lambda

(lambda (params...) body...)

Creates an anonymous function with the given parameter list and body, closing over the lexical variables in scope. The body is not evaluated when the lambda is created; it runs each time the resulting function is called, returning the value of the last body form. The function value can be called with funcall/apply or passed to higher-order functions like mapcar. In call position a lambda form may also be used directly, e.g. ((lambda (x) x) 1).

The parameter list supports the same lambda-list keywords as defun (&optional, &rest, &key, &allow-other-keys, &aux):