Add esquery.traverse

[kumavis]

Playing with esquery I found I wanted richer information than a list of matches (e.g. parents, etc)

I broke out the traversing and matching so you get a callback for each found node. I suppose this is a little more dangerous as you could accidently change the ast in such a way selector that would have been is not matched.

Let me know what you think, happy to make adjustments.

That said it looks like I'm passing the wrong parent here:
visitor(ancestry[k], parent, ancestry.slice());

[michaelficarra]

I like it. This obviously needs tests, though. Why are you cloning the ancestry list every time?

[kumavis]

I am cloning the ancestry list so the consumer doesn't modify it and break stuff. Perhaps we can leave that up to them. Since you are already compiling the selector yourself to use this, maybe it can be assumed that things are fragile.

[michaelficarra]

Yeah, if the consumer wants to break things, let them. We shouldn't take the huge perf hit of cloning the ancestry list just to protect them from themselves.