Add only type

cmd/generator/main.go

@@ -481,6 +481,121 @@ func (t opType) fieldToStringTagField() opType {
 			}
 		}
 	}
+	for _, escapedOrNot := range []string{"", "Escaped"} {
+		for _, ptrOrNot := range []string{"", "Ptr", "NPtr"} {
+			for _, headType := range []string{"", "Anonymous"} {
+				for _, opt := range []string{"", "OmitEmpty", "StringTag"} {
+					for _, typ := range []string{
+						"Int", "Int8", "Int16", "Int32", "Int64",
+						"Uint", "Uint8", "Uint16", "Uint32", "Uint64",
+						"Float32", "Float64", "Bool", "String", "EscapedString", "Bytes",
+						"IntPtr", "Int8Ptr", "Int16Ptr", "Int32Ptr", "Int64Ptr",
+						"UintPtr", "Uint8Ptr", "Uint16Ptr", "Uint32Ptr", "Uint64Ptr",
+						"Float32Ptr", "Float64Ptr", "BoolPtr", "StringPtr", "EscapedStringPtr", "BytesPtr",
+						"IntNPtr", "Int8NPtr", "Int16NPtr", "Int32NPtr", "Int64NPtr",
+						"UintNPtr", "Uint8NPtr", "Uint16NPtr", "Uint32NPtr", "Uint64NPtr",
+						"Float32NPtr", "Float64NPtr", "BoolNPtr", "StringNPtr", "EscapedStringNPtr", "BytesNPtr",
+					} {
+						escapedOrNot := escapedOrNot
+						ptrOrNot := ptrOrNot
+						headType := headType
+						opt := opt
+						typ := typ
+
+						op := fmt.Sprintf(
+							"Struct%sField%s%sHead%s%sOnly",
+							escapedOrNot,
+							ptrOrNot,
+							headType,
+							opt,
+							typ,
+						)
+						opTypes = append(opTypes, opType{
+							Op:     op,
+							Code:   "StructField",
+							Indent: func() string { return fmt.Sprintf("%sIndent", op) },
+							Escaped: func() string {
+								switch typ {
+								case "String", "StringPtr", "StringNPtr":
+									return fmt.Sprintf(
+										"StructEscapedField%s%sHead%sEscaped%sOnly",
+										ptrOrNot,
+										headType,
+										opt,
+										typ,
+									)
+								}
+								return fmt.Sprintf(
+									"StructEscapedField%s%sHead%s%sOnly",
+									ptrOrNot,
+									headType,
+									opt,
+									typ,
+								)
+							},
+							HeadToPtrHead: func() string {
+								return fmt.Sprintf(
+									"Struct%sFieldPtr%sHead%s%sOnly",
+									escapedOrNot,
+									headType,
+									opt,
+									typ,
+								)
+							},
+							HeadToNPtrHead: func() string {
+								return fmt.Sprintf(
+									"Struct%sFieldNPtr%sHead%s%sOnly",
+									escapedOrNot,
+									headType,
+									opt,
+									typ,
+								)
+							},
+							HeadToAnonymousHead: func() string {
+								return fmt.Sprintf(
+									"Struct%sField%sAnonymousHead%s%sOnly",
+									escapedOrNot,
+									ptrOrNot,
+									opt,
+									typ,
+								)
+							},
+							HeadToOmitEmptyHead: func() string {
+								return fmt.Sprintf(
+									"Struct%sField%s%sHeadOmitEmpty%sOnly",
+									escapedOrNot,
+									ptrOrNot,
+									headType,
+									typ,
+								)
+							},
+							HeadToStringTagHead: func() string {
+								return fmt.Sprintf(
+									"Struct%sField%s%sHeadStringTag%sOnly",
+									escapedOrNot,
+									ptrOrNot,
+									headType,
+									typ,
+								)
+							},
+							PtrHeadToHead: func() string {
+								return fmt.Sprintf(
+									"Struct%sField%sHead%s%sOnly",
+									escapedOrNot,
+									headType,
+									opt,
+									typ,
+								)
+							},
+							FieldToEnd:            func() string { return op },
+							FieldToOmitEmptyField: func() string { return op },
+							FieldToStringTagField: func() string { return op },
+						})
+					}
+				}
+			}
+		}
+	}
 	for _, escapedOrNot := range []string{"", "Escaped"} {
 		for _, opt := range []string{"", "OmitEmpty", "StringTag"} {
 			for _, typ := range append(primitiveTypesUpper, "") {

coverage_test.go

@@ -0,0 +1,417 @@
+package json
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+func intptr(v int) *int {
+	return &v
+}
+
+func int8ptr(v int8) *int8 {
+	return &v
+}
+
+func headIntPtrNilNotRoot() interface{} {
+	v := struct {
+		A struct {
+			A *int `json:"a"`
+		}
+	}{}
+	return v
+}
+
+func ptrHeadIntNotRoot() interface{} {
+	v := struct {
+		A *struct {
+			A int `json:"a"`
+		}
+	}{A: new(struct {
+		A int `json:"a"`
+	})}
