-

private/utils.rkt

@@ -0,0 +1,64 @@
+#lang racket/base
+
+
+(provide while
+       until
+       get-lib-path
+       do-for
+       )
+
+(define-syntax while
+(syntax-rules ()
+  ((_ cond body ...)
+   (letrec ((while-f (lambda (last-result)
+                       (if cond
+                           (let ((last-result (begin
+                                                body
+                                                ...)))
+                             (while-f last-result))
+                           last-result))))
+     (while-f #f))
+   )
+  ))
+
+(define-syntax until
+(syntax-rules ()
+  ((_ cond body ...)
+   (letrec ((until-f (lambda (last-result)
+                       (if cond
+                           last-result
+                           (let ((last-reult (begin
+                                               body
+                                               ...)))
+                             (until-f last-result))))))
+     (until-f #f)))))
+
+(define-syntax do-for
+(syntax-rules ()
+  ((_ (init cond next) body ...)
+   (begin
+     init
+     (letrec ((do-for-f (lamba ()
+                               (if cond
+                                   (begin
+                                     (begin
+                                       body
+                                       ...)
+                                     next
+                                     (do-for-f))))))
+       (do-for-f))))))
+
+(define (get-lib-path lib)
+(let ((platform (system-type)))
+  (cond
+    [(eq? platform 'windows) 
+     (let ((try1 (build-path (current-directory) ".." "lib" "dll" lib))
+           (try2 (build-path (current-directory) "lib" "dll" lib)))
+       (if (file-exists? try1)
+           try1
+           try2)
+       )]
+    [else
+     (error (format "Install the shared library: ~a" lib))]
+    )))
+