How do I do closures in Emacs Lisp?

Question

I\'m trying to create a function on the fly that would return one constant value.

In JavaScript and other modern imperative languages I would use closures:

Answer 1

Stupid idea: how about:

(defun foo (x)
  `(lambda () ,x))

(funcall (foo 10))  ;; => 10

Answer 2

Emacs lisp only has dynamic scoping. There's a lexical-let macro that approximates lexical scoping through a rather terrible hack.