Using ppx_42: BuckleScript example

You can see an example of usage in a BuckleScript project in this folder. The most relevant point is the ppx-flags in bsconfig.json, that is pointing to the ppx executable:

  "ppx-flags": [
    "esy x ppx_42"
  ],

To install and build the ppx binary so it is available to bsb (BuckleScript build tool) in the the example app:

$ esy

Then you can run:

$ yarn build

or

$ npm build

At that point, you should see the file src/Index.bs.js with the following output:

// Generated by BUCKLESCRIPT VERSION 4.0.7, PLEASE EDIT WITH CARE
'use strict';


var fourtyTwo = String(42);

console.log(fourtyTwo);

exports.fourtyTwo = fourtyTwo;
/* fourtyTwo Not a pure module */