ES class support

[bobzhang]

taken from #401, #149

The goal is to allow people to create es class in a type safe way, mostly code pattern as below:

function Set(data){
  this.data = data 
}
Set.prototype.toString = function(){
   return "" + this.data
}

inheritance support is a non-goal

[IwanKaramazow]

@bobzhang Have you had any more thoughts on improving this api?

It's quite cumbersome to extend a prototype at the moment:

type pluginPrototype;

%raw
"function AssetPlugin(config) {
  this.config = config;
}";


type t = {. [@bs.set] "prototype": pluginPrototype};

[@bs.val] external assetPlugin : t = "AssetPlugin";

[@bs.set]
external setApply :
  (
    pluginPrototype,
    [@bs.this] ((pluginPrototype, Bundler.compiler) => unit)
  ) =>
  unit =
  "apply";

[@bs.get] external config : pluginPrototype => Plugin.config = "config";

setApply(assetPlugin##prototype, [@bs.this] (self, compiler) =>
  compiler##hooks##afterEmit##tapAsync("4AssetPlugin", (compilation, cb) => {
    let c = config(self);
    let assetJson = Plugin.buildAssetJson(compilation);
    let rawAssetJson = Js.Json.stringify(Obj.magic(assetJson));
    Node.Fs.writeFileAsUtf8Sync(c##path ++ "test", rawAssetJson);
    cb(.);
  })
);

[@bs.new] external makeInstance : Plugin.config => t = "AssetPlugin";

This results in the following code, which is what I want actually:

function AssetPlugin(config) {
  this.config = config;
}
AssetPlugin.prototype.apply = function(compiler) {
  var self = this;
  return compiler.hooks.afterEmit.tapAsync("4AssetPlugin", function(compilation, cb) {
    var c = self.config;
    var assetJson = Plugin.buildAssetJson(compilation);
    var rawAssetJson = JSON.stringify(assetJson);
    Fs.writeFileSync(c.path + "test", rawAssetJson, "utf8");
    return cb();
  });
};

Couple of thoughts:

• It would be convenient if we could generate the piece of code currently in %raw from within ocaml * Reusing classes from ocaml would be a nice property. I.e. I don't want to write an external for every method I need to set on the prototype.
• The above ffi code is way to complex & can be accomplished in multiple ways.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.