Source code for evennia.contrib.rpg.rpsystem.rplanguage

"""
Language and whisper obfuscation system

Evennia contrib - Griatch 2015

This module is intented to be used with an emoting system (such as
contrib/rpsystem.py). It offers the ability to obfuscate spoken words
in the game in various ways:

- Language: The language functionality defines a pseudo-language map
    to any number of languages.  The string will be obfuscated depending
    on a scaling that (most likely) will be input as a weighted average of
    the language skill of the speaker and listener.
- Whisper: The whisper functionality will gradually "fade out" a
    whisper along as scale 0-1, where the fading is based on gradually
    removing sections of the whisper that is (supposedly) easier to
    overhear (for example "s" sounds tend to be audible even when no other
    meaning can be determined).

## Usage

```python
from evennia.contrib import rplanguage

# need to be done once, here we create the "default" lang
rplanguage.add_language()

say = "This is me talking."
whisper = "This is me whispering.

print rplanguage.obfuscate_language(say, level=0.0)
<<< "This is me talking."
print rplanguage.obfuscate_language(say, level=0.5)
<<< "This is me byngyry."
print rplanguage.obfuscate_language(say, level=1.0)
<<< "Daly ly sy byngyry."

result = rplanguage.obfuscate_whisper(whisper, level=0.0)
<<< "This is me whispering"
result = rplanguage.obfuscate_whisper(whisper, level=0.2)
<<< "This is m- whisp-ring"
result = rplanguage.obfuscate_whisper(whisper, level=0.5)
<<< "---s -s -- ---s------"
result = rplanguage.obfuscate_whisper(whisper, level=0.7)
<<< "---- -- -- ----------"
result = rplanguage.obfuscate_whisper(whisper, level=1.0)
<<< "..."

```

## Custom languages

To set up new languages, you need to run `add_language()`
helper function in this module. The arguments of this function (see below)
are used to store the new language in the database (in the LanguageHandler,
which is a type of Script).

If you want to remember the language definitions, you could put them all
in a module along with the `add_language` call as a quick way to
rebuild the language on a db reset:

```python
# a stand-alone module somewhere under mygame. Just import this
# once to automatically add the language!

from evennia.contrib.rpg.rpsystem import rplanguage
grammar = (...)
vowels = "eaouy"
# etc

rplanguage.add_language(grammar=grammar, vowels=vowels, ...)
```

The variables of `add_language` allows you to customize the "feel" of
the semi-random language you are creating. Especially
the `word_length_variance` helps vary the length of translated
words compared to the original. You can also add your own
dictionary and "fix" random words for a list of input words.

## Example

Below is an example module creating "elvish", using "rounder" vowels and sounds:

```python
# vowel/consonant grammar possibilities
grammar = ("v vv vvc vcc vvcc cvvc vccv vvccv vcvccv vcvcvcc vvccvvcc "
           "vcvvccvvc cvcvvcvvcc vcvcvvccvcvv")

# all not in this group is considered a consonant
vowels = "eaoiuy"

# you need a representative of all of the minimal grammars here, so if a
# grammar v exists, there must be atleast one phoneme available with only
# one vowel in it
phonemes = ("oi oh ee ae aa eh ah ao aw ay er ey ow ia ih iy "
            "oy ua uh uw y p b t d f v t dh s z sh zh ch jh k "
            "ng g m n l r w")

# how much the translation varies in length compared to the original. 0 is
# smallest, higher values give ever bigger randomness (including removing
# short words entirely)
word_length_variance = 1

# if a proper noun (word starting with capitalized letter) should be
# translated or not. If not (default) it means e.g. names will remain
# unchanged across languages.
noun_translate = False

# all proper nouns (words starting with a capital letter not at the beginning
# of a sentence) can have either a postfix or -prefix added at all times
noun_postfix = "'la"

# words in dict will always be translated this way. The 'auto_translations'
# is instead a list or filename to file with words to use to help build a
# bigger dictionary by creating random translations of each word in the
# list *once* and saving the result for subsequent use.
manual_translations = {"the":"y'e", "we":"uyi", "she":"semi", "he":"emi",
                      "you": "do", 'me':'mi','i':'me', 'be':"hy'e", 'and':'y'}

rplanguage.add_language(key="elvish", phonemes=phonemes, grammar=grammar,
                         word_length_variance=word_length_variance,
                         noun_translate=noun_translate,
                         noun_postfix=noun_postfix, vowels=vowels,
                         manual_translations=manual_translations,
                         auto_translations="my_word_file.txt")

