add functions for retrieving a Regex's source and flags

[michaelficarra]

Should the flags be exposed as a record or as some canonicalised string? Either way, should there be a function for converting between the two formats?

edit: JS RegExp flags can be retrieved as a string like this:

function flags(re) {
  var s = '' + re;
  return s.slice(s.lastIndexOf('/') + 1);
}

or as a record like this:

function flags(re) {
  return {
    multiline: re.multiline,
    ignoreCase: re.ignoreCase,
    global: re.global,
    sticky: !!re.sticky,
    unicode: !!re.unicode
  };
}

[garyb]

I'd much prefer the record approach personally, with a type alias RegexFlags or something. It'd make the current regex constructor a lot less opaque too, as then instead of accepting two Strings as it does now we could change one of the arguments out for RegexFlags.

Do you think there's much advantage in exposing the string version of flags within PureScript? As then you're throwing away the type information and having to deal with malformed strings etc.

[michaelficarra]

I agree, a RegexFlags record is better. Working on this.

[paf31]

👍

When this gets merged, we'll have to remember to update purescript-in-purescript since the lexer defines a few regular expressions using the old regex function.