bytecount->string, when/splice

misc.rkt

@@ -1,9 +1,13 @@
 #lang racket/base
+(require (for-syntax racket/base))
 (require racket/contract)
 
+(provide (contract-out
+          [bytecount->string (integer? . -> . string?)])
+          when/splice)
+
 ;; convert a bytecount into a string
-(define/contract (bytecount->string bytecount)
-  (integer? . -> . string?)
+(define (bytecount->string bytecount)
   (define (format-with-threshold threshold suffix)
     ;; upconvert by factor of 100 to get two digits after decimal
     (format "~a ~a" (exact->inexact (/ (round ((* bytecount 100) . / . threshold)) 100)) suffix))
@@ -24,4 +28,7 @@
 ;; for use inside quasiquote
 ;; instead of ,(when ...) use ,@(when/splice ...)
 ;; to avoid voids
-(define-syntax-rule (when/splice test body) (if test (list body) '()))
+(define-syntax (when/splice stx)
+  (syntax-case stx ()
+    [(_ test body)
+      #'(if test (list body) '())]))