Enable switch map processing at runtime

cmd/generator/main.go

@@ -238,13 +238,6 @@ func (t opType) fieldToStringTagField() opType {
 		{"RootMapKey", "RootMapKeyIndent", "MapKey"},
 		{"MapValue", "MapValueIndent", "MapValue"},
 		{"MapEnd", "MapEndIndent", "Op"},
-		{"SortedMapHead", "SortedMapHeadIndent", "MapHead"},
-		{"SortedMapHeadLoad", "SortedMapHeadLoadIndent", "MapHead"},
-		{"SortedRootMapHead", "SortedRootMapHeadIndent", "MapHead"},
-		{"SortedMapKey", "SortedMapKeyIndent", "MapKey"},
-		{"SortedRootMapKey", "SortedRootMapKeyIndent", "MapKey"},
-		{"SortedMapValue", "SortedMapValueIndent", "MapValue"},
-		{"SortedMapEnd", "SortedMapEndIndent", "MapEnd"},
 		{"StructFieldHead", "StructFieldHeadIndent", "StructField"},
 		{"StructFieldHeadOmitEmpty", "StructFieldHeadOmitEmptyIndent", "StructField"},
 		{"StructFieldHeadStringTag", "StructFieldHeadStringTagIndent", "StructField"},

encode.go

@@ -18,6 +18,7 @@ type Encoder struct {
 	buf                            []byte
 	enabledIndent                  bool
 	enabledHTMLEscape              bool
+	unorderedMap                   bool
 	prefix                         []byte
 	indentStr                      []byte
 	structTypeToCompiledCode       map[uintptr]*compiledCode
@@ -88,6 +89,16 @@ func NewEncoder(w io.Writer) *Encoder {
 //
 // See the documentation for Marshal for details about the conversion of Go values to JSON.
 func (e *Encoder) Encode(v interface{}) error {
+	return e.EncodeWithOption(v)
+}
+
+// EncodeWithOption call Encode with EncodeOption.
+func (e *Encoder) EncodeWithOption(v interface{}, opts ...EncodeOption) error {
+	for _, opt := range opts {
+		if err := opt(e); err != nil {
+			return err
+		}
+	}
 	if err := e.encode(v); err != nil {
 		return err
 	}
@@ -126,6 +137,7 @@ func (e *Encoder) reset() {
 	e.buf = e.buf[:0]
 	e.enabledHTMLEscape = true
 	e.enabledIndent = false
+	e.unorderedMap = false
 }
 
 func (e *Encoder) encodeForMarshal(v interface{}) ([]byte, error) {

encode_compile.go

@@ -452,13 +452,13 @@ func (e *Encoder) typeToHeaderType(op opType) opType {
 		return opStructFieldHeadString
 	case opBool:
 		return opStructFieldHeadBool
-	case opMapHead, opSortedMapHead:
+	case opMapHead:
 		return opStructFieldHeadMap
-	case opMapHeadLoad, opSortedMapHeadLoad:
+	case opMapHeadLoad:
 		return opStructFieldHeadMapLoad
-	case opMapHeadIndent, opSortedMapHeadIndent:
+	case opMapHeadIndent:
 		return opStructFieldHeadMapIndent
-	case opMapHeadLoadIndent, opSortedMapHeadLoadIndent:
+	case opMapHeadLoadIndent:
 		return opStructFieldHeadMapLoadIndent
 	case opArrayHead:
 		return opStructFieldHeadArray
@@ -510,13 +510,13 @@ func (e *Encoder) typeToFieldType(op opType) opType {
 		return opStructFieldString
 	case opBool:
 		return opStructFieldBool
-	case opMapHead, opSortedMapHead:
+	case opMapHead:
 		return opStructFieldMap
-	case opMapHeadLoad, opSortedMapHeadLoad:
+	case opMapHeadLoad:
 		return opStructFieldMapLoad
-	case opMapHeadIndent, opSortedMapHeadIndent:
+	case opMapHeadIndent:
 		return opStructFieldMapIndent
-	case opMapHeadLoadIndent, opSortedMapHeadLoadIndent:
+	case opMapHeadLoadIndent:
 		return opStructFieldMapLoadIndent
 	case opArrayHead:
 		return opStructFieldArray

