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zonewavezonewave
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feat(unset): support unset value to zero. (#42)
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‎go.mod‎

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module github.com/creasty/defaults
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go 1.14
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require github.com/stretchr/testify v1.7.0

‎go.sum‎

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github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
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github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
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github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
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github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
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github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
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github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
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github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
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gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
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gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
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gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
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gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

‎unset.go‎

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package defaults
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import (
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"reflect"
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)
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const (
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unsetFlag = "unset"
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// unsetRecursion means that the field will be unset recursively
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unsetRecursion = "walk"
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)
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func MustUnset(ptr interface{}) {
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if err := Unset(ptr); err != nil {
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panic(err)
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}
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}
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func Unset(obj interface{}) error {
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v := indirect(reflect.ValueOf(obj))
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if v.Kind() != reflect.Struct {
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return errInvalidType
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}
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unsetStruct(v)
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return nil
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}
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func unsetStruct(obj reflect.Value) {
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t := obj.Type()
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for i := 0; i < t.NumField(); i++ {
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unsetVal := t.Field(i).Tag.Get(unsetFlag)
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if unsetVal == "-" {
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continue
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}
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unsetField(obj.Field(i), unsetVal == unsetRecursion)
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}
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}
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func indirect(v reflect.Value) reflect.Value {
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finalValue := v
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for finalValue.Kind() == reflect.Ptr {
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finalValue = finalValue.Elem()
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}
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return finalValue
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}
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func unsetField(field reflect.Value, unsetWalk bool) {
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if !field.CanSet() {
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return
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}
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isInitial := isInitialValue(field)
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if isInitial {
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return
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}
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if !unsetWalk {
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field.Set(reflect.Zero(field.Type()))
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return
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}
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switch field.Kind() {
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default:
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field.Set(reflect.Zero(field.Type()))
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case reflect.Ptr:
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unsetField(field.Elem(), true)
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case reflect.Struct:
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unsetStruct(field)
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case reflect.Slice:
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for j := 0; j < field.Len(); j++ {
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unsetField(field.Index(j), true)
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}
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case reflect.Map:
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for _, e := range field.MapKeys() {
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var mapValue = field.MapIndex(e)
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switch mapValue.Kind() {
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case reflect.Ptr:
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unsetField(mapValue.Elem(), true)
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case reflect.Struct, reflect.Slice, reflect.Map:
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ref := reflect.New(mapValue.Type())
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ref.Elem().Set(mapValue)
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unsetField(ref.Elem(), true)
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field.SetMapIndex(e, ref.Elem().Convert(mapValue.Type()))
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default:
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field.SetMapIndex(e, reflect.Zero(mapValue.Type()))
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}
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}
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}
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}

