From de25b8ea37ae4ff3d9a6212922c5aca4c86b475a Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevin@github.com>
Date: Fri, 10 Jan 2014 12:01:56 -0800
Subject: [PATCH] Cache specificities

---
 src/key-binding.coffee | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/key-binding.coffee b/src/key-binding.coffee
index d5a12e4ef..1f3ad1d65 100644
--- a/src/key-binding.coffee
+++ b/src/key-binding.coffee
@@ -8,6 +8,15 @@ module.exports =
 class KeyBinding
   @parser: null
   @currentIndex: 1
+  @specificities: null
+
+  @calculateSpecificity: (selector) ->
+    @specificities ?= {}
+    value = @specificities[selector]
+    unless value?
+      value = specificity(selector)
+      @specificities[selector] = value
+    value
 
   @normalizeKeystroke: (keystroke) ->
     normalizedKeystroke = keystroke.split(/\s+/).map (keystroke) =>
@@ -33,7 +42,7 @@ class KeyBinding
     @command = command
     @keystroke = KeyBinding.normalizeKeystroke(keystroke)
     @selector = selector.replace(/!important/g, '')
-    @specificity = specificity(selector)
+    @specificity = KeyBinding.calculateSpecificity(selector)
     @index = KeyBinding.currentIndex++
 
   matches: (keystroke) ->