Don't store node names as a joined string

[Timmmm]

This stores the node names as an array of strings instead of a joined string. It is preparatory work for fixing lezer-parser/lezer#35 (and depends on the corresponding change in lezer.

[marijnh]

Hi, I'm not really that sure if I will ever do lezer-parser/lezer#35 anymore (since it has a bunch of other tricky implications around interface complexity for parser packages). Also, I don't really see how this PR helps with that.

[Timmmm]

This doesn't help directly, but I have a future change that lets you export Typescript instead of Javascript, and then you can do:

const nodeNames = ["foo", "bar", "baz"] as const;
type NodeName = typeof nodeNames[number];

This change is a precursor to that.

I think that would be worth doing even if it isn't integrated into the parser type, since user code still might want to do things like iterate over all of the node names, or use NodeName in their code.

[marijnh]

Iterating over node types can be done with nodeSet.types. This string is purely internal and only intended for deserialize.

[Timmmm]

Right, but you can't get a static type of all the node names from nodeSet.types because they need to be written down as a const array in the source code in order for Typescript to understand them statically.