Return a list of Integer values that is not within a range of numbers in an existing list:

Question

I have a list of values:

[0,7,4,5,3,1,4,5,5,1,7,0,7,7,0]

and would like to return any values that are not in the range of [1..8]

Answer 1

Use filter to keep elements that satisfies a condition.

Prelude> filter (`notElem` theBigListOfValues) [1..8]
[2,6,8]

Or just take the complement using the (\\) operator.

Prelude> import Data.List
Prelude Data.List> [1..8] \\ theBigListOfValues
[2,6,8]