Search code examples
schemelispracketfold

List of arguments of structures

Since I am fairly new to racket I stumbled across a problem I could not solve.

To break it down, I have a list containing several structures of the same type, and I want to create a list with only one specific argument of each elements structure. Something like this:

(define-struct sample (name number))
(define samples (list (make-sample "A" 1) (make-sample "B" 2)))

So when apply the function to this list I get the following list:

(lit "A" "B")

I want to solve this problem without recursion, only using lambda expressions and map and fold.

I tried to get access to every elements argument by using:

(foldr sample-name samples)

But that does not work.

Does anyone know how to solve this problem?

Thank you in advance! Appa

Solution

  • You're looking for map, please take a look at the documentation to understand the difference between foldr and map.

    (map sample-name samples)
=> '("A" "B")