+	v.A.A = 1
+	return v
+}
+
+func TestCoverage(t *testing.T) {
+	tests := []struct {
+		name     string
+		expected string
+		data     interface{}
+	}{
+		{
+			name:     "HeadIntZero",
+			expected: `{"a":0}`,
+			data: struct {
+				A int `json:"a"`
+			}{},
+		},
+		{
+			name:     "HeadInt",
+			expected: `{"a":1}`,
+			data: struct {
+				A int `json:"a"`
+			}{A: 1},
+		},
+		{
+			name:     "HeadIntPtr",
+			expected: `{"a":1}`,
+			data: struct {
+				A *int `json:"a"`
+			}{A: intptr(1)},
+		},
+		{
+			name:     "HeadIntPtrNil",
+			expected: `{"a":null}`,
+			data: struct {
+				A *int `json:"a"`
+			}{A: nil},
+		},
+		{
+			name:     "PtrHeadIntZero",
+			expected: `{"a":0}`,
+			data: &struct {
+				A int `json:"a"`
+			}{},
+		},
+		{
+			name:     "PtrHeadInt",
+			expected: `{"a":1}`,
+			data: &struct {
+				A int `json:"a"`
+			}{A: 1},
+		},
+		{
+			name:     "PtrHeadIntPtr",
+			expected: `{"a":1}`,
+			data: &struct {
+				A *int `json:"a"`
+			}{A: intptr(1)},
+		},
+		{
+			name:     "PtrHeadIntPtrNil",
+			expected: `{"a":null}`,
+			data: &struct {
+				A *int `json:"a"`
+			}{A: nil},
+		},
+		{
+			name:     "PtrHeadIntNil",
+			expected: `null`,
+			data: (*struct {
+				A *int `json:"a"`
+			})(nil),
+		},
+		{
+			name:     "HeadIntZeroMultiFields",
+			expected: `{"a":0,"b":0}`,
+			data: struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{},
+		},
+		{
+			name:     "HeadIntMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{A: 1, B: 2},
+		},
+		{
+			name:     "HeadIntPtrMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: intptr(1), B: intptr(2)},
+		},
+		{
+			name:     "HeadIntPtrNilMultiFieldsd",
+			expected: `{"a":null,"b":null}`,
+			data: struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: nil, B: nil},
+		},
+		{
+			name:     "PtrHeadIntZeroMultiFields",
+			expected: `{"a":0,"b":0}`,
+			data: &struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{},
+		},
+		{
+			name:     "PtrHeadIntMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: &struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{A: 1, B: 2},
+		},
+		{
+			name:     "PtrHeadIntPtrMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: &struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: intptr(1), B: intptr(2)},
+		},
+		{
+			name:     "PtrHeadIntPtrNilMultiFields",
+			expected: `{"a":null,"b":null}`,
+			data: &struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: nil, B: nil},
+		},
+		{
+			name:     "PtrHeadIntNilMultiFields",
+			expected: `null`,
+			data: (*struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			})(nil),
+		},
+
+		{
+			name:     "HeadIntZeroNotRoot",
+			expected: `{"A":{"a":0}}`,
+			data: struct {
+				A struct {
+					A int `json:"a"`
+				}
+			}{},
+		},
+		{
+			name:     "HeadIntNotRoot",
+			expected: `{"A":{"a":1}}`,
+			data: struct {
+				A struct {
+					A int `json:"a"`
+				}
+			}{A: struct {
+				A int `json:"a"`
+			}{A: 1}},
+		},
+		{
+			name:     "HeadIntPtrNotRoot",
+			expected: `{"A":{"a":1}}`,
+			data: struct {
+				A struct {
+					A *int `json:"a"`
+				}
+			}{A: struct {
+				A *int `json:"a"`
+			}{intptr(1)}},
+		},
+		/*
+				{
+					name:     "HeadIntPtrNilNotRoot",
+					expected: `{"A":{"a":null}}`,
+					data: struct {
+						A struct {
+							A *int `json:"a"`
+						}
+					}{},
+				},
+			{
+				name:     "PtrHeadIntZeroNotRoot",
+				expected: `{"A":{"a":0}}`,
+				data: struct {
+					A *struct {
+						A int `json:"a"`
+					}
+				}{A: new(struct {
+					A int `json:"a"`
+				})},
+			},
+			{
+				name:     "PtrHeadIntNotRoot",
+				expected: `{"A":{"a":1}}`,
+				data: struct {
+					A *struct {
+						A int `json:"a"`
+					}
+				}{A: &(struct {
+					A int `json:"a"`
+				}{A: 1})},
+			},
+			{
+				name:     "PtrHeadIntPtrNotRoot",
+				expected: `{"A":{"a":1}}`,
+				data: struct {
+					A *struct {
+						A *int `json:"a"`
+					}
+				}{A: &(struct {
+					A *int `json:"a"`
+				}{A: intptr(1)})},
+			},
+			{
+				name:     "PtrHeadIntPtrNilNotRoot",
+				expected: `{"A":{"a":null}}`,
+				data: struct {
