gemini-code-assist[bot] commented on code in PR #18341:
URL: https://github.com/apache/tvm/pull/18341#discussion_r2375404488


##########
python/tvm/script/parser/core/evaluator.py:
##########
@@ -324,10 +324,18 @@ def _eval_compare(self, fields: Dict[str, Any]) -> Any:
         res : Any
             The evaluation result.
         """
-        value = self._eval_expr(fields["left"])
-        for op, rhs in zip(fields["ops"], fields["comparators"]):
-            value = _eval_op(op, values=[value, self._eval_expr(rhs)])
-        return value
+        values = [self._eval_expr(fields["left"])]
+        values.extend([self._eval_expr(rhs) for rhs in fields["comparators"]])
+        result = None
+        assert len(fields["ops"]) == len(values) - 1
+
+        for index, op in enumerate(fields["ops"]):
+            sub_result = _eval_op(op, values=[values[index], values[index + 
1]])
+            if result is None:
+                result = sub_result
+            else:
+                result = _eval_op(doc.And(), values=[result, sub_result])
+        return result

Review Comment:
   ![high](https://www.gstatic.com/codereviewagent/high-priority.svg)
   
   The current implementation evaluates all comparator expressions upfront. 
This deviates from Python's chained comparison semantics, which use 
short-circuiting and evaluate expressions sequentially. For an expression like 
`a < b < f()` where `f()` has side effects, `f()` should not be called if `a < 
b` is false. Eagerly evaluating all expressions can lead to incorrect behavior 
in such cases.
   
   The implementation should be updated to evaluate expressions one by one 
within a loop, carrying over the value of the previous right-hand side for the 
next comparison. This ensures that each intermediate expression is evaluated 
only once and in the correct order, matching Python's behavior.
   
   ```python
           left_val = self._eval_expr(fields["left"])
           result = None
   
           # Per Python's chained comparison semantics, intermediate expressions
           # are evaluated only once and in order. This loop structure ensures 
that.
           # For example, `a < b < c` is equivalent to `a < b and b < c`.
           for op, comparator_expr in zip(fields["ops"], fields["comparators"]):
               right_val = self._eval_expr(comparator_expr)
               sub_result = _eval_op(op, values=[left_val, right_val])
               if result is None:
                   result = sub_result
               else:
                   result = _eval_op(doc.And(), values=[result, sub_result])
               left_val = right_val
           return result
   ```



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