Switch from a map to a string slice..

benchmark perf is more than double (334ns/op -vs- 734ns/op)

secret_handshake.go

@@ -13,31 +13,29 @@ const (
 // Handshake receives an integer argument and returns a string slice with
 // the code words in the proper sequence.
 func Handshake(i int) (h []string) {
-	m := map[int]string{
-		wnk: "wink",
-		bli: "double blink",
-		clo: "close your eyes",
-		jmp: "jump",
-	}
+	// Store the handshake phrases in a string slice (maps are slow).
+	s := []string{"wink", "double blink", "close your eyes", "jump"}
 
-	// Return the original empty slice if the integer is negative.
+	// Return the original nil slice if the integer is negative.
 	if i < 0 {
 		return h
 	}
 
+	// Build the slice by bitmasking the integer.
 	if i&wnk != 0 {
-		h = append(h, m[wnk])
+		h = append(h, s[0])
 	}
 	if i&bli != 0 {
-		h = append(h, m[bli])
+		h = append(h, s[1])
 	}
 	if i&clo != 0 {
-		h = append(h, m[clo])
+		h = append(h, s[2])
 	}
 	if i&jmp != 0 {
-		h = append(h, m[jmp])
+		h = append(h, s[3])
 	}
 
+	// Reverse the slice if the 5th bit is set.
 	if i&rev != 0 {
 		for i, j := 0, len(h)-1; i < j; i, j = i+1, j-1 {
 			h[i], h[j] = h[j], h[i]
@@ -50,4 +48,4 @@ func Handshake(i int) (h []string) {
 // Revision 1 benchmark:
 //
 // PASS
-// BenchmarkHandshake-12	 2000000	       734 ns/op
+// BenchmarkHandshake-12	 5000000	       334 ns/op