Error handling. Vendoring

Signed-off-by: Ettore Dreucci <ettore.dreucci@gmail.com>

vendor/github.com/dixonwille/wmenu/error.go

@@ -0,0 +1,86 @@
+package wmenu
+
+import "errors"
+
+var (
+	//ErrInvalid is returned if a response from user was an invalid option
+	ErrInvalid = errors.New("Invalid response")
+
+	//ErrTooMany is returned if multiSelect is false and a user tries to select multiple options
+	ErrTooMany = errors.New("Too many responses")
+
+	//ErrNoResponse is returned if there were no responses and no action to call
+	ErrNoResponse = errors.New("No response")
+
+	//ErrDuplicate is returned is a user selects an option twice
+	ErrDuplicate = errors.New("Duplicated response")
+)
+
+//MenuError records menu errors
+type MenuError struct {
+	Err       error
+	Res       string
+	TriesLeft int
+}
+
+//Error prints the error in an easy to read string.
+func (e *MenuError) Error() string {
+	if e.Res != "" {
+		return e.Err.Error() + ": " + e.Res
+	}
+	return e.Err.Error()
+}
+
+func newMenuError(err error, res string, tries int) *MenuError {
+	return &MenuError{
+		Err:       err,
+		Res:       res,
+		TriesLeft: tries,
+	}
+}
+
+//IsInvalidErr checks to see if err is of type invalid error returned by menu.
+func IsInvalidErr(err error) bool {
+	e, ok := err.(*MenuError)
+	if ok && e.Err == ErrInvalid {
+		return true
+	}
+	return false
+}
+
+//IsNoResponseErr checks to see if err is of type no response returned by menu.
+func IsNoResponseErr(err error) bool {
+	e, ok := err.(*MenuError)
+	if ok && e.Err == ErrNoResponse {
+		return true
+	}
+	return false
+}
+
+//IsTooManyErr checks to see if err is of type too many returned by menu.
+func IsTooManyErr(err error) bool {
+	e, ok := err.(*MenuError)
+	if ok && e.Err == ErrTooMany {
+		return true
+	}
+	return false
+}
+
+//IsDuplicateErr checks to see if err is of type duplicate returned by menu.
+func IsDuplicateErr(err error) bool {
+	e, ok := err.(*MenuError)
+	if ok && e.Err == ErrDuplicate {
+		return true
+	}
+	return false
+}
+
+//IsMenuErr checks to see if it is a menu err.
+//This is a general check not a specific one.
+func IsMenuErr(err error) bool {
+	_, ok := err.(*MenuError)
+	if ok {
+		return true
+	}
+	return false
+}