: mk_sp(lo, hi),
                             vis: vis }
    }

    fn parse_fn_purity() -> purity {
        if self.eat_keyword(~"fn") { impure_fn }
        else if self.eat_keyword(~"pure") {
            self.expect_keyword(~"fn");
            pure_fn
        } else if self.eat_keyword(~"unsafe") {
            self.expect_keyword(~"fn");
            unsafe_fn
        }
        else { self.unexpected(); }
    }

    fn parse_foreign_item(+attrs: ~[attribute]) -> @foreign_item {
        let vis = self.parse_visibility();
        if self.is_keyword(~"const") {
            self.parse_item_foreign_const(vis, move attrs)
        } else {
            self.parse_item_foreign_fn( move attrs)
        }
    }

    fn parse_foreign_mod_items(sort: ast::foreign_mod_sort,
                               +abi: ast::ident,
                               +first_item_attrs: ~[attribute])
                            -> foreign_mod {
        // Shouldn't be any view items since we've already parsed an item attr
        let {attrs_remaining: move attrs_remaining,
             view_items: move view_items,
             items: _,
             foreign_items: move foreign_items} =
            self.parse_items_and_view_items(first_item_attrs,
                                         VIEW_ITEMS_AND_FOREIGN_ITEMS_ALLOWED,
                                            true);

        let mut items: ~[@foreign_item] = move foreign_items;
        let mut initial_attrs = attrs_remaining;
        while self.token != token::RBRACE {
            let attrs = vec::append(initial_attrs,
                                    self.parse_outer_attributes());
            initial_attrs = ~[];
            items.push(self.parse_foreign_item(attrs));
        }
        ast::foreign_mod {
            sort: sort,
            abi: move abi,
            view_items: view_items,
            items: items
        }
    }

    fn parse_item_foreign_mod(lo: BytePos,
                              visibility: visibility,
                              attrs: ~[attribute],
                              items_allowed: bool)
                           -> item_or_view_item {

        // Parse the ABI.
        let abi_opt;
        match self.token {
            token::LIT_STR(copy found_abi) => {
                self.bump();
                abi_opt = Some(found_abi);
            }
            _ => {
                abi_opt = None;
            }
        }

        let mut must_be_named_mod = false;
        if self.is_keyword(~"mod") {
            must_be_named_mod = true;
            self.expect_keyword(~"mod");
        } else if self.token != token::LBRACE {
            self.span_fatal(copy self.span,
                            fmt!("expected `{` or `mod` but found %s",
                                 token_to_str(self.reader, self.token)));
        }

        let (sort, ident) = match self.token {
            token::IDENT(*) => (ast::named, self.parse_ident()),
            _ => {
                if must_be_named_mod {
                    self.span_fatal(copy self.span,
                                    fmt!("expected foreign module name but \
                                          found %s",
                                         token_to_str(self.reader,
                                                      self.token)));
                }

                (ast::anonymous,
                 special_idents::clownshoes_foreign_mod)
            }
        };

        // extern mod { ... }
        if items_allowed && self.eat(token::LBRACE) {
            let abi;
            match move abi_opt {
                Some(move found_abi) => abi = move found_abi,
                None => abi = special_idents::c_abi,
            }

            let extra_attrs = self.parse_inner_attrs_and_next();
            let m = self.parse_foreign_mod_items(sort,
                                                 move abi,
                                                 extra_attrs.next);
            self.expect(token::RBRACE);

            return iovi_item(self.mk_item(lo, self.last_span.hi, ident,
                                          item_foreign_mod(m), visibility,
                                          maybe_append(attrs,
                                                       Some(extra_attrs.
                                                            inner))));
        }

        match abi_opt {
            None => {}  // OK.
            Some(_) => {
                self.span_err(copy self.span, ~"an ABI may not be specified \
                                                here");
            }
        }

        // extern mod foo;
        let metadata = self.parse_optional_meta();
        self.expect(token::SEMI);
        iovi_view_item(@ast::view_item {
            node: view_item_use(ident, metadata, self.get_id()),
            attrs: attrs,
            vis: visibility,
            span: mk_sp(lo, self.last_span.hi)
        })
    }

    fn parse_type_decl() -> {lo: BytePos, ident: ident} {
        let lo = self.last_span.lo;
        let id = self.parse_ident();
        return {lo: lo, ident: id};
    }

    fn parse_item_type() -> item_info {
        let t = self.parse_type_decl();
        self.parse_region_param();
        let tps = self.parse_ty_params();
        self.expect(token::EQ);
        let ty = self.parse_ty(false);
        self.expect(token::SEMI);
        (t.ident, item_ty(ty, tps), None)
    }

