gecko/addon-sdk/source/python-lib/plural-rules-generator.py

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# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
# Program used to generate /packages/api-utils/lib/l10n/plural-rules.js
# Fetch unicode.org data in order to build functions specific to each language
# that will return for a given integer, its plural form name.
# Plural form names are: zero, one, two, few, many, other.
#
# More information here:
# http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
# http://cldr.unicode.org/index/cldr-spec/plural-rules
# Usage:
# $ python plural-rules-generator.py > ../packages/api-utils/lib/l10n/plural-rules.js
import urllib2
import xml.dom.minidom
import json
import re
PRINT_CONDITIONS_IN_COMMENTS = False
UNICODE_ORG_XML_URL = "http://unicode.org/repos/cldr/trunk/common/supplemental/plurals.xml"
CONDITION_RE = r'n( mod \d+)? (is|in|within|(not in))( not)? ([^\s]+)'
# For a given regexp.MatchObject `g` for `CONDITION_RE`,
# returns the equivalent JS piece of code
# i.e. maps pseudo conditional language from unicode.org XML to JS code
def parseCondition(g):
lvalue = "n"
if g.group(1):
lvalue = "(n %% %d)" % int(g.group(1).replace("mod ", ""))
operator = g.group(2)
if g.group(4):
operator += " not"
rvalue = g.group(5)
if operator == "is":
return "%s == %s" % (lvalue, rvalue)
if operator == "is not":
return "%s != %s" % (lvalue, rvalue)
# "in", "within" or "not in" case:
notPrefix = ""
if operator == "not in":
notPrefix = "!"
# `rvalue` is a comma seperated list of either:
# - numbers: 42
# - ranges: 42..72
sections = rvalue.split(',')
if ".." not in rvalue:
# If we don't have range, but only a list of integer,
# we can simplify the generated code by using `isIn`
# n in 1,3,6,42
return "%sisIn(%s, [%s])" % (notPrefix, lvalue, ", ".join(sections))
# n in 1..42
# n in 1..3,42
subCondition = []
integers = []
for sub in sections:
if ".." in sub:
left, right = sub.split("..")
subCondition.append("isBetween(%s, %d, %d)" % (
lvalue,
int(left),
int(right)
))
else:
integers.append(int(sub))
if len(integers) > 1:
subCondition.append("isIn(%s, [%s])" % (lvalue, ", ".join(integers)))
elif len(integers) == 1:
subCondition.append("(%s == %s)" % (lvalue, integers[0]))
return "%s(%s)" % (notPrefix, " || ".join(subCondition))
def computeRules():
# Fetch plural rules data directly from unicode.org website:
url = UNICODE_ORG_XML_URL
f = urllib2.urlopen(url)
doc = xml.dom.minidom.parse(f)
# Read XML document and extract locale to rules mapping
localesMapping = {}
algorithms = {}
for index,pluralRules in enumerate(doc.getElementsByTagName("pluralRules")):
if not index in algorithms:
algorithms[index] = {}
for locale in pluralRules.getAttribute("locales").split():
localesMapping[locale] = index
for rule in pluralRules.childNodes:
if rule.nodeType != rule.ELEMENT_NODE or rule.tagName != "pluralRule":
continue
pluralForm = rule.getAttribute("count")
algorithm = rule.firstChild.nodeValue
algorithms[index][pluralForm] = algorithm
# Go through all rules and compute a Javascript code for each of them
rules = {}
for index,rule in algorithms.iteritems():
lines = []
for pluralForm in rule:
condition = rule[pluralForm]
originalCondition = str(condition)
# Convert pseudo language to JS code
condition = rule[pluralForm].lower()
condition = re.sub(CONDITION_RE, parseCondition, condition)
condition = re.sub(r'or', "||", condition)
condition = re.sub(r'and', "&&", condition)
# Prints original condition in unicode.org pseudo language
if PRINT_CONDITIONS_IN_COMMENTS:
lines.append( '// %s' % originalCondition )
lines.append( 'if (%s)' % condition )
lines.append( ' return "%s";' % pluralForm )
rules[index] = "\n ".join(lines)
return localesMapping, rules
localesMapping, rules = computeRules()
rulesLines = []
for index in rules:
lines = rules[index]
rulesLines.append('"%d": function (n) {' % index)
rulesLines.append(' %s' % lines)
rulesLines.append(' return "other"')
rulesLines.append('},')
print """/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// This file is automatically generated with /python-lib/plural-rules-generator.py
// Fetching data from: %s
// Mapping of short locale name == to == > rule index in following list
const LOCALES_TO_RULES = %s;
// Utility functions for plural rules methods
function isIn(n, list) list.indexOf(n) !== -1;
function isBetween(n, start, end) start <= n && n <= end;
// List of all plural rules methods, that maps an integer to the plural form name to use
const RULES = {
%s
};
/**
* Return a function that gives the plural form name for a given integer
* for the specified `locale`
* let fun = getRulesForLocale('en');
* fun(1) -> 'one'
* fun(0) -> 'other'
* fun(1000) -> 'other'
*/
exports.getRulesForLocale = function getRulesForLocale(locale) {
let index = LOCALES_TO_RULES[locale];
if (!(index in RULES)) {
console.warn('Plural form unknown for locale "' + locale + '"');
return function () { return "other"; };
}
return RULES[index];
}
""" % (UNICODE_ORG_XML_URL,
json.dumps(localesMapping, sort_keys=True, indent=2),
"\n ".join(rulesLines))