refactor error handling and clean up implementations

errors/error_basic_runtime.go

@@ -13,3 +13,10 @@ func (e *ErrorBasicRuntime) GetPath() string {
 func (e *ErrorBasicRuntime) GetRemainingPathLen() int {
 	return e.remainingPathLen
 }
+
+func NewErrorBasicRuntime(path string, remainingPathLen int) ErrorBasicRuntime {
+	return ErrorBasicRuntime{
+		path:             path,
+		remainingPathLen: remainingPathLen,
+	}
+}

errors/errors.go

@@ -81,9 +81,9 @@ func (e ErrorTypeUnmatched) Error() string {
 	return fmt.Sprintf(`type unmatched (path=%s, expected=%s, found=%s)`, e.ErrorBasicRuntime.GetPath(), e.ExpectedType, e.FoundType)
 }
 
-func NewErrorTypeUnmatched(path string, remainingPathLen int, expected string, found string) ErrorTypeUnmatched {
+func NewErrorTypeUnmatched(errBasicRuntime *ErrorBasicRuntime, expected string, found string) ErrorTypeUnmatched {
 	return ErrorTypeUnmatched{
-		ErrorBasicRuntime: &ErrorBasicRuntime{path: path, remainingPathLen: remainingPathLen},
+		ErrorBasicRuntime: errBasicRuntime,
 		ExpectedType:      expected,
 		FoundType:         found,
 	}
@@ -98,9 +98,9 @@ func (e ErrorMemberNotExist) Error() string {
 	return fmt.Sprintf(`member did not exist (path=%s)`, e.ErrorBasicRuntime.GetPath())
 }
 
-func NewErrorMemberNotExist(path string, remainingPathLen int) ErrorMemberNotExist {
+func NewErrorMemberNotExist(errBasicRuntime *ErrorBasicRuntime) ErrorMemberNotExist {
 	return ErrorMemberNotExist{
-		ErrorBasicRuntime: &ErrorBasicRuntime{path: path, remainingPathLen: remainingPathLen},
+		ErrorBasicRuntime: errBasicRuntime,
 	}
 }
 

internal/syntax/jsonpath.go

@@ -1,15 +1,13 @@
 package syntax
 
 import (
-	"regexp"
 	"sync"
 
 	"github.com/AsaiYusuke/jsonpath/v2/config"
 )
 
 var parseMutex sync.Mutex
 var parser = pegJSONPathParser[uint32]{}
-var unescapeRegex = regexp.MustCompile(`\\(.)`)
 
 // Retrieve returns the retrieved JSON using the given JSONPath.
 func Retrieve(jsonPath string, src any, config ...config.Config) ([]any, error) {
@@ -42,8 +40,6 @@ func Parse(jsonPath string, config ...config.Config) (f func(src any, dst ...*[]
 		parser.Reset()
 	}
 
-	parser.jsonPathParser.unescapeRegex = unescapeRegex
-
 	if len(config) > 0 {
 		parser.jsonPathParser.filterFunctions = config[0].FilterFunctions
 		parser.jsonPathParser.aggregateFunctions = config[0].AggregateFunctions

internal/syntax/jsonpath_parser.go

@@ -8,11 +8,12 @@ import (
 	"github.com/AsaiYusuke/jsonpath/v2/errors"
 )
 
+var unescapeRegex = regexp.MustCompile(`\\(.)`)
+
 type jsonPathParser struct {
 	root               syntaxNode
 	paramsList         [][]any
 	params             []any
-	unescapeRegex      *regexp.Regexp
 	filterFunctions    map[string]func(any) (any, error)
 	aggregateFunctions map[string]func([]any) (any, error)
 	accessorMode       bool
@@ -59,8 +60,8 @@ func (p *jsonPathParser) toFloat(text string) float64 {
 }
 
 func (p *jsonPathParser) unescape(text string) string {
-	return p.unescapeRegex.ReplaceAllStringFunc(text, func(block string) string {
-		varBlockSet := p.unescapeRegex.FindStringSubmatch(block)
+	return unescapeRegex.ReplaceAllStringFunc(text, func(block string) string {
+		varBlockSet := unescapeRegex.FindStringSubmatch(block)
 		return varBlockSet[1]
 	})
 }

internal/syntax/syntax_basic_node.go

@@ -1,18 +1,26 @@
 package syntax
 
 import (
+	"reflect"
+	"sync"
+
 	"github.com/AsaiYusuke/jsonpath/v2/config"
 	"github.com/AsaiYusuke/jsonpath/v2/errors"
 )
 
