0.9.2

• Add a Semigroup IntSet instance.

0.9

• Removed identity from the Interned class, to support applications where the identity is obtained by other means (e.g. a unique Ptr value)

0.8

• Disabled cache removal as it was causing problems on large data sets. There is no good way to ensure that both references remain alive long enough to finish comparisons.
• Switched to IORef from MVar

0.7

• Fixed problem where comparisons could happen between data structures while one was still a thunk, leading to equal structures comparing as inequal in limited circumstances, by appropriately using strictness annotations.

0.6

• Widened the caches so they don't go through a single MVar per type. This has made a dramatic impact on performance. However, this broke the previous invariant that newer entries always had higher Ids than older entries.

0.5.2

• Added Data.Interned.IntSet