From: Robert Klemme <shortcutter@...>
Date: 2007-07-20T21:09:32+09:00
Subject: Re: Is there a replacement for sub?

2007/7/20, Martin DeMello <martindemello@gmail.com>:
> On 7/20/07, Robert Dober <robert.dober@gmail.com> wrote:
> >
> > I was reading this whole thread and I kind of think to be dreaming, I
> > must have missed something obvious!!!
> > Anyway maybe this is was OP wants, well I think it is ;)
> >
> > 529/29 > irb
> > irb(main):001:0> a='a b c d e f'
> > => "a b c d e f"
> > irb(main):002:0> a.gsub!(" ","")
>
> Nope, he wants a method that only replaces the first n occurrences of
> the pattern. gsub will not do this - you need to run sub in a loop.

There is a different solution that does not need a loop (see one of my
previous posts).

> (This is where perl's "continue matching where you left off" would
> have been a nice optimisation)

Well, you can always use the block form with an additional counter

irb(main):012:0> count=0
=> 0
irb(main):013:0> a.gsub(/ /) {count+=1; count<3 ? "" : " "}
=> "abc d e f"

But I guess the other solution is more efficient.

Kind regards

robert