XPost: comp.lang.scheme, fj.comp.lang.lisp
On 5/19/2024 12:41 AM, HenHanna wrote:
From the Gauche (Scheme) manual:
(cartesian-product ’((a b c) (0 1)))
⇒ ((a 0) (a 1) (b 0) (b 1) (c 0) (c 1))
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The Gauche (Scheme) manual describes
string-count and cartesian-product
as built-in functions, but I couldn't use them and ended up defining
them myself.
(define (cartesian-product x)
(if (null? (cdr x))
(map list (car x))
(apply append
(map (lambda (F)
(map (lambda (R) (cons F R)) (cartesian-product (cdr x))))
(car x)))))
(print (cartesian-product '((0 1))) ) ==> ((0) (1))
(print (cartesian-product '((a b)(0 1))) ) ==> ((a 0) (a 1) (b 0) (b 1))
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The above code works fine, but when i rename the variable (F) as (x), i
get the following error, and this must be a bug in Gauche (Scheme).
gosh> (load "CpMerge.lsp")
((0) (1))
*** ERROR: pair required, but got a
While loading "./CpMerge.lsp" at line 19
No... my bad... That's not a bug. Just my error!
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