6: Laziness
Suggested reading: In the first lesson, I mentioned that Haskell is lazy, and promised to eventually explain in more…www.schoolofhaskell.com Side effects and purity So, what’s really at issue here is the presence or absence of side effects. By “side effect” we mean anything that causes evaluation of an expression to interact with something outside itself. The root issue is that such outside interactions are time-sensitive. For example: