Исходники и презентации

lessons/errors/error/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type error interface {
+	Error() string
+}
+
+type DivisionError struct {
+	errMessage     string
+	firstArgument  int
+	secondArgument int
+}
+
+func NewDivisionError(message string, lhs, rhs int) DivisionError {
+	return DivisionError{
+		errMessage:     message,
+		firstArgument:  lhs,
+		secondArgument: rhs,
+	}
+}
+
+func (e DivisionError) Error() string {
+	if e.errMessage != "" {
+		return e.errMessage + " [" + strconv.Itoa(e.firstArgument) + ", " + strconv.Itoa(e.secondArgument) + "]"
+	} else {
+		return ""
+	}
+}
+
+func divide(lhs, rhs int) (int, error) {
+	if rhs == 0 {
+		return 0, NewDivisionError("zero number", lhs, rhs)
+	} else if lhs%2 == 0 || rhs%2 == 0 {
+		return 0, NewDivisionError("even number", lhs, rhs)
+	}
+
+	return lhs / rhs, nil
+}
+
+func main() {
+	x := 100
+	y := 0
+
+	value, err := divide(x, y)
+	fmt.Println(value)
+	fmt.Println(err)
+}