lrexlib regular expressions in LPEG Re

[Александр Машин <alex.mashin@...>]

Dear all,

In case anybody is interested, I have added regular expressions to LPEG 
Re module as used by traditio.wiki (later to be included into 
FormatterII templating engine (https://github.com/alex-mashin/FormatterII)).

The syntax is:

{flavour/regular expression/flags}, where flavour is 
pcre|pcre2|posix|onig|tre (subject to availability);
flags are [imsxUX]*

or:

{/regular expression/flags}, with the default flavour from re.rex_flavour.

The regular expression is not anchored, unless it starts from ^.

The captures from regex are propagated but named ones will become anonymous.

lpeg.Cmt is used, the implementation is at lines 175-202 and 292-311 of 
https://traditio.wiki/Module:Re.

The motivation is that Re library can be used to build grammars from, 
among other things, PECL masks for from an external source.

Alexander Mashin