On Sat, Sep 7, 2024 at 7:52 PM Maxime Devos <[email protected]> wrote:
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>
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> IIRC doing (set! some-variable some-variable) on the top-level on a
> variable of the module makes the module non-declarative by default, but
> please check the manual for details (there is some information on this, I
> don’t recall the name of the section).
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>
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> In particular, I would expect
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>
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> (define (foo ...) ...)
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> (set! foo foo)
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> to have the desired properties (at least as far as replacing ‘foo’ with an
> updated version is concerned), both in past, present and future.
>
>
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> (No comment on what the default _*should*_ be.)
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>
probably i'm a bit out of context but this make me remember some code i had
written
when doing some sort of "overloading" of procedure or operator i use
'define' instead of 'set!' i think i tried set! if i remember well but it
gave bad result, so my current code use 'define' :
(define (create-overloaded-procedure orig-funct funct pred-list)
(display "create-overloaded-procedure")
(display " : pred-list = ") (display pred-list) (newline)
(define old-funct orig-funct)
(define new-funct (lambda args ;; args is the list of arguments
;;(display "new-funct: ") (display new-funct) (newline)
;;(display "new-funct : pred-list = ") (display pred-list) (newline)
;;(display "new-funct : args = ") (display args) (newline)
(if (check-arguments pred-list args)
;;(begin
;;(display "new funct :calling:") (display funct) (newline)
(apply funct args);)
;;(begin
;;(display "new funct :calling:") (display old-funct) (newline)
(apply old-funct args))));)
(display "funct: ") (display funct) (newline)
(display "orig-funct: ") (display orig-funct) (newline)
(display "old-funct: ") (display old-funct) (newline)
(display "new-funct: ") (display new-funct) (newline)
new-funct)
i used (define old-funct orig-funct) to backup the function instead of set!
and the code can only called by a macro at top-level of a file and i can
not do this 'overloading' implementation with different scheme
implementation (Kawa,Racket,R6RS...) i had to store the overloading data in
an hash table in a global variable of a module that i probably export
instead of redefining an existing function.
