Add feature for formatting and indenting regexes on multiple lines

[pemistahl]

Generated regular expressions which are very long are often hard to read. It would be useful to have an option to indent and format the generated regexes on multiple lines to make them more readable.

[skington]

I came looking for an issue like this and was pleased that it had already been raised. IMO, anything with more than a few moving parts should automatically have the /x switch.

The corollary, though, is that if the generated regexp would contain large sequences of text including spaces, and turning on the /x flag would replace all the spaces with escaped spaces, then said large sequences of text should instead be quoted with \Q and \E.

As it is, if you take a handful of memorable phrases from e.g. the Declaration of Independence, you get the following:

Grudgingly:~ sam$ grex 'We hold these truths to be self-evident' 'that all men are created equal' 'that they are endowed by their Creator with certain unalienable Rights' 'that among these are Life, Liberty and the pursuit of Happiness.'
^(?:that (?:they are endowed by their Creator with certain unalienable Rights|a(?:mong these are Life, Liberty and the pursuit of Happiness.|ll men are created equal))|We hold these truths to be self-evident)$

(I don't know why the hyphen is escaped there, incidentally.)

As a human, I'd write the resulting regexp something like this:

^
    (?: that \s
        (?:
            \Qthey are endowed by their Creator with certain unalienable Rights\E
        |
            a (?:
                \Qmong these are Life, Liberty and the pursuit of Happiness.\E
              | \Qll men are created equal\E
            )
        )
    |
    \QWe hold these truths to be self-evident\E
    )
$

[pemistahl]

Hi @skington, thanks for your input. I haven't found the time so far to continue the development of grex but as soon as I find the time, I will consider your suggestions.

Feel free to send me a pull request if you are not afraid of the code. ;)