if

Conformance: R5RS Scheme

Purpose: Conditional evaluation.

Arguments:
P - predicate
C - consequent
A - alternative

Model:

(define-syntax if
  (syntax-rules ()
    ((_ p c a)
       (cond (p c) (else a)))))

Implementation:

; This syntax transformer is part of the primitive syntax.

Example:

(if #t 'true 'false) 
=> true

See also:
case.