+					A *struct {
+						A *int `json:"a"`
+					}
+				}{A: &(struct {
+					A *int `json:"a"`
+				}{A: nil})},
+			},
+		*/
+		/*
+			{
+				name:     "PtrHeadIntNilNotRoot",
+				expected: `{"A":null}`,
+				data: struct {
+					A *struct {
+						A *int `json:"a"`
+					}
+				}{A: nil},
+			},
+		*/
+		{
+			name:     "HeadIntZeroMultiFields",
+			expected: `{"a":0,"b":0}`,
+			data: struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{},
+		},
+		{
+			name:     "HeadIntMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{A: 1, B: 2},
+		},
+		{
+			name:     "HeadIntPtrMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: intptr(1), B: intptr(2)},
+		},
+		{
+			name:     "HeadIntPtrNilMultiFieldsd",
+			expected: `{"a":null,"b":null}`,
+			data: struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: nil, B: nil},
+		},
+		{
+			name:     "PtrHeadIntZeroMultiFields",
+			expected: `{"a":0,"b":0}`,
+			data: &struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{},
+		},
+		{
+			name:     "PtrHeadIntMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: &struct {
+				A int `json:"a"`
+				B int `json:"b"`
+			}{A: 1, B: 2},
+		},
+		{
+			name:     "PtrHeadIntPtrMultiFields",
+			expected: `{"a":1,"b":2}`,
+			data: &struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: intptr(1), B: intptr(2)},
+		},
+		{
+			name:     "PtrHeadIntPtrNilMultiFields",
+			expected: `{"a":null,"b":null}`,
+			data: &struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			}{A: nil, B: nil},
+		},
+		{
+			name:     "PtrHeadIntNilMultiFields",
+			expected: `null`,
+			data: (*struct {
+				A *int `json:"a"`
+				B *int `json:"b"`
+			})(nil),
+		},
+
+		{
+			name:     "Int8Head",
+			expected: `{"a":1}`,
+			data: struct {
+				A int8 `json:"a"`
+			}{A: 1},
+		},
+		{
+			name:     "Int8PtrHead",
+			expected: `{"a":1}`,
+			data: struct {
+				A *int8 `json:"a"`
+			}{A: int8ptr(1)},
+		},
+		/*
+			{
+				name:     "Int8PtrNilHead",
+				expected: `{"a":null}`,
+				data: struct {
+					A *int8 `json:"a"`
+				}{A: nil},
+			},
+		*/
+		{
+			name:     "PtrInt8Head",
+			expected: `{"a":1}`,
+			data: &struct {
+				A int8 `json:"a"`
+			}{A: 1},
+		},
+		{
+			name:     "PtrInt8PtrHead",
+			expected: `{"a":1}`,
+			data: &struct {
+				A *int8 `json:"a"`
+			}{A: int8ptr(1)},
+		},
+		{
+			name:     "Int8Field",
+			expected: `{"a":1,"b":2}`,
+			data: struct {
+				A int8 `json:"a"`
+				B int8 `json:"b"`
+			}{A: 1, B: 2},
+		},
+		{
+			name:     "Int8PtrField",
+			expected: `{"a":1,"b":2}`,
+			data: struct {
+				A *int8 `json:"a"`
+				B *int8 `json:"b"`
+			}{A: int8ptr(1), B: int8ptr(2)},
+		},
+	}
+	for _, test := range tests {
+		for _, htmlEscape := range []bool{true, false} {
+			var buf bytes.Buffer
+			enc := NewEncoder(&buf)
+			enc.SetEscapeHTML(htmlEscape)
+			if err := enc.Encode(test.data); err != nil {
+				t.Errorf("%s(htmlEscape:%T): %s: %s", test.name, htmlEscape, test.expected, err)
+			}
+			if strings.TrimRight(buf.String(), "\n") != test.expected {
+				t.Errorf("%s(htmlEscape:%T): expected %q but got %q", test.name, htmlEscape, test.expected, buf.String())
+			}
+		}
+	}
+}

encode_compile.go

@@ -536,126 +536,251 @@ func (e *Encoder) compileMap(ctx *encodeCompileContext, withLoad bool) (*opcode,
 	return (*opcode)(unsafe.Pointer(header)), nil
 }
 
-func (e *Encoder) typeToHeaderType(ctx *encodeCompileContext, code *opcode) opType {
-	switch code.op {
-	case opPtr:
-		ptrNum := 1
-		c := code
-		ctx.decIndex()
-		for {
-			if code.next.op == opPtr {
-				ptrNum++
-				code = code.next
-				ctx.decIndex()
+func (e *Encoder) typeToHeaderType(ctx *encodeCompileContext, code *opcode, isOnlyPtrField bool) opType {
+	if isOnlyPtrField {
+		// 1. pointer struct + primitive type field
+		// 2. struct + primitive pointer type field
+		switch code.op {
+		case opPtr:
+			ptrNum := 1
+			c := code
+			ctx.decIndex()
+			for {
+				if code.next.op == opPtr {
+					ptrNum++
+					code = code.next
+					ctx.decIndex()
+				}
+				break
 			}
-			break
+			c.ptrNum = ptrNum
+			if ptrNum > 1 {
