JavaScript Partial Application with Objects

obind.js

// NOTE: Requires Object.assign (you might need a polyfill)

Function.prototype.obind = function (ctx, obj) {
  var f = this
  var args = arguments
  return function () {
    arguments[0] = Object.assign(obj, arguments[0])
    return f.apply(ctx, arguments)
  }
}

// Example use:
var add = function (params) {
  return params.x + params.y
}
var add10 = add.obind({ x: 10 })
add10({ y: 20 }) //=> 30