The information carried in global identifiers

The only kind of information carried in Catala identifiers is the original string of the identifier annotated with the position where it is declared or used.

Identifiers have abstract types, but are comparable so they can be used as keys in maps or sets. Their underlying information can be retrieved at any time.

This is the generative functor that ensures that two modules resulting from two different calls to Make will be viewed as different types t by the OCaml typechecker. Prevents mixing up different sorts of identifiers.