From 802c048ec6c9350f0c22e4a1bc241c2cc38fee14 Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@me.com>
Date: Fri, 10 Feb 2017 17:09:54 -0500
Subject: [PATCH] Pull the drop & take into the where clause.
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This change, while semantically equivalent, causes `slice` to complete in approximately 1/3rd the time, and allocate only a fraction as much.

Maybe ghc can fuse this better or something? I honestly have no idea, but I’ll take it.

/cc @github/semantic-code
---
 src/Source.hs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Source.hs b/src/Source.hs
index c7acbe7b2..57e7445bb 100644
--- a/src/Source.hs
+++ b/src/Source.hs
@@ -56,7 +56,9 @@ fromText = Source
 
 -- | Return a Source that contains a slice of the given Source.
 slice :: Range -> Source -> Source
-slice range = Source . Text.take (rangeLength range) . Text.drop (start range) . sourceText
+slice range = Source . take . drop . sourceText
+  where drop = Text.drop (start range)
+        take = Text.take (rangeLength range)
 
 -- | Return a String with the contents of the Source.
 toString :: Source -> String