identityfrom the Interned class, to support applications where the identity is obtained by other means (e.g. a unique Ptr value)
- 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
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.
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.
- Added Data.Interned.IntSet