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Re: regexp(ing) Backus-Naurish expressions ...

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On 11.03.2013 00:24, Roedy Green wrote:
> On Sun, 10 Mar 2013 22:39:22 +0100, Robert Klemme
> <shortcutter@googlemail.com> wrote, quoted or indirectly quoted
> someone who said :
>
>> What limitations would make me want to write a FSM instead by hand?
>
> Compacting out nugatory space in HTML would be another example.

There are tools for processing tag based languages.  Why would I want to 
create a FSM by hand for that?

> Though they are quite complicated, I find FSMs very easy to write, and
> they almost always work first time. You can narrow your thinking to a
> tiny case and ignore the big picture quite safely.

Certainly you can write FSMs for a lot of things.  But you were claiming 
that a manual FSM should be used instead of a regexp engine; so the 
question remains unanswered: why would anyone create a FSM by hand for 
parsing?

> In contrast, I find my regexes (of any complexity) nearly always have
> some unexpected behaviour, often than does not show up immediately.

Well, that certainly depends on your familiarity with the tool.  To me 
this sounds suspiciously like NIH syndrome.  I am so familiar with using 
regular expressions of various kinds that it would not occur to me to 
start writing a FSM for parsing by hand.  That is such a waste of time.

> The other complicating factor is I use three different regex schemes
> in a day: Java, Funduc and SlickEdit.  I keep borrowing syntax from
> one of the other schemes than the one I am using.

And how exactly do you implement a FSM in SlickEdit?

> Some day I will
> have to write replacements that use Java syntax.

Not sure what you mean by that.

Cheers

	robert

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

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Thread

regexp(ing) Backus-Naurish expressions ... qwertmonkey@syberianoutpost.ru - 2013-03-10 02:27 +0000
  Re: regexp(ing) Backus-Naurish expressions ... Arne Vajhøj <arne@vajhoej.dk> - 2013-03-09 21:33 -0500
  Re: regexp(ing) Backus-Naurish expressions ... Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-03-09 21:00 -0600
  Re: regexp(ing) Backus-Naurish expressions ... Leif Roar Moldskred <leifm@dimnakorr.com> - 2013-03-09 23:33 -0600
  Re: regexp(ing) Backus-Naurish expressions ... lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-03-10 10:27 +0000
  Re: regexp(ing) Backus-Naurish expressions ... Martin Gregorie <martin@address-in-sig.invalid> - 2013-03-10 12:55 +0000
  Re: regexp(ing) Backus-Naurish expressions ... Roedy Green <see_website@mindprod.com.invalid> - 2013-03-10 07:57 -0700
    Re: regexp(ing) Backus-Naurish expressions ... Robert Klemme <shortcutter@googlemail.com> - 2013-03-10 22:39 +0100
      Re: regexp(ing) Backus-Naurish expressions ... Roedy Green <see_website@mindprod.com.invalid> - 2013-03-10 15:54 -0700
        Re: regexp(ing) Backus-Naurish expressions ... Robert Klemme <shortcutter@googlemail.com> - 2013-03-11 21:03 +0100
        Re: regexp(ing) Backus-Naurish expressions ... Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-03-11 17:00 -0500
          Re: regexp(ing) Backus-Naurish expressions ... Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-03-11 18:31 -0400
            Re: regexp(ing) Backus-Naurish expressions ... Arne Vajhøj <arne@vajhoej.dk> - 2013-03-11 18:40 -0400
              Re: regexp(ing) Backus-Naurish expressions ... Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-03-11 21:39 -0400
          Re: regexp(ing) Backus-Naurish expressions ... Martin Gregorie <martin@address-in-sig.invalid> - 2013-03-11 23:06 +0000
          Re: regexp(ing) Backus-Naurish expressions ... Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-03-11 20:56 -0500
            Re: regexp(ing) Backus-Naurish expressions ... Arne Vajhøj <arne@vajhoej.dk> - 2013-03-11 22:06 -0400
            Re: regexp(ing) Backus-Naurish expressions ... Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-03-12 09:30 -0400
      Re: regexp(ing) Backus-Naurish expressions ... Roedy Green <see_website@mindprod.com.invalid> - 2013-03-10 16:24 -0700
        Re: regexp(ing) Backus-Naurish expressions ... Robert Klemme <shortcutter@googlemail.com> - 2013-03-11 21:08 +0100
          Re: regexp(ing) Backus-Naurish expressions ... Arne Vajhøj <arne@vajhoej.dk> - 2013-03-11 16:59 -0400
            Re: regexp(ing) Backus-Naurish expressions ... Robert Klemme <shortcutter@googlemail.com> - 2013-03-11 22:24 +0100
      Re: regexp(ing) Backus-Naurish expressions ... Robert Klemme <shortcutter@googlemail.com> - 2013-03-11 21:00 +0100
    Re: regexp(ing) Backus-Naurish expressions ... Robert Klemme <shortcutter@googlemail.com> - 2013-03-13 08:07 +0100
  Re: regexp(ing) Backus-Naurish expressions ... markspace <markspace@nospam.nospam> - 2013-03-10 11:16 -0700

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