Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #38106

Re: regex replaceAll?

Newsgroups comp.lang.java.programmer
Date 2018-03-02 05:40 -0800
References (1 earlier) <slrnp9gjk6.5mg.avl@logic.at> <44c665e1-e965-4e9b-8aa0-72aa20607e63@googlegroups.com> <slrnp9gtn0.5mg.avl@logic.at> <8c677118-8115-409d-8d3b-396e54b063ae@googlegroups.com> <slrnp9gvpc.5mg.avl@logic.at>
Message-ID <5e445e98-76e9-4feb-9955-035a6c5a2ed5@googlegroups.com> (permalink)
Subject Re: regex replaceAll?
From Eric Douglas <e.d.programmer@gmail.com>

Show all headers | View raw

On Thursday, March 1, 2018 at 5:31:28 PM UTC-5, Andreas Leitgeb wrote:
>  2) analyze what the RE is really doing, and refine it to do
>       what you want it to do.
> 
> take your choice...

Therein lies the problem.  I analyzed the RE and apparently have no understanding of what it's doing.

I found where someone on the internet solved a similar problem and this solution seems to work.  This expression as far as I can tell does successfully replace every third whitespace, ignoring every other character.
out = in.replaceAll("(?<=\\G\\S*\\s\\S*\\s\\S*)\\s", "_");

So I try that, and get nothing.  My output looks exactly the same as my input, but why?
out = in.replaceAll("(?<=\\G.*b.*)b", "_");

The documentation on that says:
(?<=X)	X, via zero-width positive lookbehind
 (not sure what this did for the original expression here)
\G	The end of the previous match
 (this is what I expect replaceAll to always do)
\S	A non-whitespace character: [^\s]
\s	A whitespace character: [ \t\n\x0B\f\r]
X*	X, zero or more times
.	Any character (may or may not match line terminators)

Any character includes whitespace?  Why does my modified expression not replace every other "b"?

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-01 06:19 -0800
  Re: regex replaceAll? Andreas Leitgeb <avl@logic.at> - 2018-03-01 19:03 +0000
    Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-01 12:15 -0800
      Re: regex replaceAll? Daniele Futtorovic <da.futt.news@laposte.net> - 2018-03-01 21:51 +0100
        Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-01 13:36 -0800
          Re: regex replaceAll? Arne Vajhøj <arne@vajhoej.dk> - 2018-03-01 16:59 -0500
      Re: regex replaceAll? Andreas Leitgeb <avl@logic.at> - 2018-03-01 21:55 +0000
        Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-01 14:00 -0800
          Re: regex replaceAll? Andreas Leitgeb <avl@logic.at> - 2018-03-01 22:31 +0000
            Re: regex replaceAll? Arne Vajhøj <arne@vajhoej.dk> - 2018-03-01 17:52 -0500
              Re: regex replaceAll? Andreas Leitgeb <avl@logic.at> - 2018-03-02 00:14 +0000
            Re: regex replaceAll? Kiwi User <martin@mydomain.invalid> - 2018-03-02 00:43 +0000
              Re: regex replaceAll? Arne Vajhøj <arne@vajhoej.dk> - 2018-03-01 19:49 -0500
                Re: regex replaceAll? Kiwi User <martin@mydomain.invalid> - 2018-03-02 01:33 +0000
                Re: regex replaceAll? Arne Vajhøj <arne@vajhoej.dk> - 2018-03-02 13:00 -0500
                Re: regex replaceAll? Kiwi User <martin@mydomain.invalid> - 2018-03-03 20:07 +0000
            Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-02 05:40 -0800
              Re: regex replaceAll? Andreas Leitgeb <avl@logic.at> - 2018-03-02 17:46 +0000
                Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-02 10:38 -0800
                Re: regex replaceAll? Andreas Leitgeb <avl@logic.at> - 2018-03-02 20:15 +0000
                Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-02 12:43 -0800
                Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-02 12:58 -0800
                Re: regex replaceAll? Daniele Futtorovic <da.futt.news@laposte.net> - 2018-03-03 00:06 +0100
  Re: regex replaceAll? Daniele Futtorovic <da.futt.news@laposte.net> - 2018-03-01 20:29 +0100
    Re: regex replaceAll? Daniele Futtorovic <da.futt.news@laposte.net> - 2018-03-01 20:30 +0100
    Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-01 12:28 -0800
      Re: regex replaceAll? Daniele Futtorovic <da.futt.news@laposte.net> - 2018-03-01 21:40 +0100
    Re: regex replaceAll? Eric Douglas <e.d.programmer@gmail.com> - 2018-03-01 13:52 -0800
      Re: regex replaceAll? Daniele Futtorovic <da.futt.news@laposte.net> - 2018-03-02 02:25 +0100

csiph-web