🚀 go-pugleaf

In article <13951@topaz.rutgers.edu> dalal@topaz.rutgers.edu (Mukesh Dalal) writes:
>1. Is the type checking based on name equivalence or structure
>equivalence? 

Name equivalence.  E.g.
  TYPE t = [0..42];
  VAR  a : t;
       b : [0..42];
  PROCEDURE f ( VAR p : t );
       BEGIN END f;
  f(a) (*legal*);
  f(b) (*illegal*);

> More specifically, Is the following construct allowed:
>	Type
>	 P= Record
>		...
>	    End;
>	 Q = P;

Yes, as the two types are IDENTICAL, as Q is of type P.

>2. Can a global module export an item which it has imported?

  DEFINITION MODULE m;
  FROM Foo IMPORT Bar;
  EXPORT QUALIFIED Bar,  (* is not legal*)
                   Feen; (* is legal *)
  TYPE Feen = Bar;
  END m.

>3. Can the definition of a global-module M refer to a type P which is
>neither declared there (either as opaque or transparent) nor is
>imported from some other module but is defined/imported in the
>corresponding implementation module of M?

No.

>4. Is the following construct allowed:
>
>	Definition:
>		procedure abc (..);
>	Implementation:
>		var x: ...;
>		procedure abc (...);
>			...
>			x := ...;
>		end;
>		...

Yes.
-- 
Randy Bush, Compiler Group, Oregon Software, Portland Oregon (503) 245-2202
uucp: ..!tektronix!oresoft!randy       Telemail: RBush     Fidonet: 1:105/6