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From: Sebastian Gniazdowski <sgniazdowski@gmail.com>
To: Zsh hackers list <zsh-workers@zsh.org>
Subject: Pattern engine extension for \< and \> support?
Date: Fri, 27 Jan 2023 10:01:15 +0000	[thread overview]
Message-ID: <CAKc7PVCAf0roQXYK-_1HD4OGcPVPzd+474=T=5EKMV3uXDTZ-Q@mail.gmail.com> (raw)

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Hi,
in regexps, there are \<, \> and also \b sequences, that match zero-length
string on the word boundary. They are particularly useful for e.g.:
refactoring substitutions, like e.g.: with sed:

sed -r -i -e 's/\<myvar\>/other/'

This automatically protects pre/suffixed strings like str_myvar and
myvar_str. In mcedit, I often use \b that's available there (\< and \> do
not work), to obtain the same effect with the regex:

\bmyvat\b

I'm not sure if distinction of left and right boundary offered by \<, \>
actually makes a difference.

Zsh has similar sequences already - (#s) and (#e). They do match 0=length
strings on begin or end of the matched string. So maybe the topic is known
to any implementing person? Is it hard to add such \b or \<,\> sequences?
Could it be also possible to make it backward-safe, i.e. the sequence be
ignored by proceeding Zsh versions?




-- 
Best regards,
Sebastian Gniazdowski

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             reply	other threads:[~2023-01-27 10:02 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-27 10:01 Sebastian Gniazdowski [this message]
2023-01-27 13:26 ` Stephane Chazelas
2023-01-27 18:48 ` Daniel Shahaf

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