fix(aarch64): support parse map that key is float (#748)

internal/decoder/optdec/compiler.go

@@ -399,7 +399,7 @@ func tryCompileKeyUnmarshaler(vt reflect.Type) decKey {
 		return decodeKeyTextUnmarshaler
 	}
 
-	/* not support map key with `json.Unmarshaler` */
+	/* NOTE: encoding/json not support map key with `json.Unmarshaler` */
 	return nil
 }
 
@@ -413,6 +413,11 @@ func (c *compiler) compileMapKey(vt reflect.Type) decKey {
 		return decodeKeyU8
 	case reflect.Uint16:
 		return decodeKeyU16
+	// NOTE: actually, encoding/json can't use float as map key
+	case reflect.Float32:
+		return decodeFloat32Key
+	case reflect.Float64:
+		return decodeFloat64Key
 	default:
 		panic(&json.UnmarshalTypeError{Type: vt})
 	}

internal/decoder/optdec/map.go

@@ -2,7 +2,6 @@ package optdec
 
 import (
 	"encoding"
-	"encoding/json"
 	"math"
 	"reflect"
 	"unsafe"
@@ -354,26 +353,40 @@ func decodeKeyI16(dec *mapDecoder, raw string, ctx *context) (interface{}, error
 	return int16(ret), nil
 }
 
-func decodeKeyJSONUnmarshaler(dec *mapDecoder, raw string, _ *context) (interface{}, error) {
+func decodeKeyTextUnmarshaler(dec *mapDecoder, raw string, ctx *context) (interface{}, error) {
+	key, err := Unquote(raw)
+	if err != nil {
+		return nil, err
+	}
 	ret := reflect.New(dec.mapType.Key.Pack()).Interface()
-	err := ret.(json.Unmarshaler).UnmarshalJSON([]byte(raw))
+	err = ret.(encoding.TextUnmarshaler).UnmarshalText(rt.Str2Mem(key))
 	if err != nil {
 		return nil, err
 	}
 	return ret, nil
 }
 
-func decodeKeyTextUnmarshaler(dec *mapDecoder, raw string, ctx *context) (interface{}, error) {
+func decodeFloat32Key(dec *mapDecoder, raw string, _ *context) (interface{}, error) {
 	key, err := Unquote(raw)
 	if err != nil {
 		return nil, err
 	}
-	ret := reflect.New(dec.mapType.Key.Pack()).Interface()
-	err = ret.(encoding.TextUnmarshaler).UnmarshalText([]byte(key))
+	ret, err := ParseF64(key)
 	if err != nil {
 		return nil, err
 	}
-	return ret, nil
+	if ret > math.MaxFloat32 || ret < -math.MaxFloat32 {
+		return nil, error_value(key, dec.mapType.Key.Pack())
+	}
+	return float32(ret), nil
+}
+
+func decodeFloat64Key(dec *mapDecoder, raw string, _ *context) (interface{}, error) {
+	key, err := Unquote(raw)
+	if err != nil {
+		return nil, err
+	}
+	return ParseF64(key)
 }
 
 type mapDecoder struct {

issue_test/issue739_test.go

@@ -1,3 +1,17 @@
+// Copyright 2025 CloudWeGo Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package issue_test
 
 import (

issue_test/issue744_test.go

@@ -1,3 +1,17 @@
+// Copyright 2025 CloudWeGo Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package issue_test
 
 import (

issue_test/issue747_test.go

@@ -0,0 +1,63 @@
+// Copyright 2025 CloudWeGo Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package issue_test
+
+import (
+	"testing"
+
+	"encoding/json"
+	"github.com/bytedance/sonic"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIssue747(t *testing.T) {
+	tests := []struct {
+		name           string
+		input         string
+		expected interface{}
+		newfn func() interface{}
+	}{
+		{
+			name:   "unmarshal map key float64",
+			input: `{"1.2":1.8}`,
+			expected: &map[float64]float64{
+				1.2:  1.8,
+			},
+			newfn: func() interface{} { return new(map[float64]float64) },
+		},
+		{
+			name:    "unmarshal map key float32",
+			input: `{"1.2":1.8}`,
+			expected: &map[float32]float32{
+				1.2:  1.8,
+			},
+			newfn: func() interface{} { return new(map[float32]float32) },
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sv, jv := tt.newfn(), tt.newfn()
+			serr := sonic.Unmarshal([]byte(tt.input), &sv)
+			assert.Equal(t, tt.expected, sv)
+			assert.NoError(t, serr)
+
+			// Note: it is different from encoding/json 
+			jerr := json.Unmarshal([]byte(tt.input), &jv)
+			assert.NotEqual(t, jerr == nil, serr == nil)
+			assert.NotEqual(t, jv, sv)
+		})
+	}
+}