From a8a9d250e312bc04e2da1edcf641af8dce9773c7 Mon Sep 17 00:00:00 2001
From: Joshua Clayton <joshua.clayton@gmail.com>
Date: Fri, 13 May 2016 14:46:23 -0400
Subject: [PATCH] Parallelize search

Why?
====

Searching hundreds or thousands of tokens with ag can be slow; this
introduces parallel processing of search so results are returned more
quickly.
---
 src/Unused/CLI/ProgressIndicator.hs | 3 ++-
 unused.cabal                        | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Unused/CLI/ProgressIndicator.hs b/src/Unused/CLI/ProgressIndicator.hs
index 71d8a6b..046a8a2 100644
--- a/src/Unused/CLI/ProgressIndicator.hs
+++ b/src/Unused/CLI/ProgressIndicator.hs
@@ -5,6 +5,7 @@ module Unused.CLI.ProgressIndicator
     , progressWithIndicator
     ) where
 
+import Control.Concurrent.ParallelIO
 import Unused.CLI.Util
 import Unused.CLI.ProgressIndicator.Types
 import Unused.CLI.ProgressIndicator.Internal
@@ -23,6 +24,6 @@ progressWithIndicator :: (a -> IO [b]) -> ProgressIndicator -> [a] -> IO [b]
 progressWithIndicator f i terms = do
     printPrefix i
     indicator <- start i $ length terms
-    concat <$> sequence (ioOps indicator) <* stop indicator
+    concat <$> parallel (ioOps indicator) <* stop indicator <* stopGlobalPool
   where
     ioOps i' = map (\t -> f t <* increment i') terms
diff --git a/unused.cabal b/unused.cabal
index cf0f7c3..4df36d0 100644
--- a/unused.cabal
+++ b/unused.cabal
@@ -42,6 +42,7 @@ library
                      , terminal-progress-bar
                      , ansi-terminal
                      , unix
+                     , parallel-io
   ghc-options:         -Wall -Werror -O2
   default-language:    Haskell2010