From 2f3c8f5cb6c8b9e6f5be02b20910f8105a9011a6 Mon Sep 17 00:00:00 2001
From: Luke Lau <luke_lau@icloud.com>
Date: Sat, 18 May 2019 20:32:54 +0100
Subject: [PATCH] Parse parentheses

Yes, it's that easy. Try out the difference between
1 * 2 + 3
and
1 * (2 + 3)
---
 AST.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/AST.hs b/AST.hs
index 7dad3a1..e491b64 100644
--- a/AST.hs
+++ b/AST.hs
@@ -13,7 +13,7 @@ data BinOp = Add | Sub | Mul | Cmp Ordering
   deriving Show
 
 instance Read Expr where
-  readPrec = choice [ parseNum
+  readPrec = parens $ choice [ parseNum
                              , parseVar
                              , parseBinOp "<" 10 (Cmp LT)
                              , parseBinOp "+" 20 Add
-- 
2.30.2