Optimize isFoldable

Signed-off-by: Nathan Sobo <nathan@github.com>

src/tokenized-buffer.coffee

@@ -268,7 +268,7 @@ class TokenizedBuffer extends Model
   buildTokenizedLineForRowWithText: (row, text, ruleStack = @stackForRow(row - 1), openScopes = @openScopesForRow(row)) ->
     lineEnding = @buffer.lineEndingForRow(row)
     {tags, ruleStack} = @grammar.tokenizeLine(text, ruleStack, row is 0, false)
-    new TokenizedLine({openScopes, text, tags, ruleStack, lineEnding, @tokenIterator})
+    new TokenizedLine({openScopes, text, tags, ruleStack, lineEnding, @tokenIterator, @grammar})
 
   tokenizedLineForRow: (bufferRow) ->
     if 0 <= bufferRow <= @buffer.getLastRow()
@@ -278,7 +278,7 @@ class TokenizedBuffer extends Model
         text = @buffer.lineForRow(bufferRow)
         lineEnding = @buffer.lineEndingForRow(bufferRow)
         tags = [@grammar.startIdForScope(@grammar.scopeName), text.length, @grammar.endIdForScope(@grammar.scopeName)]
-        @tokenizedLines[bufferRow] = new TokenizedLine({openScopes: [], text, tags, lineEnding, @tokenIterator})
+        @tokenizedLines[bufferRow] = new TokenizedLine({openScopes: [], text, tags, lineEnding, @tokenIterator, @grammar})
 
   tokenizedLinesForRows: (startRow, endRow) ->
     for row in [startRow..endRow] by 1
@@ -344,17 +344,16 @@ class TokenizedBuffer extends Model
       @indentLevelForLine(line)
 
   indentLevelForLine: (line) ->
-    if match = line.match(/^[\t ]+/)
-      indentLength = 0
-      for character in match[0]
-        if character is '\t'
-          indentLength += @getTabLength() - (indentLength % @getTabLength())
-        else
-          indentLength++
+    indentLength = 0
+    for char in line
+      if char is '\t'
+        indentLength += @getTabLength() - (indentLength % @getTabLength())
+      else if char is ' '
+        indentLength++
+      else
+        break
 
-      indentLength / @getTabLength()
-    else
-      0
+    indentLength / @getTabLength()
 
   scopeDescriptorForPosition: (position) ->
     {row, column} = @buffer.clipPosition(Point.fromObject(position))

src/tokenized-line.coffee

@@ -1,5 +1,5 @@
 Token = require './token'
-CommentScopeRegex = /(\b|\.)comment/
+CommentScopeRegex  = /(\b|\.)comment/
 
 idCounter = 1
 
@@ -10,7 +10,7 @@ class TokenizedLine
 
     return unless properties?
 
-    {@openScopes, @text, @tags, @ruleStack, @tokenIterator} = properties
+    {@openScopes, @text, @tags, @ruleStack, @tokenIterator, @grammar} = properties
 
   getTokenIterator: -> @tokenIterator.reset(this)
 
@@ -48,17 +48,26 @@ class TokenizedLine
     return @isCommentLine if @isCommentLine?
 
     @isCommentLine = false
-    iterator = @getTokenIterator()
-    while iterator.next()
-      scopes = iterator.getScopes()
-      continue if scopes.length is 1
-      for scope in scopes
-        if CommentScopeRegex.test(scope)
-          @isCommentLine = true
-          break
-      break
+
+    for tag in @openScopes
+      if @isCommentOpenTag(tag)
+        @isCommentLine = true
+        return @isCommentLine
+
+    for tag in @tags
+      if @isCommentOpenTag(tag)
+        @isCommentLine = true
+        return @isCommentLine
+
     @isCommentLine
 
+  isCommentOpenTag: (tag) ->
+    if tag < 0 and (tag & 1) is 1
+      scope = @grammar.scopeForId(tag)
+      if CommentScopeRegex.test(scope)
+        return true
+    false
+
   tokenAtIndex: (index) ->
     @tokens[index]