encode_opcode.go

@@ -389,9 +389,9 @@ func newArrayElemCode(ctx *encodeCompileContext, head *opcode, length int, size
 func newMapHeaderCode(ctx *encodeCompileContext, withLoad bool) *opcode {
 	var op opType
 	if withLoad {
-		op = opSortedMapHeadLoad
+		op = opMapHeadLoad
 	} else {
-		op = opSortedMapHead
+		op = opMapHead
 	}
 	idx := opcodeOffset(ctx.ptrIndex)
 	ctx.incPtrIndex()
@@ -414,7 +414,7 @@ func newMapHeaderCode(ctx *encodeCompileContext, withLoad bool) *opcode {
 
 func newMapKeyCode(ctx *encodeCompileContext, head *opcode) *opcode {
 	return &opcode{
-		op:         opSortedMapKey,
+		op:         opMapKey,
 		displayIdx: ctx.opcodeIndex,
 		idx:        opcodeOffset(ctx.ptrIndex),
 		elemIdx:    head.elemIdx,
@@ -426,7 +426,7 @@ func newMapKeyCode(ctx *encodeCompileContext, head *opcode) *opcode {
 
 func newMapValueCode(ctx *encodeCompileContext, head *opcode) *opcode {
 	return &opcode{
-		op:         opSortedMapValue,
+		op:         opMapValue,
 		displayIdx: ctx.opcodeIndex,
 		idx:        opcodeOffset(ctx.ptrIndex),
 		elemIdx:    head.elemIdx,
@@ -443,7 +443,7 @@ func newMapEndCode(ctx *encodeCompileContext, head *opcode) *opcode {
 	ctx.incPtrIndex()
 	idx := opcodeOffset(ctx.ptrIndex)
 	return &opcode{
-		op:         opSortedMapEnd,
+		op:         opMapEnd,
 		displayIdx: ctx.opcodeIndex,
 		idx:        idx,
 		length:     head.length,

encode_test.go

@@ -377,14 +377,18 @@ func Test_Marshal(t *testing.T) {
 	})
 	t.Run("map", func(t *testing.T) {
 		t.Run("map[string]int", func(t *testing.T) {
-			bytes, err := json.Marshal(map[string]int{
+			v := map[string]int{
 				"a": 1,
 				"b": 2,
 				"c": 3,
 				"d": 4,
-			})
+			}
+			bytes, err := json.Marshal(v)
 			assertErr(t, err)
 			assertEq(t, "map", `{"a":1,"b":2,"c":3,"d":4}`, string(bytes))
+			b, err := json.MarshalWithOption(v, json.UnorderedMap())
+			assertErr(t, err)
+			assertEq(t, "unordered map", len(`{"a":1,"b":2,"c":3,"d":4}`), len(string(b)))
 		})
 		t.Run("map[string]interface{}", func(t *testing.T) {
 			type T struct {

