first

src/main/java/com/alibaba/qlexpress4/runtime/context/ExpressContext.java

@@ -0,0 +1,16 @@
+package com.alibaba.qlexpress4.runtime.context;
+
+import com.alibaba.qlexpress4.runtime.Value;
+
+import java.util.Map;
+
+/**
+ * Author: DQinYuan
+ */
+public interface ExpressContext {
+    
+    ExpressContext EMPTY_CONTEXT = new EmptyContext();
+    
+    Value get(Map<String, Object> attachments, String variableName);
+    
+}