Function build_regex

src/expr/src/scalar/like_pattern.rs:364–380

Builds a regular expression that matches some parsed Subpatterns.

(subpatterns: &[Subpattern], case_insensitive: bool)

/// Builds a regular expression that matches some parsed Subpatterns.
fn build_regex(subpatterns: &[Subpattern], case_insensitive: bool) -> Result<Regex, EvalError> {
    let mut r = String::from("^");
    for sp in subpatterns {
        sp.write_regex_to(&mut r);
    }
    r.push('$');
    match Regex::new(&r, case_insensitive) {
        Ok(regex) => Ok(regex),
        Err(RegexCompilationError::PatternTooLarge { .. }) => Err(EvalError::LikePatternTooLong),
        Err(RegexCompilationError::RegexError(regex::Error::CompiledTooBig(_))) => {
            Err(EvalError::LikePatternTooLong)
        }
        Err(e) => Err(EvalError::Internal(
            format!("build_regex produced invalid regex: {}", e).into(),
        )),
    }
}

// Unit Tests
//