{-
-- drop, take
drop :: Int -> [a] -> [a]
take :: Int -> [a] -> [a]

ghci> drop 10 [1..20]
[11,12,13,14,15,16,17,18,19,20]
it :: [Integer]
ghci> take 10 [1..20]
[1,2,3,4,5,6,7,8,9,10]
it :: [Integer]

Truncates a list at a certain range. For drop, it will drop the first 10 slots in the list, and for take, it will take only the first 10 slots in the list. This is useful to cut-off something endless, like...

ghci> take 10 ( cycle [1,3,3,7] )
[1,3,3,7,1,3,3,7,1,3]
it :: [Integer]

-- filter
filter :: (a -> Bool) -> [a] -> [a]

ghci> filter (>Yellow) [Red,Green,Blue,Violet,Orange,Yellow,Green]
[Green,Blue,Violet,Green]
it :: [Color]

Only keeps elements in a list that follow a certain condition given to it.

-}