1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182
|
package flags
import (
"reflect"
"strings"
"syscall"
)
// Set the value of an option to the specified value. An error will be returned
// if the specified value could not be converted to the corresponding option
// value type.
func (option *Option) set(value *string) error {
option.isSet = true
if option.isFunc() {
return option.call(value)
} else if value != nil {
return convert(*value, option.value, option.tag)
}
return convert("", option.value, option.tag)
}
func (option *Option) canCli() bool {
return option.ShortName != 0 || len(option.LongName) != 0
}
func (option *Option) canArgument() bool {
if u := option.isUnmarshaler(); u != nil {
return true
}
return !option.isBool()
}
func (option *Option) emptyValue() reflect.Value {
tp := option.value.Type()
if tp.Kind() == reflect.Map {
return reflect.MakeMap(tp)
}
return reflect.Zero(tp)
}
func (option *Option) empty() {
if !option.isFunc() {
option.value.Set(option.emptyValue())
}
}
func (option *Option) clearDefault() {
usedDefault := option.Default
if envKey := option.EnvDefaultKey; envKey != "" {
// os.Getenv() makes no distinction between undefined and
// empty values, so we use syscall.Getenv()
if value, ok := syscall.Getenv(envKey); ok {
if option.EnvDefaultDelim != "" {
usedDefault = strings.Split(value,
option.EnvDefaultDelim)
} else {
usedDefault = []string{value}
}
}
}
if len(usedDefault) > 0 {
option.empty()
for _, d := range usedDefault {
option.set(&d)
}
} else {
tp := option.value.Type()
switch tp.Kind() {
case reflect.Map:
if option.value.IsNil() {
option.empty()
}
case reflect.Slice:
if option.value.IsNil() {
option.empty()
}
}
}
}
func (option *Option) valueIsDefault() bool {
// Check if the value of the option corresponds to its
// default value
emptyval := option.emptyValue()
checkvalptr := reflect.New(emptyval.Type())
checkval := reflect.Indirect(checkvalptr)
checkval.Set(emptyval)
if len(option.Default) != 0 {
for _, v := range option.Default {
convert(v, checkval, option.tag)
}
}
return reflect.DeepEqual(option.value.Interface(), checkval.Interface())
}
func (option *Option) isUnmarshaler() Unmarshaler {
v := option.value
for {
if !v.CanInterface() {
break
}
i := v.Interface()
if u, ok := i.(Unmarshaler); ok {
return u
}
if !v.CanAddr() {
break
}
v = v.Addr()
}
return nil
}
func (option *Option) isBool() bool {
tp := option.value.Type()
for {
switch tp.Kind() {
case reflect.Bool:
return true
case reflect.Slice:
return (tp.Elem().Kind() == reflect.Bool)
case reflect.Func:
return tp.NumIn() == 0
case reflect.Ptr:
tp = tp.Elem()
default:
return false
}
}
}
func (option *Option) isFunc() bool {
return option.value.Type().Kind() == reflect.Func
}
func (option *Option) call(value *string) error {
var retval []reflect.Value
if value == nil {
retval = option.value.Call(nil)
} else {
tp := option.value.Type().In(0)
val := reflect.New(tp)
val = reflect.Indirect(val)
if err := convert(*value, val, option.tag); err != nil {
return err
}
retval = option.value.Call([]reflect.Value{val})
}
if len(retval) == 1 && retval[0].Type() == reflect.TypeOf((*error)(nil)).Elem() {
if retval[0].Interface() == nil {
return nil
}
return retval[0].Interface().(error)
}
return nil
}
|