help-gnu-emacs
[Top][All Lists]

## I'd like to marry while and mapcar...

 From: Marcin Borkowski Subject: I'd like to marry while and mapcar... Date: Fri, 06 Feb 2015 13:56:48 +0100

```Hello Emacsers and Elispers!

What I'd need is kind of a marriage of while and mapcar: I'd like to run
some function until it returns nil and make a list of all results it
gives back until then.

Mu use case is that I'm getting some info from a LaTeX file.  For
instance, assume that I want to make a list of all files \include'd by
a LaTeX document.  I've written a function `get-TeX-macro-arguments'
which finds the next occurence of a given TeX command, moves point past
it and returns its arguments; if it does not find any such occurrence,
it returns nil.  So I can say something like this:

(let (current-include (list-of-includes ()))
(while (setq current-include (get-TeX-macro-arguments "include"))
(setq list-of-includes (append list-of-includes current-include)))
list-of-includes)

This, however, looks a bit, let's say, Fortran-ish;-); I'm after a more
Lispy way.  (Of course, one step would be to use anaphoric while, but
that doesn't help my main problem of ditching list-of-includes.)

Yes, I know, I have too much time on my hands, and I bother about style.
But I'm also curious whether there is any "standard" way, or whether
I should indeed wrap something like the above code in a macro, or
something.  (Or maybe just don't care...)

TIA,

--
Marcin Borkowski               This email was proudly sent
http://mbork.pl                from my Emacs.

```