bjoernager/rust
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Add a KleeneOp enum for clarity

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This commit is contained in:
Brendan Zabarauskas 2014-10-23 11:24:20 +11:00
parent 34dacb80ce
commit 94d6eee335
6 changed files with 42 additions and 30 deletions
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29
src/libsyntax/parse/parser.rs
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@ -2497,27 +2497,30 @@ impl<'a> Parser<'a> {
return e;
}
/// Parse an optional separator followed by a kleene-style
/// Parse an optional separator followed by a Kleene-style
/// repetition token (+ or *).
pub fn parse_sep_and_zerok(&mut self) -> (Option<token::Token>, bool) {
fn parse_zerok(parser: &mut Parser) -> Option<bool> {
pub fn parse_sep_and_kleene_op(&mut self) -> (Option<token::Token>, ast::KleeneOp) {
fn parse_kleene_op(parser: &mut Parser) -> Option<ast::KleeneOp> {
match parser.token {
token::BINOP(token::STAR) | token::BINOP(token::PLUS) => {
let zerok = parser.token == token::BINOP(token::STAR);
token::BINOP(token::STAR) => {
parser.bump();
Some(zerok)
Some(ast::ZeroOrMore)
},
token::BINOP(token::PLUS) => {
parser.bump();
Some(ast::OneOrMore)
},
_ => None
}
};
match parse_zerok(self) {
Some(zerok) => return (None, zerok),
match parse_kleene_op(self) {
Some(kleene_op) => return (None, kleene_op),
None => {}
}
let separator = self.bump_and_get();
match parse_zerok(self) {
match parse_kleene_op(self) {
Some(zerok) => (Some(separator), zerok),
None => self.fatal("expected `*` or `+`")
}
@ -2564,11 +2567,11 @@ impl<'a> Parser<'a> {
seq_sep_none(),
|p| p.parse_token_tree()
);
let (s, z) = p.parse_sep_and_zerok();
let (sep, repeat) = p.parse_sep_and_kleene_op();
let seq = match seq {
Spanned { node, .. } => node,
};
TtSequence(mk_sp(sp.lo, p.span.hi), Rc::new(seq), s, z)
TtSequence(mk_sp(sp.lo, p.span.hi), Rc::new(seq), sep, repeat)
} else {
TtNonterminal(sp, p.parse_ident())
}
@ -2679,8 +2682,8 @@ impl<'a> Parser<'a> {
if ms.len() == 0u {
self.fatal("repetition body must be nonempty");
}
let (sep, zerok) = self.parse_sep_and_zerok();
MatchSeq(ms, sep, zerok, name_idx_lo, *name_idx)
let (sep, kleene_op) = self.parse_sep_and_kleene_op();
MatchSeq(ms, sep, kleene_op, name_idx_lo, *name_idx)
} else {
let bound_to = self.parse_ident();
self.expect(&token::COLON);