scratch file

EvalExample1.scala

import cats._

val eager = Eval.now {
  println("Hey !! I am eager eval")
  "Hello Eval Eager"
}

val lazyEval = Eval.later {
  println("Hey !! I am lazy eval")
  "Hello Eval Lazy"
}

val always = Eval.always {
  println("Hey !! I am always eval")
  "Hello Eval Always"
}

println(s"Eval Eager: ${eager}")
println(s"Eval Eager 1: ${eager.value}")
println(s"Eval Eager 2: ${eager.value}")
println(s"Eval Lazy: ${lazyEval}")
println(s"Eval Lazy 1: ${lazyEval.value}")
println(s"Eval Lazy 2: ${lazyEval.value}")
println(s"Eval Always: ${always}")
println(s"Eval Always 1: ${always.value}")
println(s"Eval Always 2: ${always.value}")

/* OUTPUT
Hey !! I am eager eval
Eval Eager: Now(Hello Eval Eager)
Eval Eager 1: Hello Eval Eager
Eval Eager 2: Hello Eval Eager
Eval Lazy: cats.Later@61a485d2
Hey !! I am lazy eval
Eval Lazy 1: Hello Eval Lazy
Eval Lazy 2: Hello Eval Lazy
Eval Always: cats.Always@39fb3ab6
Hey !! I am always eval
Eval Always 1: Hello Eval Always
Hey !! I am always eval
Eval Always 2: Hello Eval Always
*/