Add fold and biFold functions

[chrisdotcode]

I should probably also update the docs. I'll do that now.

[chrisdotcode]

@garyb Request to remove MODULES.md, and move the docs to the standard purescript doc location? (docs/)?

[garyb]

Yeah definitely. We could probably switch the build to pulp too I think, and then it's just pulp docs to generate everything in the appropriate place.

[chrisdotcode]

I had actually used both pulp build and pulp docs just fine to both build and generate docs respectively just now.

[chrisdotcode]

@garyb Before you merge, should I version++, and add git tags accordingly (for bower)?

[garyb]

Nah, we usually make the release via GitHub anyway so it does that automatically.

[chrisdotcode]

@garyb Ready for merging, then?

[garyb]

Could you squash the commits please? And then :+1:

[chrisdotcode]

@garyb Do you want one single commit, or do you want me to try and preserve the code changes/documentation changes if and where possible?

[garyb]

We tend to just squash into one commit unless the change is huge :wink:

I'll leave the final merging to @jdegoes though, given he has ideas about how the fold should work.

[jdegoes]

I feel this version of fold is easy to misuse: for example, if I try to construct a path string by folding over the path, then the resulting path will be inaccurate because it fails to take into account ../foo/../bar/ (ParentIn) nodes. I would be open to (a) fixing this issue, or (b) renaming it foldNames and making sure the documentation is clear it will fold only over the file and dir names, not all the nodes making up the path.

[chrisdotcode]

@jdegoes How about exposing the constructors in some way, shape or form, like in your example above?

[jdegoes]

Thanks so much for this @chrisdotcode!

[jdegoes]

Oops, accidentally merged this prior to the final revision! Sorry. :disappointed: