Merge branch 'racket'

bernardosulzbach · Jul 19, 2013 · e7533ec · e7533ec
2 parents 8076772 + 61faa58
commit e7533ec
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diff --git a/lib/rouge/demos/racket b/lib/rouge/demos/racket
@@ -0,0 +1,24 @@
+#lang racket
+
+;; draw a graph of cos and deriv^3(cos)
+(require plot)
+(define ((deriv f) x)
+  (/ (- (f x) (f (- x 0.001))) 0.001))
+(define (thrice f) (lambda (x) (f (f (f x)))))
+(plot (list (function ((thrice deriv) sin) -5 5)
+            (function cos -5 5 #:color 'blue)))
+
+;; Print the Greek alphabet
+(for ([i (in-range 25)])
+  (displayln
+   (integer->char
+    (+ i (char->integer #\u3B1)))))
+
+;; An echo server
+(define listener (tcp-listen 12345))
+(let echo-server ()
+  (define-values (in out) (tcp-accept listener))
+  (thread (λ ()
+             (copy-port in out)
+             (close-output-port out)))
+  (echo-server))