From 502afe1424b0f4addb4d018137a2d183a5e34dc8 Mon Sep 17 00:00:00 2001
From: Alan Lawrence <alan.lawrence@cambridgequantum.com>
Date: Tue, 7 Jan 2025 13:25:39 +0000
Subject: [PATCH] Compute 2^constant at compile-time

---
 brat/Brat/Checker/Helpers.hs   | 9 ++-------
 brat/test/Test/Compile/Hugr.hs | 1 -
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/brat/Brat/Checker/Helpers.hs b/brat/Brat/Checker/Helpers.hs
index 48e3268b..07bd3e3c 100644
--- a/brat/Brat/Checker/Helpers.hs
+++ b/brat/Brat/Checker/Helpers.hs
@@ -481,13 +481,8 @@ buildNatVal nv@(NumValue n gro) = case n of
 
   buildSM :: StrictMono (VVar Z) -> Checking Src
   buildSM (StrictMono k mono) = do
-    -- Calculate 2^k as `factor`
-    two <- buildNum 2
-    kDangling <- buildNum k
-    ((lhs,rhs),factor) <- buildArithOp Pow
-    req $ Wire (end two, TNat, end lhs)
-    req $ Wire (end kDangling, TNat, end rhs)
-    -- Multiply mono by 2^k
+    factor <- buildNum $ 2 ^ k
+    -- Multiply mono by 2^k; note we could avoid this if k==0
     ((lhs,rhs),out) <- buildArithOp Mul
     monoDangling <- buildMono mono
     req $ Wire (end factor, TNat, end lhs)
diff --git a/brat/test/Test/Compile/Hugr.hs b/brat/test/Test/Compile/Hugr.hs
index ef24aa26..11de7093 100644
--- a/brat/test/Test/Compile/Hugr.hs
+++ b/brat/test/Test/Compile/Hugr.hs
@@ -38,7 +38,6 @@ nonCompilingExamples = expectedCheckingFails ++ expectedParsingFails ++
   ,"fanout" -- Contains Selectors
   ,"vectorise" -- Generates MapFun nodes which aren't implemented yet
   ,"batcher-merge-sort" -- Generates MapFun nodes which aren't implemented yet
-  ,"infer" -- Generates `Pow` nodes which aren't implemented yet
   -- Victims of #13
   ,"arith"
   ,"cqcconf"