Re: [patch] Guile conditional

[Paul Smith]

On Thu, 2015-07-02 at 20:48 +0300, Dmitry Bogatov wrote:
> > Can't you write:
> >
> >   ifneq ($(guile some s-sexpression),)
> >
> > It's not quite as clean, but it doesn't require new syntax which has its
> > own advantages.

> Currently Guile integration is limited to gmk-eval and is little
> better then
> 
>         $(eval $(shell ./some-helper-script))

I don't understand.

First, Guile integration is NOT limited to gmk-eval; if you build with
Guile enabled you get a $(guile ...) GNU make built-in function which
takes its argument and sends it to the Guile interpreter, and expands to
the result.  See:

http://www.gnu.org/software/make/manual/html_node/Guile-Function.html

although definitely some examples are needed here.  To understand the
interface see:

http://www.gnu.org/software/make/manual/html_node/Guile-Types.html

Second, this is far different from the example you suggest because your
version invokes a separate shell process.  The guile function uses the
built-in interpreter just like your change does.

> This patch integrate them a little deeper. And, by the way (VAR != ls
> -A) assignment is very like this.

Again I'm not sure what you mean: != is very like what exactly?  I don't
see much similarity between != and either ifscm or $(guile ...).