+type syntaxNodeErrState struct {
+	basicRuntime errors.ErrorBasicRuntime
+}
+
 type syntaxBasicNode struct {
-	path                 string
-	remainingPath        string
-	remainingPathLen     int
-	valueGroup           bool
-	next                 syntaxNode
-	accessorMode         bool
-	preErrMemberNotExist errors.ErrorMemberNotExist
+	path             string
+	remainingPath    string
+	remainingPathLen int
+	valueGroup       bool
+	next             syntaxNode
+	accessorMode     bool
+	errState         *syntaxNodeErrState
+	onceErrState     sync.Once
 }
 
 func (i *syntaxBasicNode) setPath(path string) {
@@ -52,11 +60,24 @@ func (i *syntaxBasicNode) getNext() syntaxNode {
 	return i.next
 }
 
+func (i *syntaxBasicNode) ensureErrState() {
+	i.onceErrState.Do(func() {
+		i.errState = &syntaxNodeErrState{}
+		i.errState.basicRuntime = errors.NewErrorBasicRuntime(i.path, i.remainingPathLen)
+	})
+}
+
 func (i *syntaxBasicNode) newErrMemberNotExist() errors.ErrorMemberNotExist {
-	if i.preErrMemberNotExist.ErrorBasicRuntime == nil {
-		i.preErrMemberNotExist = errors.NewErrorMemberNotExist(i.path, i.remainingPathLen)
+	i.ensureErrState()
+	return errors.NewErrorMemberNotExist(&i.errState.basicRuntime)
+}
+
+func (i *syntaxBasicNode) newErrTypeUnmatched(expected string, current any) errors.ErrorTypeUnmatched {
+	i.ensureErrState()
+	if current != nil {
+		return errors.NewErrorTypeUnmatched(&i.errState.basicRuntime, expected, reflect.TypeOf(current).String())
 	}
-	return i.preErrMemberNotExist
+	return errors.NewErrorTypeUnmatched(&i.errState.basicRuntime, expected, msgTypeNull)
 }
 
 func (i *syntaxBasicNode) retrieveAnyValueNext(

internal/syntax/syntax_compare_query.go

@@ -16,14 +16,14 @@ func (q *syntaxCompareQuery) compute(
 		}
 	}
 
-	rightValues := q.rightParam.compute(root, currentList)
-
 	// The syntax parser always results in a literal value on the right side as input.
-	if q.comparator.comparator(leftValues, rightValues[0]) {
+	rightValue := q.rightParam.compute(root, currentList)[0]
+
+	if q.comparator.compare(leftValues, rightValue) {
 		return leftValues
 	}
 
-	if len(leftValues) == 1 && leftValues[0] == emptyEntity && rightValues[0] == emptyEntity {
+	if len(leftValues) == 1 && leftValues[0] == emptyEntity && rightValue == emptyEntity {
 		if _, ok := q.comparator.(*syntaxCompareDeepEQ); ok {
 			return currentList
 		}

internal/syntax/syntax_compare_query_comparator_deep_eq.go

@@ -5,7 +5,7 @@ import "reflect"
 type syntaxCompareDeepEQ struct {
 }
 
-func (c *syntaxCompareDeepEQ) comparator(left []any, right any) bool {
+func (c *syntaxCompareDeepEQ) compare(left []any, right any) bool {
 	var hasValue bool
 	for leftIndex := range left {
 		if left[leftIndex] == emptyEntity {

internal/syntax/syntax_compare_query_comparator_direct_eq.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareDirectEQ struct {
 }
 
-func (c *syntaxCompareDirectEQ) comparator(left []any, right any) bool {
+func (c *syntaxCompareDirectEQ) compare(left []any, right any) bool {
 	var hasValue bool
 	for leftIndex := range left {
 		if left[leftIndex] == emptyEntity {

internal/syntax/syntax_compare_query_comparator_ge.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareGE struct {
 }
 
