Data commit

Task/Anonymous-recursion/Go/anonymous-recursion-1.go

@@ -0,0 +1,45 @@
+package main
+
+import "fmt"
+
+func main() {
+    for _, n := range []int{0, 1, 2, 3, 4, 5, 10, 40, -1} {
+        f, ok := arFib(n)
+        if ok {
+            fmt.Printf("fib %d = %d\n", n, f)
+        } else {
+            fmt.Println("fib undefined for negative numbers")
+        }
+    }
+}
+
+func arFib(n int) (int, bool) {
+    switch {
+    case n < 0:
+        return 0, false
+    case n < 2:
+        return n, true
+    }
+    return yc(func(recurse fn) fn {
+        return func(left, term1, term2 int) int {
+            if left == 0 {
+                return term1+term2
+            }
+            return recurse(left-1, term1+term2, term1)
+        }
+    })(n-2, 1, 0), true
+}
+
+type fn func(int, int, int) int
+type ff func(fn) fn
+type fx func(fx) fn
+
+func yc(f ff) fn {
+    return func(x fx) fn {
+        return x(x)
+    }(func(x fx) fn {
+        return f(func(a1, a2, a3 int) int {
+            return x(x)(a1, a2, a3)
+        })
+    })
+}

Task/Anonymous-recursion/Go/anonymous-recursion-2.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+)
+
+func fib(n int) (result int, err error) {
+	var fib func(int) int // Must be declared first so it can be called in the closure
+	fib = func(n int) int {
+		if n < 2 {
+			return n
+		}
+		return fib(n-1) + fib(n-2)
+	}
+
+	if n < 0 {
+		err = errors.New("negative n is forbidden")
+		return
+	}
+
+	result = fib(n)
+	return
+}
+
+func main() {
+	for i := -1; i <= 10; i++ {
+		if result, err := fib(i); err != nil {
+			fmt.Printf("fib(%d) returned error: %s\n", i, err)
+		} else {
+			fmt.Printf("fib(%d) = %d\n", i, result)
+		}
+	}
+}