// Single-Expression, Multi-Use Functions

// is the string representation of the argument non-empty?
fun hasLength(s: String) = s.length > 0

println(listOf("a", "bb", "ccc", "").map(::hasLength))
println(listOf("a", "bb", "ccc", "").filter(::hasLength))




















// single-use, anonymous function literals
// (aka lambda functions)

repeat(5, { println("👋") })

val nums = listOf(1, 3, 5)
println(nums)

// increment the numbers
val incremented = nums.map { 
    it + 1 
}
println("incremented: $incremented")

// sum the numbers
val summed = nums.fold(0, { sum, n -> sum + n })
println("summed: $summed")

// count the enumbers (just an example, should just .size)
val counted = nums.fold(0) { 
    count, _ -> count + 1 
}
println("counted: $counted")