From 8bbc2d2867e3d0a4a1f2810b40e92175779822e1 Mon Sep 17 00:00:00 2001
From: Tom Smeding <tom@tomsmeding.com>
Date: Wed, 18 Jun 2025 13:57:45 +0200
Subject: Don't destroy effects in UnMonoid

---
 src/AST/UnMonoid.hs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/AST/UnMonoid.hs b/src/AST/UnMonoid.hs
index ac4d733..f5841e0 100644
--- a/src/AST/UnMonoid.hs
+++ b/src/AST/UnMonoid.hs
@@ -53,7 +53,8 @@ unMonoid = \case
   EError _ t s -> EError ext t s
 
 zero :: SMTy t -> Ex env (ZeroInfo t) -> Ex env t
-zero SMTNil _ = ENil ext
+-- don't destroy the effects!
+zero SMTNil e = ELet ext e $ ENil ext
 zero (SMTPair t1 t2) e =
   ELet ext e $ EPair ext (zero t1 (EFst ext (EVar ext (typeOf e) IZ)))
                          (zero t2 (ESnd ext (EVar ext (typeOf e) IZ)))
@@ -67,7 +68,8 @@ zero (SMTScal t) _ = case t of
   STF64 -> EConst ext STF64 0.0
 
 plus :: SMTy t -> Ex env t -> Ex env t -> Ex env t
-plus SMTNil _ _ = ENil ext
+-- don't destroy the effects!
+plus SMTNil a b = ELet ext a $ ELet ext (weakenExpr WSink b) $ ENil ext
 plus (SMTPair t1 t2) a b =
   let t = STPair (fromSMTy t1) (fromSMTy t2)
   in ELet ext a $
-- 
cgit v1.2.3-70-g09d2