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From: Achim Gratz
Subject: eval-when-compile
Date: Fri, 27 Jul 2012 07:01:51 +0200
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux)

[I hope this is the correct list for asking this question.]

I've been trying to use eval-when-compile to switch between alternate
versions of code based on a compile-time decision.  However it seems
that either I don't understand the documentation or something doesn't
quite work.

Compiling this source file:

--8<---------------cut here---------------start------------->8---
  (if t
      (defvar unquoted-t "true")
    (defvar unquoted-nil "false")))
  (if nil
      '(defvar quoted-t "true")
    '(defvar quoted-nil "false")))
--8<---------------cut here---------------end--------------->8---

results in an empty (except the header of course) byte-compiled file.  I
expected the quoted version to compile

`(defvar quoted-nil "false")ยด

which is what that form evaluates to.  When I wrap a defmacro around it
and call that macro outside the eval-when-compile:

--8<---------------cut here---------------start------------->8---
  (defmacro ewc-macro (&rest body)
    (if nil
        '(defvar macro-t "true")
      '(defvar macro-nil "false"))))
--8<---------------cut here---------------end--------------->8---

then I get the expected output in the byte-compiled file, but it seems
there must be an easier way to do that.  The eval-when-compile in this
version suppresses the macro definition itself being byte-compiled of

+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

SD adaptation for Waldorf rackAttack V1.04R1:

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