From fc69b38a43797fd1ca74a41e8273543c1e7d5e54 Mon Sep 17 00:00:00 2001
From: dangotbanned <125183946+dangotbanned@users.noreply.github.com>
Date: Sun, 31 Aug 2025 18:53:52 +0000
Subject: [PATCH] refactor(expr-ir): Shrink `_plan.operators`
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Looking *quite* dense now 😄
---
 narwhals/_plan/operators.py | 115 ++++++++++--------------------------
 1 file changed, 31 insertions(+), 84 deletions(-)

diff --git a/narwhals/_plan/operators.py b/narwhals/_plan/operators.py
index 09d072e7bd..38c912c1bd 100644
--- a/narwhals/_plan/operators.py
+++ b/narwhals/_plan/operators.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-import operator
+import operator as op
 from typing import TYPE_CHECKING
 
 from narwhals._plan.common import Immutable, is_function_expr
@@ -9,7 +9,6 @@
     binary_expr_multi_output_error,
     binary_expr_shape_error,
 )
-from narwhals._plan.expr import BinarySelector
 
 if TYPE_CHECKING:
     from typing import Any, ClassVar
@@ -28,30 +27,19 @@
 
 
 class Operator(Immutable):
-    _op: ClassVar[OperatorFn]
+    _func: ClassVar[OperatorFn]
+    _symbol: ClassVar[str]
 
     def __repr__(self) -> str:
-        tp = type(self)
-        if tp in {Operator, SelectorOperator}:
-            return tp.__name__
-        m = {
-            Eq: "==",
-            NotEq: "!=",
-            Lt: "<",
-            LtEq: "<=",
-            Gt: ">",
-            GtEq: ">=",
-            Add: "+",
-            Sub: "-",
-            Multiply: "*",
-            TrueDivide: "/",
-            FloorDivide: "//",
-            Modulus: "%",
-            And: "&",
-            Or: "|",
-            ExclusiveOr: "^",
-        }
-        return m[tp]
+        return self._symbol
+
+    def __init_subclass__(
+        cls, *args: Any, func: OperatorFn | None, symbol: str = "", **kwds: Any
+    ) -> None:
+        super().__init_subclass__(*args, **kwds)
+        if func:
+            cls._func = func
+        cls._symbol = symbol or cls.__name__
 
     def to_binary_expr(
         self, left: LeftT, right: RightT, /
@@ -72,7 +60,7 @@ def to_binary_expr(
 
     def __call__(self, lhs: Any, rhs: Any) -> Any:
         """Apply binary operator to `left`, `right` operands."""
-        return self.__class__._op(lhs, rhs)
+        return self.__class__._func(lhs, rhs)
 
 
 def _is_filtration(ir: ExprIR) -> bool:
@@ -81,7 +69,7 @@ def _is_filtration(ir: ExprIR) -> bool:
     return False
 
 
-class SelectorOperator(Operator):
+class SelectorOperator(Operator, func=None):
     """Operators that can *also* be used in selectors."""
 
     def to_binary_selector(
@@ -92,61 +80,20 @@ def to_binary_selector(
         return BinarySelector(left=left, op=self, right=right)
 
 
-class Eq(Operator):
-    _op = operator.eq
-
-
-class NotEq(Operator):
-    _op = operator.ne
-
-
-class Lt(Operator):
-    _op = operator.le
-
-
-class LtEq(Operator):
-    _op = operator.lt
-
-
-class Gt(Operator):
-    _op = operator.gt
-
-
-class GtEq(Operator):
-    _op = operator.ge
-
-
-class Add(Operator):
-    _op = operator.add
-
-
-class Sub(SelectorOperator):
-    _op = operator.sub
-
-
-class Multiply(Operator):
-    _op = operator.mul
-
-
-class TrueDivide(Operator):
-    _op = operator.truediv
-
-
-class FloorDivide(Operator):
-    _op = operator.floordiv
-
-
-class Modulus(Operator):
-    _op = operator.mod
-
-
-class And(SelectorOperator):
-    _op = operator.and_
-
-
-class Or(SelectorOperator):
-    _op = operator.or_
-
-
-class ExclusiveOr(SelectorOperator):
-    _op = operator.xor
+# fmt: off
+class Eq(Operator, func=op.eq, symbol="=="): ...
+class NotEq(Operator, func=op.ne, symbol="!="): ...
+class Lt(Operator, func=op.le, symbol="<"): ...
+class LtEq(Operator, func=op.lt, symbol="<="): ...
+class Gt(Operator, func=op.gt, symbol=">"): ...
+class GtEq(Operator, func=op.ge, symbol=">="): ...
+class Add(Operator, func=op.add, symbol="+"): ...
+class Sub(SelectorOperator, func=op.sub, symbol="-"): ...
+class Multiply(Operator, func=op.mul, symbol="*"): ...
+class TrueDivide(Operator, func=op.truediv, symbol="/"): ...
+class FloorDivide(Operator, func=op.floordiv, symbol="//"): ...
+class Modulus(Operator, func=op.mod, symbol="%"): ...
+class And(SelectorOperator, func=op.and_, symbol="&"): ...
+class Or(SelectorOperator, func=op.or_, symbol="|"): ...
+class ExclusiveOr(SelectorOperator, func=op.xor, symbol="^"): ...
+# fmt: on