A-M baby

Task/Generator-Exponential/Go/generator-exponential-2.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+    "fmt"
+    "math"
+)
+
+func newPowGen(e float64) chan float64 {
+    ch := make(chan float64)
+    go func() {
+        for i := 0.; ; i++ {
+            ch <- math.Pow(i, e)
+        }
+    }()
+    return ch
+}
+
+// given two input channels, a and b, both known to return monotonically
+// increasing values, supply on channel c values of a not returned by b.
+func newMonoIncA_NotMonoIncB_Gen(a, b chan float64) chan float64 {
+    ch := make(chan float64)
+    go func() {
+        for va, vb := <-a, <-b; ; {
+            switch {
+            case va < vb:
+                ch <- va
+                fallthrough
+            case va == vb:
+                va = <-a
+            default:
+                vb = <-b
+
+            }
+        }
+    }()
+    return ch
+}
+
+func main() {
+    ch := newMonoIncA_NotMonoIncB_Gen(newPowGen(2), newPowGen(3))
+    for i := 0; i < 20; i++ {
+        <-ch
+    }
+    for i := 0; i < 10; i++ {
+        fmt.Print(<-ch, " ")
+    }
+    fmt.Println()
+}