Re: autoaloading facility

[Bernard URBAN <Bernard.Urban AT meteo.fr>]

>>>>> "Greg" == Greg Badros <gjb@cs.washington.edu> writes:

    Greg> Klaus Schilling <Klaus.Schilling@home.ivm.de> writes:
    >> Emacs lisp has an autoloading facility which enables to load
    >> the full definition of a function at the time it is needed
    >> first time. Could something like that also be provided in
    >> guile? or do lexical scoping and monolithic namespace prevent
    >> that?

    Greg> I second this query/request-- Scwm would benefit from
    Greg> autoloading, for sure.

It is easy to implement such an autoloading facility for modules.

First consider the following module:

(define-module (auto auto))

(define-public *auto* '())

(define-public (autoload module . symbols)
  (for-each
   (lambda (sym)
     (let ((res (assq sym *auto*)))
       (if res 
           (if (equal? (cdr res) module)
               'deja-fait
               'pas-2-modules-actuellement)
           (set! *auto* (cons (cons sym module) *auto*)))))
   symbols))

(define autoload-binder
  (lambda (m s define?)
    (if define?
        (let ((b (make-undefined-variable s)))
          (module-obarray-set! (module-obarray m) s b)
          b)
        (begin
          (let ((res (assq s *auto*)))
            (if res 
                (begin (display ";;; autoload module ")
                       (display (cdr res)) (newline)
                       (process-use-modules (list (cdr res)))
                       (module-obarray-ref 
                        (module-obarray (resolve-interface (cdr res))) s))
                #f))))))

(set-module-binder! (module-public-interface (current-module)) autoload-binder)


Then put the following code in your application:

(use-modules (auto auto))
(autoload '(stklos-3.0b2 Button)  	 
          '<Label> '<Button> '<Check-button> '<Radio-button>)

As soon as any of the symbol '<Label> '<Button> '<Check-button> or
'<Radio-button> is read, module (stklos-3.0b2 Button) is loaded.

This code is part of guile-stklos-1.3.3 (in contrib/misc at red-bean).
Originally, this kind of autoloading was available in STklos.

-- 

B. Urban