86 lines
1.6 KiB
Rust
86 lines
1.6 KiB
Rust
use nom::
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{
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IResult,
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branch::alt,
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bytes::complete::take_while_m_n,
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combinator::{map, peek, rest_len, verify},
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};
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fn is_character_word_boundary(c: char) -> bool
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{
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if c.is_whitespace()
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{
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return true;
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}
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match c
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{
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'('
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| ')'
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| '>'
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| '<'
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| '='
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| ','
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| '+'
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| '-'
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| '*'
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| '/'
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| '%'
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| '|'
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=> true,
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_ => false,
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}
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}
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pub(crate) fn word_boundary(i: &str) -> IResult<&str, ()>
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{
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peek
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(
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alt
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((
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// Accept word boundary characters
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map
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(
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take_while_m_n(1, 1, is_character_word_boundary),
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|_| (),
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),
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// Accept end of file
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map
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(
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verify
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(
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rest_len,
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|rest_length| *rest_length == 0usize,
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),
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|_| (),
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),
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))
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)(i)
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}
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#[cfg(test)]
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mod tests
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{
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use crate::parse::*;
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#[test]
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fn detect_word_boundaries()
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{
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assert_eq!(word_boundary(" rest"), Ok((" rest", ())));
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assert_eq!(word_boundary("(rest"), Ok(("(rest", ())));
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assert_eq!(word_boundary(")rest"), Ok((")rest", ())));
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assert_eq!(word_boundary(",rest"), Ok((",rest", ())));
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assert_eq!(word_boundary("+rest"), Ok(("+rest", ())));
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assert_eq!(word_boundary("-rest"), Ok(("-rest", ())));
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assert_eq!(word_boundary("*rest"), Ok(("*rest", ())));
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assert_eq!(word_boundary("/rest"), Ok(("/rest", ())));
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assert_eq!(word_boundary("%rest"), Ok(("%rest", ())));
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assert_eq!(word_boundary("|rest"), Ok(("|rest", ())));
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assert_eq!(word_boundary("<rest"), Ok(("<rest", ())));
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assert_eq!(word_boundary(">rest"), Ok((">rest", ())));
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assert_eq!(word_boundary("=rest"), Ok(("=rest", ())));
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assert!(word_boundary("0").is_err());
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assert!(word_boundary("rest").is_err());
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}
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}
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