Email list hosting service & mailing list manager

Late binding Felix Thibault (25 Apr 2021 21:35 UTC)
Re: Late binding Felix Thibault (26 Apr 2021 00:04 UTC)
Re: Late binding Felix Thibault (26 Apr 2021 04:24 UTC)

Late binding Felix Thibault 25 Apr 2021 21:35 UTC

I have the everything in library or program form and am working on the
late binding. Marc suggesting changing the last part of match two
which binds the pattern variable to its value like:

;; Not a pair or vector or special literal, test to see if it's a
;; new symbol, in which case we just bind it, or if it's an
;; already bound symbol or some other literal, in which case we
;; compare it with EQUAL?.
((match-two v x g+s (sk ...) fk (id ...))  ;; LINE#502
(match-check-identifier
  x
  (let-syntax
    ((new-sym?
        (syntax-rules (id ...)
          ((new-sym? x sk2 fk2) sk2)
          ((new-sym? y sk2 fk2) fk2))))
    (new-sym? random-sym-to-match
                      (let ((x v)) (sk ... (id ... x)))
                            (if (equal? v x) (sk ... (id ...)) fk)))
                      (if (equal? v x) (sk ... (id ...)) fk)))

to binding the value to a temporary:
((match-two v x g+s (sk ...) fk ((id . id%) ...))  ;CHANGE
(match-check-identifier
  x
  (let-syntax
    ((new-sym?
        (syntax-rules (id ...)
          ((new-sym? x sk2 fk2) sk2)
          ((new-sym? y sk2 fk2) fk2))))
    (new-sym? random-sym-to-match
                      (let ((x% v)) (ask ... ((id . id%) ... (x . x%))) ;CHANGE
                            (if (equal? v x) (sk ... (id ...)) fk)))
                      (if (equal? v x) (sk ... (id ...)) fk)))

and then binding the temporaries at this step:
((match-next v g+s (pat (=> failure) . body) . rest) ;LINE#336
  (let ((failure (lambda () (match-next v g+s . rest))))
        ;; match-one analyzes the pattern for us
       (match-one v pat g+s (match-drop-ids (begin . body)) (failure) ())))

Which I am attempting by replacing match-drop-ids, the macro that runs
the body by dropping everything but the first expression:
(define-syntax match-drop-ids
  (syntax-rules ()
    ((_ expr ids ...)
     (expr))))

with:
(define-syntax match-bind-ids
   (syntax-rules ()
      ((_ expr ((id . id%) ...) ...)
       (let ((id id%) ... ...)
           expr))))

Which is giving me a bad let on (match 1 (a a)) that looks like
(let ((a) (a%)) (begin a))

I am thinking either one or both of these macros is wrong, (or that
there are also changes I need to make in match-extract-vars- which I
am having trouble understanding), but I am not sure which step to take
next.