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Re: RegEx - Positive Look-ahead

by sundialsvc4 (Abbot)
on Feb 05, 2013 at 13:39 UTC ( #1017160=note: print w/replies, xml ) Need Help??

in reply to RegEx - Positive Look-ahead

To me, this is the sort of problem that should be described in terms of a grammar, and then handled using Parse::RecDescent.   (I have used that module quite extensively and it works very well.)

Let me give you one small tip if you go that way...   Part of your code will consist of the grammar and Perl code that will be compiled on-the-fly into it.   This is a great place to put a use statement(s) that will link to any subroutines that you find that you need to make use of in the grammar code.

Anyway, the advantage of this approach is that you describe the structure of the language being processed and let the parser do the magic.   It takes a bit of practice to get the grammar right, heh, but the parser can handle the mechanics of regex’ing and backtracking so that your code doesn’t have to.   You can extend it to do more things without getting buried.

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Re^2: RegEx - Positive Look-ahead
by tmharish (Friar) on Feb 05, 2013 at 14:46 UTC

    Thanks sundialsvc4

    Am going through the documentation of that module.

    Will reply once I have completed that.

      I just had my first run in with Parse::RecDescent, and after I figured out the basics from the docs, I posted some beginner tips here link.

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[ambrus]: I really don't like automagic stuff. I'm happy when computers do exactly what I tell them, even if that means they sometimes do the wrong thing.
[ambrus]: And I don't much like syntax highlighters. If you need a syntax highlighter to understand your code, then your code is written unclear.
[ambrus]: And if you need a syntax highlighter to color parenthesis green and numbers black and letters blue, then you're using the wrong font.
[ambrus]: I have to tolerate syntax highlighters when other people use them, but I don't use them myself. And sorry for the rant.
[GotToBTru]: I appreciate the ability to highlight matching brackets/ parentheses/ braces, both for my own code and the inconsistently indented code of others
[Corion]: I like editors that automatically highlight the matching parenthesis (like % in vi), but that's roughly the extent to which I like editor support ;)
[GotToBTru]: same here Corion.

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