Example
#lang racket
(require mzlib/etc)
((rec sum-of-list
(λ (l)
(if (null? l)
0
(+ (car l) (sum-of-list (cdr l))))))
'(1 2 3 4 5))
;; => 15
;; Outside of the rec form, sum-of-list gives an error:
;; sum-of-list: undefined;
;; cannot reference an identifier before its definition
This is similar to define, but the sum-of-list identifier is not visible outside of the rec form.
To avoid using an explicit λ, it is possible to replace sum-of-list with (sum-of-list args ...):
#lang racket
(require mzlib/etc)
((rec (sum-of-list l)
(if (null? l)
0
(+ (car l) (sum-of-list (cdr l)))))
'(1 2 3 4 5))
;; => 15
