[Fix] 修复无法调用类函数的问题

[Feat] Context merge功能
[Feat] VSCode 拓展现已更为 fig-vscode.

include/context.hpp

@@ -46,6 +46,16 @@ namespace Fig
             return scopeName;
         }
 
+        void merge(const Context& c)
+        {
+            varTypes.insert(c.varTypes.begin(), c.varTypes.end());
+            variables.insert(c.variables.begin(), c.variables.end());
+            ams.insert(c.ams.begin(), c.ams.end());
+            functions.insert(c.functions.begin(), c.functions.end());
+            functionNames.insert(c.functionNames.begin(), c.functionNames.end());
+            structTypeNames.insert(c.structTypeNames.begin(), c.structTypeNames.end());
+        }
+
         std::optional<ObjectPtr> get(const FString &name)
         {
             auto it = variables.find(name);

include/evaluator.hpp

@@ -15,6 +15,7 @@ namespace Fig
     class EvaluatorError final : public AddressableError
     {
     public:
+        const char* errorName = errName;
         virtual FString toString() const override
         {
             std::string msg = std::format("[Eve: {}] {} in [{}] {}", errName, std::string(this->message.begin(), this->message.end()), this->src_loc.file_name(), this->src_loc.function_name());
@@ -27,6 +28,11 @@ namespace Fig
             AddressableError(_msg, aai.line, aai.column, loc)
         {
         }
+
+        virtual FString getErrorType() const override
+        {
+            return FString("[Eval]" + std::string(errorName));
+        }
     };
     struct StatementResult
     {