crocks/Endo/index.js

A collection of well known Algebraic Datatypes for your utter enjoyment.

/** @license ISC License (c) copyright 2017 original and current authors */
/** @author Ian Hofmann-Hicks (evil) */

var VERSION = 2

var _implements = require('../core/implements')
var _inspect = require('../core/inspect')
var type = require('../core/types').type('Endo')
var _type = require('../core/types').typeFn(type(), VERSION)
var fl = require('../core/flNames')

var compose = require('../core/compose')
var isFunction = require('../core/isFunction')
var isSameType = require('../core/isSameType')

var _empty =
  function () { return Endo(function (x) { return x; }); }

function Endo(runWith) {
  var obj;

  if(!isFunction(runWith)) {
    throw new TypeError('Endo: Function value required')
  }

  var valueOf =
    function () { return runWith; }

  var empty =
    _empty

  var inspect =
    function () { return ("Endo" + (_inspect(valueOf()))); }

  function concat(method) {
    return function(m) {
      if(!isSameType(Endo, m)) {
        throw new TypeError(("Endo." + method + ": Endo required"))
      }

      return Endo(compose(m.valueOf(), valueOf()))
    }
  }

  return ( obj = {
    inspect: inspect, toString: inspect,
    valueOf: valueOf, type: type, empty: empty, runWith: runWith,
    concat: concat('concat')
  }, obj[fl.empty] = empty, obj[fl.concat] = concat(fl.concat), obj['@@type'] = _type, obj.constructor = Endo, obj )
}

Endo['@@implements'] = _implements(
  [ 'concat', 'empty' ]
)

Endo.empty = _empty
Endo.type = type

Endo[fl.empty] = _empty
Endo['@@type'] = _type

module.exports = Endo