[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Evaluation of macro arguments
From: |
Marcin Borkowski |
Subject: |
Evaluation of macro arguments |
Date: |
Tue, 05 Jan 2016 11:59:24 +0100 |
User-agent: |
mu4e 0.9.13; emacs 25.1.50.1 |
Hi all,
continuing my quest to grok macro argument evaluation issues, I'd like
(again) to make sure that I get it correctly. So I have this simple
macro generating a list of consecutive numbers (which is not without
problems - I am aware of those, namely (i) it uses hard-coded symbols
instead of generating them on the fly, and (ii) it has no error
checking):
(defmacro range (from dir to)
`(let ((delta (cond ((eq ',dir 'upto) 1)
((eq ',dir 'downto) -1)))
(i ,from)
(list nil))
(while (not (= i ,to))
(push i list)
(setq i (+ i delta)))
(nreverse list)))
Do I get it correctly that if I want to write an Edebug spec for this
macro, I should mark the second argument as _not evaluated_, because its
value is actually quoted?
(Also, do I get it right that the spec for the second argument should be
e.g. `symbolp', or - if I want to have more error-checking while
edebugging - I should _define_ a predicate like this
(defun upto-or-downto-p (symbol)
(memq symbol '(upto downto)))
since the predicate in the edebug spec cannot be a lambda expression?
TIA,
--
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University
- Evaluation of macro arguments,
Marcin Borkowski <=