Fix some low hanging inefficiencies in the docs server

tools/json_comment_eater/json_comment_eater.py

+# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+'''Utility to remove comments from JSON files so that they can be parsed by
+json.loads.
+'''
+
+def _Rcount(string, chars):
+  '''Returns the number of consecutive characters from |chars| that occur at the
+  end of |string|.
+  '''
+  return len(string) - len(string.rstrip(chars))
+
+def _FindNextToken(string, tokens, start):
+  '''Finds the next token in |tokens| that occurs in |string| from |start|.
+  Returns a tuple (index, token key).
+  '''
+  min_index, min_key = (-1, None)
+  for k in tokens:
+    index = string.find(k, start)
+    if index != -1 and (min_index == -1 or index < min_index):
+      min_index, min_key = (index, k)
+  return (min_index, min_key)
+
+def _ReadString(input, start, output):
+  output.append('"')
+  start_range, end_range = (start, input.find('"', start))
+  # \" escapes the ", \\" doesn't, \\\" does, etc.
+  while (end_range != -1 and
+         _Rcount(input[start_range:end_range], '\\') % 2 == 1):
+    start_range, end_range = (end_range, input.find('"', end_range + 1))
+  if end_range == -1:
+    return start_range + 1
+  output.append(input[start:end_range + 1])
+  return end_range + 1
+
+def _ReadComment(input, start, output):
+  eol_tokens = ('\n', '\r')
+  eol_token_index, eol_token = _FindNextToken(input, eol_tokens, start)
+  if eol_token is None:
+    return len(input)
+  output.append(eol_token)
+  return eol_token_index + len(eol_token)
+
+def Nom(input):
+  token_actions = {
+    '"': _ReadString,
+    '//': _ReadComment,
+  }
+  output = []
+  pos = 0
+  while pos < len(input):
+    token_index, token = _FindNextToken(input, token_actions.keys(), pos)
+    if token is None:
+      output.append(input[pos:])
+      break
+    output.append(input[pos:token_index])
+    pos = token_actions[token](input, token_index + len(token), output)
+  return ''.join(output)