Re: unconstrainded array question

[stt@houdini.camb.inmet.com (Tucker Taft)]

Technobabble (therionics@computer.org) wrote:

: Greetings,

: anyone know if it is legal or not in Ada95 to use a RANGE attribute on
: an unconstrained array, as in the example:

There is no such thing as an "unconstrained" array object.  There are
unconstrained array *subtypes*."  In the example below, the
"first subtype" UC_Array of the array type is unconstrained, but
the subtype of the object xyz is constrained to 1..100.

Extra care here in using terminology is important.

: package My_Package is

:   procedure XYZ (This : in Object);

:   type UC_Array is array (integer <>) of integer;
:   xyz : AC_Array (1..100);
    ^^^
This is illegal overloading by the way, since you can't have both
an overloadable declaration like the procedure XYZ and a non-overloadable
declaration like the array xyz in the same declarative region
(remember upper/lower case is irrelevant in Ada identifiers).

: end My_Package;

: then in the body ....
: procedure XYZ (This : Object) is
: begin

:      for I in This.xyz'RANGE

The 'Range attribute is allowed on *all* array objects, and on
all *constrained* array subtypes.  So UC_Array'Range would be
illegal, but <any_array_obj>'Range is allowed.

:          loop 
:           ......
: end XYZ;


: Thanks,
: Richmond

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-Tucker Taft   stt@inmet.com   http://www.inmet.com/~stt/
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