burger-1.ts

// getEmptyPlate :: IxBurgerBuilder Ready EmptyPlate BurgerSpec
// getEmptyPlate = IxBurgerBuilder mempty
const getEmptyPlate = new IxBurgerBuilder<Ready, EmptyPlate, BurgerSpec>([]);

// addIngredient :: forall i o. String -> BurgerSpec -> IxBurgerBuilder i o (BurgerSpec)
// addIngredient x xs = IxBurgerBuilder $ Ingredient x : xs
const addIngredient = <I, O>(s: string) => (spec: BurgerSpec) => new IxBurgerBuilder<I ,O, BurgerSpec>(spec.concat([s]));

// -- ADDING THE BUN
// placeEmptyBun :: BurgerSpec -> IxBurgerBuilder EmptyPlate BottomBunOn BurgerSpec
// placeEmptyBun = addIngredient "Bottom Bun"
const placeEmptyBun = addIngredient<EmptyPlate, BottomBunOn> ("Bottom Bun")

// -- ADD SOME SAUCES DIRECTLY ON THE BOTTOM BUN
// addKetchup :: BurgerSpec -> IxBurgerBuilder BottomBunOn BottomBunOn BurgerSpec
// addKetchup = addIngredient "Ketchup"
const addKetchup = addIngredient<BottomBunOn, BottomBunOn> ("Ketchup")

const addMayo = addIngredient<BottomBunOn, BottomBunOn> ("Mayo")

const addMustard = addIngredient<BottomBunOn, BottomBunOn> ("Mustard")

// -- PUT THE PATTY ON, NO MORE SAUCES
// addPatty :: BurgerSpec -> IxBurgerBuilder BottomBunOn PattyOn BurgerSpec
// addPatty = addIngredient "Patty"
const addPatty = addIngredient<BottomBunOn, PattyOn> ("Patty")

// -- NEXT IS THE CHEESE, OR NONE
// addCheese :: BurgerSpec -> IxBurgerBuilder PattyOn CheeseOn BurgerSpec
// addCheese = addIngredient "Cheese"
const addCheese = addIngredient<PattyOn, CheeseOn> ("Cheese")

// noCheese :: BurgerSpec -> IxBurgerBuilder PattyOn CheeseOn BurgerSpec
// noCheese = IxBurgerBuilder
const noCheese = (spec: BurgerSpec) => new IxBurgerBuilder<PattyOn, CheeseOn, BurgerSpec>(spec);

// addOnions :: BurgerSpec -> IxBurgerBuilder CheeseOn OnionOn BurgerSpec
// addOnions = addIngredient "Onion"
const addOnions = addIngredient<CheeseOn, OnionOn> ("Onion")

// noOnions :: BurgerSpec -> IxBurgerBuilder CheeseOn OnionOn BurgerSpec
// noOnions = IxBurgerBuilder
const noOnions = (spec: BurgerSpec) => new IxBurgerBuilder<CheeseOn, OnionOn, BurgerSpec>(spec);

// -- THEN LETTUCE, OR NONE
// addLettuce :: BurgerSpec -> IxBurgerBuilder OnionOn LettuceOn BurgerSpec
// addLettuce = addIngredient "Lettuce"
const addLettuce = addIngredient<OnionOn, LettuceOn> ("Lettuce")

// noLettuce :: BurgerSpec -> IxBurgerBuilder OnionOn LettuceOn BurgerSpec
// noLettuce = IxBurgerBuilder
const noLettuce = (spec: BurgerSpec) => new IxBurgerBuilder<OnionOn, LettuceOn, BurgerSpec>(spec);

// -- THEN TOMATO, OR NONE
// addTomato :: BurgerSpec -> IxBurgerBuilder LettuceOn TomatoOn BurgerSpec
// addTomato = addIngredient "Tomato"
const addTomato = addIngredient<LettuceOn, TomatoOn> ("Tomato")

// noTomato :: BurgerSpec -> IxBurgerBuilder LettuceOn TomatoOn BurgerSpec
// noTomato = IxBurgerBuilder
const noTomato = (spec: BurgerSpec) => new IxBurgerBuilder<LettuceOn, TomatoOn, BurgerSpec>(spec);

// -- THEN FINISH THE BURGER WITH THE TOP BUN
// addTopBun :: BurgerSpec -> IxBurgerBuilder TomatoOn TopBunOn BurgerSpec
// addTopBun = addIngredient "TopBun"
const addTopBun = addIngredient<TomatoOn, TopBunOn> ("TopBun")