encode_vm.go

@@ -426,7 +426,7 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 				e.encodeBytes([]byte{']', '\n'})
 				code = code.end.next
 			}
-		case opSortedMapHead:
+		case opMapHead:
 			ptr := load(ctxptr, code.idx)
 			if ptr == 0 {
 				e.encodeNull()
@@ -440,11 +440,13 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 					store(ctxptr, code.elemIdx, 0)
 					store(ctxptr, code.length, uintptr(mlen))
 					store(ctxptr, code.mapIter, uintptr(iter))
-					pos := make([]int, 0, mlen)
+					if !e.unorderedMap {
-					pos = append(pos, len(e.buf))
+						pos := make([]int, 0, mlen)
-					posPtr := unsafe.Pointer(&pos)
+						pos = append(pos, len(e.buf))
-					ctx.keepRefs = append(ctx.keepRefs, posPtr)
+						posPtr := unsafe.Pointer(&pos)
-					store(ctxptr, code.end.mapPos, uintptr(posPtr))
+						ctx.keepRefs = append(ctx.keepRefs, posPtr)
+						store(ctxptr, code.end.mapPos, uintptr(posPtr))
+					}
 					key := mapiterkey(iter)
 					store(ctxptr, code.next.idx, uintptr(key))
 					code = code.next
@@ -453,7 +455,7 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 					code = code.end.next
 				}
 			}
-		case opSortedMapHeadLoad:
+		case opMapHeadLoad:
 			ptr := load(ctxptr, code.idx)
 			if ptr == 0 {
 				e.encodeNull()
@@ -471,41 +473,62 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 					store(ctxptr, code.mapIter, uintptr(iter))
 					key := mapiterkey(iter)
 					store(ctxptr, code.next.idx, uintptr(key))
-					pos := make([]int, 0, mlen)
+					if !e.unorderedMap {
-					pos = append(pos, len(e.buf))
+						pos := make([]int, 0, mlen)
-					posPtr := unsafe.Pointer(&pos)
+						pos = append(pos, len(e.buf))
-					ctx.keepRefs = append(ctx.keepRefs, posPtr)
+						posPtr := unsafe.Pointer(&pos)
-					store(ctxptr, code.end.mapPos, uintptr(posPtr))
+						ctx.keepRefs = append(ctx.keepRefs, posPtr)
+						store(ctxptr, code.end.mapPos, uintptr(posPtr))
+					}
 					code = code.next
 				} else {
 					e.encodeByte('}')
 					code = code.end.next
 				}
 			}
-		case opSortedMapKey:
+		case opMapKey:
 			idx := load(ctxptr, code.elemIdx)
 			length := load(ctxptr, code.length)
-			posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
-			*posPtr = append(*posPtr, len(e.buf))
 			idx++
-			if idx < length {
+			if e.unorderedMap {
-				iter := unsafe.Pointer(load(ctxptr, code.mapIter))
+				if idx < length {
-				store(ctxptr, code.elemIdx, idx)
+					e.encodeByte(',')
-				key := mapiterkey(iter)
+					iter := unsafe.Pointer(load(ctxptr, code.mapIter))
-				store(ctxptr, code.next.idx, uintptr(key))
+					store(ctxptr, code.elemIdx, idx)
-				code = code.next
+					key := mapiterkey(iter)
+					store(ctxptr, code.next.idx, uintptr(key))
+					code = code.next
+				} else {
+					e.encodeByte('}')
+					code = code.end.next
+				}
 			} else {
-				code = code.end
+				posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
+				*posPtr = append(*posPtr, len(e.buf))
+				if idx < length {
+					iter := unsafe.Pointer(load(ctxptr, code.mapIter))
+					store(ctxptr, code.elemIdx, idx)
+					key := mapiterkey(iter)
+					store(ctxptr, code.next.idx, uintptr(key))
+					code = code.next
+				} else {
+					code = code.end
+				}
+			}
+		case opMapValue:
+			if e.unorderedMap {
+				e.encodeByte(':')
+			} else {
+				posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
+				*posPtr = append(*posPtr, len(e.buf))
 			}
-		case opSortedMapValue:
-			posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
-			*posPtr = append(*posPtr, len(e.buf))
 			iter := unsafe.Pointer(load(ctxptr, code.mapIter))
 			value := mapitervalue(iter)
 			store(ctxptr, code.next.idx, uintptr(value))
 			mapiternext(iter)
 			code = code.next
-		case opSortedMapEnd:
