CODEWITHSUNDEEP
scheme
burgerhex
burgerhex

Reputation: 1048

How do you display letters one by one in Scheme?

I am new to the Scheme language and am currently using the Simply Scheme textbook. I was experimenting with some procedures, and I noticed that when I do these functions (below), it prints words in a "spoken" fashion:

(define (display-all sep . vs)
  (for-each display (insert-between sep vs)))

(define (insert-between v xs)
  (cond ((null? xs) xs)
        ((null? (cdr xs)) xs)
        (else (cons (car xs)
                    (cons v (insert-between v (cdr xs)))))))

(Code used from How to 'display' multiple parameters in R5RS Scheme)

Then commanding:

(display-all "" 'w 'o 'w " " 't 'h 'i 's " " 'i 's " " 'c 'o 'o 'l)

The letters are printed one by one as if someone was typing them. I was wondering if there was any way to make it easier for me to input these words to be spoken, instead of inputting letter by letter. I was planning to have something like this:

(define (speak . wds)
  (...))

where wds would be a string. In the above example, I would like for it to be like this: (speak "wow this is cool") and return "wow this is cool" but each letter displayed one by one.

Thank you in advance for your help!

Upvotes: 1

Views: 111

Answers (1)

Óscar López
Óscar López

Reputation: 236112

How about passing a string as input? there's no need to use variable arguments in this case, please try this:

(define (display-all sep vs)
  (for-each display (insert-between sep (string->list vs))))

(display-all "" "wow this is cool")

Upvotes: 1

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