Simplify alphabet mapping to array lookup.
Base types.
Bound generic types.
parseType is a fixpoint.
Move the type table down.
Parse base types.
Parse generic types.
Don’t print parsed symbols.
Use external names for defaulted parameters.
Assert nilness.
Require that the entire string be parsed.
Equality assertions return nil when passed, actual when failed.
The rest of the string should be empty, not nil.
Generic bounded types are terminated by _.