‎unset_test.go‎

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package defaults
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import (
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"github.com/stretchr/testify/require"
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"testing"
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)
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func TestUnset(t *testing.T) {
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t.Run("sample unset", func(t *testing.T) {
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s := &Sample{}
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MustSet(s)
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err := Unset(s)
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require.NoError(t, err)
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require.Equal(t, s, &Sample{})
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})
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t.Run("errInvalidType", func(t *testing.T) {
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tmp := 8
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require.Equal(t, Unset(&tmp), errInvalidType)
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require.Panics(t, func() { MustUnset(&tmp) })
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})
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t.Run("not reset by -", func(t *testing.T) {
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s := &struct {
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IgnoreMe string `default:"-" unset:"-"`
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}{
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IgnoreMe: "test",
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}
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MustUnset(s)
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require.Equal(t, s.IgnoreMe, "test")
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})
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t.Run("sampleUnset test", func(t *testing.T) {
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s := &SampleUnset{}
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MustSet(s)
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var testNumPtr *int = nil
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s.SliceOfIntPtrPtr[1] = &testNumPtr
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s.private = StructUnset{WithDefault: "test"}
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MustUnset(s)
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// struct
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require.Equal(t, s.private.WithDefault, "test")
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require.Equal(t, 0, s.Struct.Foo)
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require.Equal(t, 0, s.Struct.Bar)
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require.Nil(t, s.Struct.BarPtr)
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require.Equal(t, 0, *s.Struct.BarPtrWithWalk)
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require.Empty(t, s.StructPtrNoWalk)
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require.Equal(t, "foo", s.StructPtr.EmbeddedUnset.String)
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require.Equal(t, 0, s.StructPtr.EmbeddedUnset.Int)
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require.Equal(t, "foo", s.StructPtr.Struct.String)
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require.Equal(t, 0, s.StructPtr.Struct.Int)
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// slice
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require.Equal(t, 0, s.SliceOfInt[0])
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require.Equal(t, 0, *s.SliceOfIntPtr[0])
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require.Equal(t, (*int)(nil), *s.SliceOfIntPtrPtr[1])
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require.Equal(t, 0, s.SliceOfStruct[0].Foo)
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require.Equal(t, 0, s.SliceOfStructPtr[0].Foo)
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require.Equal(t, 0, s.SliceOfSliceInt[0][0])
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require.Equal(t, 0, *s.SliceOfSliceIntPtr[0][0])
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require.Equal(t, 0, s.SliceOfSliceStruct[0][0].Foo)
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require.Equal(t, 0, s.SliceOfMapOfInt[0]["int1"])
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require.Equal(t, 0, s.SliceOfMapOfStruct[0]["Struct3"].Foo)
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require.Equal(t, 0, s.SliceOfMapOfStructPtr[0]["Struct3"].Foo)
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require.Nil(t, s.SliceSetNil)
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// map
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require.Equal(t, 0, s.MapOfInt["int1"])
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require.Equal(t, 0, *s.MapOfIntPtr["int1"])
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require.Equal(t, 0, s.MapOfStruct["Struct3"].Foo)
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require.Equal(t, 0, s.MapOfStructPtr["Struct3"].Foo)
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require.Equal(t, 0, s.MapOfSliceInt["slice1"][0])
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require.Equal(t, 0, *s.MapOfSliceIntPtr["slice1"][0])
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require.Equal(t, 0, s.MapOfSliceStruct["slice1"][0].Foo)
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require.Equal(t, 0, s.MapOfMapOfInt["map1"]["int1"])
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require.Equal(t, 0, s.MapOfMapOfInt["map1"]["int1"])
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require.Equal(t, 0, s.MapOfMapOfStruct["map1"]["Struct3"].Foo, 0)
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require.Nil(t, s.MapSetNil)
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// map embed
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require.Equal(t, "foo", s.MapOfStruct["Struct3"].String)
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require.Equal(t, "foo", s.MapOfStructPtr["Struct3"].String)
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require.Equal(t, "foo", s.MapOfSliceStruct["slice1"][0].String)
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require.Equal(t, "foo", s.MapOfMapOfStruct["map1"]["Struct3"].String)
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})
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}
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type EmbeddedUnset struct {
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Int int `default:"1"`
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String string `default:"foo" unset:"-"`
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}
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type StructUnset struct {
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EmbeddedUnset `default:"{}" unset:"walk"`
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Foo int `default:"1"`
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Bar int `default:"1"`
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BarPtr *int `default:"1"`
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BarPtrWithWalk *int `default:"1" unset:"walk"`
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WithDefault string `default:"foo"`
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Struct EmbeddedUnset ` unset:"walk"`
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}
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type SampleUnset struct {
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private StructUnset `default:"{}" unset:"walk"`
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Struct StructUnset `default:"{}" unset:"walk"`
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StructPtr *StructUnset `default:"{}" unset:"walk"`
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StructPtrNoWalk *StructUnset `default:"{}"`
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SliceOfInt []int `default:"[1,2,3]" unset:"walk"`
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SliceOfIntPtr []*int `default:"[1,2,3]" unset:"walk"`
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SliceOfIntPtrPtr []**int `default:"[1,2,3]" unset:"walk"`
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SliceOfStruct []StructUnset `default:"[{\"Foo\":123}]" unset:"walk"`
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SliceOfStructPtr []*StructUnset `default:"[{\"Foo\":123}]" unset:"walk"`
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SliceOfMapOfInt []map[string]int `default:"[{\"int1\": 1}]" unset:"walk"`
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SliceOfMapOfStruct []map[string]StructUnset `default:"[{\"Struct3\": {\"Foo\":123}}]" unset:"walk"`
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SliceOfMapOfStructPtr []map[string]*StructUnset `default:"[{\"Struct3\": {\"Foo\":123}}]" unset:"walk"`
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SliceOfSliceInt [][]int `default:"[[1,2,3]]" unset:"walk"`
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SliceOfSliceIntPtr [][]*int `default:"[[1,2,3]]" unset:"walk"`
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SliceOfSliceStruct [][]StructUnset `default:"[[{\"Foo\":123}]]" unset:"walk"`
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SliceOfSliceStructPtr [][]*StructUnset `default:"[[{\"Foo\":123}]]" unset:"walk"`
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SliceSetNil []StructUnset `default:"[{\"Foo\":123}]"`
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MapOfInt map[string]int `default:"{\"int1\": 1}" unset:"walk"`
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MapOfIntPtr map[string]*int `default:"{\"int1\": 1}" unset:"walk"`
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MapOfStruct map[string]StructUnset `default:"{\"Struct3\": {\"Foo\":123}}" unset:"walk" `
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MapOfStructPtr map[string]*StructUnset `default:"{\"Struct3\": {\"Foo\":123}}" unset:"walk"`
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MapOfSliceInt map[string][]int `default:"{\"slice1\": [1,2,3]}" unset:"walk"`
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MapOfSliceIntPtr map[string][]*int `default:"{\"slice1\": [1,2,3]}" unset:"walk"`
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MapOfSliceStruct map[string][]StructUnset `default:"{\"slice1\": [{\"Foo\":123}]}" unset:"walk"`
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MapOfSliceStructPtr map[string][]*StructUnset `default:"{\"slice1\": [{\"Foo\":123}]}" unset:"walk"`
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MapOfMapOfInt map[string]map[string]int `default:"{\"map1\": {\"int1\": 1}}" unset:"walk"`
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MapOfMapOfStruct map[string]map[string]StructUnset `default:"{\"map1\": {\"Struct3\": {\"Foo\":123}}}" unset:"walk"`
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MapSetNil map[string]StructUnset `default:"{\"Struct3\": {\"Foo\":123}}"`
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}

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