VHDL Issue Number:      0100
Classification:         Language Deficiencies and Modeling Problems
Language Version:       VHDL-87
Summary:                The RANGE and REVERSE_RANGE attributes are not
                        applicable to discrete types.
Related Issues:         none
Relevant LRM Sections:  14.1
Key Words and Phrases:  Attributes, Scalar Types, RANGE, REVERSE_RANGE
Current Status:         Submitted
1076-1993 Disposition:  Bugs Fixed, Enhancements Outstanding (No ISAC Issues)
Disposition Rationale:  Non-ISAC issues outstanding.
Superseded By:          N/A
-----------------------
Date Submitted:         1988/05/10
Author of Submission:   Paul Menchini
Author's Affiliation:   CAD Language Systems, Inc.
Author's Post Address:  P.O. Box 13036
                        Research Triangle Park, NC  27709-3036
Author's Phone Number:  (919) 361-1913
Author's Fax Number:    
Author's Net Address:   mench@clsi.com
-----------------------
Date Analyzed:          TBD
Author of Analysis:     TBD
Revision Number:        $Revision: 1.9 $
Date Last Revised:      $Date: 1995/08/03 18:13:49 $


Description of Problem
----------------------
The RANGE and REVERSE_RANGE attributes (LRM Pages 14-4,5) is defined only for
array types.  It would be useful if it were also defined for all discrete
types.


Proposed Resolution
-------------------
Define the RANGE and REVERSE_RANGE attributes to be additionally applicable to
scalar types and objects of scalar types.  I would suggest that the following
entries be added to Section 14.1 immediately after the entry for T'LOW:


T'RANGE
        Kind:           Range
        Prefix:         Any scalar type or subtype T.
        Result Type:    Same type as T.
        Result:         The range T'LEFT to T'RIGHT if the range of T is
                        ascending, or the range T'LEFT downto T'RIGHT if the
                        the range of T is descending.


T'REVERSE_RANGE
        Kind:           Range
        Prefix:         Any scalar type or subtype T.
        Result Type:    Same type as T.
        Result:         The range T'RIGHT downto T'LEFT if the range of T is
                        ascending, or the range T'RIGHT to T'LEFT if the range
                        of T is descending.


VASG-ISAC Analysis & Rationale
------------------------------
TBD


VASG-ISAC Recommendation for IEEE Std 1076-1987
-----------------------------------------------
TBD


VASG-ISAC Recommendation for Future Revisions
---------------------------------------------
TBD