diff --git a/lexical.go b/lexical.go
index 57ef9b2..81790dc 100644
--- a/lexical.go
+++ b/lexical.go
@@ -7,3 +7,46 @@
 // Date : 2022-07-04 17:52
 package filter
 
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+// parseLexical 解析词法
+//
+// Author : go_developer@163.com<白茶清欢>
+//
+// Date : 18:11 2022/7/4
+func parseLexical(jsonData string) ([]*lexicalNode, error) {
+	if len(jsonData) < 2 {
+		return nil, errors.New("input data is not json")
+	}
+	for _, itemChar := range jsonData {
+		fmt.Println("============ : ", string(itemChar))
+	}
+	return nil, nil
+}
+
+// inputCharIsToken 输入字符是否为关键字
+//
+// Author : go_developer@163.com<白茶清欢>
+//
+// Date : 18:15 2022/7/4
+func inputCharIsToken(inputChar string) bool {
+	tokenCharList := []string{
+		listLeftToken,
+		listRightToken,
+		objectLeftToken,
+		objectRightToken,
+		keyRightToken,
+		kvPairSplitToken,
+		escapeCharacterToken,
+	}
+	for _, itemChar := range tokenCharList {
+		if itemChar == inputChar {
+			return true
+		}
+	}
+	return false
+}
diff --git a/lexical_test.go b/lexical_test.go
new file mode 100644
index 0000000..87e9e57
--- /dev/null
+++ b/lexical_test.go
@@ -0,0 +1,16 @@
+// Package filter ...
+//
+// Description : filter ...
+//
+// Author : go_developer@163.com<白茶清欢>
+//
+// Date : 2022-07-04 18:13
+package filter
+
+import (
+	"testing"
+)
+
+func Test_parseLexical(t *testing.T) {
+	parseLexical("{iiiiiiiii}")
+}