for-loop.swift

/**
 A for-loop using functions to evaluate and express the conditions and statements.
 
 - parameters:
    - initialize: A function that initializes a variable or tuple.
    - condition: The loop condition evaluated after each loop.
    - increment: The increment statement to move the loop closer to completion
    - body: The loop body.
 */
func loop<T>(initialize: () -> (T), condition: (T)->(Bool), increment: (T)->(T), body: (T)->()) {
    var data = initialize()
    while(condition(data)) {
        body(data)
        data = increment(data)
    }
}

// Example call with one variable.
loop(initialize: { 0 }, condition: { $0 < 10 }, increment: { $0 + 1 }) {
    print($0)
}

// Example call with two variables.
loop(initialize: { (0, 0) }, condition: { $0.0 < 10 }, increment: { ($0.0 + 1, $0.1 + 2) }) {
    print("\($0.0)\t\($0.1)")
}