From b19dae4315482eafb1ed300c9725cfe3b7dd3704 Mon Sep 17 00:00:00 2001
From: mrkkrp <markkarpov@opmbx.org>
Date: Fri, 31 Jul 2015 01:43:25 +0600
Subject: [PATCH] improve efficiency of applicative interface

---
 Text/MegaParsec/Prim.hs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Text/MegaParsec/Prim.hs b/Text/MegaParsec/Prim.hs
index 694defb..4ee0804 100644
--- a/Text/MegaParsec/Prim.hs
+++ b/Text/MegaParsec/Prim.hs
@@ -172,8 +172,10 @@ parsecMap f p = ParsecT $ \s cok cerr eok eerr ->
                 unParser p s (cok . f) cerr (eok . f) eerr
 
 instance A.Applicative (ParsecT s u m) where
-    pure  = return
-    (<*>) = ap -- TODO: Can this be optimized?
+    pure     = return
+    (<*>)    = ap -- TODO: Can this be optimized?
+    (*>)     = (>>)
+    p1 <* p2 = do { x1 <- p1 ; void p2 ; return x1 }
 
 instance A.Alternative (ParsecT s u m) where
     empty = mzero