-func (c *syntaxCompareGE) comparator(left []any, right any) bool {
+func (c *syntaxCompareGE) compare(left []any, right any) bool {
 	rightFloatValue, rightIsFloat := right.(float64)
 	rightNumberValue, rightIsNumber := right.(json.Number)
 	rightStringValue, rightIsString := right.(string)

internal/syntax/syntax_compare_query_comparator_gt.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareGT struct {
 }
 
-func (c *syntaxCompareGT) comparator(left []any, right any) bool {
+func (c *syntaxCompareGT) compare(left []any, right any) bool {
 	rightFloat, rightIsFloat := right.(float64)
 	rightNumber, rightIsNumber := right.(json.Number)
 	rightString, rightIsString := right.(string)

internal/syntax/syntax_compare_query_comparator_le.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareLE struct {
 }
 
-func (c *syntaxCompareLE) comparator(left []any, right any) bool {
+func (c *syntaxCompareLE) compare(left []any, right any) bool {
 	rightFloat, rightIsFloat := right.(float64)
 	rightNumber, rightIsNumber := right.(json.Number)
 	rightString, rightIsString := right.(string)

internal/syntax/syntax_compare_query_comparator_lt.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareLT struct {
 }
 
-func (c *syntaxCompareLT) comparator(left []any, right any) bool {
+func (c *syntaxCompareLT) compare(left []any, right any) bool {
 	rightFloat, rightIsFloat := right.(float64)
 	rightNumber, rightIsNumber := right.(json.Number)
 	rightString, rightIsString := right.(string)

internal/syntax/syntax_compare_query_comparator_number_ge.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareNumberGE struct {
 }
 
-func (c *syntaxCompareNumberGE) comparator(left []any, right any) bool {
+func (c *syntaxCompareNumberGE) compare(left []any, right any) bool {
 	rightFloatValue, _ := right.(float64)
 
 	var hasValue bool

internal/syntax/syntax_compare_query_comparator_number_gt.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareNumberGT struct {
 }
 
-func (c *syntaxCompareNumberGT) comparator(left []any, right any) bool {
+func (c *syntaxCompareNumberGT) compare(left []any, right any) bool {
 	rightFloatValue, _ := right.(float64)
 
 	var hasValue bool

internal/syntax/syntax_compare_query_comparator_number_le.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareNumberLE struct {
 }
 
-func (c *syntaxCompareNumberLE) comparator(left []any, right any) bool {
+func (c *syntaxCompareNumberLE) compare(left []any, right any) bool {
 	rightFloatValue, _ := right.(float64)
 
 	var hasValue bool

internal/syntax/syntax_compare_query_comparator_number_lt.go

@@ -5,7 +5,7 @@ import "encoding/json"
 type syntaxCompareNumberLT struct {
 }
 
-func (c *syntaxCompareNumberLT) comparator(left []any, right any) bool {
+func (c *syntaxCompareNumberLT) compare(left []any, right any) bool {
 	rightFloatValue, _ := right.(float64)
 
 	var hasValue bool

internal/syntax/syntax_compare_query_comparator_regex.go

@@ -6,7 +6,7 @@ type syntaxCompareRegex struct {
 	regex *regexp.Regexp
 }
 
-func (r *syntaxCompareRegex) comparator(left []any, _ any) bool {
+func (r *syntaxCompareRegex) compare(left []any, _ any) bool {
 	var hasValue bool
 	for leftIndex := range left {
 		if left[leftIndex] == emptyEntity {

internal/syntax/syntax_compare_query_comparator_string_ge.go

@@ -3,7 +3,7 @@ package syntax
 type syntaxCompareStringGE struct {
 }
 
-func (c *syntaxCompareStringGE) comparator(left []any, right any) bool {
+func (c *syntaxCompareStringGE) compare(left []any, right any) bool {
 	rightStringValue, _ := right.(string)
 
 	var hasValue bool

internal/syntax/syntax_compare_query_comparator_string_gt.go

@@ -3,7 +3,7 @@ package syntax
 type syntaxCompareStringGT struct {
 }
 
-func (c *syntaxCompareStringGT) comparator(left []any, right any) bool {
+func (c *syntaxCompareStringGT) compare(left []any, right any) bool {
 	rightStringValue, _ := right.(string)
 
 	var hasValue bool

internal/syntax/syntax_compare_query_comparator_string_le.go

@@ -3,7 +3,7 @@ package syntax
 type syntaxCompareStringLE struct {
 }
 
-func (c *syntaxCompareStringLE) comparator(left []any, right any) bool {
+func (c *syntaxCompareStringLE) compare(left []any, right any) bool {
 	rightStringValue, _ := right.(string)
 
