> A Mappable would be anything that has a `map` function. A `Functor` is a something that has a `map` function _AND_ obeys the rule that calling `map` with the

> A Mappable would be anything that has a `map` function. A `Functor` is a something that has a `map` function _AND_ obeys the rule that calling `map` with the identity function produces the same result. This sentence just taught me more about functional programming terminology than 4 years of university and 20 years of casual blog-post reading :O