Add support for unicode TH quotes (#11743)

I've also added cases for `IToparenbar` and `ITcparenbar` (aka banana
brackets) to `isUnicode`.

Document unicode TH quote alternatives (#11743)

Test Plan: ./validate

Reviewers: austin, goldfire, bgamari

Reviewed By: bgamari

Subscribers: thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D2185

GHC Trac Issues: #11743

1 files changed, 43 insertions, 0 deletions

diff --git a/testsuite/tests/parser/unicode/brackets.hs b/testsuite/tests/parser/unicode/brackets.hs
new file mode 100644
index 0000000000..33c8e3f44f
--- /dev/null
+++ b/testsuite/tests/parser/unicode/brackets.hs
@@ -0,0 +1,43 @@
+{-# LANGUAGE Arrows          #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE UnicodeSyntax   #-}
+
+-- See Trac #10162 and #11743 for details
+
+module ShouldCompile where
+
+import Control.Arrow
+import Language.Haskell.TH
+
+handle :: ArrowPlus a => a (b,s) c -> a (b,(String,s)) c -> a (b,s) c
+handle f h = proc (b,s) -> (f -< (b,s)) <+> (h -< (b,("FAIL",s)))
+
+f :: ArrowPlus a => a (Int,Int) String
+f = proc (x,y) ->
+  ⦇handle
+    (returnA -< show y)
+    (\s -> returnA -< s ++ show x)
+  ⦈
+
+g :: ArrowPlus a => a (Int,Int) String
+g = proc (x,y) ->
+  ⦇handle
+    (\msg -> returnA -< msg ++ show y)
+    (\s msg -> returnA -< s ++ show x)
+  ⦈ ("hello " ++ show x)
+
+h :: ArrowPlus a => a (Int,Int) Int
+h = proc (x,y) ->
+  (
+    (\z -> returnA -< x + z)
+    <+>
+    (\z -> returnA -< y + z)
+  ) (x*y)
+
+
+matches :: PatQ -> ExpQ
+matches pat = ⟦\x ->
+  case x of
+    $pat -> True
+    _    -> False
+  ⟧