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Collects all values of given type occuring as proper constituents of the given value. The results are collected in a monoid (e.g. a list)

a simple example can be collection of values from nested lists:

>>> collectValues (\(x :: Int) -> [x]) [[1,2], [3], [4 :: Int]]
[1,2,3,4]

we cal also collect constituents of a recursive data structue itself:

>>> collectValues (\(x :: [Int]) -> [x]) [1, 2, 3, 4 :: Int]
[[2,3,4],[3,4],[4],[]]

For more complex exampe, let's have the following type:

data BinTree a = N (BinTree a) a (BinTree a) | E deriving (Data, Typeable, Show)

we can collect all values from the tree:

>>> collectValues (\(x :: Bool) -> [x]) $ N (N E True (N E False E)) True E
[True,False,True]

but we can also collect all subtrees:

>>> collectValues (\(x :: BinTree Bool) -> [x]) $ N (N E True (N E False E)) True E
[N E True (N E False E),E,N E False E,E,E,E]