Maybe.js

var Maybe = function(x) {
  this.__value = x;
}

Maybe.of = function(x) {
  return new Maybe(x)
}

Maybe.prototype.isNothing = function() {
  return (this.__value === null || this.__value === undefined)
}

Maybe.prototype.map = function(f) {
  return this.isNothing() ? Maybe.of(null) : Maybe.of(f(this.__value))
}

const print = (f) => console.log(f)


var double = Maybe.of(3).map(function(value) {
  return value + 3 ;
})

print(double)

var uppercaser = Maybe.of("Salman The Brown Fish").map(function(val) {
  return val.toUpperCase()
})

print(uppercaser)


var noValue = Maybe.of().map(function(value) {
  return value + 3 ;
})

print(noValue)

Tupperware.js

var Container = function(x) {
  this.__value = x;
}

Container.of = function(x) { return new Container(x) }

const print = (f) => console.log(f)

print(Container.of(3))
// Container of string
print(Container.of('pizza'))
// Container of Container
print(Container.of(Container.of({name: 'Kiki', age: 21})))

// (a -> b) -> Container a -> Container b
Container.prototype.map = function(F) {
  return Container.of(F(this.__value))
}

var double = Container.of(3).map(function(value) {
  return value + 3 ;
})

print(double)

var uppercaser = Container.of("Salman The Brown Fish").map(function(val) {
  return val.toUpperCase()
})

print(uppercaser)