```

This will produce a decicively more "rounded" and "soft" language
than the default one. The few manual_translations also make sure
to make it at least look superficially "reasonable".

The `auto_translations` keyword is useful, this accepts either a
list or a path to a file of words (one per line) to automatically
create fixed translations for according to the grammatical rules.
This allows to quickly build a large corpus of translated words
that never change (if this is desired).

"""

import re
from collections import defaultdict
from random import choice, randint

from evennia import DefaultScript
from evennia.utils import logger

# ------------------------------------------------------------
#
# Obfuscate language
#
# ------------------------------------------------------------

# default language grammar
_PHONEMES = (
    "ea oh ae aa eh ah ao aw ai er ey ow ia ih iy oy ua uh uw a e i u y p b t d f v t dh "
    "s z sh zh ch jh k ng g m n l r w"
)
_VOWELS = "eaoiuy"
# these must be able to be constructed from phonemes (so for example,
# if you have v here, there must exist at least one single-character
# vowel phoneme defined above)
_GRAMMAR = "v cv vc cvv vcc vcv cvcc vccv cvccv cvcvcc cvccvcv vccvccvc cvcvccvv cvcvcvcvv"

_RE_FLAGS = re.MULTILINE + re.IGNORECASE + re.DOTALL + re.UNICODE
_RE_GRAMMAR = re.compile(r"vv|cc|v|c", _RE_FLAGS)
_RE_WORD = re.compile(r"\w+", _RE_FLAGS)
# superfluous chars, except ` ... `
_RE_EXTRA_CHARS = re.compile(r"\s+(?!... )(?=\W)|[,.?;](?!.. )(?=[,?;]|\s+[,.?;])", _RE_FLAGS)


