2017-02-25

stuff.js

Graph : 
  (Cell (->) a b) -> 
  (Cell (->) b c) -> 
  Either (a, Either (b, c)) -> 
  Either (a, Either (b, c))

Left.of(a, Left.of(b, c))
        A  B

Right.of([A, either(first)(first)(B)])

g = Graph(add1)(mul3)

Graph(
  Right.of([
    1,
    Left.of([2, 6])
  ])
)

h = Graph(add100, g)

h(
  Right.of([
    1,
    Right.of([
      100, 
      Left.of([
        101, 
        Left.of([
          102, Left.of(306)])
      ])
    ])
  ])
)

---

Cell -> List ChainCell -> Either (a, List Either b)

---

Cell : (a -> b) -> Either (a, b) -> Either (a, b)

Effect = f (State) BUT
State = PrevState & Diff / NextState

Effect 

// const add1Cell = Cell( add(1) )
// const multiply2Cell = Cell( multiply(2) )
// 
// add1Cell.compose(multiply2Cell)(Right([1, 2])) => Right([2, 3])
Graph([
  Right.of([1, null]),
  [
    [
      Right.of([null, null]),
      [
        Right.of([null, null])
        Right.of([null, null])
      ]
    ],
    Right.of([null, null])
  ]
])

// => 
Left.of([
  [1, null],
  [
    [
      [2, null],
      [
        [5, null],
        [5, null]
      ]
    ],
    [2, null]
  ]
])

Right.of([
  [1, 2],
  [
    Right.of([
      [2, null],
      [
        Left.of([5, null]),
        Left.of([5, null])
      ]      
    ]),
    Left.of([2, null])
  ]
])

[
  Right.of([1, 2]),
  [
    [
      Right.of([2, null]),
      [
        Left.of([5, null]),
        Left.of([5, null])
      ]      
    ],
    Left.of([2, null])
  ]
]

Graph : (Cell, Cell) -> Either ( Either (a, b), Either (c, d) )

mATH()
Graph : (Cell, Graph)

[a, b] => 
  Right.of([
    Right.of([1, 2]),
    Right.of([
      2
      Right.of(3, 4)]
    ])
  ])

  => [
    1
    Right.of([2, 3])
  ]

graph (2) = [
  Left.of([1, 2]),
  [
    [
      Left.of([2, null]),
      [
        Left.of([5, null]),
        Left.of([5, null])
      ]      
    ],
    Left.of([2, null])
  ])
]

graph (3) = [
  Left.of([1, 2]),
  [
    [
      Left.of([2, null]),
      [
        Left.of([5, null]),
        Left.of([5, null])
      ]      
    ],
    Left.of([2, null])
  ]
]

const Branch = (north, west, east) => ({
  '@@value': {north, west, east},
  '@@type': Symbol.for('Branch'),
  fold: f => f(north),
  map: f => {
    const newBranch = f({north, west['@@value'].north, east['@@value'].north})

    const newWest = match({
      Branch: x => Branch(
        newBranch.west, 
        west['@@value'].west, 
        west['@@value'].east
      ),
      Leaf: x => Leaf(newBranch.west)
    })(west)

    const newEast = match({
      Branch: x => Branch(
        newBranch.east, 
        east['@@value'].west, 
        east['@@value'].east
      ),
      Leaf: x => Leaf(newBranch.east)
    })(west)

    return Branch(newBranch.north, newWest.map(f), newEast.map(f))
  }
})

const Leaf = (north) => ({
  '@@value': {north},
  '@@type': Symbol.for('Leaf'),
  fold: f => f(north),
  map: f => Leaf(f({north}).north)
})

const myTree = Branch(
  1,
  Branch(3, 5, 4),
  Leaf(6)
)

myTree.map(({north, west, east}) => ({
  north: north,
  west: north + west,
  east: north + east
}))

Branch(
  1, 
  Branch(4, 9, 8),
  7
)