(j3.2006) Is a pointer a data object?

Cohen Malcolm malcolm
Wed Jan 27 00:37:59 EST 2016

>Is a pointer a data object,

A data pointer is a data object.  A procedure pointer is a procedure.

(1) A data pointer is defined to be a "data entity with the POINTER 
(2) a variable is defined to be a "data entity that can be defined and 
redefined during execution of a program";
(3) and finally, a "data object" is defined to be a "variable" (or some 
other stuff).

> or is only its target (if it is associated) a data object?

There is no, maybe a typo for 5.5.14.

> suggests it's not a data object because it claims a pointer can
>be associated with different data objects during execution.

Oh good, so dummy data objects are not data objects either, since they can 
be associated with different data objects during execution.  Nice to know.

>  Pointers
>cannot be associated with pointers -- only with their targets.

Untrue.  A data pointer can only be pointer-associated with a data object 
that has the TARGET attribute, which rules out lots of things, including all 
constants and all pointers.

But a pointer can potentially be argument-associated, 
inheritance-associated, host-associated, or use-associated with another 

However, what this point has to do with the question is at best unclear.

>If a pointer is not a data object

Since we defined it to be a data object, we need not worry about that.

>Also, data entity and data object are circularly defined:

Well, that is careless.

>data object (1.3.45) -> variable (1.3.54) -> data entity (1.3.44) ->
>data object (1.3.45).
>Is that a problem?

No.  Variable could be defined as "data object that ...", which is even more 
tightly circular, but anyway it is the "can be defined" etc. bit of the 
definition which is the important bit.

........................Malcolm Cohen, Nihon NAG, Tokyo. 

More information about the J3 mailing list