diff --git a/lib/vast/ExprParser.py b/lib/vast/ExprParser.py
index c55b0e7..b78282c 100644
--- a/lib/vast/ExprParser.py
+++ b/lib/vast/ExprParser.py
@@ -46,6 +46,11 @@ class TokenStream:
         self.Source: str = source
         self.LineStarts: list[int] = line_starts
         self.Idx: int = 0
+        # _Peek(0) 缓存：递归下降解析常在同一游标位置重复窥视
+        # （_At/_AtOp/_AtName 等），命中时跳过 len() 与列表索引。
+        # 游标移动后 Idx 变化自然失配，无需显式失效。
+        self._PeekCacheIdx: int = -1
+        self._PeekCacheTok: Token | None = None
 
     # ------------------------------------------------------------------
     # 游标操作
@@ -54,6 +59,12 @@ class TokenStream:
         i: int = self.Idx + offset
         if i >= len(self.Tokens):
             return self.Tokens[-1]
+        if offset == 0:
+            if self._PeekCacheIdx == i:
+                return self._PeekCacheTok
+            self._PeekCacheIdx = i
+            self._PeekCacheTok = self.Tokens[i]
+            return self._PeekCacheTok
         return self.Tokens[i]
 
     def _Next(self) -> Token: