Make PositionEncodingKind a type

[michaelpj]

As discussed here:
f9c85d5#r70968669

I made a change that reflected the existing state, but looking at it, it still reads somewhat ambiguously to me.
We are talking about an overall "position encoding", but in fact it only has quite a specific meaning: what is counted by character offsets.

If we were open to a slightly bigger change, we could consider something like:

// with a proper type obviously
type CharacterOffsetUnit = 'utf-8-codeunits'|'utf-16-codeunits'|'unicode-codepoints';
interface PositionCapabilities {
  characterOffsetUnits: CharacterOffsetUnit;
}

[ghost]

All CLA requirements met.

[nemethf]

Maybe I'm overthinking this, but explaining the original a𐐀b example of the current specification for each encoding would make this even clearer. Or not. Thank you.

[michaelpj]

Maybe I'm overthinking this, but explaining the original a𐐀b example of the current specification for each encoding would make this even clearer. Or not. Thank you.

I think so long as we're referring to clearly understood ways of dealing with text, we can assume that programmers will go elsewhere to understand what e.g. "indexing in UTF-8 code units" means.

[dbaeumer]

I think so long as we're referring to clearly understood ways of dealing with text, we can assume that programmers will go elsewhere to understand what e.g. "indexing in UTF-8 code units" means.

@michaelpj are you willing to provide this as a PR as well?

[michaelpj]

I meant that I think the current text is clear enough, since it uses standard terminology. Perhaps @nemethf disagrees?

[dbaeumer]

@michaelpj sorry misunderstood.

[nemethf]

Perhaps @nemethf disagrees?

I don't.