+		case opMapEnd:
+			// this operation only used by sorted map.
 			length := int(load(ctxptr, code.length))
 			type mapKV struct {
 				key   string
@@ -545,204 +568,6 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 			e.buf = e.buf[:pos[0]]
 			e.buf = append(e.buf, buf...)
 			code = code.next
-		case opMapHead:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				e.encodeNull()
-				code = code.end.next
-			} else {
-				e.encodeByte('{')
-				mlen := maplen(unsafe.Pointer(ptr))
-				if mlen > 0 {
-					iter := mapiterinit(code.typ, unsafe.Pointer(ptr))
-					ctx.keepRefs = append(ctx.keepRefs, iter)
-					store(ctxptr, code.elemIdx, 0)
-					store(ctxptr, code.length, uintptr(mlen))
-					store(ctxptr, code.mapIter, uintptr(iter))
-					key := mapiterkey(iter)
-					store(ctxptr, code.next.idx, uintptr(key))
-					code = code.next
-				} else {
-					e.encodeByte('}')
-					code = code.end.next
-				}
-			}
-		case opMapHeadLoad:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				e.encodeNull()
-				code = code.end.next
-			} else {
-				// load pointer
-				ptr = uintptr(*(*unsafe.Pointer)(unsafe.Pointer(ptr)))
-				e.encodeByte('{')
-				mlen := maplen(unsafe.Pointer(ptr))
-				if mlen > 0 {
-					iter := mapiterinit(code.typ, unsafe.Pointer(ptr))
-					ctx.keepRefs = append(ctx.keepRefs, iter)
-					store(ctxptr, code.elemIdx, 0)
-					store(ctxptr, code.length, uintptr(mlen))
-					store(ctxptr, code.mapIter, uintptr(iter))
-					key := mapiterkey(iter)
-					store(ctxptr, code.next.idx, uintptr(key))
-					code = code.next
-				} else {
-					e.encodeByte('}')
-					code = code.end.next
-				}
-			}
-		case opMapKey:
-			idx := load(ctxptr, code.elemIdx)
-			length := load(ctxptr, code.length)
-			idx++
-			if idx < length {
-				e.encodeByte(',')
-				iter := unsafe.Pointer(load(ctxptr, code.mapIter))
-				store(ctxptr, code.elemIdx, idx)
-				key := mapiterkey(iter)
-				store(ctxptr, code.next.idx, uintptr(key))
-				code = code.next
-			} else {
-				e.encodeByte('}')
-				code = code.end.next
-			}
-		case opMapValue:
-			e.encodeByte(':')
-			iter := unsafe.Pointer(load(ctxptr, code.mapIter))
-			value := mapitervalue(iter)
-			store(ctxptr, code.next.idx, uintptr(value))
-			mapiternext(iter)
-			code = code.next
-		case opSortedMapHeadIndent:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				e.encodeNull()
-				code = code.end.next
-			} else {
-				mlen := maplen(unsafe.Pointer(ptr))
-				if mlen > 0 {
-					e.encodeBytes([]byte{'{', '\n'})
-
-					iter := mapiterinit(code.typ, unsafe.Pointer(ptr))
-					ctx.keepRefs = append(ctx.keepRefs, iter)
-					store(ctxptr, code.elemIdx, 0)
-					store(ctxptr, code.length, uintptr(mlen))
-					store(ctxptr, code.mapIter, uintptr(iter))
-					pos := make([]int, 0, mlen)
-					pos = append(pos, len(e.buf))
-					posPtr := unsafe.Pointer(&pos)
-					ctx.keepRefs = append(ctx.keepRefs, posPtr)
-					store(ctxptr, code.end.mapPos, uintptr(posPtr))
-					key := mapiterkey(iter)
-					store(ctxptr, code.next.idx, uintptr(key))
-					code = code.next
-				} else {
-					e.encodeIndent(code.indent)
-					e.encodeBytes([]byte{'{', '}'})
-					code = code.end.next
-				}
-			}
-		case opSortedMapHeadLoadIndent:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				e.encodeNull()
-				code = code.end.next
-			} else {
-				// load pointer
-				ptr = uintptr(*(*unsafe.Pointer)(unsafe.Pointer(ptr)))
-				mlen := maplen(unsafe.Pointer(ptr))
-				if mlen > 0 {
-					e.encodeBytes([]byte{'{', '\n'})
-
-					iter := mapiterinit(code.typ, unsafe.Pointer(ptr))
-					ctx.keepRefs = append(ctx.keepRefs, iter)
-					store(ctxptr, code.elemIdx, 0)
-					store(ctxptr, code.length, uintptr(mlen))
