This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.
Expresso is a minimal statically-typed functional programming language, designed with embedding and/or extensibility in mind.
Possible use cases for such a minimal language include configuration (à la Nix), data exchange (à la JSON) or even a starting point for a custom external DSL.