RegExp `x` flag

Isiah Meadows isiahmeadows at gmail.com
Tue Jun 4 03:19:08 UTC 2019


Let me clarify that previous message: I mean "newline restriction" in
the sense that newlines are not permitted in regexp literals. A `/x`
flag would make removing it practically required for it to have any
utility.

-----

Isiah Meadows
contact at isiahmeadows.com
www.isiahmeadows.com

On Mon, Jun 3, 2019 at 11:14 PM Isiah Meadows <isiahmeadows at gmail.com> wrote:
>
> I would personally love this (as well as interpolations in regexp
> literals). I do have a concern about whether removing the newline
> restriction creates ambiguities with division, but I suspect this is
> *not* the case.
>
> -----
>
> Isiah Meadows
> contact at isiahmeadows.com
> www.isiahmeadows.com
>
> On Mon, Jun 3, 2019 at 10:03 PM Jacob Pratt <jhprattdev at gmail.com> wrote:
> >
> > Has there been any previous discussion of adding the `x` flag to JS? It exists in other languages, and can make relatively complicated regex _much_ easier to read. It also allows for comments, which are incredibly helpful when trying to understand some regexes.
> >
> > For prior art, XRegExp has this flag (though I've no idea to figure out how frequently it's used), as do a few other languages.
> >
> > Quick overview: https://www.regular-expressions.info/freespacing.html
> >
> > Language references:
> > Python: https://docs.python.org/3/library/re.html#re.X
> > Rust: https://docs.rs/regex/1.1.6/regex/
> > XRegExp: http://xregexp.com/xregexp/flags/#extended
> > .NET: https://docs.microsoft.com/en-us/dotnet/standard/base-types/regular-expression-language-quick-reference#regular-expression-options
> >
> > Jacob Pratt
> > _______________________________________________
> > es-discuss mailing list
> > es-discuss at mozilla.org
> > https://mail.mozilla.org/listinfo/es-discuss


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