[docs]class LanguageError(RuntimeError): pass
[docs]class LanguageExistsError(LanguageError): pass
[docs]class LanguageHandler(DefaultScript): """ This is a storage class that should usually not be created on its own. It's automatically created by a call to `obfuscate_language` or `add_language` below. Languages are implemented as a "logical" pseudo- consistent language algorith here. The idea is that a language is built up from phonemes. These are joined together according to a "grammar" of possible phoneme- combinations and allowed characters. It may sound simplistic, but this allows to easily make "similar-sounding" languages. One can also custom-define a dictionary of some common words to give further consistency. Optionally, the system also allows an input list of common words to be loaded and given random translations. These will be stored to disk and will thus not change. This gives a decent "stability" of the language but if the goal is to obfuscate, this may allow players to eventually learn to understand the gist of a sentence even if their characters can not. Any number of languages can be created this way. This nonsense language will partially replace the actual spoken language when so desired (usually because the speaker/listener don't know the language well enough). """
[docs] def at_script_creation(self): "Called when script is first started" self.key = "language_handler" self.persistent = True self.db.language_storage = {}
[docs] def add( self, key="default", phonemes=_PHONEMES, grammar=_GRAMMAR, word_length_variance=0, noun_translate=False, noun_prefix="", noun_postfix="", vowels=_VOWELS, manual_translations=None, auto_translations=None, force=False, ): """ Add a new language. Note that you generally only need to do this once per language and that adding an existing language will re-initialize all the random components to new permanent values. Args: key (str, optional): The name of the language. This will be used as an identifier for the language so it should be short and unique. phonemes (str, optional): Space-separated string of all allowed phonemes in this language. If either of the base phonemes (c, v, cc, vv) are present in the grammar, the phoneme list must at least include one example of each. grammar (str): All allowed consonant (c) and vowel (v) combinations allowed to build up words. Grammars are broken into the base phonemes (c, v, cc, vv) prioritizing the longer bases. So cvv would be a the c + vv (would allow for a word like 'die' whereas cvcvccc would be c+v+c+v+cc+c (a word like 'galosch'). word_length_variance (real): The variation of length of words. 0 means a minimal variance, higher variance may mean words have wildly varying length; this strongly affects how the language "looks". noun_translate (bool, optional): If a proper noun should be translated or not. By default they will not, allowing for e.g. the names of characters to be understandable. A 'noun' is identified as a capitalized word *not at the start of a sentence*. This simple metric means that names starting a sentence always will be translated (- but hey, maybe the fantasy language just never uses a noun at the beginning of sentences, who knows?) noun_prefix (str, optional): A prefix to go before every noun in this language (if any). noun_postfix (str, optuonal): A postfix to go after every noun in this language (if any, usually best to avoid combining with `noun_prefix` or language becomes very wordy). vowels (str, optional): Every vowel allowed in this language. manual_translations (dict, optional): This allows for custom-setting certain words in the language to mean the same thing. It is on the form `{real_word: fictional_word}`, for example `{"the", "y'e"}` . auto_translations (str or list, optional): These are lists words that should be auto-translated with a random, but fixed, translation. If a path to a file, this file should contain a list of words to produce translations for, one word per line. If a list, the list's elements should be the words to translate. The `manual_translations` will always override overlapping translations created automatically. force (bool, optional): Unless true, will not allow the addition of a language that is already created. Raises: LanguageExistsError: Raised if trying to adding a language with a key that already exists, without `force` being set. Notes: The `word_file` is for example a word-frequency list for the N most common words in the host language. The translations will be random, but will be stored persistently to always be the same. This allows for building a quick, decently-sounding fictive language that tend to produce the same "translation" (mostly) with the same input sentence. """ if key in self.db.language_storage and not force: raise LanguageExistsError( "Language is already created. Re-adding it will re-build" " its dictionary map. Use 'force=True' keyword if you are sure." ) # create grammar_component->phoneme mapping # {"vv": ["ea", "oh", ...], ...