Traversable sample [contribution welcome]

[SimonMeskens]

I need a sample in plain JavaScript for traversables, contributions are welcome. If you have a sample, just leave it in here, mentioning you're allowing the code to be licensed under Apache License 2.0.

[masaeedu]

I have three or four instances of traversable in https://github.com/masaeedu/fp/tree/wip/src/instances. See for example arrays, objects and eithers (last one is defined using traverse instead of sequence, for variety).

There's also more abstract stuff like derivations of sequence from traverse and vice versa, or the free recursive traversable functor over any other set of traversable functors.

There should be snapshot tests next to each file showing how to use each thing.

[KiaraGrouwstra]

also see FL, Ramda, npm-ramda.