The <span>letrec</span> namebinding construct

Introduction to Functional Programming in Scheme - slide 41 : 49

The letrec namebinding construct

The letrec name binding construct allows for definition of mutually recursive functions

 
(letrec ((n<sub>1</sub> e<sub>1</sub>)
         ...
         (n<sub>k</sub> e<sub>k</sub>))
    body-expr)

(letrec ((f1 (lambda (...) ... (f2 ...)))
         (f2 (lambda (...) ... (f1 ...)))
        )
  body-expr)

Characteristics of letrec
- Each of the name bindings have effect in the entire letrec construct, including e₁ ... e_k
- letrec can be implemented by assignments to the bound names