-					store(ctxptr, code.mapIter, uintptr(iter))
-					key := mapiterkey(iter)
-					store(ctxptr, code.next.idx, uintptr(key))
-					pos := make([]int, 0, mlen)
-					pos = append(pos, len(e.buf))
-					posPtr := unsafe.Pointer(&pos)
-					ctx.keepRefs = append(ctx.keepRefs, posPtr)
-					store(ctxptr, code.end.mapPos, uintptr(posPtr))
-					code = code.next
-				} else {
-					e.encodeIndent(code.indent)
-					e.encodeBytes([]byte{'{', '}'})
-					code = code.end.next
-				}
-			}
-		case opSortedMapKeyIndent:
-			idx := load(ctxptr, code.elemIdx)
-			length := load(ctxptr, code.length)
-			posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
-			*posPtr = append(*posPtr, len(e.buf))
-			idx++
-			if idx < length {
-				iter := unsafe.Pointer(load(ctxptr, code.mapIter))
-				store(ctxptr, code.elemIdx, idx)
-				key := mapiterkey(iter)
-				store(ctxptr, code.next.idx, uintptr(key))
-				code = code.next
-			} else {
-				code = code.end
-			}
-		case opSortedMapValueIndent:
-			posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
-			*posPtr = append(*posPtr, len(e.buf))
-			iter := unsafe.Pointer(load(ctxptr, code.mapIter))
-			value := mapitervalue(iter)
-			store(ctxptr, code.next.idx, uintptr(value))
-			mapiternext(iter)
-			code = code.next
-		case opSortedMapEndIndent:
-			length := int(load(ctxptr, code.length))
-			type mapKV struct {
-				key   string
-				value string
-			}
-			kvs := make([]mapKV, 0, length)
-			pos := *(*[]int)(unsafe.Pointer(load(ctxptr, code.mapPos)))
-			for i := 0; i < length; i++ {
-				startKey := pos[i*2]
-				startValue := pos[i*2+1]
-				var endValue int
-				if i+1 < length {
-					endValue = pos[i*2+2]
-				} else {
-					endValue = len(e.buf)
-				}
-				kvs = append(kvs, mapKV{
-					key:   string(e.buf[startKey:startValue]),
-					value: string(e.buf[startValue:endValue]),
-				})
-			}
-			fmt.Println("kvs = ", kvs)
-			sort.Slice(kvs, func(i, j int) bool {
-				return kvs[i].key < kvs[j].key
-			})
-			buf := e.buf[pos[0]:]
-			buf = buf[:0]
-			for idx, kv := range kvs {
-				if idx != 0 {
-					buf = append(buf, []byte{',', '\n'}...)
-				}
-
-				buf = append(buf, e.prefix...)
-				buf = append(buf, bytes.Repeat(e.indentStr, code.indent+1)...)
-
-				buf = append(buf, []byte(kv.key)...)
-				buf = append(buf, []byte{':', ' '}...)
-				buf = append(buf, []byte(kv.value)...)
-			}
-			buf = append(buf, '\n')
-			buf = append(buf, e.prefix...)
-			buf = append(buf, bytes.Repeat(e.indentStr, code.indent)...)
-			buf = append(buf, '}')
-			e.buf = e.buf[:pos[0]]
-			e.buf = append(e.buf, buf...)
-			code = code.next
 		case opMapHeadIndent:
 			ptr := load(ctxptr, code.idx)
 			if ptr == 0 {
@@ -758,10 +583,20 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 					store(ctxptr, code.elemIdx, 0)
 					store(ctxptr, code.length, uintptr(mlen))
 					store(ctxptr, code.mapIter, uintptr(iter))
+
+					if !e.unorderedMap {
+						pos := make([]int, 0, mlen)
+						pos = append(pos, len(e.buf))
+						posPtr := unsafe.Pointer(&pos)
+						ctx.keepRefs = append(ctx.keepRefs, posPtr)
+						store(ctxptr, code.end.mapPos, uintptr(posPtr))
+					} else {
+						e.encodeIndent(code.next.indent)
+					}
+
 					key := mapiterkey(iter)
 					store(ctxptr, code.next.idx, uintptr(key))
 					code = code.next
-					e.encodeIndent(code.indent)
 				} else {
 					e.encodeIndent(code.indent)
 					e.encodeBytes([]byte{'{', '}'})
@@ -787,8 +622,18 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 					store(ctxptr, code.mapIter, uintptr(iter))
 					key := mapiterkey(iter)
 					store(ctxptr, code.next.idx, uintptr(key))
+
+					if !e.unorderedMap {
+						pos := make([]int, 0, mlen)
+						pos = append(pos, len(e.buf))
+						posPtr := unsafe.Pointer(&pos)
