Given string 'a.bc.' -- each dot(.) is to be replaced with 0 or 1

[HenHanna]

How can i write this function simply? (in Scheme (Gauche))

-- Given a string 'a.bc.' -- each dot(.) is to be replaced with 0 or 1.

-- So the value is a list of 4 strings:
['a0bc0', 'a0bc1', 'a1bc0', 'a1bc1']

-- The order is not important.
If the string has 3 dots, the value is a list of length 8.

If the program is going to be simpler,
pls use, say, (a $ b c $) rather than 'a.bc.'

[HenHanna]

How can i write this function simply?   (in Scheme (Gauche))
-- Given a string  'a.bc.' -- each dot(.) is to be replaced with 0 or 1.

                       (a0bc0 a0bc1 a1bc0
a1bc1)

-- The order is not important.
            If the string has 3 dots, the value is a list of length 8.
If the program is going to be simpler,
                       pls use, say,   (a $ b c $)  rather than  'a.bc.'

___________________________________________________
From the Gauche (Scheme) manual:

(cartesian-product ’((a b c) (0 1)))
⇒ ((a 0) (a 1) (b 0) (b 1) (c 0) (c 1))


________________________________________

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 -- Why is that?
Do i have to import libraries, as in Python?




(define (countDots s)
(count (lambda (c) (equal? c #\.))
(string->list s)))

[Jens Thiele]

Post by HenHanna

How can i write this function simply?   (in Scheme (Gauche))
-- Given a string  'a.bc.' -- each dot(.) is to be replaced with 0 or 1.

                       (a0bc0 a0bc1 a1bc0
a1bc1)

-- The order is not important.
            If the string has 3 dots, the value is a list of length 8.
If the program is going to be simpler,
                       pls use, say,   (a $ b c $)  rather than  'a.bc.'

___________________________________________________
(cartesian-product ’((a b c) (0 1)))
⇒ ((a 0) (a 1) (b 0) (b 1) (c 0) (c 1))
________________________________________
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 -- Why is that?
Do i have to import libraries, as in Python?

yes.
As the manual states this is in the util.combinations library:

gosh> (cartesian-product '((a b c) (0 1)))
*** UNBOUND-VARIABLE-ERROR: unbound variable: cartesian-product
Stack Trace:
_______________________________________
0 (report-error e)
1 (eval expr env)
at "/usr/share/gauche-0.98/0.9.14/lib/gauche/interactive.scm":359
2 (evaluator exp (vm-current-module))
3 (with-error-handler (^e (report-error e) #t) (^ () (let loop2 ...
gosh> (use util.combinations)
gosh> (cartesian-product '((a b c) (0 1)))
((a 0) (a 1) (b 0) (b 1) (c 0) (c 1))

Greetings
karme