more index work

029-errors/errors.go

@@ -0,0 +1,24 @@
+// ## Errors
+
+package main
+
+import ("fmt"; "errors")
+
+func myFun(arg int) (int, error) {
+	if arg == 42 {
+		return -1, errors.New("Can't work with 42")
+		
+	}
+	return arg + 3, nil
+}
+
+func main() {
+	r, _ := myFun(7)
+	fmt.Println(r)
+
+	_, e := myFun(42)
+	fmt.Println(e)
+}
+
+// todo: custom errors
+// todo: data conveying errors