From b135b85201d11c78c66e6f438259f659f6900a13 Mon Sep 17 00:00:00 2001
From: Denis Buzdalov <public@buzden.ru>
Date: Thu, 24 Oct 2024 18:11:59 +0300
Subject: [PATCH] [ fix ] Fix ability to declare fixities in `do`

---
 src/Idris/Desugar.idr                        | 12 ++++-----
 tests/idris2/operators/operators012/Y.idr    | 27 ++++++++++++++++++++
 tests/idris2/operators/operators012/expected |  1 +
 tests/idris2/operators/operators012/run      |  3 +++
 4 files changed, 37 insertions(+), 6 deletions(-)
 create mode 100644 tests/idris2/operators/operators012/Y.idr
 create mode 100644 tests/idris2/operators/operators012/expected
 create mode 100755 tests/idris2/operators/operators012/run

diff --git a/src/Idris/Desugar.idr b/src/Idris/Desugar.idr
index 02b41723e1..8f317d1d9c 100644
--- a/src/Idris/Desugar.idr
+++ b/src/Idris/Desugar.idr
@@ -737,10 +737,10 @@ mutual
            pure $ seqFun fc ns tm' rest'
   expandDo side ps topfc ns (DoBind fc nameFC n rig ty tm :: rest)
       = do tm' <- desugarDo side ps ns tm
-           rest' <- expandDo side ps topfc ns rest
            whenJust (isConcreteFC nameFC) $ \nfc => addSemanticDecorations [(nfc, Bound, Just n)]
            ty' <- maybe (pure $ Implicit (virtualiseFC fc) False)
                         (\ty => desugarDo side ps ns ty) ty
+           rest' <- expandDo side ps topfc ns rest
            pure $ bindFun fc ns tm'
                 $ ILam nameFC rig Explicit (Just n) ty' rest'
   expandDo side ps topfc ns (DoBindPat fc pat ty exp alts :: rest)
@@ -749,12 +749,12 @@ mutual
            exp' <- desugarDo side ps ns exp
            alts' <- traverse (map snd . desugarClause ps True) alts
            let ps' = newps ++ ps
-           rest' <- expandDo side ps' topfc ns rest
            let fcOriginal = fc
            let fc = virtualiseFC fc
            let patFC = virtualiseFC (getFC bpat)
            ty' <- maybe (pure $ Implicit fc False)
                         (\ty => desugarDo side ps ns ty) ty
+           rest' <- expandDo side ps' topfc ns rest
            pure $ bindFun fc ns exp'
                 $ ILam EmptyFC top Explicit (Just (MN "_" 0))
                           ty'
@@ -788,12 +788,12 @@ mutual
                        (PatClause fc bpat rest'
                                   :: alts')
   expandDo side ps topfc ns (DoLetLocal fc decls :: rest)
-      = do rest' <- expandDo side ps topfc ns rest
-           decls' <- traverse (desugarDecl ps) decls
+      = do decls' <- traverse (desugarDecl ps) decls
+           rest' <- expandDo side ps topfc ns rest
            pure $ ILocal fc (concat decls') rest'
   expandDo side ps topfc ns (DoRewrite fc rule :: rest)
-      = do rest' <- expandDo side ps topfc ns rest
-           rule' <- desugarDo side ps ns rule
+      = do rule' <- desugarDo side ps ns rule
+           rest' <- expandDo side ps topfc ns rest
            pure $ IRewrite fc rule' rest'
 
   -- Replace all operator by function application
diff --git a/tests/idris2/operators/operators012/Y.idr b/tests/idris2/operators/operators012/Y.idr
new file mode 100644
index 0000000000..0b9459ec5b
--- /dev/null
+++ b/tests/idris2/operators/operators012/Y.idr
@@ -0,0 +1,27 @@
+f : Nat
+f =
+  let (%^%) : Nat -> Nat -> Nat
+      (%^%) = (+)
+      private infixl 1 %^%
+  in 1 %^% 2
+
+g : Nat
+g = do
+  let (%^%%) : Nat -> Nat -> Nat
+      (%^%%) = (+)
+      private infixl 1 %^%%
+  1 %^%% 2
+
+crazy1 : Nat
+crazy1 = do
+  let (%^%%%) : Nat -> Nat -> Nat
+      (%^%%%) = (+)
+  rewrite let private infixl 1 %^%%% in the (Nat = Nat) Refl
+  1 %^%%% 2
+
+crazy2 : List Nat
+crazy2 = do
+  let (%^%%%%) : Nat -> Nat -> Nat
+      (%^%%%%) = (+)
+  x : (let private infixl 1 %^%%%% in Nat) <- [1]
+  pure $ x %^%%%% 2
diff --git a/tests/idris2/operators/operators012/expected b/tests/idris2/operators/operators012/expected
new file mode 100644
index 0000000000..257dbc7427
--- /dev/null
+++ b/tests/idris2/operators/operators012/expected
@@ -0,0 +1 @@
+1/1: Building Y (Y.idr)
diff --git a/tests/idris2/operators/operators012/run b/tests/idris2/operators/operators012/run
new file mode 100755
index 0000000000..946196f02f
--- /dev/null
+++ b/tests/idris2/operators/operators012/run
@@ -0,0 +1,3 @@
+. ../../../testutils.sh
+
+check Y.idr