CODEWITHSUNDEEP
haskell
Michiru
Michiru

Reputation: 13

How do I give the argument to a function which is used inside other function in haskell

So basically I have:

numList = [0,1..]
numList' = take 2 numList
listsList = [] : [new : old | old <- listsList, new <- numList'] -- list of all possible binary numbers (infinite)
listsList' = take 10000 listsList -- just to not stuck because of infinite list

finalList n = [ x | x <- listsList', length x == n] -- taking n-sized lists

and it is working (even if I change 2 to a different number in the second line) but I need last function to have two arguments like this:

finalList n k

where k should be given to the numList' to be something like

numList' = take k numList

I also can not make 

numList' k = take k numList

because then the function listsList do not work. How can I solve this?

Upvotes: 0

Views: 86

Answers (1)

chepner
chepner

Reputation: 531165

numList' isn't a function; it's simply the list resulting from a call to take. As such, you can't pass a different argument to it; the function has already been called. The simplest thing to do is define a function digits that takes k as an argument and returns the desired subset of integers.

digits k = [0..k-1]
listsList k = [] : [new : old | old <- listsList k, new <- digits k] -- list of all possible binary numbers (infinite)
listsList' k = take 10000 $ listsList k -- just to not stuck because of infinite list

finalList n k = [ x | x <- listsList' k, length x == n] -- taking n-sized lists

Upvotes: 2

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