aiken/book/src/language-tour/blocks.md

Blocks

If statements

if condition {

} else {

}

Case Patterns

when color is {
    Green -> "Success."
    Blue -> "Warning."
    Red -> "Error!"
}

Let bindings with blocks

let num = -5
let absNum = if num>=0 {num} else {-num}

let message = when color is {
    Green -> "Success."
    Blue -> "Warning."
    Red -> "Error!"
}

Since everything is secretly a function, the last statement in any block is implicitly its return.