intern

Efficient hash-consing for arbitrary data types

BSD-3-Clause licensed by Edward A. Kmett

Maintained by Edward A. Kmett

This version can be pinned in stack with:intern-0.9.4@sha256:c7183d0794cae7c4bf6a96b4b891ed409d2e272ce965db8a381c633b79ca802b,1670

Depends on 6 packages(full list with versions):

Used by 2 packages in nightly-2021-02-23(full list with versions):

Efficient hash-consing for arbitrary data types.

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.

-Edward Kmett

Add Hashable instances for InternedString, InternedByteString, InternedText, and IntSet.

Removed identity from 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.