Summary

A Haskell implementation of JSON Schema (Draft 4).

Hackage / GitHub / Travis CI

Example

See here.

Design

hjsonschema was an attempt to build a very modular JSON Schema library. Validators have a concrete type and can be mixed and matched into new Specs.

However this flexibility comes at the price of complicating the code. I'm no longer sure it was the right tradeoff, especially since situations where you'd want to change what validators make up a Spec at runtime seem rare.

Also, there are edge cases of JSON Schema that hjsonschema doesn't implement properly (as you can see from the issue tracker). My motivation to fix them myself has ended. However, I'll still maintain the library, give feedback on issues, and merge PRs. I'd also be happy to advise any Haskellers who are interested in writing their own JSON Schema libraries.

System dependencies

• Requires pcre (pkgs.pcre in Nixpkgs).

Tests

Run all: stack test

Run only local tests: stack test hjsonschema:local

Run only remote tests (temporarily starts an HTTP server on port 1234 and makes GETs to json-schema.org): stack test hjsonschema:remote

Vendoring

• JSON-Schema-Test-Suite is vendored from commit # c1b12bf699f29a04b4286711c6e3bbfba66f21e5 here.

• src/draft4.json is from commit # c1b12bf699f29a04b4286711c6e3bbfba66f21e5 here. The root ref in remote ref test has been modified to fix #175.

• .travis.yml was created with make_travis_yml_2.hs commit # ea6c7d177a97bfbfb2fdc4deba943d60d2aff199.