7.4. Boost package for REGEX

The REGEX_BOOST module extends regular expressions with the %regex~ reader macro for compile-time regex construction. Inside the reader macro, backslashes are literal — no double-escaping is needed (e.g. %regex~\d{3}%% instead of "\\d\{3}").

Optional flags can be appended after a second ~ separator:

• %regex~pattern~i%% — case-insensitive matching

• %regex~pattern~s%% — dot-all mode (. matches \n)

• %regex~pattern~is%% — both flags combined

See Regular expression library for the full list of supported syntax. See Regular Expressions for a hands-on tutorial.

All functions and symbols are in “regex_boost” module, use require to get access to it.

require daslib/regex_boost

Example:

require daslib/regex_boost
    require strings

    [export]
    def main() {
        var inscope re <- %regex~\d+%%
        let m = regex_match(re, "123abc")
        print("match length = {m}\n")
        let text = "age 25, height 180"
        regex_foreach(re, text) $(r) {
            print("found: {slice(text, r.x, r.y)}\n")
            return true
        }
    }
    // output:
    // match length = 3
    // found: 25
    // found: 180

7.4.1. Reader macros

regex_boost::regex

Reader macro that converts %regex~ literals into precompiled regex::Regex objects at compilation time. Optional flags can follow a second ~: %regex~pattern~i%% for case-insensitive, %regex~pattern~s%% for dot-all, %regex~pattern~is%% for both.