} grammar2phonemes = defaultdict(list) for phoneme in phonemes.split(): if re.search(r"\W", phoneme, re.U): raise LanguageError("The phoneme '%s' contains an invalid character." % phoneme) gram = "".join(["v" if char in vowels else "c" for char in phoneme]) grammar2phonemes[gram].append(phoneme) # allowed grammar are grouped by length gramdict = defaultdict(list) for gram in grammar.split(): if re.search(r"\W|(!=[cv])", gram): raise LanguageError( "The grammar '%s' is invalid (only 'c' and 'v' are allowed)" % gram ) gramdict[len(gram)].append(gram) grammar = dict(gramdict) # create automatic translation translation = {} if auto_translations: if isinstance(auto_translations, str): # path to a file rather than a list with open(auto_translations, "r") as f: auto_translations = f.readlines() for word in auto_translations: word = word.strip() lword = len(word) new_word = "" wlen = max(0, lword + sum(randint(-1, 1) for i in range(word_length_variance))) if wlen not in grammar: # always create a translation, use random length structure = choice(grammar[choice(list(grammar))]) else: # use the corresponding length structure = choice(grammar[wlen]) for match in _RE_GRAMMAR.finditer(structure): try: new_word += choice(grammar2phonemes[match.group()]) except IndexError: raise IndexError( "Could not find a matching phoneme for the grammar " f"'{match.group()}'. Make there is at least one phoneme matching this " "combination of consonants and vowels." ) translation[word.lower()] = new_word.lower() if manual_translations: # update with manual translations translation.update( dict((key.lower(), value.lower()) for key, value in manual_translations.items()) ) # store data storage = { "translation": translation, "grammar": grammar, "grammar2phonemes": dict(grammar2phonemes), "word_length_variance": word_length_variance, "noun_translate": noun_translate, "noun_prefix": noun_prefix, "noun_postfix": noun_postfix, } self.db.language_storage[key] = storage
def _translate_sub(self, match): """ Replacer method called by re.sub when traversing the language string. Args: match (re.matchobj): Match object from regex. Returns: converted word. Notes: Assumes self.lastword and self.level is available on the object. """ word = match.group() lword = len(word) # find out what preceeded this word wpos = match.start() preceeding = match.string[:wpos].strip() start_sentence = preceeding.endswith((".", "!", "?")) or not preceeding if len(word) <= self.level: # below level. Don't translate new_word = word else: # try to translate the word from dictionary new_word = self.language["translation"].get(word.lower(), "") if not new_word: # no dictionary translation. Generate one # make up translation on the fly. Length can # vary from un-translated word. wlen = max( 0, lword + sum(randint(-1, 1) for i in range(self.language["word_length_variance"])), ) grammar = self.language["grammar"] if wlen not in grammar: if randint(0, 1) == 0: # this word has no direct translation! wlen = 0 new_word = "" else: # use random word length wlen = choice(list(grammar.keys())) if wlen: structure = choice(grammar[wlen]) grammar2phonemes = self.language["grammar2phonemes"] for match in _RE_GRAMMAR.finditer(structure): # there are only four combinations: vv,cc,c,v try: new_word += choice(grammar2phonemes[match.group()]) except KeyError: logger.log_trace( "You need to supply at least one example of each of " "the four base phonemes (c, v, cc, vv)" ) # abort translation here new_word = "" break if word.istitle(): if not start_sentence: # this is a noun. We miss nouns at the start of # sentences this way, but it's as good as we can get # with this simple analysis. Maybe the fantasy language # just don't consider nouns at the beginning of # sentences, who knows? if not self.language.get("noun_translate", False): # don't translate what we identify as proper nouns (names) new_word = word # add noun prefix and/or postfix new_word = "{prefix}{word}{postfix}".format( prefix=self.language["noun_prefix"], word=new_word.capitalize(), postfix=self.language["noun_postfix"], ) if len(word) > 1 and word.isupper(): # keep LOUD words loud also when translated new_word = new_word.upper() if start_sentence: new_word = new_word.capitalize() return new_word
