Re: Warning: `mapcar' called for effect; use `mapc' or `dolist'

[Reiner Steib]

On Wed, Oct 31 2007, Richard Stallman wrote:

>     >   > (defun gnus-group-highlight-line ()
>     >   >   "Highlight the current line according to `gnus-group-highlight'."
>     [...]
>     > It seems that `mailp' is not used in that function. 
>
>     `mailp' is used implicitly through the variable `gnus-group-highlight'
>     which is let-bound to `list'.  `list' is used in the body of the
>     let-form.
>
>     > Adding a use for it makes the warning go away...
>
> If the byte compiler warns about that case, it is being too ambitious.
> Thus, if the value of an expression is stored into a variable, the
> compiler should consider the value "used".
>
> So if this warning really happens, it is a bug.
> Can it be reproduced?

I can't reproduce it.  I just updated and bootstrapped.  There was no
warning for `gnus-group.el':

  Compiling [...]/cvs-HEAD/emacs/lisp/./gnus/gnus-group.el
  Wrote [...]/cvs-HEAD/emacs/lisp/gnus/gnus-group.elc

Bye, Reiner.
-- 
       ,,,
      (o o)
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