json: support omitzero

json/codec.go

@@ -4,6 +4,7 @@ import (
 	"encoding"
 	"encoding/json"
 	"fmt"
+	"maps"
 	"math/big"
 	"reflect"
 	"sort"
@@ -73,12 +74,9 @@ func cacheLoad() map[unsafe.Pointer]codec {
 
 func cacheStore(typ reflect.Type, cod codec, oldCodecs map[unsafe.Pointer]codec) {
 	newCodecs := make(map[unsafe.Pointer]codec, len(oldCodecs)+1)
+	maps.Copy(newCodecs, oldCodecs)
 	newCodecs[typeid(typ)] = cod
 
-	for t, c := range oldCodecs {
-		newCodecs[t] = c
-	}
-
 	cache.Store(&newCodecs)
 }
 
@@ -205,7 +203,7 @@ func constructCodec(t reflect.Type, seen map[reflect.Type]*structType, canAddr b
 		c = constructUnsupportedTypeCodec(t)
 	}
 
-	p := reflect.PtrTo(t)
+	p := reflect.PointerTo(t)
 
 	if canAddr {
 		switch {
@@ -291,7 +289,7 @@ func constructSliceCodec(t reflect.Type, seen map[reflect.Type]*structType) code
 		// Go 1.7+ behavior: slices of byte types (and aliases) may override the
 		// default encoding and decoding behaviors by implementing marshaler and
 		// unmarshaler interfaces.
-		p := reflect.PtrTo(e)
+		p := reflect.PointerTo(e)
 		c := codec{}
 
 		switch {
@@ -391,7 +389,7 @@ func constructMapCodec(t reflect.Type, seen map[reflect.Type]*structType) codec
 	kc := codec{}
 	vc := constructCodec(v, seen, false)
 
-	if k.Implements(textMarshalerType) || reflect.PtrTo(k).Implements(textUnmarshalerType) {
+	if k.Implements(textMarshalerType) || reflect.PointerTo(k).Implements(textUnmarshalerType) {
 		kc.encode = constructTextMarshalerEncodeFunc(k, false)
 		kc.decode = constructTextUnmarshalerDecodeFunc(k, true)
 
@@ -1068,51 +1066,51 @@ type sliceHeader struct {
 
 var (
 	nullType = reflect.TypeOf(nil)
-	boolType = reflect.TypeOf(false)
-
-	intType   = reflect.TypeOf(int(0))
-	int8Type  = reflect.TypeOf(int8(0))
-	int16Type = reflect.TypeOf(int16(0))
-	int32Type = reflect.TypeOf(int32(0))
-	int64Type = reflect.TypeOf(int64(0))
-
-	uintType    = reflect.TypeOf(uint(0))
-	uint8Type   = reflect.TypeOf(uint8(0))
-	uint16Type  = reflect.TypeOf(uint16(0))
-	uint32Type  = reflect.TypeOf(uint32(0))
-	uint64Type  = reflect.TypeOf(uint64(0))
-	uintptrType = reflect.TypeOf(uintptr(0))
-
-	float32Type = reflect.TypeOf(float32(0))
-	float64Type = reflect.TypeOf(float64(0))
-
-	bigIntType     = reflect.TypeOf(new(big.Int))
-	numberType     = reflect.TypeOf(json.Number(""))
-	stringType     = reflect.TypeOf("")
-	stringsType    = reflect.TypeOf([]string(nil))
-	bytesType      = reflect.TypeOf(([]byte)(nil))
-	durationType   = reflect.TypeOf(time.Duration(0))
-	timeType       = reflect.TypeOf(time.Time{})
-	rawMessageType = reflect.TypeOf(RawMessage(nil))
-
-	numberPtrType     = reflect.PtrTo(numberType)
-	durationPtrType   = reflect.PtrTo(durationType)
-	timePtrType       = reflect.PtrTo(timeType)
-	rawMessagePtrType = reflect.PtrTo(rawMessageType)
-
-	sliceInterfaceType       = reflect.TypeOf(([]any)(nil))
-	sliceStringType          = reflect.TypeOf(([]any)(nil))
-	mapStringInterfaceType   = reflect.TypeOf((map[string]any)(nil))
-	mapStringRawMessageType  = reflect.TypeOf((map[string]RawMessage)(nil))
-	mapStringStringType      = reflect.TypeOf((map[string]string)(nil))
-	mapStringStringSliceType = reflect.TypeOf((map[string][]string)(nil))
-	mapStringBoolType        = reflect.TypeOf((map[string]bool)(nil))
-
-	interfaceType       = reflect.TypeOf((*any)(nil)).Elem()
-	jsonMarshalerType   = reflect.TypeOf((*Marshaler)(nil)).Elem()
-	jsonUnmarshalerType = reflect.TypeOf((*Unmarshaler)(nil)).Elem()
-	textMarshalerType   = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
-	textUnmarshalerType = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+	boolType = reflect.TypeFor[bool]()
+
+	intType   = reflect.TypeFor[int]()
+	int8Type  = reflect.TypeFor[int8]()
+	int16Type = reflect.TypeFor[int16]()
+	int32Type = reflect.TypeFor[int32]()
+	int64Type = reflect.TypeFor[int64]()
+
+	uintType    = reflect.TypeFor[uint]()
+	uint8Type   = reflect.TypeFor[uint8]()
+	uint16Type  = reflect.TypeFor[uint16]()
+	uint32Type  = reflect.TypeFor[uint32]()
+	uint64Type  = reflect.TypeFor[uint64]()
+	uintptrType = reflect.TypeFor[uintptr]()
+
+	float32Type = reflect.TypeFor[float32]()
+	float64Type = reflect.TypeFor[float64]()
+
+	bigIntType     = reflect.TypeFor[*big.Int]()
+	numberType     = reflect.TypeFor[json.Number]()
+	stringType     = reflect.TypeFor[string]()
+	stringsType    = reflect.TypeFor[[]string]()
+	bytesType      = reflect.TypeFor[[]byte]()
+	durationType   = reflect.TypeFor[time.Duration]()
+	timeType       = reflect.TypeFor[time.Time]()
+	rawMessageType = reflect.TypeFor[RawMessage]()
+
+	numberPtrType     = reflect.PointerTo(numberType)
+	durationPtrType   = reflect.PointerTo(durationType)
+	timePtrType       = reflect.PointerTo(timeType)
+	rawMessagePtrType = reflect.PointerTo(rawMessageType)
+
+	sliceInterfaceType       = reflect.TypeFor[[]any]()
+	sliceStringType          = reflect.TypeFor[[]any]()
+	mapStringInterfaceType   = reflect.TypeFor[map[string]any]()
+	mapStringRawMessageType  = reflect.TypeFor[map[string]RawMessage]()
+	mapStringStringType      = reflect.TypeFor[map[string]string]()
+	mapStringStringSliceType = reflect.TypeFor[map[string][]string]()
+	mapStringBoolType        = reflect.TypeFor[map[string]bool]()
+
+	interfaceType       = reflect.TypeFor[any]()
+	jsonMarshalerType   = reflect.TypeFor[Marshaler]()
+	jsonUnmarshalerType = reflect.TypeFor[Unmarshaler]()
+	textMarshalerType   = reflect.TypeFor[encoding.TextMarshaler]()
+	textUnmarshalerType = reflect.TypeFor[encoding.TextUnmarshaler]()
 
 	bigIntDecoder = constructJSONUnmarshalerDecodeFunc(bigIntType, false)
 )