Description
(Continuing discussion from #1198)
There are differences between how regex behaves on the JVM vs generated JS. Some things shouldn't be too hard to fix, others will be near impossible without either creative hacks or switching to a bundled regex engine. It would also be beneficial to have a document somewhere stating the differences so that devs are aware. If you don't object, let's use this issue to at least start compiling a list of differences and see what (if anything) to do about it.
Off the top of my head we've got:
- Look-behinds (
(?<=),(?<!)). JS regex doesn't support this. - Java-style quotes/literals.
Pattern.quoteuses\Qand\Ewhich doesn't work in JS. - Java-style character sets, example:
/[\p{S}\p{P}]/.
I'll add more as I think of them.
A semi-fix for Pattern.quote would be to use the a regex escaping function from a mature JS library, Google Closure's is short and sweet. Handling \Q..\E on the other hand would be harder.
Funny story about [\p{S}\p{P}], I actually needed that in my JS so I wrote a little converter for that kind of regex so that it would work in Scala.js. I replaced it with [\u0021-\u002f\u003a-\u0040\\[-\u0060\u007b-\u007e\u00a1-\u00a9\u00ab\u00ac\u00ae-\u00b1\u00b4\u00b6-\u00b8\u00bb\u00bf\u00d7\u00f7\u02c2-\u02c5\u02d2-\u02df\u02e5-\u02eb\u02ed\u02ef-\u02ff\u0375\u037e\u0384\u0385\u0387\u03f6\u0482\u055a-\u055f\u0589\u058a\u058f\u05be\u05c0\u05c3\u05c6\u05f3\u05f4\u0606-\u060f\u061b\u061e\u061f\u066a-\u066d\u06d4\u06de\u06e9\u06fd\u06fe\u0700-\u070d\u07f6-\u07f9\u0830-\u083e\u085e\u0964\u0965\u0970\u09f2\u09f3\u09fa\u09fb\u0af0\u0af1\u0b70\u0bf3-\u0bfa\u0c7f\u0d79\u0df4\u0e3f\u0e4f\u0e5a\u0e5b\u0f01-\u0f17\u0f1a-\u0f1f\u0f34\u0f36\u0f38\u0f3a-\u0f3d\u0f85\u0fbe-\u0fc5\u0fc7-\u0fcc\u0fce-\u0fda\u104a-\u104f\u109e\u109f\u10fb\u1360-\u1368\u1390-\u1399\u1400\u166d\u166e\u169b\u169c\u16eb-\u16ed\u1735\u1736\u17d4-\u17d6\u17d8-\u17db\u1800-\u180a\u1940\u1944\u1945\u19de-\u19ff\u1a1e\u1a1f\u1aa0-\u1aa6\u1aa8-\u1aad\u1b5a-\u1b6a\u1b74-\u1b7c\u1bfc-\u1bff\u1c3b-\u1c3f\u1c7e\u1c7f\u1cc0-\u1cc7\u1cd3\u1fbd\u1fbf-\u1fc1\u1fcd-\u1fcf\u1fdd-\u1fdf\u1fed-\u1fef\u1ffd\u1ffe\u2010-\u2027\u2030-\u205e\u207a-\u207e\u208a-\u208e\u20a0-\u20ba\u2100\u2101\u2103-\u2106\u2108\u2109\u2114\u2116-\u2118\u211e-\u2123\u2125\u2127\u2129\u212e\u213a\u213b\u2140-\u2144\u214a-\u214d\u214f\u2190-\u23f3\u2400-\u2426\u2440-\u244a\u249c-\u24e9\u2500-\u26ff\u2701-\u2775\u2794-\u2b4c\u2b50-\u2b59\u2ce5-\u2cea\u2cf9-\u2cfc\u2cfe\u2cff\u2d70\u2e00-\u2e2e\u2e30-\u2e3b\u2e80-\u2e99\u2e9b-\u2ef3\u2f00-\u2fd5\u2ff0-\u2ffb\u3001-\u3004\u3008-\u3020\u3030\u3036\u3037\u303d-\u303f\u309b\u309c\u30a0\u30fb\u3190\u3191\u3196-\u319f\u31c0-\u31e3\u3200-\u321e\u322a-\u3247\u3250\u3260-\u327f\u328a-\u32b0\u32c0-\u32fe\u3300-\u33ff\u4dc0-\u4dff\ua490-\ua4c6\ua4fe\ua4ff\ua60d-\ua60f\ua673\ua67e\ua6f2-\ua6f7\ua700-\ua716\ua720\ua721\ua789\ua78a\ua828-\ua82b\ua836-\ua839\ua874-\ua877\ua8ce\ua8cf\ua8f8-\ua8fa\ua92e\ua92f\ua95f\ua9c1-\ua9cd\ua9de\ua9df\uaa5c-\uaa5f\uaa77-\uaa79\uaade\uaadf\uaaf0\uaaf1\uabeb\ufb29\ufbb2-\ufbc1\ufd3e\ufd3f\ufdfc\ufdfd\ufe10-\ufe19\ufe30-\ufe52\ufe54-\ufe66\ufe68-\ufe6b\uff01-\uff0f\uff1a-\uff20\uff3b-\uff40\uff5b-\uff65\uffe0-\uffe6\uffe8-\uffee\ufffc\ufffd]