performance - Why should recursion be preferred over iteration?

Question

Iteration is more performant than recursion, right? Then why do some people opine that recursion is better (more elegant, in their words) than iteration? I really don't see why some languages like Haskell do not allow iteration and encourage recursion? Isn't that absurd to encourage something that has bad performance (and that too when more performant option i.e. recursion is available) ? Please shed some light on this. Thanks.

Answer 1

Iteration is more performant than recursion, right?

Not necessarily. This conception comes from many C-like languages, where calling a function, recursive or not, had a large overhead and created a new stackframe for every call.

For many languages this is not the case, and recursion is equally or more performant than an iterative version. These days, even some C compilers rewrite some recursive constructs to an iterative version, or reuse the stack frame for a tail recursive call.