Add the accumulate problem

[sturmer]

Getting my feet wet. Any feedback would be appreciated :)

[yurrriq]

I think the general idea is to avoid built-in functions like map.

You could implement accumulate using pattern-matching like this:

(define/match (accumulate proc lst)
  [(proc '())          '()]
  [(proc `(,x . ,rst)) `(,(proc x) . ,(accumulate proc rst))])

or more traditionally like this:

(define (accumulate proc lst)
  (if (null? lst)
      '()
      (cons (proc (car lst))
            (accumulate proc (cdr lst)))))

[yurrriq]

I'm assuming you meant (* arg arg) here.

application: not a procedure;
 expected a procedure that can be applied to arguments
  given: 1
  arguments...:
   #<procedure:*>
   1
  context...:
   accumulate

[bennn]

or (arg . * . arg)

[yurrriq]

It would probably be helpful to have a couple more tests. You might find some inspiration in the LFE version.

[yurrriq]

Sorry if my comments come off as terse or overly critical. That's not my intention. It's late here and I shouldn't be coding any more tonight...

Thanks very much for getting involved! I hope my feedback is constructive rather than discouraging.

[sturmer]

Hi @yurrriq no worries, your comments are very constructive and I'll address them carefully later today (it was very early here and I missed silly stuff like (* arg arg) instead of (arg * arg) :-) )

[sturmer]

I have addressed the immediate concerns. I am trying to reproduce also the last test from LFE but I am still a 3-year-old when it comes to list comprehensions (I am using this chance to learn that too). Thanks again for your comments @yurrriq and @bennn, please go ahead if you have other comments.

[sturmer]

Hi, anyone has any other comments? If the initial comments are addressed, I'd be happy to know how I can help to have it merged.

[yurrriq]

Without running the code it looks good to me. @arguello, will you check it out and merge?

[arguello]

looks good, thank you.

[yurrriq]

🎉

[sturmer]

Whooo thanks @arguello and @yurrriq!