+				switch code.next.op {
+				case opInt:
+					return opStructFieldHeadIntNPtrOnly
+				case opInt8:
+					return opStructFieldHeadInt8NPtrOnly
+				case opInt16:
+					return opStructFieldHeadInt16NPtrOnly
+				case opInt32:
+					return opStructFieldHeadInt32NPtrOnly
+				case opInt64:
+					return opStructFieldHeadInt64NPtrOnly
+				case opUint:
+					return opStructFieldHeadUintNPtrOnly
+				case opUint8:
+					return opStructFieldHeadUint8NPtrOnly
+				case opUint16:
+					return opStructFieldHeadUint16NPtrOnly
+				case opUint32:
+					return opStructFieldHeadUint32NPtrOnly
+				case opUint64:
+					return opStructFieldHeadUint64NPtrOnly
+				case opFloat32:
+					return opStructFieldHeadFloat32NPtrOnly
+				case opFloat64:
+					return opStructFieldHeadFloat64NPtrOnly
+				case opString:
+					return opStructFieldHeadStringNPtrOnly
+				case opBool:
+					return opStructFieldHeadBoolNPtrOnly
+				}
+			} else {
+				switch code.next.op {
+				case opInt:
+					return opStructFieldHeadIntPtrOnly
+				case opInt8:
+					return opStructFieldHeadInt8PtrOnly
+				case opInt16:
+					return opStructFieldHeadInt16PtrOnly
+				case opInt32:
+					return opStructFieldHeadInt32PtrOnly
+				case opInt64:
+					return opStructFieldHeadInt64PtrOnly
+				case opUint:
+					return opStructFieldHeadUintPtrOnly
+				case opUint8:
+					return opStructFieldHeadUint8PtrOnly
+				case opUint16:
+					return opStructFieldHeadUint16PtrOnly
+				case opUint32:
+					return opStructFieldHeadUint32PtrOnly
+				case opUint64:
+					return opStructFieldHeadUint64PtrOnly
+				case opFloat32:
+					return opStructFieldHeadFloat32PtrOnly
+				case opFloat64:
+					return opStructFieldHeadFloat64PtrOnly
+				case opString:
+					return opStructFieldHeadStringPtrOnly
+				case opBool:
+					return opStructFieldHeadBoolPtrOnly
+				}
+			}
+		case opInt:
+			return opStructFieldHeadIntOnly
+		case opInt8:
+			return opStructFieldHeadInt8Only
+		case opInt16:
+			return opStructFieldHeadInt16Only
+		case opInt32:
+			return opStructFieldHeadInt32Only
+		case opInt64:
+			return opStructFieldHeadInt64Only
+		case opUint:
+			return opStructFieldHeadUintOnly
+		case opUint8:
+			return opStructFieldHeadUint8Only
+		case opUint16:
+			return opStructFieldHeadUint16Only
+		case opUint32:
+			return opStructFieldHeadUint32Only
+		case opUint64:
+			return opStructFieldHeadUint64Only
+		case opFloat32:
+			return opStructFieldHeadFloat32Only
+		case opFloat64:
+			return opStructFieldHeadFloat64Only
+		case opString:
+			return opStructFieldHeadStringOnly
+		case opBool:
+			return opStructFieldHeadBoolOnly
+		case opMapHead:
+			return opStructFieldHeadMap
+		case opMapHeadLoad:
+			return opStructFieldHeadMapLoad
+		case opArrayHead:
+			return opStructFieldHeadArray
+		case opSliceHead:
+			return opStructFieldHeadSlice
+		case opStructFieldHead:
+			return opStructFieldHeadStruct
+		case opMarshalJSON:
+			return opStructFieldHeadMarshalJSON
+		case opMarshalText:
+			return opStructFieldHeadMarshalText
 		}
-		c.ptrNum = ptrNum
-		if ptrNum > 1 {
-			switch code.next.op {
-			case opInt:
-				return opStructFieldHeadIntNPtr
-			case opInt8:
-				return opStructFieldHeadInt8NPtr
-			case opInt16:
-				return opStructFieldHeadInt16NPtr
-			case opInt32:
-				return opStructFieldHeadInt32NPtr
-			case opInt64:
-				return opStructFieldHeadInt64NPtr
-			case opUint:
-				return opStructFieldHeadUintNPtr
-			case opUint8:
-				return opStructFieldHeadUint8NPtr
-			case opUint16:
-				return opStructFieldHeadUint16NPtr
-			case opUint32:
-				return opStructFieldHeadUint32NPtr
-			case opUint64:
-				return opStructFieldHeadUint64NPtr
-			case opFloat32:
-				return opStructFieldHeadFloat32NPtr
-			case opFloat64:
-				return opStructFieldHeadFloat64NPtr
-			case opString:
-				return opStructFieldHeadStringNPtr
-			case opBool:
-				return opStructFieldHeadBoolNPtr
+	} else {
+		switch code.op {
+		case opPtr:
+			ptrNum := 1
+			c := code
+			ctx.decIndex()
+			for {
+				if code.next.op == opPtr {
+					ptrNum++
+					code = code.next
+					ctx.decIndex()
+				}
+				break
