Re: Ada language problem/question

[joe@petsd.UUCP (Joe Orost)]

In article <91@houligan.UUCP> bseymour@houligan.UUCP (Burch Seymour) writes:
>package A is
>type my_type is (st_1,st_2,st_3);
>end A;
>
>package body A is
>x : my_type;
>begin
>x := st_1; -- no errors here
>end A;
>------------------------------------------------------------------------
>with A;
>package B is
--Solution #1 : replace next line with "TYPE my_type IS NEW a.my_type"
>subtype my_type is a.my_type;
--Solution #2 : add the following lines:
FUNCTION st_1 RETURN my_type RENAMES a.st_1;
FUNCTION st_2 RETURN my_type RENAMES a.st_2;
FUNCTION st_3 RETURN my_type RENAMES a.st_3;
>end B;
>
>Package body B is
>y : my_type;
>begin
--Change the following to "y := st_2;"
>y := A.st_2;  -- no errors here
>end B;
>------------------------------------------------------------------------
>with B;
>package C is
>I : B.my_type;  -- type is OK but appears to fail to bring along
>                -- enumeration values (see below). The question is...
>                -- should it?
>end C;
>
>Package body C is
>begin
>I := B.st_3;   -- undeclared identifier error on this assign
>               -- sites section 8.3 of LRM
>end c;

Explanation: A subtype declaration does not bring with it the operations 
(enumeration literals) of the parent type.  A DERIVED type declaration does
[3.4(6)].  So either use a derived type, or rename all the literals.

				regards,
				joe

--

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