Pack consecutive duplicates of list elements into sublists

	;; P09 (**) Pack consecutive duplicates of list elements into sublists.
	;; If a list contains repeated elements they should be placed in separate sublists.
	;; Example:
	;; * (pack '(a a a a b c c a a d e e e e))
	;; ((A A A A) (B) (C C) (A A) (D) (E E E E))
	(require srfi/1)
	(define (pack lst)
	(let loop ((lst lst) (acc '()))
	(if (null? lst)
	(reverse acc)
	(loop (strip lst) (cons (picks lst) acc)))))
	(define-syntax define-pack-aux
	(syntax-rules ()
	((_ name proc)
	(define (name lst)
	(let ((head (car lst)))
	(proc (lambda (x)
	(eq? head x)) lst))))))
	;; Using a procedure, take-while, defined in SRFI-1
	(define-pack-aux picks take-while)
	;; Using a procedure, drop-while, defined in SRFI-1
	(define-pack-aux strip drop-while)

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