 			}
-		} else {
-			switch code.next.op {
-			case opInt:
-				return opStructFieldHeadIntPtr
-			case opInt8:
-				return opStructFieldHeadInt8Ptr
-			case opInt16:
-				return opStructFieldHeadInt16Ptr
-			case opInt32:
-				return opStructFieldHeadInt32Ptr
-			case opInt64:
-				return opStructFieldHeadInt64Ptr
-			case opUint:
-				return opStructFieldHeadUintPtr
-			case opUint8:
-				return opStructFieldHeadUint8Ptr
-			case opUint16:
-				return opStructFieldHeadUint16Ptr
-			case opUint32:
-				return opStructFieldHeadUint32Ptr
-			case opUint64:
-				return opStructFieldHeadUint64Ptr
-			case opFloat32:
-				return opStructFieldHeadFloat32Ptr
-			case opFloat64:
-				return opStructFieldHeadFloat64Ptr
-			case opString:
-				return opStructFieldHeadStringPtr
-			case opBool:
-				return opStructFieldHeadBoolPtr
+			c.ptrNum = ptrNum
+			if ptrNum > 1 {
+				switch code.next.op {
+				case opInt:
+					return opStructFieldHeadIntNPtr
+				case opInt8:
+					return opStructFieldHeadInt8NPtr
+				case opInt16:
+					return opStructFieldHeadInt16NPtr
+				case opInt32:
+					return opStructFieldHeadInt32NPtr
+				case opInt64:
+					return opStructFieldHeadInt64NPtr
+				case opUint:
+					return opStructFieldHeadUintNPtr
+				case opUint8:
+					return opStructFieldHeadUint8NPtr
+				case opUint16:
+					return opStructFieldHeadUint16NPtr
+				case opUint32:
+					return opStructFieldHeadUint32NPtr
+				case opUint64:
+					return opStructFieldHeadUint64NPtr
+				case opFloat32:
+					return opStructFieldHeadFloat32NPtr
+				case opFloat64:
+					return opStructFieldHeadFloat64NPtr
+				case opString:
+					return opStructFieldHeadStringNPtr
+				case opBool:
+					return opStructFieldHeadBoolNPtr
+				}
+			} else {
+				switch code.next.op {
+				case opInt:
+					return opStructFieldHeadIntPtr
+				case opInt8:
+					return opStructFieldHeadInt8Ptr
+				case opInt16:
+					return opStructFieldHeadInt16Ptr
+				case opInt32:
+					return opStructFieldHeadInt32Ptr
+				case opInt64:
+					return opStructFieldHeadInt64Ptr
+				case opUint:
+					return opStructFieldHeadUintPtr
+				case opUint8:
+					return opStructFieldHeadUint8Ptr
+				case opUint16:
+					return opStructFieldHeadUint16Ptr
+				case opUint32:
+					return opStructFieldHeadUint32Ptr
+				case opUint64:
+					return opStructFieldHeadUint64Ptr
+				case opFloat32:
+					return opStructFieldHeadFloat32Ptr
+				case opFloat64:
+					return opStructFieldHeadFloat64Ptr
+				case opString:
+					return opStructFieldHeadStringPtr
+				case opBool:
+					return opStructFieldHeadBoolPtr
+				}
 			}
+		case opInt:
+			return opStructFieldHeadInt
+		case opInt8:
+			return opStructFieldHeadInt8
+		case opInt16:
+			return opStructFieldHeadInt16
+		case opInt32:
+			return opStructFieldHeadInt32
+		case opInt64:
+			return opStructFieldHeadInt64
+		case opUint:
+			return opStructFieldHeadUint
+		case opUint8:
+			return opStructFieldHeadUint8
+		case opUint16:
+			return opStructFieldHeadUint16
+		case opUint32:
+			return opStructFieldHeadUint32
+		case opUint64:
+			return opStructFieldHeadUint64
+		case opFloat32:
+			return opStructFieldHeadFloat32
+		case opFloat64:
+			return opStructFieldHeadFloat64
+		case opString:
+			return opStructFieldHeadString
+		case opBool:
+			return opStructFieldHeadBool
+		case opMapHead:
+			return opStructFieldHeadMap
+		case opMapHeadLoad:
+			return opStructFieldHeadMapLoad
+		case opArrayHead:
+			return opStructFieldHeadArray
+		case opSliceHead:
+			return opStructFieldHeadSlice
+		case opStructFieldHead:
+			return opStructFieldHeadStruct
+		case opMarshalJSON:
+			return opStructFieldHeadMarshalJSON
+		case opMarshalText:
+			return opStructFieldHeadMarshalText
 		}
-	case opInt:
-		return opStructFieldHeadInt
-	case opInt8:
-		return opStructFieldHeadInt8
-	case opInt16:
-		return opStructFieldHeadInt16
-	case opInt32:
-		return opStructFieldHeadInt32
-	case opInt64:
-		return opStructFieldHeadInt64
-	case opUint:
-		return opStructFieldHeadUint
-	case opUint8:
-		return opStructFieldHeadUint8
-	case opUint16:
-		return opStructFieldHeadUint16
