Version 1.5 of ais/ai-00053.txt
!standard 03.05 (43) 00-01-25 AI95-00053/05
!class confirmation 95-06-25
!status Response 2000 00-01-25
!status WG9 approved 95-06-14
!status ARG approved (subject to editorial review) 7-0-2 95-11-01
!status received 95-06-25
!qualifier Clarification
!subject Case sensitivity of Wide_Value and Value attributes
!summary
S'Wide_Value and S'Value are not case sensitive for nongraphic
characters.
!question
For S'Wide_Value in the case of a nongraphic character, 3.5(43) gives
the following condition under which the normal result is returned;
otherwise, Constraint_Error is raised:
"...if the sequence of characters of the parameter (ignoring leading and
trailing spaces) has the syntax of an enumeration literal and if it
... corresponds to the result of S'Wide_Image for a nongraphic character
of the type..."
Is the use of the term "corresponds" intended to imply case
sensitivity? (No.)
!response
A sequence of characters corresponds to the result of S'Wide_Image if it
is the same ignoring case. Thus, S'Wide_Value is not case sensitive in
the case of a nongraphic character. The same applies to S'Value.
It is clearly the intent that the "correspondence" mentioned above be
case insensitive. Thus, Character'Wide_Value("nul") does not raise
Constraint_Error, even though Character'Wide_Value returns "NUL" for the nul
character.
!ACATS test
ACATS test C352001 checks that the character names can be given in lower case.
!appendix
!section 03.05(43)
!subject: Unspecified case sensitivity for non-graphic images
!reference as: 95-5150.a Michael Hirasuna 95-6-4>>
!reference RM95-03.05(43)
!from: Michael Hirasuna 95-06-04
!keywords: case sensitivity, non-graphic characters, wide_value attribute
!discussion:
It is not specified if the text image of a non-graphic character, when
passed as an argument to S'Wide_Value, is case sensitive. The paragraph
states that the image should correspond to the result of S'Wide_Image for
that non-graphic character, which would imply that the image had to be in
upper case. This would be inconsistent with other language constructs.
Because the image of a non-graphic character is not part of the language
syntax, the rule for case independent identifiers (2.3(5)) does not apply.
In other areas involving letters, the reference manual explicitly states
case independence, i.e. for based literals (2.4.2(8)) and for the 'E'
exponent notation (2.4.1(6)).
Since there is no global to rule to cover it, the case sensitivity for
non-graphic images should be clearly defined, or defined as being
implementation dependent.
Mike (hirasuna@acm.org)
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