refactor(wgsl-in): add Lexer::peek_ident_with_span

1. Break out `word_as_ident*` helpers to keep validation of identifiers
   DRY.
2. Add `peek_*` variant of `Lexer::next_ident_with_span`.

This will be consumed immediately in the subsequent commit.
This commit is contained in:
Erich Gubler 2024-10-01 10:21:49 -04:00
parent f669024eeb
commit cb31465811

View File

@ -350,27 +350,43 @@ impl<'a> Lexer<'a> {
&mut self,
) -> Result<(&'a str, Span), Error<'a>> {
match self.next() {
(Token::Word("_"), span) => Err(Error::InvalidIdentifierUnderscore(span)),
(Token::Word(word), span) if word.starts_with("__") => {
Err(Error::ReservedIdentifierPrefix(span))
}
(Token::Word(word), span) => Ok((word, span)),
(Token::Word(word), span) => Self::word_as_ident_with_span(word, span),
other => Err(Error::Unexpected(other.1, ExpectedToken::Identifier)),
}
}
#[allow(dead_code)]
pub(in crate::front::wgsl) fn peek_ident_with_span(
&mut self,
) -> Result<(&'a str, Span), Error<'a>> {
match self.peek() {
(Token::Word(word), span) => Self::word_as_ident_with_span(word, span),
other => Err(Error::Unexpected(other.1, ExpectedToken::Identifier)),
}
}
fn word_as_ident_with_span(word: &'a str, span: Span) -> Result<(&'a str, Span), Error<'a>> {
match word {
"_" => Err(Error::InvalidIdentifierUnderscore(span)),
word if word.starts_with("__") => Err(Error::ReservedIdentifierPrefix(span)),
word => Ok((word, span)),
}
}
pub(in crate::front::wgsl) fn next_ident(
&mut self,
) -> Result<super::ast::Ident<'a>, Error<'a>> {
let ident = self
.next_ident_with_span()
.map(|(name, span)| super::ast::Ident { name, span })?;
self.next_ident_with_span()
.and_then(|(word, span)| Self::word_as_ident(word, span))
.map(|(name, span)| super::ast::Ident { name, span })
}
if crate::keywords::wgsl::RESERVED.contains(&ident.name) {
return Err(Error::ReservedKeyword(ident.span));
fn word_as_ident(word: &'a str, span: Span) -> Result<(&'a str, Span), Error<'a>> {
if crate::keywords::wgsl::RESERVED.contains(&word) {
Err(Error::ReservedKeyword(span))
} else {
Ok((word, span))
}
Ok(ident)
}
/// Parses a generic scalar type, for example `<f32>`.