Lookbehind regexes don't work in Safari

[ronaldtse]

For Safari compatibility we need to convert the lookbehind regexes (or via another mechanism) in some interscript maps to non-lookbehind.

UPDATE: Looks like this works: http://blog.stevenlevithan.com/archives/javascript-regex-lookbehind (which uses https://github.com/slevithan/xregexp)

Ref:

• https://caniuse.com/#feat=js-regexp-lookbehind
• https://stackoverflow.com/questions/58460501/js-regex-lookbehind-not-working-in-firefox-and-safari
• https://stackoverflow.com/questions/641407/javascript-negative-lookbehind-equivalent
• https://stackoverflow.com/questions/50011366/javascript-regex-negative-lookbehind-not-working-in-firefox
• https://stackoverflow.com/questions/53278989/negative-lookbehind-how-to-fix-regex-to-use-it-in-ie11-safary

Some systems like the following will generate an error:

The reason is:

Specifically:

These systems specifically contain these rules that can't be run without lookbehind:

• alalc-bul-cyrl-latn-1997
• alalc-srp-cyrl-latn-2013
• alalc-mkd-cyrl-latn-2013
• bgnpcgn-mkd-cyrl-latn-1981
• bgnpcgn-mkd-cyrl-latn-2013
• bgnpcgn-ukr-cyrl-latn-2019
• by-bel-cyrl-latn-1998
• gki-bel-cyrl-latn-2000
• mvd-rus-cyrl-latn-2008
• mvd-bel-cyrl-latn-2010
• odni-rus-cyrl-latn-2015
• stategeocadastre-ukr-cyrl-latn-1993
• un-bel-cyrl-latn-2007

[ronaldtse]

We will need to override the Regexp creation mechanism to utilize XRegExp with Opal-specific overrides.

[ronaldtse]

@webdev778 can you help handle this (after implementation of XRegExp in latexmath)? Thanks.

[ronaldtse]

@webdev778 agree with using a JS engine for Safari, might be the easiest approach now.

The source for that package is this: https://github.com/bellard/quickjs

[xyzshantaram]

Came across this issue while working on one of my own projects. Found this thread. Not sure if this will be helpful at all, but the solution I ended up using was to match the preceding character with a negated character set and discard those matches.

Sorry if this is unhelpful, but thought I might offer it in case it is.