Re: a little parsing challenge ☺

From	Robert Klemme <shortcutter@googlemail.com>
Newsgroups	comp.lang.lisp, comp.lang.python, comp.lang.perl.misc, comp.lang.ruby, comp.lang.scheme
Subject	Re: a little parsing challenge ☺
Date	2011-07-20 08:23 +0200
Message-ID	<98naiiFlf4U1@mid.individual.net> (permalink)
References	<36037253-086b-4467-a1db-9492d3772e78@r5g2000prf.googlegroups.com> <99245842-e205-4a34-8f9d-c64d41e044b6@j9g2000prj.googlegroups.com> <87f46fe8-5d1d-4ed0-b6e3-87c5f9262c38@t38g2000prj.googlegroups.com>

Cross-posted to 5 groups.

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On 18.07.2011 16:39, Xah Lee wrote:
>
> On Jul 17, 12:47 am, Xah Lee<xah...@gmail.com>  wrote:
>> 2011-07-16
>>
>> folks, this one will be interesting one.
>>
>> the problem is to write a script that can check a dir of text files
>> (and all subdirs) and reports if a file has any mismatched matching
>> brackets.
>> …
>
> Ok, here's my solution (pasted at bottom). I haven't tried to make it
> elegant or terse, yet, seeing that many are already much elegent than
> i could possibly do so with my code.
>
> my solution basically use a stack. (i think all of us are doing
> similar) Here's the steps:
>
> • Go thru the file char by char, find a bracket char.
> • check if the one on stack is a matching opening char. If so remove
> it. Else, push the current onto the stack.
> • Repeat the above till end of file.
> • If the stack is not empty, then the file got mismatched brackets.
> Report it.
> • Do the above on all files.

Small correction: my solution works differently (although internally the 
regexp engine will roughly do the same).  So, my approach summarized

- traverse a directory tree
- for each found item of type "file"
-    read the whole content
-    throw it at a regexp which is anchored at the beginning
      and does the recursive parsing
-    report file if the match is shorter than the file

Note: special feature for recursive matching is used which Perl's regexp 
engine likely can do as well but many others don't.

