University
of Washington • CSE583 • D. Notkin © 2000
12
Special forms
lStandard rule: evaluate all arguments
before invocation
–This is called eager
evaluation
lCan cause computational (and performance)
problems
lCan define your own
l(define x
0)
l(define y
5)
l(if (= x
0)0 (/ y x))
0 l(define (my-if c t e)
(if c t e)) l(my-if (= x 0)
0 (/ y x))
error!
l(fact 3)
