Initial data commit

Task/Generator-Exponential/Racket/generator-exponential.rkt

@@ -0,0 +1,23 @@
+#lang racket
+
+(require racket/generator)
+
+;; this is a function that returns a powers generator, not a generator
+(define (powers m)
+  (generator ()
+    (for ([n (in-naturals)]) (yield (expt n m)))))
+
+(define squares (powers 2))
+(define cubes   (powers 3))
+
+;; same here
+(define (filtered g1 g2)
+  (generator ()
+    (let loop ([n1 (g1)] [n2 (g2)])
+      (cond [(< n1 n2) (yield n1) (loop (g1) n2)]
+            [(> n1 n2) (loop n1 (g2))]
+            [else (loop (g1) (g2))]))))
+
+(for/list ([x (in-producer (filtered squares cubes) (lambda (_) #f))]
+           [i 30] #:when (>= i 20))
+  x)