Question

I think I followed the example literally, but it doesn’t work. If I use defimage macro, the image descriptor isn’t created, but when I use create-image will all the same arguments it does. Below is what I tried:

(defimage test ((:type png :file "/home/wvxvw/Projects/haxe-mode/trunk/ede/etc/images/interface.png")))
test                                    ; nil
(defimage test (:type png :file "/home/wvxvw/Projects/haxe-mode/trunk/ede/etc/images/interface.png"))
test                                    ; nil
(insert-image test)                     ; error
(setq test (create-image "/home/wvxvw/Projects/haxe-mode/trunk/ede/etc/images/interface.png" 'png nil))
(image :type png :file "/home/wvxvw/Projects/haxe-mode/trunk/ede/etc/images/interface.png")
(insert-image test)                     ; shows image

Any hints?

EDIT:

While the code above should illustrate the problem, the actual code that I’m trying to run is a bit more involved. Posting it just in case:

(require 'cl)

(defvar haxe-images-dir
  (concat (file-name-directory load-file-name) "etc/images/"))

(defmacro haxe-define-images (images)
  (append
   '(progn)
   (loop for image in images
         collect
         `(defimage ,(intern (concat "haxe-" image "-icon"))
            ((:type png :file
                    (concat haxe-images-dir ,(concat image ".png"))))))))

(haxe-define-images
 ("private" "public" "static" "instance" "inline"
  "volatile" "variable" "class" "interface" "macro"
  "enum" "deftype" "function"))

EDIT2:

This is how it finally works. Perhaps I had some parts of the code compiled and thus loaded from a different place or some such mystery…

(require 'cl)
(require 'haxe-project)

(defmacro haxe-define-images (images)
  (append
   `(progn)
   (loop for image in images
         with images-root = (concat haxe-install-dir "etc/images/")
         collect
         `(defimage ,(intern (concat "haxe-" image "-icon"))
            ((:type png :file
                    ,(concat images-root image ".png")))))))

(haxe-define-images 
 ("private" "public" "static" "instance" "inline"
  "volatile" "variable" "class" "interface" "macro"
  "enum" "deftype" "function"))

Answer 1

It’s a feature of defimage and other def- forms that they only set the variable if it is not already set. From the documentation for defvar:

The defvar special form is similar to setq in that it sets the value of a variable. It is unlike setq in two ways: first, it only sets the value of the variable if the variable does not already have a value. If the variable already has a value, defvar does not override the existing value. Second, […]

So I presume that you already have assigned something to test, so the defimage form does nothing. If you are in the process of editing the code, you can force a def- form to be evaluated by putting point on the form, and using the command eval-defun (C-M-x).

Note that you should use defimage only for declaring a global variable. For other cases (where you are going to be using the image locally), use find-image instead.

---

In your updated code, your macro haxe-define-images fails to evaluate the expression (concat haxe-images-dir ...). You can see this by expanding the macro:

 ELISP> (print (macroexpand-all '(haxe-define-images ("foo"))))
 (progn (defvar haxe-address-icon (find-image (quote ((:type png :file (concat haxe-images-dir "address.png"))))) nil))

This won’t work because the concat is inside quote and so is not evaluated. You need to write something like this instead:

(defmacro haxe-define-images (images)
  (append
   '(progn)
   (loop for image in images
         collect
         `(defimage ,(intern (concat "haxe-" image "-icon"))
            ((:type png :file
                    ,(concat haxe-images-dir image ".png")))))))

(If you actually intend to delay evaluation of haxe-images-dir then the macro will need to be more complex than this, but I’m sure you can figure it out from here.)