从球拍列表中删除空格

Question

I'm working on a PL logic resolver, and I need to make sure the input either has no spaces, or evenly spaced. I think removing the spaces will be easier. So I'm writing a function that removes the spaces from an input.

So far I have:

;sample input
(define KB&!alpha
  '((Girl)
    (~ Boy)
    (~~Boy)
    ( ~(FirstGrade ^ ~ ~ Girl))
    (Boy / Child)))

(define formatted null)

;formatting function
(define (Format_Spaces KB&!alpha)
  (for/list ((item KB&!alpha))
    (cond 
      ((list? item)(Format_Spaces item))
      ((not (eq? item " "))(set! formatted (append formatted (list item))))
      ((eq? item " ")(Format_Spaces (cdr KB&!alpha)))
    )
  )
)

But it's clearly giving me the wrong output.

Not only are the spaces still there, the output is a weird combination of the input. Can anybody help me out on this?

I want to get something like this:

'((FirstGrade)
    (FirstGrade=>Child)
    (Child^Male=>Boy)
    (Kindergarten=>Child)
    (Child^Female=>Girl)
    (Female)))

Thanks for reading.

EDIT: I'm trying to make the input uniform in format. In the new sample input, (~ Boy) is parsed as 2 symbols, (~~Boy) as 1 symbol, and (~ ~ Girl) as 3. I think this will be difficult to parse. Especially with different variations of symbols/operators/spaces. (ie. is "Child^" to be parsed as "Child","^" or as "Child^" a whole symbol?)

Answer 1

RE-EDIT:

Based on the comments you've made below, it looks to me like you're actually going to be writing this algorithm in Racket.

In that case, I have a much simpler prescription for you: Don't Do Anything. In particular, your input doesn't currently contain any spaces at all. The spaces you see are being inserted as part of Racket's display mechanism, in much the same way that a database printer might print fields separated with commas or tabs.

Rather than worrying about the commas, focus on the resolution algorithm. What does it take, and what does it produce?