Re: Replacing substrings in a string

[Philippe Lhoste <PhiLho@...>]

Mildred wrote:
> Philippe Lhoste wrote:
> > Perhaps that:
> >
> > oldString = "Sale: 10% off, plus additional 5% off if 100% insured"
> > generatedPattern = "0%"
> > replace = "$"
> > pattern = string.gsub(generatedPattern, "%%", "%%%%")
> > newString = string.gsub(oldString, pattern, replace)
> > print(newString)
> >
> > Seems to work, at least with this simplistic test...
> What if the pattern contains characters like |^$()%.[]*+-?| ?

Watch your mouth! :-P

IIRC, the original message was concerned only by the percent sign (or so 
I understood), so I addressed only this case.

> I suggest that (not tested) :
>
> pattern = string.gsub(generatedPattern, "(%c)", "%1")
> newString = string.gsub(oldString, pattern, replace)
>
> %c represents all control characters

I think that the control characters are those below Ascii 32, not the 
chars listed above.

> If it does not work, [^%w] must work because all escaped
> non-alphanumeric character represent the character itself
>
> Is it possible to add a parameter to switch to a plain text replacement
> ...? It would be very useful ...
> Why should I use regular expressions when I only need plain text
> replacement ?

Well, I don't disagree with you, it should be easy to add an additional, 
optional argument, without breaking compatibility.

--
Philippe Lhoste
--  (near) Paris -- France
--  http://Phi.Lho.free.fr
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