* bug#26635: 25.1; elisp docs bug
@ 2017-04-24 3:35 zhangjg
2017-04-24 9:59 ` Andreas Schwab
0 siblings, 1 reply; 4+ messages in thread
From: zhangjg @ 2017-04-24 3:35 UTC (permalink / raw)
To: 26635
[-- Attachment #1: Type: text/plain, Size: 385 bytes --]
The elisp docs in the session "12.1 What Is a Function?" distinction the funtion and the function-like object.
But in some pages, some function-like object is give as a function.
For example:
In session "3.4 Comparison of Numbers", "=" is a set to a "function" but, in fact it a "special forms".
In the same resason, I think, "<", "<=", ">", ">=" also should be "special forms".
[-- Attachment #2: Type: text/html, Size: 415 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#26635: 25.1; elisp docs bug
2017-04-24 3:35 bug#26635: 25.1; elisp docs bug zhangjg
@ 2017-04-24 9:59 ` Andreas Schwab
2017-04-24 10:31 ` bug#26635: 回复: " zhangjg
0 siblings, 1 reply; 4+ messages in thread
From: Andreas Schwab @ 2017-04-24 9:59 UTC (permalink / raw)
To: zhangjg; +Cc: 26635
On Apr 24 2017, "zhangjg" <jinguozhang@qq.com> wrote:
> In session "3.4 Comparison of Numbers", "=" is a set to a "function" but, in fact it a "special forms".
Why do you think `=' is a special form?
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#26635: 回复: bug#26635: 25.1; elisp docs bug
2017-04-24 9:59 ` Andreas Schwab
@ 2017-04-24 10:31 ` zhangjg
2017-04-24 10:50 ` Andreas Schwab
0 siblings, 1 reply; 4+ messages in thread
From: zhangjg @ 2017-04-24 10:31 UTC (permalink / raw)
To: Andreas Schwab; +Cc: 26635
[-- Attachment #1: Type: text/plain, Size: 1009 bytes --]
Like the fellow code:
(= 1 1 t) ; error
(= 1 2 t) ; nil
t is a symbol, (= 1 1 t) signal a error, that is what we expect.
But in the second form there is no error, because "=" get the
result before to eval the third argument "t".
So "=" not to eval all arguments, that is a "sepecial form" activation.
------------------ 原始邮件 ------------------
发件人: "Andreas Schwab";<schwab@linux-m68k.org>;
发送时间: 2017年4月24日(星期一) 下午5:59
收件人: "zhangjg"<jinguozhang@qq.com>;
抄送: "26635"<26635@debbugs.gnu.org>;
主题: Re: bug#26635: 25.1; elisp docs bug
On Apr 24 2017, "zhangjg" <jinguozhang@qq.com> wrote:
> In session "3.4 Comparison of Numbers", "=" is a set to a "function" but, in fact it a "special forms".
Why do you think `=' is a special form?
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
[-- Attachment #2: Type: text/html, Size: 1415 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#26635: 回复: bug#26635: 25.1; elisp docs bug
2017-04-24 10:31 ` bug#26635: 回复: " zhangjg
@ 2017-04-24 10:50 ` Andreas Schwab
0 siblings, 0 replies; 4+ messages in thread
From: Andreas Schwab @ 2017-04-24 10:50 UTC (permalink / raw)
To: zhangjg; +Cc: 26635
On Apr 24 2017, "zhangjg" <jinguozhang@qq.com> wrote:
> Like the fellow code:
>
> (= 1 1 t) ; error
> (= 1 2 t) ; nil
>
> t is a symbol, (= 1 1 t) signal a error, that is what we expect.
> But in the second form there is no error, because "=" get the
> result before to eval the third argument "t".
All arguments are evaluated, by the caller. Try (= 1 2 (foo)), for
example.
> So "=" not to eval all arguments, that is a "sepecial form" activation.
It may _ignore_ some of its arguments, but that's not what `special
form' is about. Any function is free to ignore arguments.
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-04-24 10:50 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-04-24 3:35 bug#26635: 25.1; elisp docs bug zhangjg
2017-04-24 9:59 ` Andreas Schwab
2017-04-24 10:31 ` bug#26635: 回复: " zhangjg
2017-04-24 10:50 ` Andreas Schwab
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).