-	case opUint32:
-		return opStructFieldHeadUint32
-	case opUint64:
-		return opStructFieldHeadUint64
-	case opFloat32:
-		return opStructFieldHeadFloat32
-	case opFloat64:
-		return opStructFieldHeadFloat64
-	case opString:
-		return opStructFieldHeadString
-	case opBool:
-		return opStructFieldHeadBool
-	case opMapHead:
-		return opStructFieldHeadMap
-	case opMapHeadLoad:
-		return opStructFieldHeadMapLoad
-	case opArrayHead:
-		return opStructFieldHeadArray
-	case opSliceHead:
-		return opStructFieldHeadSlice
-	case opStructFieldHead:
-		return opStructFieldHeadStruct
-	case opMarshalJSON:
-		return opStructFieldHeadMarshalJSON
-	case opMarshalText:
-		return opStructFieldHeadMarshalText
 	}
 	return opStructFieldHead
 }
@@ -784,8 +909,8 @@ func (e *Encoder) typeToFieldType(ctx *encodeCompileContext, code *opcode) opTyp
 	return opStructField
 }
 
-func (e *Encoder) optimizeStructHeader(ctx *encodeCompileContext, code *opcode, tag *structTag) opType {
-	headType := e.typeToHeaderType(ctx, code)
+func (e *Encoder) optimizeStructHeader(ctx *encodeCompileContext, code *opcode, tag *structTag, isOnlyPtrField bool) opType {
+	headType := e.typeToHeaderType(ctx, code, isOnlyPtrField)
 	switch {
 	case tag.isOmitEmpty:
 		headType = headType.headToOmitEmptyHead()
@@ -821,9 +946,9 @@ func (e *Encoder) compiledCode(ctx *encodeCompileContext) *opcode {
 	return nil
 }
 
-func (e *Encoder) structHeader(ctx *encodeCompileContext, fieldCode *opcode, valueCode *opcode, tag *structTag) *opcode {
+func (e *Encoder) structHeader(ctx *encodeCompileContext, fieldCode *opcode, valueCode *opcode, tag *structTag, isOnlyPtrField bool) *opcode {
 	fieldCode.indent--
-	op := e.optimizeStructHeader(ctx, valueCode, tag)
+	op := e.optimizeStructHeader(ctx, valueCode, tag, isOnlyPtrField)
 	fieldCode.op = op
 	fieldCode.ptrNum = valueCode.ptrNum
 	switch op {
@@ -1102,17 +1227,11 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 				anonymousFields[k] = append(anonymousFields[k], v...)
 			}
 		}
-		if fieldNum == 1 && valueCode.op == opPtr {
-			// if field number is one and primitive pointer type,
-			// it should encode as **not** pointer .
-			switch valueCode.next.op {
-			case opInt, opInt8, opInt16, opInt32, opInt64,
-				opUint, opUint8, opUint16, opUint32, opUint64,
-				opFloat32, opFloat64, opBool, opString, opBytes:
-				valueCode = valueCode.next
-				ctx.decOpcodeIndex()
-			}
-		}
+
+		// if field number is one and primitive pointer type,
+		// it should encode as special opcode.
+		isOnlyPtrField := fieldNum == 1 && (valueCode.op == opPtr && !isPtr || valueCode.op != opPtr && isPtr)
+
 		key := fmt.Sprintf(`"%s":`, tag.key)
 		escapedKey := fmt.Sprintf(`%s:`, string(encodeEscapedString([]byte{}, tag.key)))
 		fieldCode := &opcode{
@@ -1130,7 +1249,7 @@ func (e *Encoder) compileStruct(ctx *encodeCompileContext, isPtr bool) (*opcode,
 		}
 		if fieldIdx == 0 {
 			fieldCode.headIdx = fieldCode.idx
-			code = e.structHeader(ctx, fieldCode, valueCode, tag)
+			code = e.structHeader(ctx, fieldCode, valueCode, tag, isOnlyPtrField)
 			head = fieldCode
 			prevField = fieldCode
 		} else {

encode_vm.go

@@ -1236,6 +1236,22 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				code = code.next
 				store(ctxptr, code.idx, ptr)
 			}
+		case opStructFieldPtrHeadIntOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			fallthrough
+		case opStructFieldHeadIntOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.key...)
+			b = appendInt(b, int64(e.ptrToInt(p)))
+			b = encodeComma(b)
+			code = code.next
 		case opStructFieldPtrHeadInt:
 			p := load(ctxptr, code.idx)
 			if p == 0 {
@@ -1247,22 +1263,28 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 			store(ctxptr, code.idx, e.ptrToPtr(p))
 			fallthrough
 		case opStructFieldHeadInt:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				if code.op == opStructFieldPtrHeadInt {
-					b = encodeNull(b)
-					b = encodeComma(b)
-				} else {
-					b = append(b, '{', '}', ',')
-				}
-				code = code.end.next
-			} else {
-				b = append(b, '{')
-				b = append(b, code.key...)
