refactor: refactor ExpressionAdaptor

agents-flex-core/src/main/java/com/agentsflex/store/condition/ExpressionAdaptor.java

@@ -24,7 +24,7 @@ public interface ExpressionAdaptor {
 
     default String toCondition(Condition condition) {
         return toLeft(condition.left)
-            + toSymbol(condition.type)
+            + toOperationSymbol(condition.type)
             + toRight(condition.right);
     }
 
@@ -32,7 +32,7 @@ public interface ExpressionAdaptor {
         return operand.toExpression(this);
     }
 
-    default String toSymbol(ConditionType type) {
+    default String toOperationSymbol(ConditionType type) {
         return type.getDefaultSymbol();
     }
 
@@ -67,7 +67,6 @@ public interface ExpressionAdaptor {
         return connector.getValue();
     }
 
-
     default String toGroupStart(Group group) {
         return "(";
     }

agents-flex-store/agents-flex-store-milvus/src/main/java/com/agentsflex/store/milvus/MilvusExpressionAdaptor.java

@@ -27,24 +27,22 @@ public class MilvusExpressionAdaptor implements ExpressionAdaptor {
     public static final MilvusExpressionAdaptor DEFAULT = new MilvusExpressionAdaptor();
 
     @Override
-    public String toSymbol(ConditionType type) {
+    public String toOperationSymbol(ConditionType type) {
         if (type == ConditionType.EQ) {
             return " == ";
         }
-
-        return ExpressionAdaptor.super.toSymbol(type);
+        return type.getDefaultSymbol();
     }
 
-
     @Override
     public String toCondition(Condition condition) {
         if (condition.getType() == ConditionType.BETWEEN) {
             Object[] values = (Object[]) ((Value) condition.getRight()).getValue();
             return "(" + toLeft(condition.getLeft())
-                + toSymbol(ConditionType.GE)
+                + toOperationSymbol(ConditionType.GE)
                 + values[0] + " && "
                 + toLeft(condition.getLeft())
-                + toSymbol(ConditionType.LE)
+                + toOperationSymbol(ConditionType.LE)
                 + values[1] + ")";
         }