+						ctx.keepRefs = append(ctx.keepRefs, posPtr)
+						store(ctxptr, code.end.mapPos, uintptr(posPtr))
+					} else {
+						e.encodeIndent(code.next.indent)
+					}
+
 					code = code.next
-					e.encodeIndent(code.indent)
 				} else {
 					e.encodeIndent(code.indent)
 					e.encodeBytes([]byte{'{', '}'})
@@ -824,19 +669,33 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 			idx := load(ctxptr, code.elemIdx)
 			length := load(ctxptr, code.length)
 			idx++
-			if idx < length {
+			if e.unorderedMap {
-				e.encodeBytes([]byte{',', '\n'})
+				if idx < length {
-				e.encodeIndent(code.indent)
+					e.encodeBytes([]byte{',', '\n'})
-				store(ctxptr, code.elemIdx, idx)
+					e.encodeIndent(code.indent)
-				iter := unsafe.Pointer(load(ctxptr, code.mapIter))
+					store(ctxptr, code.elemIdx, idx)
-				key := mapiterkey(iter)
+					iter := unsafe.Pointer(load(ctxptr, code.mapIter))
-				store(ctxptr, code.next.idx, uintptr(key))
+					key := mapiterkey(iter)
-				code = code.next
+					store(ctxptr, code.next.idx, uintptr(key))
+					code = code.next
+				} else {
+					e.encodeByte('\n')
+					e.encodeIndent(code.indent - 1)
+					e.encodeByte('}')
+					code = code.end.next
+				}
 			} else {
-				e.encodeByte('\n')
+				posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
-				e.encodeIndent(code.indent - 1)
+				*posPtr = append(*posPtr, len(e.buf))
-				e.encodeByte('}')
+				if idx < length {
-				code = code.end.next
+					iter := unsafe.Pointer(load(ctxptr, code.mapIter))
+					store(ctxptr, code.elemIdx, idx)
+					key := mapiterkey(iter)
+					store(ctxptr, code.next.idx, uintptr(key))
+					code = code.next
+				} else {
+					code = code.end
+				}
 			}
 		case opRootMapKeyIndent:
 			idx := load(ctxptr, code.elemIdx)
@@ -857,12 +716,64 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 				code = code.end.next
 			}
 		case opMapValueIndent:
-			e.encodeBytes([]byte{':', ' '})
+			if e.unorderedMap {
+				e.encodeBytes([]byte{':', ' '})
+			} else {
+				posPtr := (*[]int)(unsafe.Pointer(load(ctxptr, code.end.mapPos)))
+				*posPtr = append(*posPtr, len(e.buf))
+			}
 			iter := unsafe.Pointer(load(ctxptr, code.mapIter))
 			value := mapitervalue(iter)
 			store(ctxptr, code.next.idx, uintptr(value))
 			mapiternext(iter)
 			code = code.next
+		case opMapEndIndent:
+			// this operation only used by sorted map
+			length := int(load(ctxptr, code.length))
+			type mapKV struct {
+				key   string
+				value string
+			}
+			kvs := make([]mapKV, 0, length)
+			pos := *(*[]int)(unsafe.Pointer(load(ctxptr, code.mapPos)))
+			for i := 0; i < length; i++ {
+				startKey := pos[i*2]
+				startValue := pos[i*2+1]
+				var endValue int
+				if i+1 < length {
+					endValue = pos[i*2+2]
+				} else {
+					endValue = len(e.buf)
+				}
+				kvs = append(kvs, mapKV{
+					key:   string(e.buf[startKey:startValue]),
+					value: string(e.buf[startValue:endValue]),
+				})
+			}
+			sort.Slice(kvs, func(i, j int) bool {
+				return kvs[i].key < kvs[j].key
+			})
+			buf := e.buf[pos[0]:]
+			buf = buf[:0]
+			for idx, kv := range kvs {
+				if idx != 0 {
+					buf = append(buf, []byte{',', '\n'}...)
+				}
+
+				buf = append(buf, e.prefix...)
+				buf = append(buf, bytes.Repeat(e.indentStr, code.indent+1)...)
+
+				buf = append(buf, []byte(kv.key)...)
+				buf = append(buf, []byte{':', ' '}...)
+				buf = append(buf, []byte(kv.value)...)
+			}
+			buf = append(buf, '\n')
+			buf = append(buf, e.prefix...)
+			buf = append(buf, bytes.Repeat(e.indentStr, code.indent)...)
+			buf = append(buf, '}')
+			e.buf = e.buf[:pos[0]]
+			e.buf = append(e.buf, buf...)
+			code = code.next
 		case opStructFieldRecursive:
 			ptr := load(ctxptr, code.idx)
 			if ptr != 0 {