-				b = appendInt(b, int64(e.ptrToInt(ptr+code.offset)))
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.key...)
+			b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
+			b = encodeComma(b)
+			code = code.next
+		case opStructEscapedFieldPtrHeadIntOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
 				b = encodeComma(b)
-				code = code.next
+				code = code.end.next
+				break
 			}
+			fallthrough
+		case opStructEscapedFieldHeadIntOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			b = appendInt(b, int64(e.ptrToInt(p)))
+			b = encodeComma(b)
+			code = code.next
 		case opStructEscapedFieldPtrHeadInt:
 			p := load(ctxptr, code.idx)
 			if p == 0 {
@@ -1274,51 +1296,107 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 			store(ctxptr, code.idx, e.ptrToPtr(p))
 			fallthrough
 		case opStructEscapedFieldHeadInt:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				if code.op == opStructEscapedFieldPtrHeadInt {
-					b = encodeNull(b)
-					b = encodeComma(b)
-				} else {
-					b = append(b, '{', '}', ',')
-				}
-				code = code.end.next
-			} else {
-				b = append(b, '{')
-				b = append(b, code.escapedKey...)
-				b = appendInt(b, int64(e.ptrToInt(ptr+code.offset)))
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
+			b = encodeComma(b)
+			code = code.next
+		case opStructFieldPtrHeadIntPtrOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
 				b = encodeComma(b)
-				code = code.next
+				code = code.end.next
+				break
 			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
+		case opStructFieldHeadIntPtrOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.key...)
+			if p == 0 {
+				b = encodeNull(b)
+			} else {
+				b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
+			}
+			b = encodeComma(b)
+			code = code.next
+		case opStructFieldPtrHeadIntPtr:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
 		case opStructFieldHeadIntPtr:
 			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			b = append(b, '{')
+			b = append(b, code.key...)
+			p = e.ptrToPtr(p)
 			if p == 0 {
 				b = encodeNull(b)
 			} else {
-				b = append(b, '{')
-				b = append(b, code.key...)
-				p = e.ptrToPtr(p)
-				if p == 0 {
-					b = encodeNull(b)
-				} else {
-					b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
-				}
+				b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
 			}
 			b = encodeComma(b)
 			code = code.next
+		case opStructEscapedFieldPtrHeadIntPtrOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
+		case opStructEscapedFieldHeadIntPtrOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			if p == 0 {
+				b = encodeNull(b)
+			} else {
+				b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
+			}
+			b = encodeComma(b)
+			code = code.next
+		case opStructEscapedFieldPtrHeadIntPtr:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
 		case opStructEscapedFieldHeadIntPtr:
 			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			p = e.ptrToPtr(p)
 			if p == 0 {
 				b = encodeNull(b)
 			} else {
-				b = append(b, '{')
-				b = append(b, code.escapedKey...)
-				p = e.ptrToPtr(p)
-				if p == 0 {
-					b = encodeNull(b)
-				} else {
-					b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
-				}
+				b = appendInt(b, int64(e.ptrToInt(p+code.offset)))
 			}
 			b = encodeComma(b)
 			code = code.next
@@ -1326,6 +1404,7 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 			p := load(ctxptr, code.idx)
 			if p == 0 {
 				b = encodeNull(b)
+				code = code.end.next
 			} else {
 				b = append(b, '{')
 				b = append(b, code.key...)
@@ -1390,6 +1469,22 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				b = encodeComma(b)
 				code = code.next
 			}
+		case opStructFieldPtrHeadInt8Only:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			fallthrough
+		case opStructFieldHeadInt8Only:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.key...)
+			b = appendInt(b, int64(e.ptrToInt8(p)))
+			b = encodeComma(b)
+			code = code.next
 		case opStructFieldPtrHeadInt8:
 			p := load(ctxptr, code.idx)
 			if p == 0 {
@@ -1417,6 +1512,22 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				b = encodeComma(b)
 				code = code.next
 			}
+		case opStructEscapedFieldPtrHeadInt8Only:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			fallthrough
+		case opStructEscapedFieldHeadInt8Only:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			b = appendInt(b, int64(e.ptrToInt8(p)))
+			b = encodeComma(b)
+			code = code.next
 		case opStructEscapedFieldPtrHeadInt8:
 			p := load(ctxptr, code.idx)
 			if p == 0 {
@@ -1444,6 +1555,102 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				b = encodeComma(b)
 				code = code.next
 			}
+		case opStructFieldPtrHeadInt8PtrOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
+		case opStructFieldHeadInt8PtrOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.key...)
+			if p == 0 {
+				b = encodeNull(b)
+			} else {
+				b = appendInt(b, int64(e.ptrToInt8(p)))
+			}
+			b = encodeComma(b)
+			code = code.next
+		case opStructFieldPtrHeadInt8Ptr:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
+		case opStructFieldHeadInt8Ptr:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				code = code.end.next
+			} else {
+				b = append(b, '{')
+				b = append(b, code.key...)
