Language service: open Type.id

I am using language service to "traverse" the program, and I would like very much to "remember" which types and symbols I already saw, and to cache my computation results for them. Performance boost and avoiding infinite loops.

The compiler very helpfully supplies id for Type, Symbol and Node, and it seems to be "really, really" unique for symbols and nodes, and "relatively unique" (i.e. within a given typechecker) for types.

The problem is, however, that, unlike nodes and symbols, types hide their ids behind the "internal" qualifier and the lack of accessor function, making them not legally visible to me as a consumer of the language service. Of course, this being JavaScript, nothing prevents me from accessing them anyway, and that is what I currently do, but this is not ideal, because I am not protected from the code evolution in the future.

So it seems to me that nothing stands in the way of adding a getTypeId method to the typechecker, unless I'm missing something very important.

Commencez par src/compiler/checker.ts et src/compiler/types.ts, en particulier la définition de Type et la gestion existante de l’identité du typechecker décrite dans l’issue. Suivez la manière dont les API publiques de language-service et de type-checker sont déclarées et testées, puis déterminez ce qui est nécessaire pour un accesseur d’identifiant de type pris en charge et vérifiez que l’identifiant exposé reste utile au sein d’un typechecker.