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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;
use codemap::BytePos;
use parse::common::*; //resolve bug?
use parse::token;
use parse::parser::Parser;
// a parser that can parse attributes.
pub trait parser_attr {
fn parse_outer_attributes(&self) -> ~[ast::attribute];
fn parse_attribute(&self, style: ast::attr_style) -> ast::attribute;
fn parse_attribute_naked(
&self,
style: ast::attr_style,
lo: BytePos
) -> ast::attribute;
fn parse_inner_attrs_and_next(&self) ->
(~[ast::attribute], ~[ast::attribute]);
fn parse_meta_item(&self) -> @ast::meta_item;
fn parse_meta_seq(&self) -> ~[@ast::meta_item];
fn parse_optional_meta(&self) -> ~[@ast::meta_item];
}
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 {
match *self.token {
token::POUND => {
if self.look_ahead(1u) != token::LBRACKET {
break;
}
attrs += ~[self.parse_attribute(ast::attr_outer)];
}
token::DOC_COMMENT(s) => {
let attr = ::attr::mk_sugared_doc_attr(
copy *self.id_to_str(s),
self.span.lo,
self.span.hi
);
if attr.node.style != ast::attr_outer {
self.fatal(~"expected outer comment");
}
attrs += ~[attr];
self.bump();
}
_ => break
}
}
return attrs;
}
// matches attribute = # attribute_naked
fn parse_attribute(&self, style: ast::attr_style) -> ast::attribute {
let lo = self.span.lo;
self.expect(&token::POUND);
return self.parse_attribute_naked(style, lo);
}
// matches attribute_naked = [ meta_item ]
fn parse_attribute_naked(&self, style: ast::attr_style, lo: BytePos) ->
ast::attribute {
self.expect(&token::LBRACKET);
let meta_item = self.parse_meta_item();
self.expect(&token::RBRACKET);
let hi = self.span.hi;
return spanned(lo, hi, ast::attribute_ { style: style,
value: meta_item,
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 {
match *self.token {
token::POUND => {
if self.look_ahead(1u) != token::LBRACKET {
// This is an extension
break;
}
let attr = self.parse_attribute(ast::attr_inner);
if *self.token == token::SEMI {
self.bump();
inner_attrs += ~[attr];
} else {
// It's not really an inner attribute
let outer_attr =
spanned(attr.span.lo, attr.span.hi,
ast::attribute_ { style: ast::attr_outer,
value: attr.node.value,
is_sugared_doc: false });
next_outer_attrs += ~[outer_attr];
break;
}
}
token::DOC_COMMENT(s) => {
let attr = ::attr::mk_sugared_doc_attr(
copy *self.id_to_str(s),
self.span.lo,
self.span.hi
);
self.bump();
if attr.node.style == ast::attr_inner {
inner_attrs += ~[attr];
} else {
next_outer_attrs += ~[attr];
break;
}
}
_ => break
}
}
(inner_attrs, next_outer_attrs)
}
// matches meta_item = IDENT
// | IDENT = lit
// | IDENT meta_seq
fn parse_meta_item(&self) -> @ast::meta_item {
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::meta_name_value(name, lit))
}
token::LPAREN => {
let inner_items = self.parse_meta_seq();
let hi = self.span.hi;
@spanned(lo, hi, ast::meta_list(name, inner_items))
}
_ => {
let hi = self.span.hi;
@spanned(lo, hi, ast::meta_word(name))
}
}
}
// matches meta_seq = ( COMMASEP(meta_item) )
fn parse_meta_seq(&self) -> ~[@ast::meta_item] {
copy 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::meta_item] {
match *self.token {
token::LPAREN => self.parse_meta_seq(),
_ => ~[]
}
}
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//
|
