Name: bb33257 Date: 07/16/98


RuleBasedCollator has a set of complicated data structures that
it uses to store collation rules. These include a MergeCollation
object (and its subobjects), a CompactIntArray, and the contract
and expand tables, which are vectors of arrays.

Once a collator is built, all of this data is immutable. But
currently, it's not shared. This means that cloning a Collator
can take a long time. If we made the internal data shared, this
would be much, much faster. Since Collator.getInstance always
clones an object from its internal cache, this would have a big
perceived performance impact from the user's point of view.
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