notes on what should happen

Author: ym-pett

narwhals/_sql/typing.py

@@ -14,5 +14,34 @@
 SQLLazyFrameT = TypeVar("SQLLazyFrameT", bound="SQLLazyFrameAny")
 
 
-# it needs to inherit from SQLExpr, but getting errors if passing SQLExprT
-class NativeSQLExpr(Any): ...
+# it needs to inherit from SQLExpr, but getting errors if passing SQLExprT. I have not sorted out what relation 
+# (covarinant, contravariant or intravariant it needs to be yet) it needs to have to its parent class
+class NativeSQLExpr(SQLExprT):
+    # not sure how to initialise the class, I want it to have all the methods etc of SQLExprT and add its own operator
+    # methods in addition to those 
+    def __init__(self, other: [Int | Float]) -> None:
+        super().__init__(other)
+
+    # I've seen lots of examples of the operator dunder methods being used, but I'm struggling with 
+    # the typing. for sql, there are nice binary examples, but that's not the right method
+    # e.g.
+    def __gt__(self, other: Self) -> Self:
+        return self._with_binary(lambda expr, other: expr.__gt__(other), other)
+    
+    def __and__(self, other: Self) -> Self:
+        return self._with_binary(lambda expr, other: expr.__and__(other), other)
+    
+    # so it should probably look more like something from the polars examples,
+    # where we just apply the native method: 
+    def __gt__(self, other: Any) -> Self:
+        return self._with_native(self.native.__gt__(extract_native(other)))
+
+    def __le__(self, other: Any) -> Self:
+        return self._with_native(self.native.__le__(extract_native(other)))
+
+    
+       
+
+    
+
+