    fn parse_region_param() {
        if self.eat(token::BINOP(token::SLASH)) {
            self.expect(token::BINOP(token::AND));
        }
    }

    fn parse_struct_def() -> @struct_def {
        let mut the_dtor: Option<(blk, ~[attribute], codemap::span)> = None;
        let mut fields: ~[@struct_field] = ~[];
        while self.token != token::RBRACE {
            match self.parse_class_item() {
                dtor_decl(ref blk, ref attrs, s) => {
                    match the_dtor {
                        Some((_, _, s_first)) => {
                            self.span_note(s, ~"duplicate destructor \
                                                declaration");
                            self.span_fatal(copy s_first,
                                            ~"first destructor \
                                              declared here");
                        }
                        None => {
                            the_dtor = Some(((*blk), (*attrs), s));
                        }
                    }
                }
                members(mms) => {
                    for mms.each |struct_field| {
                        fields.push(*struct_field);
                    }
                }
            }
        }
        self.bump();
        let mut actual_dtor = do the_dtor.map |dtor| {
            let (d_body, d_attrs, d_s) = *dtor;
            ast::spanned { node: ast::struct_dtor_ { id: self.get_id(),
                                                     attrs: d_attrs,
                                                     self_id: self.get_id(),
                                                     body: d_body },
                      span: d_s }
        };

        return @ast::struct_def {
            fields: fields,
            dtor: actual_dtor,
            ctor_id: None
        };
    }

    fn parse_enum_def(ty_params: ~[ast::ty_param])
                   -> enum_def {
        let mut variants: ~[variant] = ~[];
        let mut all_nullary = true, have_disr = false;
        let mut common_fields = None;

        while self.token != token::RBRACE {
            let variant_attrs = self.parse_outer_attributes();
            let vlo = self.span.lo;

            // Is this a common field declaration?
            if self.eat_keyword(~"struct") {
                if common_fields.is_some() {
                    self.fatal(~"duplicate declaration of shared fields");
                }
                self.expect(token::LBRACE);
                common_fields = Some(self.parse_struct_def());
                loop;
            }

            let vis = self.parse_visibility();

            // Is this a nested enum declaration?
            let ident, needs_comma, kind;
            let mut args = ~[], disr_expr = None;
            if self.eat_keyword(~"enum") {
                ident = self.parse_ident();
                self.expect(token::LBRACE);
                let nested_enum_def = self.parse_enum_def(ty_params);
                kind = enum_variant_kind(move nested_enum_def);
                needs_comma = false;
            } else {
                ident = self.parse_value_ident();
                if self.eat(token::LBRACE) {
                    // Parse a struct variant.
                    all_nullary = false;
                    kind = struct_variant_kind(self.parse_struct_def());
                } else if self.token == token::LPAREN {
                    all_nullary = false;
                    let arg_tys = self.parse_unspanned_seq(
                        token::LPAREN, token::RPAREN,
                        seq_sep_trailing_disallowed(token::COMMA),
                        |p| p.parse_ty(false));
                    for arg_tys.each |ty| {
                        args.push(ast::variant_arg {
                            ty: *ty,
                            id: self.get_id(),
                        });
                    }
                    kind = tuple_variant_kind(args);
                } else if self.eat(token::EQ) {
                    have_disr = true;
                    disr_expr = Some(self.parse_expr());
                    kind = tuple_variant_kind(args);
                } else {
                    kind = tuple_variant_kind(~[]);
                }
                needs_comma = true;
            }

            let vr = ast::variant_ {
                name: ident,
                attrs: variant_attrs,
                kind: kind,
                id: self.get_id(),
                disr_expr: disr_expr,
                vis: vis,
            };
            variants.push(spanned(vlo, self.last_span.hi, vr));

            if needs_comma && !self.eat(token::COMMA) { break; }
        }
        self.expect(token::RBRACE);
        if (have_disr && !all_nullary) {
            self.fatal(~"discriminator values can only be used with a c-like \
                        enum");
        }

        enum_def(ast::enum_def_ { variants: variants, common: common_fields })
    }

    fn parse_item_enum() -> item_info {
        let id = self.parse_ident();
        self.parse_region_param();
        let ty_params = self.parse_ty_params();
        // Newtype syntax
        if self.token == token::EQ {
            self.bump();
            let ty = self.parse_ty(false);
            self.expect(token::SEMI);
            let variant = spanned(ty.span.lo, ty.span.hi, ast::variant_ {
                name: id,
                attrs: ~[],
                kind: tuple_variant_kind(
                    ~[ast::variant_arg {ty: ty, id: self.get_id()}]
                ),
                id: self.get_id(),
                disr_expr: None,
                vis: public,
            });

