Syntax
- -- defining a function with no arguments looks the same as simply defining a value
language = "Elm"
- -- calling a function with no arguments by stating its name
language
- -- parameters are separated by spaces and follow the function's name
add x y = x + y
- -- call a function in the same way
add 5 2
- -- partially apply a function by providing only some of its parameters
increment = add 1
- -- use the |> operator to pass the expression on the left to the function on the right
ten = 9 |> increment
- -- the <| operator passes the expression on the right to the function on the left
increment <| add 5 4
- -- chain/compose two functions together with the >> operator
backwardsYell = String.reverse >> String.toUpper
- -- the << works the same in the reverse direction
backwardsYell = String.toUpper << String.reverse
- -- a function with a non-alphanumeric name in parentheses creates a new operator
(#) x y = x * y
ten = 5 # 2
- -- any infix operator becomes a normal function when you wrap it in parentheses
ten = (+) 5 5
- -- optional type annotations appear above function declarations
isTen : Int -> Bool
isTen n = if n == 10 then True else False
