Now I understand what you mean by cursors, setll, and setgt.

I posted a code example earlier, but i suppose it was rather cryptic.

cursor = rm_sll(rm_cur(map));
dow rm_rdn(cursor);
sum += rm_p_(rm_itm(cursor));
enddo;
rm_dis(cursor);

Explanation:
To iterate through all key/item pairs, procedure "rm_cur" creates a cursor,
"rm_sll" does a setll (set lower limit, without key so the cursor is set at
the beginning), "rm_rdn" (reads the next key/item pair) and "rm_itm"
returns the current item. "rm_sll" returns it's first argument which is the
cursor, to enable "chaining" of procedure calls. Procedure "rm_p_" is the
opposite of "rm_p" and converts a packed decimal value stored in the map to
a "normal" RPG packed decimal. "rm_dis" disposes the cursor.



On Wed, Jul 5, 2017 at 6:52 PM, John Yeung <gallium.arsenide@xxxxxxxxx>
wrote:

On Wed, Jul 5, 2017 at 11:43 AM, jacobus erps <jacobus.erps@xxxxxxxxx>
wrote:
Interesting. This is not my idea of a map, then. If you have two
identical keys, does a lookup always find the same one? Or can it
sometimes find one but sometimes find the other? Or do you get both
values back on the same operation?

On a "get", by default you get the first one, but you can choose to get
the
last one if you want.
Of course, you can iterate over all dup keys, starting with the first one
(setll), or the last one.(setgt).

Now I understand what you mean by cursors, setll, and setgt.

I am still a little puzzled by this:

The keys are mutable ifd they're maps, thats true.
Once inserted into the map, you shouldn't mutate the keys, of course.

So we *shouldn't* mutate the keys, but what if we do anyway? Can the
tree become corrupted?

John Y.
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