decode: Have .decodeObject take and return *DecodeError

1 files changed, 34 insertions, 20 deletions

diff --git a/decode.go b/decode.go
index 976ab9b..275b18c 100644
--- a/decode.go
+++ b/decode.go
@@ -530,12 +530,13 @@ func (dec *Decoder) decode(val reflect.Value, nullOK bool) (_err *DecodeError) {
 			}
 			index := jsonstruct.IndexStruct(typ)
 			var nameBuf strings.Builder
-			dec.decodeObject(typ, func() {
+			return dec.decodeObject(typ, func() *DecodeError {
 				dec.posStackPush()
 				defer dec.posStackPop()
 				nameBuf.Reset()
 				dec.decodeString(nil, &nameBuf)
-			}, func() {
+				return nil
+			}, func() *DecodeError {
 				dec.posStackPush()
 				defer dec.posStackPop()
 				name := nameBuf.String()
@@ -556,7 +557,7 @@ func (dec *Decoder) decode(val reflect.Value, nullOK bool) (_err *DecodeError) {
 						dec.panicType("", typ, fmt.Errorf("json: unknown field %q", name))
 					}
 					dec.scan(fastio.Discard)
-					return
+					return nil
 				}
 				field := index.ByPos[idx]
 				fVal := val
@@ -604,10 +605,9 @@ func (dec *Decoder) decode(val reflect.Value, nullOK bool) (_err *DecodeError) {
 							fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal unquoted value into %v",
 								fVal.Type()))
 					}
+					return nil
 				} else {
-					if err := dec.decode(fVal, true); err != nil {
-						panic(decodeError(*err))
-					}
+					return dec.decode(fVal, true)
 				}
 			})
 		case reflect.Map:
@@ -621,7 +621,7 @@ func (dec *Decoder) decode(val reflect.Value, nullOK bool) (_err *DecodeError) {
 				}
 				var nameBuf bytes.Buffer
 				var nameValPtr reflect.Value
-				dec.decodeObject(typ, func() {
+				return dec.decodeObject(typ, func() *DecodeError {
 					dec.posStackPush()
 					defer dec.posStackPop()
 					nameBuf.Reset()
@@ -654,7 +654,8 @@ func (dec *Decoder) decode(val reflect.Value, nullOK bool) (_err *DecodeError) {
 							dec.panicType("object", typ, &DecodeArgumentError{Type: nameValTyp})
 						}
 					}
-				}, func() {
+					return nil
+				}, func() *DecodeError {
 					dec.posStackPush()
 					defer dec.posStackPop()
 					dec.structStackPush(typ, nameValPtr.Elem())
@@ -666,6 +667,7 @@ func (dec *Decoder) decode(val reflect.Value, nullOK bool) (_err *DecodeError) {
 					}
 
 					val.SetMapIndex(nameValPtr.Elem(), fValPtr.Elem())
+					return nil
 				})
 			default:
 				dec.panicType(t.JSONType(), typ, nil)
@@ -799,19 +801,23 @@ func (dec *Decoder) decodeAny() any {
 		ret := make(map[string]any)
 		typ := reflect.TypeOf(ret)
 		var nameBuf strings.Builder
-		dec.decodeObject(typ, func() {
+		if err := dec.decodeObject(typ, func() *DecodeError {
 			dec.posStackPush()
 			defer dec.posStackPop()
 			nameBuf.Reset()
 			dec.decodeString(nil, &nameBuf)
-		}, func() {
+			return nil
+		}, func() *DecodeError {
 			dec.posStackPush()
 			defer dec.posStackPop()
 			name := nameBuf.String()
 			dec.structStackPush(typ, name)
 			defer dec.structStackPop()
 			ret[name] = dec.decodeAny()
-		})
+			return nil
+		}); err != nil {
+			panic(decodeError(*err))
+		}
 		return ret
 	case '[':
 		ret := []any{}
@@ -877,8 +883,8 @@ func DecodeObject(r io.RuneScanner, decodeKey, decodeVal func(io.RuneScanner) er
 	}
 	dec.posStackPush()
 	defer dec.posStackPop()
-	dec.decodeObject(nil,
-		func() {
+	if err := dec.decodeObject(nil,
+		func() *DecodeError {
 			dec.posStackPush()
 			defer dec.posStackPop()
 			l := dec.limitingScanner()
@@ -890,8 +896,9 @@ func DecodeObject(r io.RuneScanner, decodeKey, decodeVal func(io.RuneScanner) er
 				// TODO: Find a better Go type to use than `nil`.
 				dec.panicType("string", nil, fmt.Errorf("did not consume entire string"))
 			}
+			return nil
 		},
-		func() {
+		func() *DecodeError {
 			dec.posStackPush()
 			defer dec.posStackPop()
 			t := dec.peekRuneType()
@@ -904,29 +911,36 @@ func DecodeObject(r io.RuneScanner, decodeKey, decodeVal func(io.RuneScanner) er
 				// TODO: Find a better Go type to use than `nil`.
 				dec.panicType(t.JSONType(), nil, fmt.Errorf("did not consume entire %s", t.JSONType()))
 			}
-		})
+			return nil
+		}); err != nil {
+		return err
+	}
 	return nil
 }
 
-func (dec *Decoder) decodeObject(gTyp reflect.Type, decodeKey, decodeVal func()) {
+func (dec *Decoder) decodeObject(gTyp reflect.Type, decodeKey, decodeVal func() *DecodeError) *DecodeError {
 	dec.expectRuneType('{', jsonparse.RuneTypeObjectBeg, gTyp)
 	_, t := dec.readRune()
 	switch t {
 	case jsonparse.RuneTypeObjectEnd:
-		return
+		return nil
 	case jsonparse.RuneTypeStringBeg:
 	decodeMember:
 		dec.unreadRune()
-		decodeKey()
+		if err := decodeKey(); err != nil {
+			return err
+		}
 		dec.expectRune(':', jsonparse.RuneTypeObjectColon)
-		decodeVal()
+		if err := decodeVal(); err != nil {
+			return err
+		}
 		_, t := dec.readRune()
 		switch t {
 		case jsonparse.RuneTypeObjectComma:
 			dec.expectRune('"', jsonparse.RuneTypeStringBeg)
 			goto decodeMember
 		case jsonparse.RuneTypeObjectEnd:
-			return
+			return nil
 		default:
 			panic("should not happen")
 		}