:: [Int] -> Int -package:ghc -package:github package:base-prelude
Extract the last element of a list, which must be finite
and non-empty.
Extract the first element of a list, which must be
non-empty.
Fold a list using the monoid.
For most types, the default definition for
mconcat will be
used, but the function is included in the class definition so that an
optimized version can be provided for specific types.
>>> mconcat ["Hello", " ", "Haskell", "!"]
"Hello Haskell!"