diff --git a/eqpalg/utility/expression_engine.cpp b/eqpalg/utility/expression_engine.cpp
index 0260c29..f66c9b6 100644
--- a/eqpalg/utility/expression_engine.cpp
+++ b/eqpalg/utility/expression_engine.cpp
@@ -70,3 +70,77 @@ bool ExpressionEngine::evaluateBool(const std::string& name) {
 int ExpressionEngine::initHoldExpStr(const std::string& exp_str) {
   return 0;  // stub — Task 5 will implement
 }
+
+void ExpressionEngine::refreshFromMemory(
+    const TimePoint& now_time,
+    mix_cc::time_range_t& query_time_range) {
+
+  ensureVarCache(var_cache_, m_tags_.size());
+
+  for (size_t i = 0; i < m_tags_.size(); i++) {
+    double current =
+        SingletonTemplate<GlobaltemSharedMemory>::GetInstance()[m_tags_[i]];
+
+    // pN = 旧 tagN
+    mm_vars_[var_cache_.p_keys[i]] = mm_vars_[var_cache_.tag_keys[i]];
+    // tagN = 当前值
+    mm_vars_[var_cache_.tag_keys[i]] = current;
+
+    // pvN 历史移位
+    for (size_t j = PV_NUM - 1; j > 0; j--) {
+      mm_vars_[var_cache_.pv_keys[i][j]] =
+          mm_vars_[var_cache_.pv_keys[i][j - 1]];
+    }
+    mm_vars_[var_cache_.pv_keys[i][0]] = current;
+  }
+
+  mm_vars_["now"] = std::chrono::duration_cast<std::chrono::milliseconds>(
+                        now_time.time_since_epoch())
+                        .count();
+
+  fun_vars_.refresh_fun_vars(false, &mm_vars_);
+  query_time_range.set_right(now_time);
+  refreshHoldVars();
+}
+
+void ExpressionEngine::refreshFromIhdRow(
+    int row,
+    const Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic>& queried_data,
+    const std::vector<TimePoint>& queried_time,
+    TimePoint& now_time,
+    mix_cc::time_range_t& query_time_range) {
+
+  if (queried_data.rows() == 0 || queried_data.cols() == 0) return;
+  if (row < 0 || row >= queried_data.rows()) return;
+  if (static_cast<int>(m_tags_.size()) > queried_data.cols()) return;
+
+  ensureVarCache(var_cache_, m_tags_.size());
+
+  for (size_t i = 0; i < m_tags_.size(); i++) {
+    // pN = 旧 tagN
+    mm_vars_[var_cache_.p_keys[i]] = mm_vars_[var_cache_.tag_keys[i]];
+    // tagN = 当前行数据
+    mm_vars_[var_cache_.tag_keys[i]] = queried_data(row, i);
+
+    // pvN 历史移位
+    for (size_t j = PV_NUM - 1; j > 0; j--) {
+      mm_vars_[var_cache_.pv_keys[i][j]] =
+          mm_vars_[var_cache_.pv_keys[i][j - 1]];
+    }
+    mm_vars_[var_cache_.pv_keys[i][0]] =
+        mm_vars_[var_cache_.tag_keys[i]];
+  }
+
+  mm_vars_["now"] =
+      mix_cc::mix_time_t(queried_time[row]).to_milliseconds();
+
+  now_time = queried_time[row];
+  query_time_range.set_right(queried_time[row]);
+
+  fun_vars_.refresh_fun_vars(false, &mm_vars_);
+  refreshHoldVars();
+}
+
+void ExpressionEngine::refreshHoldVars() {
+  // stub — Task 5 will implement
+}