Elm

Functional language that compiles to js

• No runtime errors in practice. No null. No undefined is not a function.

• You must handle all cases, statically typed

Functions

Elm has implicit functions, cant change global variables in its

add : Int -> Int -> Int
add num1 num2 = num1 + num2

No loops in elm, currying by default(give one argument returns curried ft)

babyAnimals a b = "i love a" ++ a ++ " and " ++ b
babyKoalas = babyAnimals "koalas"
babyKoalas "puppies" -- "i love koalas and puppies"

Chaining so no unneeded variables(like lodash chain)

Types

Would have to deal with if mix every time

type Disposition = Surly | Friendly | Ambivalent | Mix Disposition Disposition
type alias Cat = {
    name: String,
    weight: Float,
    disposition: Disposition
}
seamus = Cat "Seamus" 22.2 Surly

Maybe

type Maybe a
   = Just a 
   | 

type alias User = 
{ name: String
  , age: Maybe Int
}

sue: User
sue = {name = "Sue", age = "Nothing"}
canBuyAlcohol user = 
  case user.age of 
    Nothing -> False
    Just age -> age >= 21

Json

Must decode and type JSON, must write decoder

Build for Production

elm-make src/Main.elm --output=build/main.js

<script src="Build/main.js"></script>
<script>
    const node = document.getElementbyId('main');
  const app = Elm.Main.embed(node);
</script>