RetroBBS - comp.lang.tcl - Re: possible "regsub/regexp" bug

possible "regsub/regexp" bug

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https://www.rocksolidbbs.com/devel/article-flat.php?id=19610&group=comp.lang.tcl#19610

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From: clt.to.davebr@dfgh.net
Newsgroups: comp.lang.tcl
Subject: possible "regsub/regexp" bug
Date: Thu, 30 Jun 22 16:28:33 GMT
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by: clt.to.davebr@dfgh.net - Thu, 30 Jun 2022 16:28 UTC

>That's because you repeatedly reprocess the result of the previous
>substitution. The online regexp does the processing in one go. If you do
>the same with regsub, you get the requested result:
>
> regsub -all {(?!$)([A-Z][a-z]+)(?!$)} $match {(?:\1)?} match
>

Why are the (?!\() bits necessary?

regsub -all {([A-Z][a-z]+) $match {(?:\1)?}

seems to work

Dave B

Re: possible "regsub/regexp" bug

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From: nospam@wanadoo.nl (Schelte)
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by: Schelte - Thu, 30 Jun 2022 19:01 UTC

On 30/06/2022 18:28, clt.to.davebr@dfgh.net wrote:
>> That's because you repeatedly reprocess the result of the previous
>> substitution. The online regexp does the processing in one go. If you do
>> the same with regsub, you get the requested result:
>>
>> regsub -all {(?!$)([A-Z][a-z]+)(?!$)} $match {(?:\1)?} match
>>
>
> Why are the (?!\() bits necessary?
>
They're not. But I tend to change as little as possible from the
original code to focus on the problem at hand.

Why do you start a new thread, instead of following up in the existing one?

Schelte.

Is a computer language with goto's totally Wirth-less?

devel / comp.lang.tcl / Re: possible "regsub/regexp" bug

Subject	Author
possible "regsub/regexp" bug	clt.to.davebr
Re: possible "regsub/regexp" bug	Schelte