> Now that (nearly) every mainstream language has lambda expressions, there are very few patterns in functional programming that cannot be replicated in mainstr

> Now that (nearly) every mainstream language has lambda expressions, there are very few patterns in functional programming that cannot be replicated in mainstream languages, which means that moving to a pure functional language now provides strictly fewer choices when problem solving Those patterns in functional programming compose cleanly. They do not compose cleanly once you introduce imperative constructs, which is what you get if all you've done is important lambdas to your OO language, so you've presented a bit of a false choice. All you have is some surface semantics of FP but none of the deep reuse and top to bottom clean, understandable semantics.