Data commit

Task/Compile-time-calculation/Racket/compile-time-calculation.rkt

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+#lang racket
+
+;; Import the math library for compile-time
+;; Note: included in Racket v5.3.2
+(require (for-syntax math))
+
+;; In versions older than v5.3.2, just define the function
+;; for compile-time
+;;
+;; (begin-for-syntax
+;;   (define (factorial n)
+;;     (if (zero? n)
+;;         1
+;;         (factorial (- n 1)))))
+
+;; define a macro that calls factorial at compile-time
+(define-syntax (fact10 stx)
+  #`#,(factorial 10))
+
+;; use the macro defined above
+(fact10)