Which languages support *recursive* function literals / anonymous functions?

Question

It seems quite a few mainstream languages support function literals these days. They are also called anonymous functions, but I don\'t care if they have a name. The important th

Answer 1

You've mixed up some terminology here, function literals don't have to be anonymous.

In javascript the difference depends on whether the function is written as a statement or an expression. There's some discussion about the distinction in the answers to this question.

Lets say you are passing your example to a function:

foo(function(n){if (n<2) {return 1;} else {return n * arguments.callee(n-1);}});

This could also be written:

foo(function fac(n){if (n<2) {return 1;} else {return n * fac(n-1);}});

In both cases it's a function literal. But note that in the second example the name is not added to the surrounding scope - which can be confusing. But this isn't widely used as some javascript implementations don't support this or have a buggy implementation. I've also read that it's slower.

Anonymous recursion is something different again, it's when a function recurses without having a reference to itself, the Y Combinator has already been mentioned. In most languages, it isn't necessary as better methods are available. Here's a link to a javascript implementation.