Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/mbe/src/parser.rs')
| -rw-r--r-- | crates/mbe/src/parser.rs | 52 |
1 files changed, 19 insertions, 33 deletions
diff --git a/crates/mbe/src/parser.rs b/crates/mbe/src/parser.rs index 7543054494..ef29380557 100644 --- a/crates/mbe/src/parser.rs +++ b/crates/mbe/src/parser.rs @@ -41,7 +41,7 @@ impl MetaTemplate { let mut res = Vec::new(); while let Some(first) = src.next() { let op = next_op(first, &mut src, mode)?; - res.push(op) + res.push(op); } Ok(MetaTemplate(res)) @@ -110,12 +110,6 @@ macro_rules! err { }; } -macro_rules! bail { - ($($tt:tt)*) => { - return Err(err!($($tt)*)) - }; -} - fn next_op<'a>(first: &tt::TokenTree, src: &mut TtIter<'a>, mode: Mode) -> Result<Op, ParseError> { let res = match first { tt::TokenTree::Leaf(leaf @ tt::Leaf::Punct(tt::Punct { char: '$', .. })) => { @@ -131,26 +125,24 @@ fn next_op<'a>(first: &tt::TokenTree, src: &mut TtIter<'a>, mode: Mode) -> Resul Op::Repeat { tokens, separator, kind } } tt::TokenTree::Leaf(leaf) => match leaf { - tt::Leaf::Punct(_) => return Err(ParseError::Expected("ident".to_string())), tt::Leaf::Ident(ident) if ident.text == "crate" => { // We simply produce identifier `$crate` here. And it will be resolved when lowering ast to Path. Op::Leaf(tt::Leaf::from(tt::Ident { text: "$crate".into(), id: ident.id })) } tt::Leaf::Ident(ident) => { - let name = ident.text.clone(); let kind = eat_fragment_kind(src, mode)?; + let name = ident.text.clone(); let id = ident.id; Op::Var { name, kind, id } } - tt::Leaf::Literal(lit) => { - if is_boolean_literal(lit) { - let name = lit.text.clone(); - let kind = eat_fragment_kind(src, mode)?; - let id = lit.id; - Op::Var { name, kind, id } - } else { - bail!("bad var 2"); - } + tt::Leaf::Literal(lit) if is_boolean_literal(lit) => { + let kind = eat_fragment_kind(src, mode)?; + let name = lit.text.clone(); + let id = lit.id; + Op::Var { name, kind, id } + } + tt::Leaf::Punct(_) | tt::Leaf::Literal(_) => { + return Err(ParseError::Expected("ident".to_string())) } }, } @@ -166,8 +158,8 @@ fn next_op<'a>(first: &tt::TokenTree, src: &mut TtIter<'a>, mode: Mode) -> Resul fn eat_fragment_kind(src: &mut TtIter<'_>, mode: Mode) -> Result<Option<SmolStr>, ParseError> { if let Mode::Pattern = mode { - src.expect_char(':').map_err(|()| err!("bad fragment specifier 1"))?; - let ident = src.expect_ident().map_err(|()| err!("bad fragment specifier 1"))?; + src.expect_char(':').map_err(|()| err!("missing fragment specifier"))?; + let ident = src.expect_ident().map_err(|()| err!("missing fragment specifier"))?; return Ok(Some(ident.text.clone())); }; Ok(None) @@ -199,21 +191,15 @@ fn parse_repeat(src: &mut TtIter) -> Result<(Option<Separator>, RepeatKind), Par '*' => RepeatKind::ZeroOrMore, '+' => RepeatKind::OneOrMore, '?' => RepeatKind::ZeroOrOne, - _ => { - match &mut separator { - Separator::Puncts(puncts) => { - if puncts.len() == 3 { - return Err(ParseError::InvalidRepeat); - } - puncts.push(*punct) - } - _ => return Err(ParseError::InvalidRepeat), + _ => match &mut separator { + Separator::Puncts(puncts) if puncts.len() != 3 => { + puncts.push(*punct); + continue; } - continue; - } + _ => return Err(ParseError::InvalidRepeat), + }, }; - let separator = if has_sep { Some(separator) } else { None }; - return Ok((separator, repeat_kind)); + return Ok((has_sep.then(|| separator), repeat_kind)); } } } |