This library is a partial port of RE2. As such, it offers "fast" expression matching of the full PRCE syntax (except backreferences) but is not exponential in the length of the input text.
This library is still in very rough condition and only minimally tested. Proceed with caution. There may be dragons.
For now, it only supports RE2’s general NFA execution engine and none of RE2’s conditional fast-paths (DFA, single-pass NFA, …). So "fast" isn’t as fast as it could be for some subsets of regular expressions.
See Russ Cox’s excellent article series for more information about fast regular expression implementations and details about the different execution engines.
The simplest form is:
// Match anywhere in the text:
matched, captures := match("text_to_search", "some\\sexpression\\b");
defer array_free(captures);
// … or anchor it to require the expression to match the whole text:
matched, captures := match("text_to_search", "some\\sexpression\\b", .Anchored_Both);
defer array_free(captures);
… after which:
matchedindicates whether the expression matched the text,captures[0]contains the whole match andcaptures[1]through[n]the content of each capture group ((…)) in the expression.
The captures reference segments of the original text, so they’re only valid as long as the text exists. You need to copy them if you want them to persist. This also means that you need to free only the capture array, but not its contents.
Compiling the regular expression is the slowest part. If you use an expression multiple times (or want more control about available regular expression features), you should definitely compile it beforehand:
regexp, success := compile("some\\sexpression\\b");
defer uninit(*regexp);
// Use regexp as often as you want…
for text: texts {
matched, captures := match(text, regexp);
defer array_free(captures);
}
See compile.jai and match.jai for additional options.
Running the tests requires the stubborn module.
It’s already included as a submodule, but don’t forget the usual git submodule shenanigans to fetch it.
Compile with <compiler> first.jai -- test, then run the test binary.
(The tests should run at compile-time but this is currently broken in the compiler.)
If you want to compile the library (even though it doesn’t produce any binary),
you need the ctags module in your main jai folder.
This library is heavily based on RE2, so their original BSD-style license might still be applicable to some parts. Otherwise, this library is licensed under the MIT license.