[acorn] Missing `value` property in `Token` (TypeScript) about acorn

[marijnh]

There's such a thing as private properties—the types not describing every property in the code does not mean the types are incorrect.

I guess this one can be useful to external code in some situations. It is hidden because its type is a complete mess—what kind of value it holds depends on the token type, and even varies within a token type like Literal. Exporting it would mean documenting all that and, probably, giving it a type of any. What are you using the value for?