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From: buschman@tubsibr.uucp (Andreas Buschmann)
Newsgroups: comp.lang.modula3
Subject: names of methods and instance variables of OBJECTs
Keywords: OBJECT names methods
Message-ID: <1991Apr20.191644.11028@tubsibr.uucp>
Date: 20 Apr 91 19:16:44 GMT
Sender: buschman@tubsibr.uucp (Andreas Buschmann)
Organization: TU Braunschweig, Informatik (Bueltenweg), Germany
Lines: 54

Hello,

If I declare a type A beeing an OBJECT with a field named x and a
method named y, am I allowed to declare B beeing A OBJECT with a field
named y and a method named x, or only one of them?

In the report I find:

	The names introduced in FieldList and MethodList must be	(1)
	distinct.

	...

	A field or method in a subtype masks any field or method with	(2)
	the same name in the supertype. To access such a masked field,
	use NARROW to view the subtype variable as a member of the
	supertype. 

The following example compiles ok, but terminates while running with:
fatal error: can't open display ''

MODULE Main;

TYPE O1 = OBJECT i : INTEGER; METHODS m () := p; END;

TYPE O2 = O1 OBJECT m : INTEGER; END;

TYPE O3 = O1 OBJECT METHODS i (); END;

PROCEDURE p (self : O1) =
BEGIN END p;

BEGIN
  EVAL NEW (O2, m := 2);
  EVAL NEW (O3, i := p);
END Main.

this is SRC Modula-3 v1.5 running on a SUN3
on a SUN4 running v1.6 ther is no error message, it just runs.

so does (1) include the names used in the super classes or not? And
why? 

						Tschuess
							Andreas


 /|)			Andreas	Buschmann
/-|)			TU Braunschweig, Germany (West)	
						  ^^^^  was

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