README.md

parse_transform_compiled_regex

Erlang parse_transform to have regex compiled on build time

How to use:

Include it as a dependency and add the parse_transform compile option to each module or globally:

-compile({parse_transform, parse_transform_compiled_regex}).

The calls to re:compile, re:replace, re:run and re:split that have the regex and options directly available in the call have the regex precompiled.
E.g.:

    _ = re:compile(?HTTP_REGEX), %% Transformed

    _ = re:compile([$a | ?HTTP_REGEX]), %% Transformed

    _ = re:compile(give_me_the_regex()), %% Not transformed

    HttpRegex = ?HTTP_REGEX,
    _ = re:compile(HttpRegex), %% Not transformed

    _ = re:compile(?HTTP_REGEX, [caseless]), %% Transformed

    Options = [caseless],
    _ = re:compile(?HTTP_REGEX, Options), %% Not transformed

Results:

From the timed test included in this project

re:run time:
Precompiled (10000 iterations): 30619
Repeated compile (10000 Iterations): 50553

re:compile time:
Precompiled (10000 iterations): 433
Repeated compile (10000 Iterations): 22052

(re:compile with the precompiled regex is a noop)

Run tests:

rebar3 ct

Authors

• Jose M Perez Ramos - Kuroneer

License

MIT License