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lexer: Add Invalid token to aid in implementing features

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John 2023-09-27 21:17:35 -05:00
parent 335fea8d73
commit d4245844ce
1 changed files with 14 additions and 0 deletions
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14
libconlang/src/lib.rs
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@ -7,6 +7,7 @@ pub mod token {
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum Type {
Invalid,
Comment,
Identifier,
// Keywords
@ -99,6 +100,7 @@ pub mod lexer {
.or_else(|| self.identifier())
.or_else(|| self.literal())
.or_else(|| self.delimiter())
.or_else(|| self.invalid())
}
pub fn keyword(&mut self) -> Option<Token> {
None.or_else(|| self.kw_else())
@ -123,6 +125,10 @@ pub mod lexer {
.or_else(|| self.r_paren())
}
// functions for lexing individual tokens
pub fn invalid(&mut self) -> Option<Token> {
self.skip_whitespace();
self.produce_token(Type::Invalid, Rule::new(self.text()).invalid().end()?)
}
// comments
pub fn comment(&mut self) -> Option<Token> {
self.skip_whitespace();
@ -222,6 +228,10 @@ pub mod lexer {
}
impl<'t> Rule<'t> {
/// Matches any sequence of non-whitespace characters
pub fn invalid(self) -> Self {
self.and_many(Self::not_whitespace)
}
/// Matches a block, line, or shebang comment
pub fn comment(self) -> Self {
self.and_either(Self::line_comment, Self::block_comment)
@ -324,6 +334,10 @@ pub mod lexer {
pub fn whitespace(self) -> Self {
self.char_fn(|c| c.is_whitespace())
}
/// Matches anything but whitespace
pub fn not_whitespace(self) -> Self {
self.char_fn(|c| !c.is_whitespace())
}
/// Matches one XID_START
pub fn xid_start(self) -> Self {
use unicode_xid::UnicodeXID;