diff options
| -rw-r--r-- | src/libsyntax/ext/tt/macro_parser.rs | 44 |
1 files changed, 21 insertions, 23 deletions
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs index e067bbecce2..b35beedfff7 100644 --- a/src/libsyntax/ext/tt/macro_parser.rs +++ b/src/libsyntax/ext/tt/macro_parser.rs @@ -181,6 +181,8 @@ struct MatcherPos { match_hi: usize, // Specifically used if we are matching a repetition. If we aren't both should be `None`. + /// The KleeneOp of this sequence if we are in a repetition. + seq_op: Option<quoted::KleeneOp>, /// The separator if we are in a repetition sep: Option<Token>, /// The "parent" matcher position if we are in a repetition. That is, the matcher position just @@ -263,6 +265,7 @@ fn initial_matcher_pos(ms: Vec<TokenTree>, lo: BytePos) -> Box<MatcherPos> { stack: vec![], // Haven't descended into any sequences, so both of these are `None`. + seq_op: None, sep: None, up: None, }) @@ -464,10 +467,11 @@ fn inner_parse_loop( item.idx += 1; next_items.push(item); } - } + } // We don't need a separator. Move the "dot" back to the beginning of the matcher - // and try to match again. - else { + // and try to match again UNLESS we are only allowed to have _one_ repetition. + else if item.seq_op != Some(quoted::KleeneOp::ZeroOrOne) { + // we don't need a separator item.match_cur = item.match_lo; item.idx = 0; cur_items.push(item); @@ -499,26 +503,20 @@ fn inner_parse_loop( cur_items.push(new_item); } - // For ZeroOrMore and OneOrMore, we want to examine the case were there is at - // least one match. For ZeroOrOne, we only want the case where there is exactly - // one match. - if (seq.op == quoted::KleeneOp::ZeroOrOne && seq.num_captures == 1) - || seq.op != quoted::KleeneOp::ZeroOrOne - { - let matches = create_matches(item.matches.len()); - cur_items.push(Box::new(MatcherPos { - stack: vec![], - sep: seq.separator.clone(), - idx: 0, - matches, - match_lo: item.match_cur, - match_cur: item.match_cur, - match_hi: item.match_cur + seq.num_captures, - up: Some(item), - sp_lo: sp.lo(), - top_elts: Tt(TokenTree::Sequence(sp, seq)), - })); - } + let matches = create_matches(item.matches.len()); + cur_items.push(Box::new(MatcherPos { + stack: vec![], + sep: seq.separator.clone(), + seq_op: Some(seq.op), + idx: 0, + matches, + match_lo: item.match_cur, + match_cur: item.match_cur, + match_hi: item.match_cur + seq.num_captures, + up: Some(item), + sp_lo: sp.lo(), + top_elts: Tt(TokenTree::Sequence(sp, seq)), + })); } // We need to match a metavar (but the identifier is invalid)... this is an error |