新增赋值操作

Parsing/Expression.grammar

@@ -1,9 +1,9 @@
 %header%
 
-DESCRIPTION = "A general expression grammar"
-AUTHOR      = "Eugene Ciloci"
-VERSION     = "1.0"
-DATE        = "May 2007"
+DESCRIPTION = "A general expression grammar with assignment support"
+AUTHOR      = "Eugene Ciloci (Modified By LiuBai)"
+VERSION     = "2.0"
+DATE        = "October 2025"
 
 GRAMMARTYPE = "LL"
 CASESENSITIVE = "False"
@@ -71,10 +71,13 @@ DATETIME			= <<#[^#]+#>>
 // Special Functions
 IF			     = "if"
 CAST			     = "cast"
+ASSIGN			     = "="
 
 %productions%
 
-Expression = XorExpression;
+Expression = AssignmentExpression | XorExpression;
+
+AssignmentExpression = IDENTIFIER "=" XorExpression;
 
 XorExpression = OrExpression {XOR OrExpression};