CODEWITHSUNDEEP
liststructschemeracket
user10630000
user10630000

Reputation:

How do I get a list out of a struct?

I have the given struct : 

(define-struct clr ( r g b a)

and I want to have a list out of it:

(list (list r)(list g)(list b)(list a)

My current code:

(define clrTolist
    (lambda (clr)
    (map list (list clr))))

(clrTolist (make-clr 0 0 0 0))

That is the result i'm getting :

list (list (make-clr 0 0 0 0)))

I don't want the structure name to be shown on my end list.

Upvotes: 1

Views: 91

Answers (1)

rzume
rzume

Reputation: 33

You can "access" single values from struct by using this syntax:

id-field

So in your case 

clr-r myred

will return specific value of r for element myred

You want to create a list, consisting of all values of your element so just try

(list (clr-r clr) (clr-g clr) (clr-b clr) clr-a clr))

Make sure to understand structs and its definitions. I recommend this Chapter from HtdP https://htdp.org/2003-09-26/Book/curriculum-Z-H-9.html#node_chap_6

Upvotes: 1

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