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From: Bart Schaefer <schaefer@brasslantern.com>
To: Andy Kluger <andykluger@gmail.com>
Cc: zsh-users@zsh.org
Subject: Re: Help: f (repeat) modifier, and histsubstpattern + :s/l/r/ modifier escaping of [{()}]
Date: Wed, 16 Aug 2023 20:19:37 -0700	[thread overview]
Message-ID: <CAH+w=7Y+zos=sRfAv2769iJEzazHRfT4u6v+3B3mGoxy8Yv0-w@mail.gmail.com> (raw)
In-Reply-To: <CAO4D9E=+O-=66w0um7OzENVEiV11QfVUWYSTocacUX4rhYr1=Q@mail.gmail.com>

On Wed, Aug 16, 2023 at 11:33 AM Andy Kluger <andykluger@gmail.com> wrote:
>
>     setopt histsubstpattern
>     s='left[()]over'
>     print -rl -- ${s:fs/(\\{\\}|\\(\\)|\\[\\])//}
>     # printed: left[]over
>     # expected: leftover
>
> I'm having two confusions:
>
> 1. Why do I need to double-backslash before each
> brace/bracket/parenthesis, rather than single-backslash?

Because the pattern is being passed through possible parameter
substitution before being passed through the pattern parser.

> 2. Why doesn't the replacement seem to happen to each subsequent
> result of a former replacement?

Because there's a bug.  The pattern (and the replacement, though it's
empty in this case) are both rewritten in-place by at least one of
those two substitution passes, so the pattern isn't the same the
second time around and no longer matches.


  reply	other threads:[~2023-08-17  3:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-16 18:32 Andy Kluger
2023-08-17  3:19 ` Bart Schaefer [this message]
2023-08-17 23:09   ` Bart Schaefer

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