Re: Prototypes, /COPY and LIKE()

[Barbara Morris <bmorris@xxxxxxxxxx>]

Joe Pluta wrote:
> 
> I could include an externally described data structure, but now I'm
> looking at wasted storage and possible name space collisions.  Thus my
> dilemma.
> 
> My current thinking is to use a based external DS with a prefix.  This
> would "waste" only the space for a pointer, thus:
> 
> d __SCCKW       e ds                  extname(SCCKW) based(__)
> prefix(__)
> d SccIOKWClear    pr
> d   ID                                like(__KWDFID) value
> d   Format                            like(__KWFMT ) value

Joe, that's a good and standard technique, to use
based(always_the_same_namee) for anything that's only to be used as a
"type" definition.  The compiler won't allow __ as a name, though.

For the prefix, you might want to use the name of the structure, to
avoid name collisions.

d SCCKW_types   e ds                  extname(SCCKW)
based(type_defn_ptr)
D                                     prefix(SCCKW_types_)
d SccIOKWClear    pr
d   ID                                like(SCCKW_types_KWDFID) value
d   Format                            like(SCCKW_types_KWFMT ) value

Qualified wouldn't really get you much extra:

d SCCKW_types   e ds                  extname(SCCKW)
based(type_defn_ptr)
D                                     qualified
d SccIOKWClear    pr
d   ID                                like(SCCKW_types.KWDFID) value
d   Format                            like(SCCKW_types.KWFMT ) value

(Except you'd be able to tell for sure what was the DS name and what was
the subfield name, in cases where the subfield have underscores.)
d   Whatever                           like(SCCKW_types.KW_XYZ ) value
vs
d   Whatever                           like(SCCKW_types_KW_XYZ ) value