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mirror of https://github.com/rclone/rclone synced 2024-11-02 23:09:23 +01:00
rclone/fs/tristate.go
Nick Craig-Wood e43b5ce5e5 Remove github.com/pkg/errors and replace with std library version
This is possible now that we no longer support go1.12 and brings
rclone into line with standard practices in the Go world.

This also removes errors.New and errors.Errorf from lib/errors and
prefers the stdlib errors package over lib/errors.
2021-11-07 11:53:30 +00:00

73 lines
1.3 KiB
Go

package fs
import (
"encoding/json"
"fmt"
"strconv"
"strings"
)
// Tristate is a boolean that can has the states, true, false and
// unset/invalid/nil
type Tristate struct {
Value bool
Valid bool
}
// String renders the tristate as true/false/unset
func (t Tristate) String() string {
if !t.Valid {
return "unset"
}
if t.Value {
return "true"
}
return "false"
}
// Set the List entries
func (t *Tristate) Set(s string) error {
s = strings.ToLower(s)
if s == "" || s == "nil" || s == "null" || s == "unset" {
t.Valid = false
return nil
}
value, err := strconv.ParseBool(s)
if err != nil {
return fmt.Errorf("failed to parse Tristate %q: %w", s, err)
}
t.Value = value
t.Valid = true
return nil
}
// Type of the value
func (Tristate) Type() string {
return "Tristate"
}
// Scan implements the fmt.Scanner interface
func (t *Tristate) Scan(s fmt.ScanState, ch rune) error {
token, err := s.Token(true, nil)
if err != nil {
return err
}
return t.Set(string(token))
}
// UnmarshalJSON parses it as a bool or nil for unset
func (t *Tristate) UnmarshalJSON(in []byte) error {
var b *bool
err := json.Unmarshal(in, &b)
if err != nil {
return err
}
if b != nil {
t.Valid = true
t.Value = *b
} else {
t.Valid = false
}
return nil
}