Question

I haven’t had any luck creating function that removes sublists.

I have this list:

'((("a" "c") ("a" "l")) (("b" "c") ("b" "l")) (("c" "hmm")))

This should be result:

'(("a" "c") ("a" "l") ("b" "c") ("b" "l") ("c" "hmm"))

Any help would be appreciated.

Answer 1

Used two functions flatten (found on the net) and createPairs.

First function flattens list to 1 level deep list like this:

'("a" "c" "a" "l" "b" "c" "b" "l" "c" "hmm")

And second function createPairs joins list by pairs like this:

'(("a" "c") ("a" "l") ("b" "c") ("b" "l") ("c" "hmm"))

Here are the used functions:

Flatten:

 (define (flatten list)
   (cond ((null? list) '())
         ((list? (car list)) (append (flatten (car list)) (flatten (cdr list))))
         (else
          (cons (car list) (flatten (cdr list))))))

CreatePairs:

(define (createPairs a)
  (cond ((null? a) '()) 
        (else 
         (cons (list (car a) (car (cdr a)))
               (createPairs (cdr (cdr a)))))))