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From: Jean Louis <bugs@gnu.support>
To: Michael Heerdegen <michael_heerdegen@web.de>
Cc: help-gnu-emacs@gnu.org
Subject: Re: Adding String to Beginning of Lines
Date: Wed, 11 Nov 2020 00:22:24 +0300	[thread overview]
Message-ID: <X6sEkAejuU+ZqquI@protected.rcdrun.com> (raw)
In-Reply-To: <87y2j9f186.fsf@web.de>

* Michael Heerdegen <michael_heerdegen@web.de> [2020-11-10 22:42]:
> If you look at the definition:
> 
> (defsubst string-empty-p (string)
>   "Check whether STRING is empty."
>   (string= string ""))

I looked as my thing collided and I did not know what is happening
that suddenly everything is breaks. I cannot even see how that helps,
it just gives better meaning maybe:

(string-empty-p string)
(string= st "") -- shorter and does same

> and check the doc of `string=' you'll see that for symbols (like `nil')
> their name is used as string.  This is surely not useful for
> `string-empty-p', but thus a symbol which has the empty string as name
> (the interned one has a reader syntax "##") fulfills the predicate:
> 
> (string-empty-p '##) ==> t
> 
> No, that's not useful, just a side effect of the implementation.
> 
> | (defun rcd-string-empty-p (s)
> |   "Returns T if string is empty or NIL"
> |   (let ((s (if (null s) "" s)))
> |     (if (stringp s)
> | 	(if (zerop (length s)) t nil))))
> 
> That's more or less the same as
> 
> (defun rcd-string-empty-p (s)
>   (or (null s) (and (stringp s) (zerop (length s)))))

Alright.

> But why handling an empty list specially, and not other empty sequences,
> like the empty vector?  That's what `seq-empty-p' in seq.el does,
> btw.

If I understand well I can simply remove my function and instead use
seq-empty-p? It looks that it does what we discussed here.





  reply	other threads:[~2020-11-10 21:22 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-10 10:43 Adding String to Beginning of Lines Christopher Dimech
2020-11-10 11:10 ` tomas
2020-11-10 11:19   ` Christopher Dimech
2020-11-10 11:29   ` Christopher Dimech
2020-11-10 11:54     ` Michael Heerdegen
2020-11-10 11:58       ` Christopher Dimech
2020-11-10 12:07         ` Michael Heerdegen
2020-11-10 12:03       ` Christopher Dimech
2020-11-10 12:16         ` Michael Heerdegen
2020-11-10 13:40           ` Christopher Dimech
2020-11-10 14:06             ` Jean Louis
2020-11-10 14:29               ` Michael Heerdegen
2020-11-10 19:12                 ` Jean Louis
2020-11-10 19:42                   ` Michael Heerdegen
2020-11-10 21:22                     ` Jean Louis [this message]
2020-11-11 10:59                       ` Michael Heerdegen
2020-11-17 16:06                         ` Jean Louis
2020-11-17 16:28                           ` Michael Heerdegen
2020-11-10 22:31                     ` Stefan Monnier
2020-11-10 23:00                       ` Drew Adams
2020-11-11 21:37                         ` Michael Heerdegen
2020-11-10 14:16             ` Michael Heerdegen
2020-11-10 14:38               ` Christopher Dimech
2020-11-10 14:49                 ` Michael Heerdegen
2020-11-10 17:52                   ` Christopher Dimech
2020-11-10 18:03                     ` Michael Heerdegen
2020-11-10 18:25                       ` Christopher Dimech
2020-11-10 18:49                         ` Michael Heerdegen
2020-11-10 18:56                           ` Christopher Dimech
2020-11-10 19:02                             ` Michael Heerdegen
2020-11-10 19:29                               ` Christopher Dimech
2020-11-10 20:07                                 ` Michael Heerdegen
2020-11-10 22:45             ` tomas
2020-11-11 11:16               ` Michael Heerdegen
2020-11-11 13:22                 ` Christopher Dimech
2020-11-11 13:56                   ` Michael Heerdegen
2020-11-11 14:07                   ` tomas
2020-11-11 14:49                     ` Christopher Dimech
2020-11-11 17:20                 ` Christopher Dimech
2020-11-11 18:12                   ` Michael Heerdegen
2020-11-11 18:25                     ` Stefan Monnier
2020-11-11 18:35                     ` Christopher Dimech
2020-11-10 14:03         ` Jean Louis
2020-11-10 11:42 ` Michael Heerdegen
2020-11-10 18:47   ` H. Dieter Wilhelm
2020-11-12 19:01 ` Dante Catalfamo
2020-11-14 22:09   ` Jamie Beardslee
2020-11-14 23:17     ` Stefan Monnier
2020-11-14 23:39       ` Jamie Beardslee
2020-11-15  9:12       ` tomas

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