The Voyage

###Objects

• containers/Wrappers for values
• no methods
• not nouns (we won't have user object or blog object...)
• probably won't be making them your own very often

(uses the word functors for them.)

  var _Container = function (val) {
  this.val = val
}

  add(1,1)
// 2

You look at this will immediately know what it does. 

  // associative
add(add(1,2),4) == add(1, add(2,4))

// commulative
add(4,1) == add(1,4)

// identity
add(n, 0) == n

// distributive
multiply(2, add(3,4)) == add(multiply(2,3), multiply(2,4))

it's even polymorphic

  add('ta', 'cos')
//  tacos

add(9.2, 0.5)
// 9.7

add([1,2,3], [4,5,6])
// [1,2,3,4,5,6]

we can add anything together

Category theory

  compose :: (b -> c) -> (a -> b) -> (a -> c)

id :: a -> a

It's got laws and properties. It's polymorphic. 

The identity function

Category Laws

  // left identity
compose(id, f) == f

// right identity
compose(f, id) == f

// associativity
compose(compose(f, g), h) == compose(f, compose(g,h))

It doesn't matter how they are grouped. So we can grab out any group of arguments and create subcompositions. This comes from the associativity quality.