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// 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 ast;
use codemap::{spanned, Spanned, mk_sp};
use parse::common::*; //resolve bug?
use parse::token;
use parse::parser::Parser;
use parse::token::INTERPOLATED;
// a parser that can parse attributes.
pub trait parser_attr {
fn parse_outer_attributes(&self) -> ~[ast::Attribute];
fn parse_attribute(&self, permit_inner: bool) -> ast::Attribute;
fn parse_inner_attrs_and_next(&self) ->
(~[ast::Attribute], ~[ast::Attribute]);
fn parse_meta_item(&self) -> @ast::MetaItem;
fn parse_meta_seq(&self) -> ~[@ast::MetaItem];
fn parse_optional_meta(&self) -> ~[@ast::MetaItem];
}
impl parser_attr for Parser {
// Parse attributes that appear before an item
fn parse_outer_attributes(&self) -> ~[ast::Attribute] {
let mut attrs: ~[ast::Attribute] = ~[];
loop {
debug!("parse_outer_attributes: self.token=%?",
self.token);
match *self.token {
token::INTERPOLATED(token::nt_attr(*)) => {
attrs.push(self.parse_attribute(false));
}
token::POUND => {
if self.look_ahead(1, |t| *t != token::LBRACKET) {
break;
}
attrs.push(self.parse_attribute(false));
}
token::DOC_COMMENT(s) => {
let attr = ::attr::mk_sugared_doc_attr(
self.id_to_str(s),
self.span.lo,
self.span.hi
);
if attr.node.style != ast::AttrOuter {
self.fatal("expected outer comment");
}
attrs.push(attr);
self.bump();
}
_ => break
}
}
return attrs;
}
// matches attribute = # [ meta_item ]
//
// if permit_inner is true, then a trailing `;` indicates an inner
// attribute
fn parse_attribute(&self, permit_inner: bool) -> ast::Attribute {
debug!("parse_attributes: permit_inner=%? self.token=%?",
permit_inner, self.token);
let (span, value) = match *self.token {
INTERPOLATED(token::nt_attr(attr)) => {
assert!(attr.node.style == ast::AttrOuter);
self.bump();
(attr.span, attr.node.value)
}
token::POUND => {
let lo = self.span.lo;
self.bump();
self.expect(&token::LBRACKET);
let meta_item = self.parse_meta_item();
self.expect(&token::RBRACKET);
let hi = self.span.hi;
(mk_sp(lo, hi), meta_item)
}
_ => {
self.fatal(fmt!("expected `#` but found `%s`",
self.this_token_to_str()));
}
};
let style = if permit_inner && *self.token == token::SEMI {
self.bump();
ast::AttrInner
} else {
ast::AttrOuter
};
return Spanned {
span: span,
node: ast::Attribute_ {
style: style,
value: value,
is_sugared_doc: false
}
};
}
// Parse attributes that appear after the opening of an item, each
// terminated by a semicolon. In addition to a vector of inner attributes,
// this function also returns a vector that may contain the first outer
// attribute of the next item (since we can't know whether the attribute
// is an inner attribute of the containing item or an outer attribute of
// the first contained item until we see the semi).
// matches inner_attrs* outer_attr?
// you can make the 'next' field an Option, but the result is going to be
// more useful as a vector.
fn parse_inner_attrs_and_next(&self)
-> (~[ast::Attribute], ~[ast::Attribute]) {
let mut inner_attrs: ~[ast::Attribute] = ~[];
let mut next_outer_attrs: ~[ast::Attribute] = ~[];
loop {
let attr = match *self.token {
token::INTERPOLATED(token::nt_attr(*)) => {
self.parse_attribute(true)
}
token::POUND => {
if self.look_ahead(1, |t| *t != token::LBRACKET) {
// This is an extension
break;
}
self.parse_attribute(true)
}
token::DOC_COMMENT(s) => {
self.bump();
::attr::mk_sugared_doc_attr(self.id_to_str(s),
self.span.lo,
self.span.hi)
}
_ => {
break;
}
};
if attr.node.style == ast::AttrInner {
inner_attrs.push(attr);
} else {
next_outer_attrs.push(attr);
break;
}
}
(inner_attrs, next_outer_attrs)
}
// matches meta_item = IDENT
// | IDENT = lit
// | IDENT meta_seq
fn parse_meta_item(&self) -> @ast::MetaItem {
let lo = self.span.lo;
let name = self.id_to_str(self.parse_ident());
match *self.token {
token::EQ => {
self.bump();
let lit = self.parse_lit();
let hi = self.span.hi;
@spanned(lo, hi, ast::MetaNameValue(name, lit))
}
token::LPAREN => {
let inner_items = self.parse_meta_seq();
let hi = self.span.hi;
@spanned(lo, hi, ast::MetaList(name, inner_items))
}
_ => {
let hi = self.last_span.hi;
@spanned(lo, hi, ast::MetaWord(name))
}
}
}
// matches meta_seq = ( COMMASEP(meta_item) )
fn parse_meta_seq(&self) -> ~[@ast::MetaItem] {
self.parse_seq(&token::LPAREN,
&token::RPAREN,
seq_sep_trailing_disallowed(token::COMMA),
|p| p.parse_meta_item()).node
}
fn parse_optional_meta(&self) -> ~[@ast::MetaItem] {
match *self.token {
token::LPAREN => self.parse_meta_seq(),
_ => ~[]
}
}
}
|
