Move snippet body parsing to web worker

src/packages/snippets/index.coffee

@@ -1,7 +1,5 @@
 AtomPackage = require 'atom-package'
 fs = require 'fs'
-PEG = require 'pegjs'
-_ = require 'underscore'
 SnippetExpansion = require './src/snippet-expansion'
 Snippet = require './src/snippet'
 SnippetsTask = require './src/load-snippets-task'
@@ -10,7 +8,6 @@ module.exports =
 class Snippets extends AtomPackage
 
   snippetsByExtension: {}
-  parser: PEG.buildParser(fs.read(require.resolve 'snippets/snippets.pegjs'), trackLineAndColumn: true)
   loaded: false
 
   activate: (@rootView) ->
@@ -36,8 +33,7 @@ class Snippets extends AtomPackage
     for selector, snippetsByName of snippetsBySelector
       snippetsByPrefix = {}
       for name, attributes of snippetsByName
-        { prefix, body } = attributes
-        bodyTree = @parser.parse(body)
+        { prefix, body, bodyTree } = attributes
         snippet = new Snippet({name, prefix, bodyTree})
         snippetsByPrefix[snippet.prefix] = snippet
       syntax.addProperties(selector, snippets: snippetsByPrefix)

src/packages/snippets/src/load-snippets-handler.coffee

@@ -1,8 +1,17 @@
 fs = require 'fs'
 TextMatePackage = require 'text-mate-package'
+PEG = require 'pegjs'
 
 module.exports =
-  snippetsLoaded: (snippets) -> callTaskMethod('snippetsLoaded', snippets)
+
+  parser: PEG.buildParser(fs.read(require.resolve 'snippets/snippets.pegjs'), trackLineAndColumn: true)
+
+  snippetsLoaded: (snippets) ->
+    for snippet in snippets
+      for selector, snippetsByName of snippet
+        for name, attributes of snippetsByName
+          attributes.bodyTree = @parser.parse(attributes.body)
+    callTaskMethod('snippetsLoaded', snippets)
 
   loadTextmateSnippets: (path) ->
     snippetsDirPath = fs.join(path, 'Snippets')