1package types
2
3import (
4	"fmt"
5	"io"
6	"reflect"
7)
8
9// ScanFully uses fmt.Sscanf with verb to fully scan val into ptr.
10func ScanFully(ptr interface{}, val string, verb byte) error {
11	t := reflect.ValueOf(ptr).Elem().Type()
12	// attempt to read extra bytes to make sure the value is consumed
13	var b []byte
14	n, err := fmt.Sscanf(val, "%"+string(verb)+"%s", ptr, &b)
15	switch {
16	case n < 1 || n == 1 && err != io.EOF:
17		return fmt.Errorf("failed to parse %q as %v: %v", val, t, err)
18	case n > 1:
19		return fmt.Errorf("failed to parse %q as %v: extra characters %q", val, t, string(b))
20	}
21	// n == 1 && err == io.EOF
22	return nil
23}
24