From: Nick Dokos <ndokos@gmail.com>
To: help-gnu-emacs@gnu.org
Subject: Re: Executing part of the code instead of another
Date: Wed, 07 Oct 2020 13:29:24 -0400 [thread overview]
Message-ID: <87pn5uvtaj.fsf@alphaville.usersys.redhat.com> (raw)
In-Reply-To: trinity-064edf7c-a27c-4eb2-b57c-75c657d33355-1602076166887@3c-app-mailcom-bs01
Christopher Dimech <dimech@gmx.com> writes:
> I have tried executing the following condition (if (nb > na))
>
> (setq na 2)
> (setq nb 5)
> ( if (> nb na)
> (message "nb > na [condition true]")
> (message "condition false")
> )
>
> I highlighted the region then pressed C-x C-e
> It returned the first message as expected, but when I tried
> the next one, I still got the first message.
>
`C-x C-e` is bound to `eval-last-sexp` which evaluates the *last*
sexp: the if. It does not evaluate the setq's (setting the region does
*NOT* matter for it - try `M-x eval-region' for that)
> (setq na 2)
> (setq nb 1)
> ( if (> nb na)
> (message "nb > na [condition true]")
> (message "condition false")
> )
>
>
>
>
>> Sent: Wednesday, October 07, 2020 at 9:20 AM
>> From: "Robert Pluim" <rpluim@gmail.com>
>> To: "Christopher Dimech" <dimech@gmx.com>
>> Cc: moasenwood@zoho.eu, help-gnu-emacs@gnu.org
>> Subject: Re: Executing part of the code instead of another
>>
>> >>>>> On Wed, 7 Oct 2020 09:01:00 +0200, Christopher Dimech <dimech@gmx.com> said:
>>
>> Christopher> What can one use if there is an else branch with multiple commands, as I would
>> Christopher> like to use it.
>>
>> From 'C-h f if'
>>
>> if is a special form in `C source code'.
>>
>> (if COND THEN ELSE...)
>>
>> Probably introduced at or before Emacs version 1.1.
>>
>> If COND yields non-nil, do THEN, else do ELSE...
>> Returns the value of THEN or the value of the last of the ELSE's.
>> => THEN must be one expression, but ELSE... can be zero or more expressions.
>> If COND yields nil, and there are no ELSE's, the value is nil.
>>
>>
>> Robert
>> --
>>
>
>
--
Nick
"There are only two hard problems in computer science: cache
invalidation, naming things, and off-by-one errors." -Martin Fowler
next prev parent reply other threads:[~2020-10-07 17:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 0:19 Executing part of the code instead of another Christopher Dimech
2020-10-07 0:50 ` Emanuel Berg via Users list for the GNU Emacs text editor
2020-10-07 0:55 ` Christopher Dimech
2020-10-07 1:05 ` Emanuel Berg via Users list for the GNU Emacs text editor
2020-10-07 7:01 ` Christopher Dimech
2020-10-07 7:13 ` Emanuel Berg via Users list for the GNU Emacs text editor
2020-10-07 7:20 ` Robert Pluim
2020-10-07 13:09 ` Christopher Dimech
2020-10-07 17:29 ` Nick Dokos [this message]
2020-10-07 18:01 ` Christopher Dimech
2020-10-07 9:38 ` Gregory Heytings via Users list for the GNU Emacs text editor
2020-10-07 9:46 ` Emanuel Berg via Users list for the GNU Emacs text editor
2020-10-07 9:53 ` Robert Pluim
2020-10-07 11:17 ` Emanuel Berg via Users list for the GNU Emacs text editor
2020-10-07 11:28 ` Robert Pluim
2020-10-07 13:28 ` Stefan Monnier
2020-10-07 13:40 ` Robert Pluim
2020-10-07 13:48 ` Christopher Dimech
2020-10-07 14:01 ` tomas
2020-10-07 14:05 ` Christopher Dimech
2020-10-08 17:43 ` Leo Butler
2020-10-07 15:15 ` Drew Adams
2020-10-18 23:02 ` Douglas Lewan
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