features.praia

// Test various Praia features

// Arithmetic & precedence
let x = 2 + 3 * 4
print("2 + 3 * 4 =", x)  // 14

// String interpolation with expressions
let name = "Praia"
let version = 1
print("%{name} v%{version}")

// Truthiness: only nil and false are falsy
if (1)     { print("1 is truthy") }
if ("")    { print("empty string is truthy") }
if (0)     { print("0 is truthy") }
if (nil)   { print("BUG: nil should be falsy") }
if (false) { print("BUG: false should be falsy") }

// elif
let score = 85
if (score >= 90) {
    print("A")
} elif (score >= 80) {
    print("B")
} elif (score >= 70) {
    print("C")
} else {
    print("F")
}

// Functions with return values
func fib(n) {
    if (n <= 1) { return n }
    return fib(n - 1) + fib(n - 2)
}
print("fib(10) =", fib(10))

// Closures
func makeCounter() {
    let count = 0
    func increment() {
        count = count + 1
        return count
    }
    return increment
}

let counter = makeCounter()
print(counter())
print(counter())
print(counter())

// Postfix increment
let i = 0
i++
i++
i++
print("After 3 increments:", i)