From: Philip Kaludercic <philipk@posteo.net>
To: Alan Mackenzie <acm@muc.de>
Cc: "Stefan Kangas" <stefankangas@gmail.com>,
emacs-devel@gnu.org, "Mattias Engdegård" <mattiase@acm.org>
Subject: Re: Why shouldn't we have a #if .... #else .... #endif construct in Emacs Lisp?
Date: Sat, 02 Sep 2023 19:20:29 +0000 [thread overview]
Message-ID: <87pm30e60y.fsf@posteo.net> (raw)
In-Reply-To: <ZPNPhh_My1P6k0vw@ACM> (Alan Mackenzie's message of "Sat, 2 Sep 2023 15:06:46 +0000")
Alan Mackenzie <acm@muc.de> writes:
> +;; Note: `static-if' handles the version of `eval' without the &optional
> +;; parameter LEXICAL so that it can be copied unchanged for use in older
> +;; Emacsen.
Is this really a concern for the version that would be added to Emacs itself?
> +(defmacro static-if (condition then-form &rest else-forms)
> + "A conditional compilation macro analogous to C's #if.
> +Evaluate CONDITION at macro-expansion time. If it is non-nil,
> +expand the macro to THEN-FORM. Otherwise expand it to ELSE-FORMS
> +enclosed in a `progn' form. ELSE-FORMS may be empty."
> + (declare (indent 2)
> + (debug (sexp sexp &rest sexp)))
> + (if (condition-case err
> + (eval condition lexical-binding)
> + ((wrong-number-of-arguments void-variable) (eval condition))
> + ((debug error) (signal (car err) (cdr err))))
> + then-form
> + (cons 'progn else-forms)))
next prev parent reply other threads:[~2023-09-02 19:20 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-28 19:37 Why shouldn't we have a #if .... #else .... #endif construct in Emacs Lisp? Alan Mackenzie
2023-08-28 19:47 ` Ulrich Mueller
2023-08-28 20:06 ` Alan Mackenzie
2023-08-28 21:01 ` Ulrich Mueller
2023-08-28 21:46 ` Alan Mackenzie
2023-08-31 2:07 ` Richard Stallman
2023-08-31 7:50 ` Alan Mackenzie
2023-09-04 1:34 ` Richard Stallman
2023-09-04 10:50 ` Alan Mackenzie
2023-09-04 11:02 ` tomas
2023-09-04 15:19 ` Emanuel Berg
2023-09-04 18:57 ` tomas
2023-09-06 0:58 ` Richard Stallman
2023-09-06 0:58 ` Richard Stallman
2023-09-06 7:28 ` Andreas Schwab
2023-09-06 9:31 ` Alan Mackenzie
2023-09-06 9:56 ` Alan Mackenzie
2023-09-09 0:39 ` Richard Stallman
2023-09-09 10:32 ` Ihor Radchenko
2023-09-10 0:22 ` Richard Stallman
2023-09-10 8:36 ` Ihor Radchenko
2023-09-13 23:53 ` Richard Stallman
2023-09-20 12:59 ` Ihor Radchenko
2023-09-05 0:30 ` Why have a #if .... #else .... #endif construct in Emacs Lisp, when we could make the existing code DTRT unchanged? Richard Stallman
2023-09-05 0:41 ` Emanuel Berg
2023-09-08 17:54 ` Emanuel Berg
2023-09-05 4:37 ` tomas
2023-09-05 5:53 ` Ihor Radchenko
2023-09-05 6:28 ` tomas
2023-09-05 11:06 ` Adam Porter
2023-09-05 11:26 ` Lynn Winebarger
2023-09-05 14:11 ` Alan Mackenzie
2023-09-08 1:01 ` Richard Stallman
2023-09-08 2:45 ` Po Lu
2023-09-10 0:24 ` Richard Stallman
2023-09-05 8:14 ` Why shouldn't we have a #if .... #else .... #endif construct in Emacs Lisp? Ulrich Mueller
2023-08-28 19:53 ` Emanuel Berg
2023-08-29 9:19 ` Alan Mackenzie
2023-08-29 10:36 ` João Távora
2023-08-29 11:09 ` Ihor Radchenko
2023-08-29 11:20 ` João Távora
2023-08-30 20:48 ` Sean Whitton
2023-08-30 20:59 ` João Távora
2023-09-02 23:12 ` Stefan Monnier via Emacs development discussions.
2023-09-03 0:18 ` Emanuel Berg
2023-09-03 12:27 ` João Távora
2023-08-29 12:54 ` Philip Kaludercic
2023-08-29 13:23 ` Alan Mackenzie
2023-09-02 23:09 ` Stefan Monnier via Emacs development discussions.
2023-08-29 16:28 ` LdBeth
2023-08-29 20:09 ` Stefan Kangas
2023-08-30 10:31 ` Alan Mackenzie
2023-08-30 17:36 ` Stefan Kangas
2023-08-30 18:03 ` Alan Mackenzie
2023-08-30 18:17 ` Stefan Kangas
2023-09-02 15:06 ` Alan Mackenzie
2023-09-02 15:17 ` Eli Zaretskii
2023-09-02 19:43 ` Alan Mackenzie
2023-09-03 4:42 ` Eli Zaretskii
2023-09-03 10:48 ` Alan Mackenzie
2023-09-03 11:02 ` Eli Zaretskii
2023-09-03 13:24 ` Alan Mackenzie
2023-09-02 19:20 ` Philip Kaludercic [this message]
2023-09-02 19:37 ` Stefan Kangas
2023-09-02 19:58 ` Alan Mackenzie
2023-09-04 11:12 ` Lynn Winebarger
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