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// Copyright 2017 Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package getopt
import (
"errors"
"fmt"
"sync"
)
type enumValue string
var (
enumValuesMu sync.Mutex
enumValues = make(map[*enumValue]map[string]struct{})
)
func (s *enumValue) Set(value string, opt Option) error {
enumValuesMu.Lock()
es, ok := enumValues[s]
enumValuesMu.Unlock()
if !ok || es == nil {
return errors.New("this option has no values")
}
if _, ok := es[value]; !ok {
return errors.New("invalid value: " + value)
}
*s = enumValue(value)
return nil
}
func (s *enumValue) String() string {
return string(*s)
}
// Enum creates an option that can only be set to one of the enumerated strings
// passed in values. Passing nil or an empty slice results in an option that
// will always fail. If not "", value is the default value of the enum. If
// value is not listed in values then Enum will produce an error on standard
// error and then exit the program with a status of 1.
func Enum(name rune, values []string, value string, helpvalue ...string) *string {
return CommandLine.Enum(name, values, value, helpvalue...)
}
func (s *Set) Enum(name rune, values []string, value string, helpvalue ...string) *string {
var p enumValue
p.define(values, value, &option{short: name})
s.FlagLong(&p, "", name, helpvalue...)
return (*string)(&p)
}
func EnumLong(name string, short rune, values []string, value string, helpvalue ...string) *string {
return CommandLine.EnumLong(name, short, values, value, helpvalue...)
}
func (s *Set) EnumLong(name string, short rune, values []string, value string, helpvalue ...string) *string {
var p enumValue
p.define(values, value, &option{short: short, long: name})
s.FlagLong(&p, name, short, helpvalue...)
return (*string)(&p)
}
func (e *enumValue) define(values []string, def string, opt Option) {
m := make(map[string]struct{})
for _, v := range values {
m[v] = struct{}{}
}
enumValuesMu.Lock()
enumValues[e] = m
enumValuesMu.Unlock()
if def != "" {
if err := e.Set(def, nil); err != nil {
fmt.Fprintf(stderr, "setting default for %s: %v\n", opt.Name(), err)
exit(1)
}
}
}
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