In your example, MyError2 does not have an Error() method so it is not
called. From the fmt package docs (golang.org/pkg/fmt):
- 3. If the %v verb is used with the # flag (%#v) and the operand
implements the GoStringer interface, that will be invoked.
- If the format (which is implicitly
Yup, doesn't quite make sense to me that Error() is called if it's an
embedded struct and not when it's a struct field.
See https://play.golang.org/p/Vp6Y-RETWZ
On Friday, July 15, 2016 at 2:03:25 PM UTC-7, Thorsten von Eicken wrote:
>
> You're probably correct, see this:
>
> package main
>
> im
This might make it clearer as well: https://play.golang.org/p/g3KdJUQRlK
On Fri, Jul 15, 2016 at 2:03 PM Thorsten von Eicken
wrote:
> You're probably correct, see this:
>
> package main
>
> import (
> "fmt"
> )
>
> type MyError struct{ error }
> type MyError2 struct {
> foo int
> err error
> }
>
You're probably correct, see this:
package main
import (
"fmt"
)
type MyError struct{ error }
type MyError2 struct {
foo int
err error
}
func main() {
err := MyError{}
fmt.Printf("%%#v %#v\n", err)
fmt.Printf("%%+v %+v\n", err)
fmt.Printf("%%v %v\n", err)
err2 := MyError2{}
fmt.Printf("%%#v %#
I think MyError has the Error method, which %v will use but %#v will not.
Then it panics because it's trying to call error(nil).Error().
On Fri, Jul 15, 2016, 13:22 Thorsten von Eicken wrote:
> I was surprised to see Printf %v panic on a struct that %#v prints fine.
> Is this expected / intentio
I was surprised to see Printf %v panic on a struct that %#v prints fine. Is
this expected / intentional / as designed?
Test case:
package main
import (
"fmt"
)
type MyError struct{ error }
func main() {
err := MyError{}
fmt.Printf("%%#v %#v\n", err)
fmt.Printf("%%+v %+v\n", err)
fmt.Printf("%%
