concat -package:ghc -is:exact package:text

O(n) Concatenate a list of Texts.
O(n) Concatenate a list of streams. Properties
unstream . concat . fmap stream  = concat
O(n) Map a function over a Text that results in a Text, and concatenate the results.
Map a function over a stream that results in a stream and concatenate the results. Properties
unstream . concatMap (stream . f) . stream = concatMap f