If can be implemented as a primitive function instead of a special form given the fn operator. It could take three arguments: a condition, a then function, and an else function and then call the appropriate function. An example implementation is:
(def if2 (cond then else)
(if cond (then) (else)))
If2 would be given as a primitive function and its implementation would be hidden like that of cons is. Given access to if2, a basic if construct is:
(mac basic-if (cond then (o else))
`(if2 ,cond (fn () ,then) (fn () ,else)))
This would make code walkers easier because they wouldn't have to know about as many special forms.
