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...

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