            return (
                id,
                item_enum(
                    enum_def(
                        ast::enum_def_ { variants: ~[variant], common: None }
                    ),
                    ty_params),
                None
            );
        }
        self.expect(token::LBRACE);

        let enum_definition = self.parse_enum_def(ty_params);
        (id, item_enum(enum_definition, ty_params), None)
    }

    fn parse_fn_ty_proto() -> Option<Proto> {
        match self.token {
            token::AT => {
                self.bump();
                Some(ProtoBox)
            }
            token::TILDE => {
                self.bump();
                Some(ProtoUniq)
            }
            token::BINOP(token::AND) => {
                self.bump();
                Some(ProtoBorrowed)
            }
            _ => {
                None
            }
        }
    }

    fn fn_expr_lookahead(tok: token::Token) -> bool {
        match tok {
          token::LPAREN | token::AT | token::TILDE | token::BINOP(_) => true,
          _ => false
        }
    }

    fn parse_item_or_view_item(+attrs: ~[attribute], items_allowed: bool,
                               foreign_items_allowed: bool,
                               macros_allowed: bool)
                            -> item_or_view_item {
        assert items_allowed != foreign_items_allowed;

        maybe_whole!(iovi self,nt_item);
        let lo = self.span.lo;

        let visibility;
        if self.eat_keyword(~"pub") {
            visibility = public;
        } else if self.eat_keyword(~"priv") {
            visibility = private;
        } else {
            visibility = inherited;
        }

        if items_allowed && self.eat_keyword(~"const") {
            let (ident, item_, extra_attrs) = self.parse_item_const();
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if foreign_items_allowed && self.is_keyword(~"const") {
            let item = self.parse_item_foreign_const(visibility, attrs);
            return iovi_foreign_item(item);
        } else if items_allowed &&
            self.is_keyword(~"fn") &&
            !self.fn_expr_lookahead(self.look_ahead(1u)) {
            self.bump();
            let (ident, item_, extra_attrs) = self.parse_item_fn(impure_fn);
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if items_allowed && self.eat_keyword(~"pure") {
            self.expect_keyword(~"fn");
            let (ident, item_, extra_attrs) = self.parse_item_fn(pure_fn);
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if foreign_items_allowed &&
            (self.is_keyword(~"fn") || self.is_keyword(~"pure") ||
             self.is_keyword(~"unsafe")) {
                let item = self.parse_item_foreign_fn(attrs);
                return iovi_foreign_item(item);
        } else if items_allowed && self.is_keyword(~"unsafe")
            && self.look_ahead(1u) != token::LBRACE {
            self.bump();
            self.expect_keyword(~"fn");
            let (ident, item_, extra_attrs) = self.parse_item_fn(unsafe_fn);
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if self.eat_keyword(~"extern") {
            if items_allowed && self.eat_keyword(~"fn") {
                let (ident, item_, extra_attrs) =
                    self.parse_item_fn(extern_fn);
                return iovi_item(self.mk_item(lo, self.last_span.hi, ident,
                                              item_, visibility,
                                              maybe_append(attrs,
                                                           extra_attrs)));
            }
            return self.parse_item_foreign_mod(lo, visibility, attrs,
                                               items_allowed);
        } else if items_allowed && self.eat_keyword(~"mod") {
            let (ident, item_, extra_attrs) = self.parse_item_mod(attrs);
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if items_allowed && self.eat_keyword(~"type") {
            let (ident, item_, extra_attrs) = self.parse_item_type();
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if items_allowed && self.eat_keyword(~"enum") {
            let (ident, item_, extra_attrs) = self.parse_item_enum();
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if items_allowed && self.eat_keyword(~"trait") {
            let (ident, item_, extra_attrs) = self.parse_item_trait();
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if items_allowed && self.eat_keyword(~"impl") {
            let (ident, item_, extra_attrs) = self.parse_item_impl();
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if items_allowed && self.eat_keyword(~"struct") {
            let (ident, item_, extra_attrs) = self.parse_item_struct();
            return iovi_item(self.mk_item(lo, self.last_span.hi, ident, item_,
                                          visibility,
                                          maybe_append(attrs, extra_attrs)));
        } else if self.eat_keyword(~"use") {
            let view_item = self.parse_use();
            self.expect(token::SEMI);
            return iovi_view_item(@ast::view_item {
                node: view_item,
                attrs: attrs,
                vis: visibility,
                span: mk_sp(lo, self.last_span.hi)
            });
        } else if macros_allowed && !self.is_any_keyword(copy self.token)
                && self.look_ahead(1) == token::NOT
                && (is_plain_ident(self.look_ahead(2))
                    || self.look_ahead(2) == token::LPAREN
                    || self.look_ahead(2) == token::LBRACE) {
            if attrs.len() > 0 {
                self.fatal(~"attrs on macros are not yet supported");
            }

