13 Jun
2010
13 Jun
'10
10:16 a.m.
Philippa Cowderoy wrote:
On 13/06/2010 14:52, Andrew Coppin wrote:
Marc Weber wrote:
Does anybody have a less-insane way of doing this?
Sure: type MyMap = Map (KeyID, Key) Value
Don't use multiple keys. Put the keys into a tuple and use that as key.
Let me know whether this is what you were looking for.
Trouble is, this requires you to have *all* the keys to perform a single lookup. You can't do a lookup on just one attribute.
No it doesn't - think sum/or, not product/and, your tuple's (KeyID, Key) not (Key1, Key2, Key3...).
Oh, I see - so you enter (1, author), (2, date), (3, time), etc? That then requires all keys to have the same type - although I think for my needs I can put together an ADT to fix that...