Rel8 1.8 released!

The Rel8 team released Rel8 1.8, a Haskell library for interacting with PostgreSQL built on top of Opaleye, adding Rel8.TH.deriveRel8able and Rel8.TH.deriveRel8ables for deriving Rel8able instances via TemplateHaskell. The release notes state the new TemplateHaskell deriving can be significantly faster than Generics, with testing showing 80% reductions in build time. Rel8 1.8 also adds Conflict and Index types, notElem and notElem1 to Rel8.Array, preliminary PostgreSQL range support, GHC-9.14 support, and requires at least opaleye version 0.10.8.0.

TeofilC https://discourse.haskell.org/u/TeofilC 1 Hi folks We’re happy to announce the release of Rel8 1.8 https://hackage.haskell.org/package/rel8-1.8.0.0 Rel8 is a Haskell library for interacting with PostgreSQL databases, built on top of the fantastic Opaleye library. The main objectives of Rel8 are: - Conciseness: Users using Rel8 should not need to write boiler-plate code. By using expressive types, we can provide sufficient information for the compiler to infer code whenever possible. - Inferrable: Despite using a lot of type level magic, Rel8 aims to have excellent and predictable type inference. - Familiar: writing Rel8 queries should feel like normal Haskell programming. I would like to highlight the new TH deriving functionality. This has been a long time coming, and can give very significant compile-time improvements. In the wild, I have seen it reduce the time taken to compile a module by 80%. It doesn’t yet support all of the use-cases of Generics deriving and is somewhat experimental, so feedback is greatly appreciated If you encounter any issues please let us know https://github.com/circuithub/rel8/issues . Here’s the full changelog for this release: - Added Rel8.TH.deriveRel8able and Rel8.TH.deriveRel8ables for deriving Rel8able instances using TemplateHaskell . This can be significantly faster than using Generics . In testing, we have seen 80% reductions in build time - Expose all rel8 internal modules from the rel8-internal package. - Added new Conflict and Index types. Conflict represents a conflict target https://www.postgresql.org/docs/current/sql-insert.html SQL-ON-CONFLICT in an ON CONFLICT . It can be either a named constraint ON CONSTRAINT or a an Index . - Added Index . Index is a description of a unique index which PostgreSQL can use for unique index inference . This is an alternative to specifying an explicit named constraint in a conflict target . - Add notElem and notElem1 to Rel8.Array - Added preliminary support for PostgreSQL ranges. - Support GHC-9.14 and semialign = 1.4 . - Added notElem and notElem1 to Rel8.Array . - Added DBType Aeson.Object instance. - Bumped a variety of bounds. - The Upsert type was changed. Previously it had the columns index , predicate of what is now the Index type baked into its record. It now instead has a single conflict column of type Conflict , which can be either an Index or a named constraint . - The DoNothing constructor of OnConflict was changed to also take an optional Conflict value. Even though ON CONFLICT DO NOTHING does not generally require a conflict target , there are cases where it can be necessary, e.g., if you have table that has both deferrable and non-deferrable constraints. - rel8 now requires at least version 0.10.8.0 of opaleye - elem and elem1 now use IS NOT DISTINCT FROM semantics matching ==. when the element type is nullable, so null is found in an array containing null . Previously they were implemented with the array containment operator <@ , which never matches null . - Fixed some issues around the truncation of long column names. - Improved documentation. 21 Likes jackdk https://discourse.haskell.org/u/jackdk 2 rel8 is my favourite Haskell DB library because it’s managed to avoid becoming a type labyrinth most of the time, but you still get a lot of power and safety. Congrats on the new release.