Re: PLEASE: debugging embedded guile code

[Bruce Korb]

OK.  Some real progress.  (Remember this all works when I evaluate
the Guile commands using gh_eval_str):

../agen5/autogen -L ../autoopts -Taginfo -bcolumns -DLEVEL=section \
        ../columns/opts.def
ERROR: Unbound variable: optname-to
Error in template ../autoopts/aginfo.tpl, line 154
        DEFINITIONS ERROR in ../autoopts/aginfo.tpl line 154 for columns.texi:
        exiting
Failing Guile command:  = = = = =
(set! opt-name (string-tr! (get "name") optname-from optname-to))
    (string-append down-prog-name " " opt-name)
* * * * * * * * * * * * * * * * *

The issue here is that gh_eval_str processes the *entire* string and
returns the result of the last expression.  This "eval-client-input"
function does not behave in the same way:

> (define (eval-client-input str)
>   (stack-catch #t
>     (lambda ()
>       (call-with-input-string str
>         (lambda (p)
>           (set-port-filename! p (tpl-file))
>           (set-port-line! p (string->number (tpl-file-line "%2$d")))
>           (list (primitive-eval (read p))))))
>     (lambda (key . args)
>       (apply display-error
>          (fluid-ref the-last-stack)
>          (current-error-port)
>          args)
>       (set! stack-saved? #f)
>       #f
> ) ) )

Before this failing command, the following was eval-ed at once:

> (define optname-from "A-Z_^")
> (define optname-to   "a-z--")

so "optname-from" is found, but "optname-to" is not.  How do I make
that ``(list (primitive-eval (read p)))'' thing into a loop that
yields the last value?

ALSO: notice that the Guile error message is not including the file
and line numbers.  Someone suggested:

> (read-enable 'positions)
> (debug-enable 'show-file-name)

but I get errors when I do that.

BY THE WAY:  when I finally have this working, I'll write it up
so nobody has to go through all this pain again.  It's pretty awful. :(