            // item macro.
            let pth = self.parse_path_without_tps();
            self.expect(token::NOT);

            // a 'special' identifier (like what `macro_rules!` uses)
            // is optional. We should eventually unify invoc syntax
            // and remove this.
            let id = if is_plain_ident(self.token) {
                self.parse_ident()
            } else {
                token::special_idents::invalid // no special identifier
            };
            let tts = match self.token {
              token::LPAREN | token::LBRACE => {
                let ket = token::flip_delimiter(copy self.token);
                self.parse_unspanned_seq(copy self.token, ket,
                                         seq_sep_none(),
                                         |p| p.parse_token_tree())
              }
              _ => self.fatal(~"expected open delimiter")
            };
            let m = ast::mac_invoc_tt(pth, tts);
            let m: ast::mac = ast::spanned { node: m,
                                             span: mk_sp(self.span.lo,
                                                         self.span.hi) };
            let item_ = item_mac(m);
            return iovi_item(self.mk_item(lo, self.last_span.hi, id, item_,
                                          visibility, attrs));
        } else {
            if visibility != inherited {
                let mut s = ~"unmatched visibility `";
                s += if visibility == public { ~"pub" } else { ~"priv" };
                s += ~"`";
                self.span_fatal(copy self.last_span, s);
            }
            return iovi_none;
        };
    }

    fn parse_item(+attrs: ~[attribute]) -> Option<@ast::item> {
        match self.parse_item_or_view_item(attrs, true, false, true) {
            iovi_none =>
                None,
            iovi_view_item(_) =>
                self.fatal(~"view items are not allowed here"),
            iovi_foreign_item(_) =>
                self.fatal(~"foreign items are not allowed here"),
            iovi_item(item) =>
                Some(item)
        }
    }

    fn parse_use() -> view_item_ {
        return view_item_import(self.parse_view_paths());
    }

    fn parse_view_path() -> @view_path {
        let lo = self.span.lo;

        let namespace;
        if self.eat_keyword(~"mod") {
            namespace = module_ns;
        } else {
            namespace = type_value_ns;
        }

        let first_ident = self.parse_ident();
        let mut path = ~[first_ident];
        debug!("parsed view_path: %s", *self.id_to_str(first_ident));
        match self.token {
          token::EQ => {
            // x = foo::bar
            self.bump();
            path = ~[self.parse_ident()];
            while self.token == token::MOD_SEP {
                self.bump();
                let id = self.parse_ident();
                path.push(id);
            }
            let path = @ast::path { span: mk_sp(lo, self.span.hi),
                                    global: false,
                                    idents: path,
                                    rp: None,
                                    types: ~[] };
            return @spanned(lo, self.span.hi,
                         view_path_simple(first_ident, path, namespace,
                                          self.get_id()));
          }

          token::MOD_SEP => {
            // foo::bar or foo::{a,b,c} or foo::*
            while self.token == token::MOD_SEP {
                self.bump();

                match copy self.token {

                  token::IDENT(i, _) => {
                    self.bump();
                    path.push(i);
                  }

                  // foo::bar::{a,b,c}
                  token::LBRACE => {
                    let idents = self.parse_unspanned_seq(
                        token::LBRACE, token::RBRACE,
                        seq_sep_trailing_allowed(token::COMMA),
                        |p| p.parse_path_list_ident());
                    let path = @ast::path { span: mk_sp(lo, self.span.hi),
                                            global: false,
                                            idents: path,
                                            rp: None,
                                            types: ~[] };
                    return @spanned(lo, self.span.hi,
                                 view_path_list(path, idents, self.get_id()));
                  }

                  // foo::bar::*
                  token::BINOP(token::STAR) => {
                    self.bump();
                    let path = @ast::path { span: mk_sp(lo, self.span.hi),
                                            global: false,
                                            idents: path,
                                            rp: None,
                                            types: ~[] };
                    return @spanned(lo, self.span.hi,
                                 view_path_glob(path, self.get_id()));
                  }

