Lambda Functions
An expression (lambda args code) is a way of producing an anonymous procedure (one without a name). In fact, the following do the same thing:
(define (sum x y) (+ x y)) (define sum (lambda (x y) (+ x y)))
A lambda expression can be used as a procedure:
> ((lambda (x) (+ x x)) 4) 8
lambda expressions are especially useful with functions such as map:
> (map (lambda (x) (+ x 2)) '(1 2 3)) (3 4 5)> (some odd? '(a b 2 3)) *** ERROR -- INTEGER expected
> (some (lambda (x) (and (integer? x) (odd? x))) '(a b 2 3)) #t