From f0c07b34fba0bd72bafe7b5d6848ef354d8d468a Mon Sep 17 00:00:00 2001
From: Dominic Orchard <dom.orchard@gmail.com>
Date: Mon, 16 Sep 2024 15:29:21 +0100
Subject: [PATCH] extend case of exponentiation, but make failure be a pattern
 match issues for now

---
 src/Language/Fortran/Repr/Eval/Value.hs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/Language/Fortran/Repr/Eval/Value.hs b/src/Language/Fortran/Repr/Eval/Value.hs
index 09bfa0b1..a3407a75 100644
--- a/src/Language/Fortran/Repr/Eval/Value.hs
+++ b/src/Language/Fortran/Repr/Eval/Value.hs
@@ -273,10 +273,12 @@ evalBOp bop l r = do
           (FSVInt li, FSVInt ri) ->
             pure $ MkFScalarValue $ FSVInt $ fIntBOpInplace (^) li ri
           (FSVReal lr, FSVReal ri) ->
-            pure $ MkFScalarValue $ FSVReal $ fRealBOpInplace' exp exp lr ri
-              where
-                exp x y = x ** y
-          _ -> err $ ELazy "exponentiation: unsupported types"
+            pure $ MkFScalarValue $ FSVReal $ fRealBOpInplace' (**) (**) lr ri
+          (FSVReal lr, FSVInt ri) ->
+            -- Handle case of a real raised to an integer power.
+            pure $ MkFScalarValue $ FSVReal $ fRealBOpInplace' (**) (**) lr (FReal8 $ withFInt ri)
+
+--          _ -> err $ ELazy "exponentiation: unsupported types"
 
       F.Concatenation  ->
         case (l', r') of