From 9359dbcc2d01db19d251e68adf6c428eac7c7144 Mon Sep 17 00:00:00 2001
From: Ben Gamari <ben@smart-cactus.org>
Date: Tue, 27 Oct 2015 20:10:46 +0100
Subject: [PATCH] TcRnMonad: Backport pushLevelAndCaptureConstraints
---
compiler/typecheck/TcRnMonad.hs | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/compiler/typecheck/TcRnMonad.hs b/compiler/typecheck/TcRnMonad.hs
index 74f80996b725..dd700111bda7 100644
--- a/compiler/typecheck/TcRnMonad.hs
+++ b/compiler/typecheck/TcRnMonad.hs
@@ -1170,6 +1170,17 @@ captureTcLevel thing_inside
thing_inside
; return (res, tclvl') }
+pushLevelAndCaptureConstraints :: TcM a -> TcM (a, TcLevel, WantedConstraints)
+pushLevelAndCaptureConstraints thing_inside
+ = do { env <- getLclEnv
+ ; lie_var <- newTcRef emptyWC ;
+ ; let tclvl' = pushTcLevel (tcl_tclvl env)
+ ; res <- setLclEnv (env { tcl_tclvl = tclvl'
+ , tcl_lie = lie_var })
+ thing_inside
+ ; lie <- readTcRef lie_var
+ ; return (res, tclvl', lie) }
+
pushTcLevelM :: TcM a -> TcM a
pushTcLevelM thing_inside
= do { env <- getLclEnv
--
GitLab