Re: Distinguishing type names from other identifiers

[Mats Weber <Mats.Weber@elca-matrix.ch>]

Modula-3 has adopted the convention (it's really a convention, not part of the
language) of using T as the name of the type (usually the single type) that is
defined in an interface (package spec). I think that convention works pretty
well. Here is a small example:

    INTERFACE Stack;
      TYPE T <: REFANY;
      PROCEDURE Create(): T;
      PROCEDURE Push(VAR s: T; x: REAL);
      PROCEDURE Pop(VAR s: T): REAL;
    END Stack.

    MODULE Stack;
      REVEAL T = BRANDED OBJECT item: REAL; link: T END;
      PROCEDURE Create(): T = BEGIN RETURN NIL END Create;

      PROCEDURE Push(VAR s: T; x: REAL) =
        BEGIN 
          s := NEW(T, item := x, link := s)
        END Push;

      PROCEDURE Pop(VAR s: T): REAL =
        VAR res: REAL;
        BEGIN 
          res := s.item; s := s.link; RETURN res
        END Pop;

    BEGIN
    END Stack.