tools/json_comment_eater.py

   1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 """ Utility to remove comments from JSON files so that they can be parsed by
   6 json.loads."""
   7
   8 def _ReadString(input, start, output):
   9   output.append('"')
  10   in_escape = False
  11   for pos in xrange(start, len(input)):
  12     output.append(input[pos])
  13     if in_escape:
  14       in_escape = False
  15     else:
  16       if input[pos] == '\\':
  17         in_escape = True
  18       elif input[pos] == '"':
  19         return pos + 1
  20   return pos
  21
  22 def _ReadComment(input, start, output):
  23   for pos in xrange(start, len(input)):
  24     if input[pos] in ['\r', '\n']:
  25       output.append(input[pos])
  26       return pos + 1
  27   return pos
  28
  29 def Nom(input):
  30   output = []
  31   pos = 0
  32   while pos < len(input):
  33     if input[pos] == '"':
  34       pos = _ReadString(input, pos + 1, output)
  35     elif input[pos:pos+2] == '//':
  36       pos = _ReadComment(input, pos + 2, output)
  37     else:
  38       output.append(input[pos])
  39       pos += 1
  40   return ''.join(output)