Functors representing data structures that can be transformed to
structures of the
same shape by performing an
Applicative (or, therefore,
Monad) action on each
element from left to right.
A more detailed description of what
same shape means, the
various methods, how traversals are constructed, and example advanced
use-cases can be found in the
Overview section of
Data.Traversable#overview.
For the class laws see the
Laws section of
Data.Traversable#laws.