roddyyaga / bs-ppx_deriving_yojson

A Yojson codec generator for OCaml >= 4.02.

An npm package of the ppx_deriving_yojson plugin.

Usage

Add bs-deriving, @roddynpm/bs-yojson and @roddynpm/bs-ppx_deriving_yojson as dependencies in package.json and bs-dependencies in bsconfig.json. Additionally you must add "pp-flags": "@roddynpm/bs-ppx_deriving_yojson/ppx.exe" to bsconfig.json.

Limitations

The actual ppx rewriter is a hack (it is just the executable generated when a dummy project that uses ppx_deriving_yojson is built with dune). It was built on 64-bit Linux using OCaml 4.07.0, so if you have a setup that is incompatible with that you will need to create your own executable. This can be done with dune clean && dune build -- dummy/test.exe && cp _build/default/.ppx/*/ppx.exe . in the root of the package.

It is possible to use both this and ppx-deriving in the same project. To do this you should only include the "pp-flags": "@roddynpm/bs-ppx_deriving_yojson/ppx.exe" line in your bsconfig.json, and not the usual "ppx-flags": ... line for ppx-deriving. This is because the ppx-deriving executables don't contain the yojson deriver and so break on code that uses it. To allow both sets of derivers to be used together, the ppx executable in this package was built to include the standard ppx_deriving plugins.