 	var hasValue bool

internal/syntax/syntax_compare_query_comparator_string_lt.go

@@ -3,7 +3,7 @@ package syntax
 type syntaxCompareStringLT struct {
 }
 
-func (c *syntaxCompareStringLT) comparator(left []any, right any) bool {
+func (c *syntaxCompareStringLT) compare(left []any, right any) bool {
 	rightStringValue, _ := right.(string)
 
 	var hasValue bool

internal/syntax/syntax_if_comparator.go

@@ -1,5 +1,5 @@
 package syntax
 
 type syntaxComparator interface {
-	comparator(left []any, right any) bool
+	compare(left []any, right any) bool
 }

internal/syntax/syntax_node_identifier_child_multi.go

@@ -1,8 +1,6 @@
 package syntax
 
 import (
-	"reflect"
-
 	"github.com/AsaiYusuke/jsonpath/v2/errors"
 )
 
@@ -30,12 +28,7 @@ func (i *syntaxChildMultiIdentifier) retrieve(
 		return i.retrieveMap(root, srcMap, results)
 	}
 
-	if current != nil {
-		return errors.NewErrorTypeUnmatched(
-			i.path, i.remainingPathLen, msgTypeObject, reflect.TypeOf(current).String())
-	}
-	return errors.NewErrorTypeUnmatched(
-		i.path, i.remainingPathLen, msgTypeObject, msgTypeNull)
+	return i.newErrTypeUnmatched(msgTypeObject, current)
 }
 
 func (i *syntaxChildMultiIdentifier) retrieveMap(

internal/syntax/syntax_node_identifier_child_single.go

@@ -1,8 +1,6 @@
 package syntax
 
 import (
-	"reflect"
-
 	"github.com/AsaiYusuke/jsonpath/v2/errors"
 )
 
@@ -19,10 +17,5 @@ func (i *syntaxChildSingleIdentifier) retrieve(
 		return i.retrieveMapNext(root, srcMap, i.identifier, results)
 	}
 
-	if current != nil {
-		return errors.NewErrorTypeUnmatched(
-			i.path, i.remainingPathLen, msgTypeObject, reflect.TypeOf(current).String())
-	}
-	return errors.NewErrorTypeUnmatched(
-		i.path, i.remainingPathLen, msgTypeObject, msgTypeNull)
+	return i.newErrTypeUnmatched(msgTypeObject, current)
 }

internal/syntax/syntax_node_identifier_child_wildcard.go

@@ -1,8 +1,6 @@
 package syntax
 
 import (
-	"reflect"
-
 	"github.com/AsaiYusuke/jsonpath/v2/errors"
 )
 
@@ -21,12 +19,7 @@ func (i *syntaxChildWildcardIdentifier) retrieve(
 		return i.retrieveList(root, typedNodes, results)
 
 	default:
-		if current != nil {
-			return errors.NewErrorTypeUnmatched(
-				i.path, i.remainingPathLen, msgTypeObjectOrArray, reflect.TypeOf(current).String())
-		}
-		return errors.NewErrorTypeUnmatched(
-			i.path, i.remainingPathLen, msgTypeObjectOrArray, msgTypeNull)
+		return i.newErrTypeUnmatched(msgTypeObjectOrArray, current)
 	}
 }
 

internal/syntax/syntax_node_identifier_recursive_child.go

@@ -1,7 +1,6 @@
 package syntax
 
 import (
-	"reflect"
 	"slices"
 
 	"github.com/AsaiYusuke/jsonpath/v2/errors"
@@ -20,12 +19,7 @@ func (i *syntaxRecursiveChildIdentifier) retrieve(
 	switch current.(type) {
 	case map[string]any, []any:
 	default:
-		if current != nil {
-			return errors.NewErrorTypeUnmatched(
-				i.path, i.remainingPathLen, msgTypeObjectOrArray, reflect.TypeOf(current).String())
-		}
-		return errors.NewErrorTypeUnmatched(
-			i.path, i.remainingPathLen, msgTypeObjectOrArray, msgTypeNull)
+		return i.newErrTypeUnmatched(msgTypeObjectOrArray, current)
 	}
 
 	var deepestError errors.ErrorRuntime