+				p = e.ptrToPtr(p)
+				if p == 0 {
+					b = encodeNull(b)
+				} else {
+					b = appendInt(b, int64(e.ptrToInt8(p+code.offset)))
+				}
+				code = code.next
+			}
+			b = encodeComma(b)
+		case opStructEscapedFieldPtrHeadInt8PtrOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
+		case opStructEscapedFieldHeadInt8PtrOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			if p == 0 {
+				b = encodeNull(b)
+			} else {
+				b = appendInt(b, int64(e.ptrToInt8(p)))
+			}
+			b = encodeComma(b)
+			code = code.next
+		case opStructEscapedFieldPtrHeadInt8Ptr:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, e.ptrToPtr(p))
+			fallthrough
+		case opStructEscapedFieldHeadInt8Ptr:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				code = code.end.next
+			} else {
+				b = append(b, '{')
+				b = append(b, code.escapedKey...)
+				p = e.ptrToPtr(p)
+				if p == 0 {
+					b = encodeNull(b)
+				} else {
+					b = appendInt(b, int64(e.ptrToInt8(p+code.offset)))
+				}
+				code = code.next
+			}
+			b = encodeComma(b)
 		case opStructFieldPtrAnonymousHeadInt8:
 			store(ctxptr, code.idx, e.ptrToPtr(load(ctxptr, code.idx)))
 			fallthrough
@@ -2313,6 +2520,22 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				b = encodeComma(b)
 				code = code.next
 			}
+		case opStructEscapedFieldPtrHeadEscapedStringOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			fallthrough
+		case opStructEscapedFieldHeadEscapedStringOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			b = encodeEscapedString(b, e.ptrToString(p))
+			b = encodeComma(b)
+			code = code.next
 		case opStructEscapedFieldPtrHeadEscapedString:
 			p := load(ctxptr, code.idx)
 			if p == 0 {
@@ -2393,6 +2616,22 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				b = encodeComma(b)
 				code = code.next
 			}
+		case opStructEscapedFieldPtrHeadBoolOnly:
+			p := load(ctxptr, code.idx)
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			fallthrough
+		case opStructEscapedFieldHeadBoolOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			b = encodeBool(b, e.ptrToBool(p))
+			b = encodeComma(b)
+			code = code.next
 		case opStructEscapedFieldPtrHeadBool:
 			p := load(ctxptr, code.idx)
 			if p == 0 {
@@ -3750,6 +3989,24 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 					code = code.next
 				}
 			}
+		case opStructEscapedFieldPtrHeadOmitEmptyIntOnly:
+			ptr := load(ctxptr, code.idx)
+			if ptr != 0 {
+				store(ctxptr, code.idx, e.ptrToPtr(ptr))
+			}
+			fallthrough
+		case opStructEscapedFieldHeadOmitEmptyIntOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			v := e.ptrToInt(p)
+			if v == 0 {
+				code = code.nextField
+			} else {
+				b = append(b, code.escapedKey...)
+				b = appendInt(b, int64(v))
+				b = encodeComma(b)
+				code = code.next
+			}
 		case opStructEscapedFieldPtrHeadOmitEmptyInt:
 			ptr := load(ctxptr, code.idx)
 			if ptr != 0 {
@@ -6705,6 +6962,22 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				b = encodeComma(b)
 				code = code.next
 			}
+
+		case opStructEscapedFieldPtrHeadStringTagInt64PtrOnly:
+			ptr := load(ctxptr, code.idx)
+			if ptr != 0 {
+				store(ctxptr, code.idx, e.ptrToPtr(ptr))
+			}
+			fallthrough
+		case opStructEscapedFieldHeadStringTagInt64PtrOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			b = append(b, '"')
+			b = appendInt(b, e.ptrToInt64(p))
+			b = append(b, '"')
+			b = encodeComma(b)
+			code = code.next
 		case opStructEscapedFieldPtrHeadStringTagInt64:
 			ptr := load(ctxptr, code.idx)
 			if ptr != 0 {
@@ -7419,6 +7692,21 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 				b = encodeComma(b)
 				code = code.next
 			}
+		case opStructEscapedFieldPtrHeadStringTagBoolOnly:
+			ptr := load(ctxptr, code.idx)
+			if ptr != 0 {
+				store(ctxptr, code.idx, e.ptrToPtr(ptr))
+			}
+			fallthrough
+		case opStructEscapedFieldHeadStringTagBoolOnly:
+			p := load(ctxptr, code.idx)
+			b = append(b, '{')
+			b = append(b, code.escapedKey...)
+			b = append(b, '"')
+			b = encodeBool(b, e.ptrToBool(p))
+			b = append(b, '"')
+			b = encodeComma(b)
+			code = code.next
 		case opStructEscapedFieldPtrHeadStringTagBool:
 			ptr := load(ctxptr, code.idx)
 			if ptr != 0 {