Can match key patterns with the '-' character

Add a parser to parse keystroke patterns instead of splitting on '-' with a regex

src/app/binding-set.coffee

@@ -1,13 +1,18 @@
 $ = require 'jquery'
 _ = require 'underscore'
 Specificity = require 'specificity'
+fs = require 'fs'
+
+PEG = require 'pegjs'
 
 module.exports =
 class BindingSet
   selector: null
   commandForEvent: null
+  keystrokePatternParser: null
 
   constructor: (@selector, mapOrFunction) ->
+    @parser = PEG.buildParser(fs.read(require.resolve 'keystroke-pattern.pegjs'))
     @specificity = Specificity(@selector)
     @commandForEvent = @buildEventHandler(mapOrFunction)
 
@@ -18,13 +23,9 @@ class BindingSet
       mapOrFunction = @normalizeKeystrokePatterns(mapOrFunction)
       (event) =>
         for pattern, command of mapOrFunction
-          return command if @eventMatchesPattern(event, pattern)
+          return command if event.keystroke == pattern
         null
 
-  eventMatchesPattern: (event, pattern) ->
-    pattern = pattern.replace(/^<|>$/g, '')
-    event.keystroke == pattern
-
   normalizeKeystrokePatterns: (map) ->
     normalizedMap = {}
     for pattern, event of map
@@ -32,7 +33,7 @@ class BindingSet
     normalizedMap
 
   normalizeKeystrokePattern: (pattern) ->
-    keys = pattern.split('-')
+    keys = @parser.parse(pattern)
     modifiers = keys[0...-1]
     modifiers.sort()
     [modifiers..., _.last(keys)].join('-')

src/app/keystroke-pattern.pegjs

@@ -0,0 +1,3 @@
+keystrokePattern = key:key additionalKeys:additionalKey* { return [key].concat(additionalKeys); }
+additionalKey = '-' key:key { return key; }
+key = '-' / chars:[^-]+ { return chars.join('') }