Keeping run-time code from running at compile-time

Keeping run-time code from running at compile-time

[Bill Wohler]

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I'm having some compiling trouble. File B which requires file A fails to
compile because file A contains code that should not be run at
compile-time, just run-time.

I've distilled the essence into a tiny example. Save the attachments
with "K a" and then run the script doit. Right now, I'm getting the
output:

    [wohler@olgas:807]$ sh doit
    While compiling toplevel forms in file /tmp/b.el:
      !! error (("Shouldn't hit this when compiling"))
    Done
    Loading b (source)...
    Shouldn't hit this when compiling

I'd like to get the output:

    [wohler@olgas:807]$ sh doit
    Wrote /tmp/b.elc
    Done
    Loading b (source)...
    Shouldn't hit this when compiling

Thanks for any help you can provide.


[-- Attachment #2: doit --]
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[-- Attachment #3: a.el --]
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(defun foo ()
  (error "Shouldn't hit this when compiling"))
(foo)
(provide 'a)

[-- Attachment #4: b.el --]
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(require 'a)
(defun doit ()
  (message "%s" "Hello, world!"))

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-- 
Bill Wohler <wohler@newt.com>  http://www.newt.com/wohler/  GnuPG ID:610BD9AD
Maintainer of comp.mail.mh FAQ and MH-E. Vote Libertarian!
If you're passed on the right, you're in the wrong lane.

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Re: Keeping run-time code from running at compile-time

[rgb]

> (defun foo ()
>   (error "Shouldn't hit this when compiling"))
> (foo)

You are explicitly invoking foo here.
The only difference between (defun ...) and (foo ...) in
any file that you require or load is in your mind.
They are just functions to be executed.  Lisp doesn't
care if they are named def<something> or not.

> (provide 'a)
>
> (require 'a)
> (defun doit ()
>   (message "%s" "Hello, world!"))
>

To achieve what you seem to want you need:

---x---
(defun foo ()
  (error "Shouldn't hit this when compiling"))
(provide 'x)
---a---
(require 'x)
(foo)
(provide 'a)
---b---
> (require 'x)
> (defun doit ()
>   (message "%s" "Hello, world!"))

Re: Keeping run-time code from running at compile-time

[Stefan Monnier]

> I'm having some compiling trouble. File B which requires file A fails to
> compile because file A contains code that should not be run at
> compile-time, just run-time.

Basically you're saying that the compiler should either not load file A when
compiling file B, or load it be "weakly".

Such issues is one of the reasons why toplevel expressions in .el files
should do as little as possible.  So most likely the problem is that your
toplevel expressions in file A should be moved to a function that is called
explicitly from elsewhere (e.g. from a major mode function).


        Stefan