From Newsgroup: comp.lang.scheme


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.'
--- Synchronet 3.22a-Linux NewsLink 1.2

From Newsgroup: comp.lang.scheme


On 5/18/2024 1:28 AM, HenHanna wrote:

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

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

-a-a-a-a-a-a -- So the value is a list of 4 strings:

-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a (a0bc0 a0bc1 a1bc0
a1bc1)

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

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

___________________________________________________
From the Gauche (Scheme) manual:

(cartesian-product rCO((a b c) (0 1)))
rcA ((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)))


--- Synchronet 3.22a-Linux NewsLink 1.2

From Newsgroup: comp.lang.scheme

HenHanna <HenHanna@devnull.tb> writes:

On 5/18/2024 1:28 AM, HenHanna wrote:

How can i write this function simply?-a-a (in Scheme (Gauche))
-- Given a string-a 'a.bc.' -- each dot(.) is to be replaced with 0
or 1.
-a-a-a-a-a-a -- So the value is a list of 4 strings:

-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a (a0bc0 a0bc1 a1bc0
a1bc1)

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

___________________________________________________
From the Gauche (Scheme) manual:

(cartesian-product rCO((a b c) (0 1)))
rcA ((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
--- Synchronet 3.22a-Linux NewsLink 1.2