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From: Christopher Dimech <dimech@gmx.com>
To: moasenwood@zoho.eu
Cc: help-gnu-emacs@gnu.org
Subject: Re: bounds for strings with - between subwords
Date: Fri, 7 May 2021 01:58:43 +0200	[thread overview]
Message-ID: <trinity-6b187a8a-0639-4e2b-b523-80804b16e01a-1620345523240@3c-app-mailcom-bs12> (raw)
In-Reply-To: <87h7jf1l7s.fsf@zoho.eu>

> Sent: Friday, May 07, 2021 at 11:44 AM
> From: "Emanuel Berg via Users list for the GNU Emacs text editor" <help-gnu-emacs@gnu.org>
> To: help-gnu-emacs@gnu.org
> Subject: Re: bounds for strings with - between subwords
>
> Christopher Dimech wrote:
>
> >> > (defun alpha-bounds ()
> >> >    "Gets bounds of a subword unit defined by regular expression [a-zA-Z]."
> >> >    (let ( ($bounds nil) $ma $mb )
> >> >       (skip-chars-backward "[:alpha:]")
> >> >       (setq $ma (point))
> >> >       (skip-chars-forward "[:alpha:]")
> >> >       (setq $mb (point))
> >> >       (setq $bounds (bounds-of-thing-at-point 'word))
> >> >       (cons $ma $mb) ))
> >>
> >> You can put all that in the `let' to avoid the use of `setq'.
> >>
> >> Also $bounds doesn't seem to do anything?
> >
> > bounds are used in another function. You can see there is
> > (cons $ma $mb) at the end,
> > which is used as output when you call "alpha-bounds".
>
> $bounds still isn't used anywhere else and cannot be, either.

You are right, the use of the function is merely to set $ma and $mb.
The last $bounds can be removed.

> >> And what's the purpose of the $?
> >
> > I use $ no tell me the variable is local and not being
> > modified from outside. It is coming from the $1, $2, $3, ...
> > function parameter idea.
>
> But they cannot be modified from the outside so no need to
> worry about that.

It is a question of readability, particularly for long functions so not
to get confused when making changes or debugging.  The function is very
short as you say.  It is simply a standard I put in anyway.

> --
> underground experts united
> https://dataswamp.org/~incal
>
>
>



  reply	other threads:[~2021-05-06 23:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-06 22:32 bounds for strings with - between subwords steve-humphreys
2021-05-06 22:49 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-05-06 23:37   ` Christopher Dimech
2021-05-06 23:44     ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-05-06 23:58       ` Christopher Dimech [this message]
2021-05-07  1:17       ` steve-humphreys

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