RE: Opinions Wanted: List API loop logic

[Scott Klement <klemscot@xxxxxxxxxxxx>]

Hi Joe,

Just curious, but doing it that way, why not use a MODS or an array of
qualified structures?  Then you wouldn't have to use pointer math to walk
through the list.  (Though, you'd still have to use it to set the start of
the list.)

I was actually using this with the system "List APIs" however, and the
size of each entry is not necesarily a fixed number.  (or, even if it is,
it can change from release to release, which would break the code the way
you've written it)

Thanks for the input!



> If your entries have a predefined size and you're using an externally
> described data structure to access them, I have a rather elegant way to
> do it (at least IMHO):
>
> d Entry         e ds                  extname(myEntry)
> d                                     based(p_Entry)
> d Entries         s                   like(Entry) dim(MAX)
> d                                     based(p_Entries)
>
> c                   eval      pEntries = p_ListHeader + DataOff
> c                   for       EntryNo = 1 to NumEntries
> c                   eval      pEntry = %addr(Entries(EntryNo))
>    (process entry)
> c                   endfor
>
> Set MAX to some reasonable maximum value, and voila, you should have no
> problems.  (Famous last words!)