fix: Display instance of pow was wrong.

Author: mchav

dataframe-symbolic-regression/dataframe-symbolic-regression.cabal

@@ -22,7 +22,7 @@ library
     -- other-modules:
     -- other-extensions:
     build-depends:    base >= 4 && <5
-                    , dataframe
+                    , dataframe ^>= 0.4
                     , attoparsec >=0.14.4 && <0.15
                     , attoparsec-expr >=0.1.1.2 && <0.2
                     , base >=4.19 && <5

src/DataFrame/Functions.hs

@@ -216,7 +216,7 @@ pow :: (Columnable a, Num a) => Expr a -> Int -> Expr a
 pow _ 0 = Lit 1
 pow (Lit n) i = Lit (n ^ i)
 pow expr 1 = expr
-pow expr i = UnaryOp ("pow " <> T.pack (show i)) (^ i) expr
+pow expr i = BinaryOp "pow" (^) expr (lit i)
 
 relu :: (Columnable a, Num a) => Expr a -> Expr a
 relu = UnaryOp "relu" (Prelude.max 0)

src/DataFrame/Internal/Expression.hs

@@ -69,7 +69,7 @@ instance (Num a, Columnable a) => Num (Expr a) where
     (*) e (Lit 1) = e
     (*) (Lit x) (Lit y) = Lit (x * y)
     (*) e1 e2
-        | e1 == e2 = UnaryOp "pow 2" (^ 2) e1
+        | e1 == e2 = BinaryOp "pow" (^) e1 (Lit @Int 2)
         | otherwise = BinaryOp "mult" (*) e1 e2
 
     fromInteger :: Integer -> Expr a