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use ast::{AttrStyle};
use codemap::{Span};
use ext::base;
use ext::tt::macro_parser;
use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
use parse::lexer;
use parse::token;
use std::rc::Rc;
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
pub struct Delimited {
pub delim: token::DelimToken,
pub open_span: Span,
pub tts: Vec<TokenTree>,
pub close_span: Span,
}
impl Delimited {
pub fn open_token(&self) -> token::Token {
token::OpenDelim(self.delim)
}
pub fn close_token(&self) -> token::Token {
token::CloseDelim(self.delim)
}
pub fn open_tt(&self) -> TokenTree {
TokenTree::Token(self.open_span, self.open_token())
}
pub fn close_tt(&self) -> TokenTree {
TokenTree::Token(self.close_span, self.close_token())
}
}
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
pub struct SequenceRepetition {
pub tts: Vec<TokenTree>,
pub separator: Option<token::Token>,
pub op: KleeneOp,
pub num_captures: usize,
}
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
pub enum KleeneOp {
ZeroOrMore,
OneOrMore,
}
#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
pub enum TokenTree {
Token(Span, token::Token),
Delimited(Span, Rc<Delimited>),
Sequence(Span, Rc<SequenceRepetition>),
}
impl TokenTree {
pub fn len(&self) -> usize {
match *self {
TokenTree::Token(_, token::DocComment(name)) => {
match doc_comment_style(&name.as_str()) {
AttrStyle::Outer => 2,
AttrStyle::Inner => 3
}
}
TokenTree::Token(_, token::SpecialVarNt(..)) => 2,
TokenTree::Token(_, token::MatchNt(..)) => 3,
TokenTree::Delimited(_, ref delimed) => {
delimed.tts.len() + 2
}
TokenTree::Sequence(_, ref seq) => {
seq.tts.len()
}
TokenTree::Token(..) => 0
}
}
pub fn get_tt(&self, index: usize) -> TokenTree {
match (self, index) {
(&TokenTree::Token(sp, token::DocComment(_)), 0) => {
TokenTree::Token(sp, token::Pound)
}
(&TokenTree::Token(sp, token::DocComment(name)), 1)
if doc_comment_style(&name.as_str()) == AttrStyle::Inner => {
TokenTree::Token(sp, token::Not)
}
(&TokenTree::Token(sp, token::DocComment(name)), _) => {
let stripped = strip_doc_comment_decoration(&name.as_str());
let num_of_hashes = stripped.chars().scan(0, |cnt, x| {
*cnt = if x == '"' {
1
} else if *cnt != 0 && x == '#' {
*cnt + 1
} else {
0
};
Some(*cnt)
}).max().unwrap_or(0);
TokenTree::Delimited(sp, Rc::new(Delimited {
delim: token::Bracket,
open_span: sp,
tts: vec![TokenTree::Token(sp, token::Ident(token::str_to_ident("doc"))),
TokenTree::Token(sp, token::Eq),
TokenTree::Token(sp, token::Literal(
token::StrRaw(token::intern(&stripped), num_of_hashes), None))],
close_span: sp,
}))
}
(&TokenTree::Delimited(_, ref delimed), _) => {
if index == 0 {
return delimed.open_tt();
}
if index == delimed.tts.len() + 1 {
return delimed.close_tt();
}
delimed.tts[index - 1].clone()
}
(&TokenTree::Token(sp, token::SpecialVarNt(var)), _) => {
let v = [TokenTree::Token(sp, token::Dollar),
TokenTree::Token(sp, token::Ident(token::str_to_ident(var.as_str())))];
v[index].clone()
}
(&TokenTree::Token(sp, token::MatchNt(name, kind)), _) => {
let v = [TokenTree::Token(sp, token::SubstNt(name)),
TokenTree::Token(sp, token::Colon),
TokenTree::Token(sp, token::Ident(kind))];
v[index].clone()
}
(&TokenTree::Sequence(_, ref seq), _) => {
seq.tts[index].clone()
}
_ => panic!("Cannot expand a token tree")
}
}
pub fn get_span(&self) -> Span {
match *self {
TokenTree::Token(span, _) => span,
TokenTree::Delimited(span, _) => span,
TokenTree::Sequence(span, _) => span,
}
}
pub fn parse(cx: &base::ExtCtxt, mtch: &[TokenTree], tts: &[TokenTree])
-> macro_parser::NamedParseResult {
let arg_rdr = lexer::new_tt_reader_with_doc_flag(&cx.parse_sess().span_diagnostic,
None,
None,
tts.iter().cloned().collect(),
true);
macro_parser::parse(cx.parse_sess(), cx.cfg(), arg_rdr, mtch)
}
}