Initial source commit to grit-i18n project.

grit/pseudo.py

+#!/usr/bin/python2.4
+# Copyright (c) 2006-2008 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.
+
+'''Pseudotranslation support.  Our pseudotranslations are based on the
+P-language, which is a simple vowel-extending language.  Examples of P:
+  - "hello" becomes "hepellopo"
+  - "howdie" becomes "hopowdiepie"
+  - "because" becomes "bepecaupause" (but in our implementation we don't
+    handle the silent e at the end so it actually would return "bepecaupausepe"
+
+The P-language has the excellent quality of increasing the length of text
+by around 30-50% which is great for pseudotranslations, to stress test any
+GUI layouts etc.
+
+To make the pseudotranslations more obviously "not a translation" and to make
+them exercise any code that deals with encodings, we also transform all English
+vowels into equivalent vowels with diacriticals on them (rings, acutes,
+diaresis, and circumflex), and we write the "p" in the P-language as a Hebrew
+character Qof.  It looks sort of like a latin character "p" but it is outside
+the latin-1 character set which will stress character encoding bugs.
+'''
+
+import re
+import types
+
+from grit import tclib
+
+
+# An RFC language code for the P pseudolanguage.
+PSEUDO_LANG = 'x-P-pseudo'
+
+# Hebrew character Qof.  It looks kind of like a 'p' but is outside
+# the latin-1 character set which is good for our purposes.
+# TODO(joi) For now using P instead of Qof, because of some bugs it used.  Find
+# a better solution, i.e. one that introduces a non-latin1 character into the
+# pseudotranslation.
+#_QOF = u'\u05e7'
+_QOF = u'P'
+
+# How we map each vowel.
+_VOWELS = {
+  u'a' : u'\u00e5',  # a with ring
+  u'e' : u'\u00e9',  # e acute
+  u'i' : u'\u00ef',  # i diaresis
+  u'o' : u'\u00f4',  # o circumflex
+  u'u' : u'\u00fc',  # u diaresis
+  u'y' : u'\u00fd',  # y acute
+  u'A' : u'\u00c5',  # A with ring
+  u'E' : u'\u00c9',  # E acute
+  u'I' : u'\u00cf',  # I diaresis
+  u'O' : u'\u00d4',  # O circumflex
+  u'U' : u'\u00dc',  # U diaresis
+  u'Y' : u'\u00dd',  # Y acute
+}
+
+# Matches vowels and P
+_PSUB_RE = re.compile("(%s)" % '|'.join(_VOWELS.keys() + ['P']))
+
+
+# Pseudotranslations previously created.  This is important for performance
+# reasons, especially since we routinely pseudotranslate the whole project
+# several or many different times for each build.
+_existing_translations = {}
+
+
+def MapVowels(str, also_p = False):
+  '''Returns a copy of 'str' where characters that exist as keys in _VOWELS
+  have been replaced with the corresponding value.  If also_p is true, this
+  function will also change capital P characters into a Hebrew character Qof.
+  '''
+  def Repl(match):
+    if match.group() == 'p':
+      if also_p:
+        return _QOF
+      else:
+        return 'p'
+    else:
+      return _VOWELS[match.group()]
+  return _PSUB_RE.sub(Repl, str)
+
+
+def PseudoString(str):
+  '''Returns a pseudotranslation of the provided string, in our enhanced
+  P-language.'''
+  if str in _existing_translations:
+    return _existing_translations[str]
+
+  outstr = u''
+  ix = 0
+  while ix < len(str):
+    if str[ix] not in _VOWELS.keys():
+      outstr += str[ix]
+      ix += 1
+    else:
+      # We want to treat consecutive vowels as one composite vowel.  This is not
+      # always accurate e.g. in composite words but good enough.
+      consecutive_vowels = u''
+      while ix < len(str) and str[ix] in _VOWELS.keys():
+        consecutive_vowels += str[ix]
+        ix += 1
+      changed_vowels = MapVowels(consecutive_vowels)
+      outstr += changed_vowels
+      outstr += _QOF
+      outstr += changed_vowels
+
+  _existing_translations[str] = outstr
+  return outstr
+
+
+def PseudoMessage(message):
+  '''Returns a pseudotranslation of the provided message.
+
+  Args:
+    message: tclib.Message()
+
+  Return:
+    tclib.Translation()
+  '''
+  transl = tclib.Translation()
+
+  for part in message.GetContent():
+    if isinstance(part, tclib.Placeholder):
+      transl.AppendPlaceholder(part)
+    else:
+      transl.AppendText(PseudoString(part))
+
+  return transl
+