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Re: Adding String to Beginning of Lines
From: |
Jean Louis |
Subject: |
Re: Adding String to Beginning of Lines |
Date: |
Wed, 11 Nov 2020 00:22:24 +0300 |
User-agent: |
Mutt/2.0 (3d08634) (2020-11-07) |
* 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.
- Re: Adding String to Beginning of Lines, (continued)
- Re: Adding String to Beginning of Lines, Christopher Dimech, 2020/11/10
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/10
- Re: Adding String to Beginning of Lines, Christopher Dimech, 2020/11/10
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/10
- Re: Adding String to Beginning of Lines, Christopher Dimech, 2020/11/10
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/10
- Re: Adding String to Beginning of Lines, Jean Louis, 2020/11/10
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/10
- Re: Adding String to Beginning of Lines, Jean Louis, 2020/11/10
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/10
- Re: Adding String to Beginning of Lines,
Jean Louis <=
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/11
- Re: Adding String to Beginning of Lines, Jean Louis, 2020/11/17
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/17
- Re: Adding String to Beginning of Lines, Stefan Monnier, 2020/11/10
- RE: Adding String to Beginning of Lines, Drew Adams, 2020/11/10
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/11
- Re: Adding String to Beginning of Lines, tomas, 2020/11/10
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/11
- Re: Adding String to Beginning of Lines, Christopher Dimech, 2020/11/11
- Re: Adding String to Beginning of Lines, Michael Heerdegen, 2020/11/11