json.go

@@ -154,8 +154,18 @@ type Unmarshaler interface {
 // an infinite recursion.
 //
 func Marshal(v interface{}) ([]byte, error) {
+	return MarshalWithOption(v)
+}
+
+// MarshalWithOption returns the JSON encoding of v with EncodeOption.
+func MarshalWithOption(v interface{}, opts ...EncodeOption) ([]byte, error) {
 	var b *bytes.Buffer
 	enc := NewEncoder(b)
+	for _, opt := range opts {
+		if err := opt(enc); err != nil {
+			return nil, err
+		}
+	}
 	bytes, err := enc.encodeForMarshal(v)
 	if err != nil {
 		enc.release()
@@ -169,8 +179,18 @@ func Marshal(v interface{}) ([]byte, error) {
 // Each JSON element in the output will begin on a new line beginning with prefix
 // followed by one or more copies of indent according to the indentation nesting.
 func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
+	return MarshalIndentWithOption(v, prefix, indent)
+}
+
+// MarshalIndentWithOption is like Marshal but applies Indent to format the output with EncodeOption.
+func MarshalIndentWithOption(v interface{}, prefix, indent string, opts ...EncodeOption) ([]byte, error) {
 	var b *bytes.Buffer
 	enc := NewEncoder(b)
+	for _, opt := range opts {
+		if err := opt(enc); err != nil {
+			return nil, err
+		}
+	}
 	enc.SetIndent(prefix, indent)
 	bytes, err := enc.encodeForMarshal(v)
 	if err != nil {