From Newsgroup: comp.lang.lisp

Drew Krause wrote:

Maybe someone can help me with this?

I start with a list, e.g.

((0) (1 3) (1 2) (4 6) (5 7) (7 8))

and want all members of intersecting lists to appear in the same sublist:

((0) (1 2 3) (4 6) (5 7 8))

Gauche Scheme

(use srfi-1) ;; lset- functions

(define (coalesce lists)
(define result '())
(dolist (xs lists)
(let ((tmp0 '()) (tmp1 (list xs)))
(dolist (ys result)
(if (pair? (lset-intersection eqv? ys xs))
(push! tmp1 ys)
(push! tmp0 ys)))
(set! result
(cons (apply lset-union eqv? tmp1) tmp0))))
result)


(coalesce '((0) (1 3) (1 2) (4 6) (5 7) (7 8)))
===>
((8 5 7) (4 6) (0) (2 1 3))

(coalesce '((2 4) (8 9) (4 5 8)))
===>
((5 9 8 2 4))

(coalesce '((3 4) (7 8) (4 8) (0) (5 9)))
===>
((5 9) (8 7 3 4) (0))

(coalesce '((3 4) (7 8) (4 5 8) (0) (5 9)))
===>
((9 5 8 7 3 4) (0))
--
[T]he problem is that lispniks are as cultish as any other devout group and basically fall down frothing at the mouth if they see [heterodoxy].
--- Kenny Tilton
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