[docs] def translate(self, text, level=0.0, language="default"): """ Translate the text according to the given level. Args: text (str): The text to translate level (real): Value between 0.0 and 1.0, where 0.0 means no obfuscation (text returned unchanged) and 1.0 means full conversion of every word. The closer to 1, the shorter words will be translated. language (str): The language key identifier. Returns: text (str): A translated string. """ if level == 0.0: # no translation return text language = self.db.language_storage.get(language, None) if not language: return text self.language = language # configuring the translation self.level = int(10 * (1.0 - max(0, min(level, 1.0)))) translation = _RE_WORD.sub(self._translate_sub, text) # the substitution may create too long empty spaces, remove those return _RE_EXTRA_CHARS.sub("", translation)
# Language access functions _LANGUAGE_HANDLER = None
[docs]def obfuscate_language(text, level=0.0, language="default"): """ Main access method for the language parser. Args: text (str): Text to obfuscate. level (real, optional): A value from 0.0-1.0 determining the level of obfuscation where 0 means no obfuscation (string returned unchanged) and 1.0 means the entire string is obfuscated. language (str, optional): The identifier of a language the system understands. Returns: translated (str): The translated text. """ # initialize the language handler and cache it global _LANGUAGE_HANDLER if not _LANGUAGE_HANDLER: try: _LANGUAGE_HANDLER = LanguageHandler.objects.get(db_key="language_handler") except LanguageHandler.DoesNotExist: if not _LANGUAGE_HANDLER: from evennia import create_script _LANGUAGE_HANDLER = create_script(LanguageHandler) return _LANGUAGE_HANDLER.translate(text, level=level, language=language)
[docs]def add_language(**kwargs): """ Access function to creating a new language. See the docstring of `LanguageHandler.add` for list of keyword arguments. """ global _LANGUAGE_HANDLER if not _LANGUAGE_HANDLER: try: _LANGUAGE_HANDLER = LanguageHandler.objects.get(db_key="language_handler") except LanguageHandler.DoesNotExist: if not _LANGUAGE_HANDLER: from evennia import create_script _LANGUAGE_HANDLER = create_script(LanguageHandler) _LANGUAGE_HANDLER.add(**kwargs)
[docs]def available_languages(): """ Returns all available language keys. Returns: languages (list): List of key strings of all available languages. """ global _LANGUAGE_HANDLER if not _LANGUAGE_HANDLER: try: _LANGUAGE_HANDLER = LanguageHandler.objects.get(db_key="language_handler") except LanguageHandler.DoesNotExist: if not _LANGUAGE_HANDLER: from evennia import create_script _LANGUAGE_HANDLER = create_script(LanguageHandler) return list(_LANGUAGE_HANDLER.attributes.get("language_storage", {}))
# ----------------------------------------------------------------------------- # # Whisper obscuration # # This obsucration table is designed by obscuring certain vowels first, # following by consonants that tend to be more audible over long distances, # like s. Finally it does non-auditory replacements, like exclamation marks and # capitalized letters (assumed to be spoken louder) that may still give a user # some idea of the sentence structure. Then the word lengths are also # obfuscated and finally the whisper length itself. # # ------------------------------------------------------------------------------ _RE_WHISPER_OBSCURE = [ re.compile(r"^$", _RE_FLAGS), # This is a Test! #0 full whisper re.compile(r"[ae]", _RE_FLAGS), # This -s - Test! #1 add uy re.compile(r"[aeuy]", _RE_FLAGS), # This -s - Test! #2 add oue re.compile(r"[aeiouy]", _RE_FLAGS), # Th-s -s - T-st! #3 add all consonants re.compile(r"[aeiouybdhjlmnpqrv]", _RE_FLAGS), # T--s -s - T-st! #4 add hard consonants re.compile(r"[a-eg-rt-z]", _RE_FLAGS), # T--s -s - T-s-! #5 add all capitals re.compile(r"[A-EG-RT-Za-eg-rt-z]", _RE_FLAGS), # ---s -s - --s-! #6 add f re.compile(r"[A-EG-RT-Za-rt-z]", _RE_FLAGS), # ---s -s - --s-! #7 add s re.compile(r"[A-EG-RT-Za-z]", _RE_FLAGS), # ---- -- - ----! #8 add capital F re.compile(r"[A-RT-Za-z]", _RE_FLAGS), # ---- -- - ----! #9 add capital S re.compile(r"[\w]", _RE_FLAGS), # ---- -- - ----! #10 non-alphanumerals re.compile(r"[\S]", _RE_FLAGS), # ---- -- - ---- #11 words re.compile(r"[\w\W]", _RE_FLAGS), # -------------- #12 whisper length re.compile(r".*", _RE_FLAGS), ] # ... #13 (always same length)
[docs]def obfuscate_whisper(whisper, level=0.0): """ Obfuscate whisper depending on a pre-calculated level (that may depend on distance, listening skill etc) Args: whisper (str): The whisper string to obscure. The entire string will be considered in the obscuration. level (real, optional): This is a value 0-1, where 0 means not obscured (whisper returned unchanged) and 1 means fully obscured. """ level = min(max(0.0, level), 1.0) olevel = int(13.0 * level) if olevel == 13: return "..." else: return _RE_WHISPER_OBSCURE[olevel].sub("-", whisper)