| 57 | } |
| 58 | |
| 59 | func formatValue(v interface{}) (string, error) { |
| 60 | if vr, ok := v.(driver.Valuer); ok { |
| 61 | var err error |
| 62 | v, err = vr.Value() |
| 63 | if err != nil { |
| 64 | return "", xerrors.Errorf("error calling Value: %w", err) |
| 65 | } |
| 66 | } |
| 67 | if v == nil { |
| 68 | return "<nil>", nil |
| 69 | } |
| 70 | switch v.(type) { |
| 71 | case error, fmt.Stringer: |
| 72 | return quote(fmt.Sprintf("%+v", v)), nil |
| 73 | } |
| 74 | typ := reflect.TypeOf(v) |
| 75 | switch typ.Kind() { |
| 76 | case reflect.Struct, reflect.Map: |
| 77 | byt, err := json.Marshal(v) |
| 78 | if err != nil { |
| 79 | // don't panic |
| 80 | return "", xerrors.Errorf("error marshalling value: %w", err) |
| 81 | } |
| 82 | return string(byt), nil |
| 83 | case reflect.Slice: |
| 84 | // Byte slices are optimistically readable. |
| 85 | if typ.Elem().Kind() == reflect.Uint8 { |
| 86 | return fmt.Sprintf("%q", v), nil |
| 87 | } |
| 88 | fallthrough |
| 89 | default: |
| 90 | return quote(fmt.Sprintf("%+v", v)), nil |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | const tab = " " |
| 95 | |