map f xs
is the list obtained by applying f
to each element of xs
map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn]
map f [x1, x2, ...] == [f x1, f x2, ...]
Map each element of a structure to a monadic action, evaluate these
actions from left to right, and ignore the results. For a version that
doesn't ignore the results see mapM
As of base 18.104.22.168, mapM_
is just traverse_
An associative operation
: This method is redundant and has the default
implementation mappend = '(<>)'
Map a function over all the elements of a container and concatenate
the resulting lists.
Map each element of the structure to a monoid, and combine the