Re: Doc organization (Re: Around again, and docs lead role)

[Rob Browning]

Neil Jerram <address@hidden> writes:

>     Rob> hack something like that up if they needed to with a makefile
>     Rob> and appropriate use of "cat"...
>
> #include <foo.scm> would be very nice, but we'll probably need
> something more dynamic as well.  I don't see what you mean by cat
> though.

I hadn't thought very hard about it, but I meant that instead of
#include <foo.scm> in file foo.c (which would still require some
non-scheme code in foo.scm) you could do something primitive like
this:

  foo-real.c: foo-pre.c foo.scm foo-post.c
        cat foo-pre.c > foo-real.c.tmp
        echo 'startup_eval_code = "' >> foo-real.c.tmp
        cat foo.scm >> foo-real.c.tmp
        echo '";' >> foo-real.c.tmp
        cat foo-post.c >> foo-real.c.tmp
        mv foo-real.c.tmp foo-real.c

very ugly, of course (really too ugly), but something that could be
done right now.  I suppose you could also use perl, sed, etc. with
similar effect.
        
>     Rob> Actually, I've been playing around with code that would
>     Rob> make something like this possible (as a dumb example):
>
>     Rob>   (define (double x)
>     Rob>     (c-syntax
>     Rob>       (if ("SCM_INUMP" x)
>     Rob>           (return (* x x))
>     Rob>           (return ("scm_apply" ("scm_lookup" "+") x x)))))
>
> I don't see how this helps - please explain.

Well in one possible approach you'd be able to write a file that
contained both scheme and this "inline C" code.  That file would then
be compiled to object code via C.  In that arrangement, you wouldn't
need a separate file or a giant unwieldy C string for any large
embedded Scheme fragments. i.e. as a psuedo-example:

  (define (show-c-+ x y)
    (simple-format #t "In C (+ ~A ~A) would yield ~A\n"
                   x y
                   (c-style-int-+ x y)))

  (define (c-style-int-+ x y)
    (c-syntax
      (auto int c_x ("scm_num2int" 1 x %function-name))
      (auto int c_y ("scm_num2int" 1 y %function-name))
      (return ("scm_int2num" (+ c_x c_y)))))

Of course that's not the primary reason I've been playing around with
this, but it's another effect.

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
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