                  _ => break
                }
            }
          }
          _ => ()
        }
        let last = path[vec::len(path) - 1u];
        let path = @ast::path { span: mk_sp(lo, self.span.hi),
                                global: false,
                                idents: path,
                                rp: None,
                                types: ~[] };
        return @spanned(lo, self.span.hi,
                     view_path_simple(last, path, namespace, self.get_id()));
    }

    fn parse_view_paths() -> ~[@view_path] {
        let mut vp = ~[self.parse_view_path()];
        while self.token == token::COMMA {
            self.bump();
            vp.push(self.parse_view_path());
        }
        return vp;
    }

    fn is_view_item() -> bool {
        let tok, next_tok;
        if !self.is_keyword(~"pub") && !self.is_keyword(~"priv") {
            tok = self.token;
            next_tok = self.look_ahead(1);
        } else {
            tok = self.look_ahead(1);
            next_tok = self.look_ahead(2);
        };
        self.token_is_keyword(~"use", tok)
            || (self.token_is_keyword(~"extern", tok) &&
                self.token_is_keyword(~"mod", next_tok))
    }

    fn parse_view_item(+attrs: ~[attribute], vis: visibility) -> @view_item {
        let lo = self.span.lo;
        let node = if self.eat_keyword(~"use") {
            self.parse_use()
        } else if self.eat_keyword(~"extern") {
            self.expect_keyword(~"mod");
            let ident = self.parse_ident();
            let metadata = self.parse_optional_meta();
            view_item_use(ident, metadata, self.get_id())
        } else {
            fail;
        };
        self.expect(token::SEMI);
        @ast::view_item { node: node,
                          attrs: attrs,
                          vis: vis,
                          span: mk_sp(lo, self.last_span.hi) }
    }

    fn parse_items_and_view_items(+first_item_attrs: ~[attribute],
                                  mode: view_item_parse_mode,
                                  macros_allowed: bool)
                               -> {attrs_remaining: ~[attribute],
                                   view_items: ~[@view_item],
                                   items: ~[@item],
                                   foreign_items: ~[@foreign_item]} {
        let mut attrs = vec::append(first_item_attrs,
                                    self.parse_outer_attributes());

        let items_allowed = match mode {
            VIEW_ITEMS_AND_ITEMS_ALLOWED | IMPORTS_AND_ITEMS_ALLOWED => true,
            VIEW_ITEMS_AND_FOREIGN_ITEMS_ALLOWED => false
        };

        let restricted_to_imports = match mode {
            IMPORTS_AND_ITEMS_ALLOWED => true,
            VIEW_ITEMS_AND_ITEMS_ALLOWED |
            VIEW_ITEMS_AND_FOREIGN_ITEMS_ALLOWED => false
        };

        let foreign_items_allowed = match mode {
            VIEW_ITEMS_AND_FOREIGN_ITEMS_ALLOWED => true,
            VIEW_ITEMS_AND_ITEMS_ALLOWED | IMPORTS_AND_ITEMS_ALLOWED => false
        };

        let (view_items, items, foreign_items) = (DVec(), DVec(), DVec());
        loop {
            match self.parse_item_or_view_item(attrs, items_allowed,
                                               foreign_items_allowed,
                                               macros_allowed) {
                iovi_none =>
                    break,
                iovi_view_item(view_item) => {
                    if restricted_to_imports {
                            match view_item.node {
                                view_item_import(_) => {}
                                view_item_use(*) =>
                                    self.fatal(~"\"extern mod\" \
                                                 declarations are not \
                                                 allowed here")
                            }
                    }
                    view_items.push(view_item);
                }
                iovi_item(item) => {
                    assert items_allowed;
                    items.push(item)
                }
                iovi_foreign_item(foreign_item) => {
                    assert foreign_items_allowed;
                    foreign_items.push(foreign_item);
                }
            }
            attrs = self.parse_outer_attributes();
        }

        {attrs_remaining: attrs,
         view_items: dvec::unwrap(move view_items),
         items: dvec::unwrap(move items),
         foreign_items: dvec::unwrap(move foreign_items)}
    }

    // Parses a source module as a crate
    fn parse_crate_mod(_cfg: crate_cfg) -> @crate {
        let lo = self.span.lo;
        let crate_attrs = self.parse_inner_attrs_and_next();
        let first_item_outer_attrs = crate_attrs.next;
        let m = self.parse_mod_items(token::EOF, first_item_outer_attrs);
        @spanned(lo, self.span.lo,
                 ast::crate_ { module: m,
                               attrs: crate_attrs.inner,
                               config: self.cfg })
    }

    fn parse_str() -> @~str {
        match copy self.token {
          token::LIT_STR(s) => { self.bump(); self.id_to_str(s) }
          _ =>  self.fatal(~"expected string literal")
        }
    }
}

//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//