Cheers

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

Thread

a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-17 00:47 -0700
  Re: a little parsing challenge ☺ Raymond Hettinger <python@rcn.com> - 2011-07-17 02:48 -0700
    Re: a little parsing challenge ☺ Robert Klemme <shortcutter@googlemail.com> - 2011-07-17 15:20 +0200
      Re: a little parsing challenge ☺ mhenn <michihenn@hotmail.com> - 2011-07-17 15:55 +0200
        Re: a little parsing challenge ☺ Robert Klemme <shortcutter@googlemail.com> - 2011-07-17 18:01 +0200
          Re: a little parsing challenge ☺ Robert Klemme <shortcutter@googlemail.com> - 2011-07-17 18:54 +0200
    Re: a little parsing challenge ☺ Thomas Boell <tboell@domain.invalid> - 2011-07-17 17:49 +0200
      Re: a little parsing challenge ☺ Raymond Hettinger <python@rcn.com> - 2011-07-17 12:16 -0700
    Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-18 07:39 -0700
      Re: a little parsing challenge ☺ Robert Klemme <shortcutter@googlemail.com> - 2011-07-20 08:23 +0200
      Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-20 03:31 -0700
        Re: a little parsing challenge ☺ "Uri Guttman" <uri@StemSystems.com> - 2011-07-20 12:31 -0400
          Re: a little parsing challenge ☺ rusi <rustompmody@gmail.com> - 2011-07-20 10:30 -0700
          Re: a little parsing challenge ☺ merlyn@stonehenge.com (Randal L. Schwartz) - 2011-07-20 12:06 -0700
            Re: a little parsing challenge ☺ Jason Earl <jearl@notengoamigos.org> - 2011-07-20 14:57 -0600
    Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-19 09:54 -0700
      Re: a little parsing challenge ☺ Thomas Jollans <t@jollybox.de> - 2011-07-19 20:07 +0200
        Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-21 05:58 -0700
          Re: a little parsing challenge ☺ Ian Kelly <ian.g.kelly@gmail.com> - 2011-07-21 08:26 -0600
            Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-21 08:36 -0700
              Re: a little parsing challenge ☺ python@bdurham.com - 2011-07-21 12:43 -0400
                Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-21 11:53 -0700
                Re: a little parsing challenge ☺ Terry Reedy <tjreedy@udel.edu> - 2011-07-21 18:37 -0400
          Re: a little parsing challenge ☺ John O'Hagan <research@johnohagan.com> - 2011-07-25 15:57 +1000
      Re: a little parsing challenge ☺ Ian Kelly <ian.g.kelly@gmail.com> - 2011-07-19 12:08 -0600
  Re: a little parsing challenge ☺ Chris Angelico <rosuav@gmail.com> - 2011-07-17 21:34 +1000
    Re: a little parsing challenge ☺ rusi <rustompmody@gmail.com> - 2011-07-17 04:52 -0700
    Re: a little parsing challenge ☺ Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-07-17 16:15 +0200
      Re: a little parsing challenge ☺ Raymond Hettinger <python@rcn.com> - 2011-07-17 12:18 -0700
        Re: a little parsing challenge ☺ Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-07-17 22:16 +0200
          Re: a little parsing challenge ☺ Thomas Jollans <t@jollybox.de> - 2011-07-17 22:57 +0200
      Re: a little parsing challenge ☺ Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-07-17 23:43 +0200
      Re: a little parsing challenge ☺ Rouslan Korneychuk <rouslank@msn.com> - 2011-07-18 03:09 -0400
        Re: a little parsing challenge ☺ Stefan Behnel <stefan_ml@behnel.de> - 2011-07-18 09:24 +0200
          Re: a little parsing challenge ☺ Rouslan Korneychuk <rouslank@msn.com> - 2011-07-18 04:04 -0400
        Re: a little parsing challenge ☺ Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-07-18 18:46 +0200
          Re: a little parsing challenge ☺ Rouslan Korneychuk <rouslank@msn.com> - 2011-07-18 14:14 -0400
        Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-21 06:23 -0700
          Re: a little parsing challenge ☺ Rouslan Korneychuk <rouslank@msn.com> - 2011-07-21 17:54 -0400
  Re: a little parsing challenge ☺ gene heskett <gheskett@wdtv.com> - 2011-07-17 10:26 -0400
  Re: a little parsing challenge ☺ Thomas Jollans <t@jollybox.de> - 2011-07-17 08:31 -0700
    Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-19 10:49 -0700
      Re: a little parsing challenge ☺ Thomas Jollans <t@jollybox.de> - 2011-07-19 20:14 +0200
        Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-21 05:29 -0700
          Re: a little parsing challenge ☺ Thomas Jollans <t@jollybox.de> - 2011-07-21 15:21 +0200
      Re: a little parsing challenge ☺ Thomas Jollans <t@jollybox.de> - 2011-07-19 20:17 +0200
  Re: a little parsing challenge ☺ rantingrick <rantingrick@gmail.com> - 2011-07-17 18:52 -0700
  Re: a little parsing challenge ☺ Billy Mays <81282ed9a88799d21e77957df2d84bd6514d9af6@myhashismyemail.com> - 2011-07-18 13:12 -0400
    Re: a little parsing challenge ☺ Ian Kelly <ian.g.kelly@gmail.com> - 2011-07-18 12:10 -0600
      Re: a little parsing challenge ☺ Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-07-18 23:59 +0200
        Re: a little parsing challenge ☺ Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-07-19 08:09 +0200
        Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-19 10:32 -0700
    Re: a little parsing challenge ☺ Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-19 09:56 +1000
      Re: a little parsing challenge ☺ Billy Mays <noway@nohow.com> - 2011-07-18 22:07 -0400
        Re: a little parsing challenge ☺ rusi <rustompmody@gmail.com> - 2011-07-18 19:50 -0700
          Re: a little parsing challenge ☺ Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-19 13:11 +1000
            Re: a little parsing challenge ☺ rusi <rustompmody@gmail.com> - 2011-07-18 21:59 -0700
              Re: a little parsing challenge ☺ Chris Angelico <rosuav@gmail.com> - 2011-07-19 15:36 +1000
        Re: a little parsing challenge ☺ MRAB <python@mrabarnett.plus.com> - 2011-07-19 04:08 +0100
        Re: a little parsing challenge ☺ Benjamin Kaplan <benjamin.kaplan@case.edu> - 2011-07-18 20:54 -0700
        Re: a little parsing challenge ☺ Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-19 14:30 +1000
        Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-19 01:58 -0700
    Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-19 10:14 -0700
      Re: a little parsing challenge ☺ Billy Mays <81282ed9a88799d21e77957df2d84bd6514d9af6@myhashismyemail.com> - 2011-07-19 13:33 -0400
        Re: a little parsing challenge ☺ Xah Lee <xahlee@gmail.com> - 2011-07-19 11:12 -0700
          Re: a little parsing challenge ☺ Terry Reedy <tjreedy@udel.edu> - 2011-07-19 15:09 -0400
            Re: a little parsing challenge ☺ jmfauth <wxjmfauth@gmail.com> - 2011-07-19 23:29 -0700
              Re: a little parsing challenge ☺ Ian Kelly <ian.g.kelly@gmail.com> - 2011-07-20 01:29 -0600
                Re: a little parsing challenge ☺ jmfauth <wxjmfauth@gmail.com> - 2011-07-20 00:54 -0700
                Re: a little parsing challenge ☺ Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-20 18:18 +1000
  Re: a little parsing challenge ? sln@netherlands.com - 2011-07-18 12:34 -0700
  Re: a little parsing challenge ☺ Mark Tarver <dr.mtarver@gmail.com> - 2011-07-19 22:43 -0700

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