60 lines
1006 B
Go
60 lines
1006 B
Go
package dataext
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import (
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"encoding/json"
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"errors"
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)
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type JsonOpt[T any] struct {
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isSet bool
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value T
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}
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// MarshalJSON returns m as the JSON encoding of m.
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func (m JsonOpt[T]) MarshalJSON() ([]byte, error) {
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if !m.isSet {
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return []byte("null"), nil // actually this would be undefined - but undefined is not valid JSON
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}
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return json.Marshal(m.value)
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}
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// UnmarshalJSON sets *m to a copy of data.
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func (m *JsonOpt[T]) UnmarshalJSON(data []byte) error {
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if m == nil {
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return errors.New("JsonOpt: UnmarshalJSON on nil pointer")
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}
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m.isSet = true
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return json.Unmarshal(data, &m.value)
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}
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func (m JsonOpt[T]) IsSet() bool {
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return m.isSet
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}
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func (m JsonOpt[T]) IsUnset() bool {
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return !m.isSet
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}
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func (m JsonOpt[T]) Value() (T, bool) {
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if !m.isSet {
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return *new(T), false
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}
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return m.value, true
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}
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func (m JsonOpt[T]) ValueOrNil() *T {
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if !m.isSet {
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return nil
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}
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return &m.value
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}
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func (m JsonOpt[T]) MustValue() T {
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if !m.isSet {
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panic("value not set")
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}
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return m.value
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}
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