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