gistfile1.js

var segments = Immutable.List()
undefined

segments
Object {size: 0, _origin: 0, _capacity: 0, _level: 5, _root: undefined…}

segments.push({id: 1, name: "Un"})
Object {size: 1, _origin: 0, _capacity: 1, _level: 5, _root: null…}

segments.push({id: 1, name: "Un"}).size
1

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).size
2

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).get(0)
Object {id: 1, name: "Un"}

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).get(1)
Object {id: 2, name: "Deux"}

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).splice(0, 1, {id:3, name: "Trois"})
Object {size: 2, _origin: 0, _capacity: 2, _level: 5, _root: null…}

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).splice(0, 1, {id:3, name: "Trois"}).get(1)
Object {id: 2, name: "Deux"}

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).splice(0, 1, {id:3, name: "Trois"}).get(0)
Object {id: 3, name: "Trois"}

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).splice(1, 1, {id:3, name: "Trois"}).get(0)
Object {id: 1, name: "Un"}

segments.push({id: 1, name: "Un"}).push({id: 2, name: "Deux"}).splice(1, 1, {id:3, name: "Trois"}).get(1)
Object {id: 3, name: "Trois"}