Describes the usage of non-strict functions in scala using lazy and => syntax.

lazy_eval_functions.scala

//passing functions as params and executing them when required
def if2[A](cond: Boolean, onTrue: () => A, onFalse: () => A): A ={
 if (cond) onTrue() else onFalse()
}

//=> using arrow syntax pass params as unevaluated but they will be 
//evaluated once they are referenced no need to mention () to execute them
def if2[A](cond: Boolean, onTrue: => A, onFalse: => A): A ={
if (cond) onTrue else onFalse
}


def maybeTwice(b: Boolean, i: => Int) = {
if (b) i+i else 0
}

val x = maybeTwice(true, { println("hi"); 1+41 })
//hi
//hi
//x: Int = 84


//Using lazy with => syntax you can pass functions unevaluated and return values
//unevaluated which will be evaluated once referenced
def maybeTwice2(b: Boolean, i: => Int) = {  
  lazyvalj = i
  if (b) j+j else 0
}
//maybeTwice: (b: Boolean, i: => Int)Int
val x = maybeTwice2(true, { println("hi"); 1+41 })
//hi
//x: Int = 84