The Tor Browser / file revision

 /* 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.EXPORTED_SYMBOLS = [ "PluralForm" ];

 /**

  * This module provides the PluralForm object which contains a method to figure

  * out which plural form of a word to use for a given number based on the

  * current localization. There is also a makeGetter method that creates a get

  * function for the desired plural rule. This is useful for extensions that

  * specify their own plural rule instead of relying on the browser default.

  * (I.e., the extension hasn't been localized to the browser's locale.)

  *

  * See: http://developer.mozilla.org/en/docs/Localization_and_Plurals

  *

  * List of methods:

  *

  * string pluralForm

  * get(int aNum, string aWords)

  *

  * int numForms

  * numForms()

  *

  * [string pluralForm get(int aNum, string aWords), int numForms numForms()]

  * makeGetter(int aRuleNum)

  * Note: Basically, makeGetter returns 2 functions that do "get" and "numForm"

  */

 const Cc = Components.classes;

 const Ci = Components.interfaces;

 const kIntlProperties = "chrome://global/locale/intl.properties";

 // These are the available plural functions that give the appropriate index

 // based on the plural rule number specified. The first element is the number

 // of plural forms and the second is the function to figure out the index.

 let gFunctions = [

   // 0: Chinese

   [1, function(n) 0],

   // 1: English

   [2, function(n) n!=1?1:0],

   // 2: French

   [2, function(n) n>1?1:0],

   // 3: Latvian

   [3, function(n) n%10==1&&n%100!=11?1:n!=0?2:0],

   // 4: Scottish Gaelic

   [4, function(n) n==1||n==11?0:n==2||n==12?1:n>0&&n<20?2:3],

   // 5: Romanian

   [3, function(n) n==1?0:n==0||n%100>0&&n%100<20?1:2],

   // 6: Lithuanian

   [3, function(n) n%10==1&&n%100!=11?0:n%10>=2&&(n%100<10||n%100>=20)?2:1],

   // 7: Russian

   [3, function(n) n%10==1&&n%100!=11?0:n%10>=2&&n%10<=4&&(n%100<10||n%100>=20)?1:2],

   // 8: Slovak

   [3, function(n) n==1?0:n>=2&&n<=4?1:2],

   // 9: Polish

   [3, function(n) n==1?0:n%10>=2&&n%10<=4&&(n%100<10||n%100>=20)?1:2],

   // 10: Slovenian

   [4, function(n) n%100==1?0:n%100==2?1:n%100==3||n%100==4?2:3],

   // 11: Irish Gaeilge

   [5, function(n) n==1?0:n==2?1:n>=3&&n<=6?2:n>=7&&n<=10?3:4],

   // 12: Arabic

   [6, function(n) n==0?5:n==1?0:n==2?1:n%100>=3&&n%100<=10?2:n%100>=11&&n%100<=99?3:4],

   // 13: Maltese

   [4, function(n) n==1?0:n==0||n%100>0&&n%100<=10?1:n%100>10&&n%100<20?2:3],

   // 14: Macedonian

   [3, function(n) n%10==1?0:n%10==2?1:2],

   // 15: Icelandic

   [2, function(n) n%10==1&&n%100!=11?0:1],

   // 16: Breton

   [5, function(n) n%10==1&&n%100!=11&&n%100!=71&&n%100!=91?0:n%10==2&&n%100!=12&&n%100!=72&&n%100!=92?1:(n%10==3||n%10==4||n%10==9)&&n%100!=13&&n%100!=14&&n%100!=19&&n%100!=73&&n%100!=74&&n%100!=79&&n%100!=93&&n%100!=94&&n%100!=99?2:n%1000000==0&&n!=0?3:4],

 ];

 this.PluralForm = {

   /**

    * Get the correct plural form of a word based on the number

    *

    * @param aNum

    *        The number to decide which plural form to use

    * @param aWords

    *        A semi-colon (;) separated string of words to pick the plural form

    * @return The appropriate plural form of the word

    */

   get get()

   {

     // This method will lazily load to avoid perf when it is first needed and

     // creates getPluralForm function. The function it creates is based on the

     // value of pluralRule specified in the intl stringbundle.

     // See: http://developer.mozilla.org/en/docs/Localization_and_Plurals

     // Delete the getters to be overwritten

     delete PluralForm.numForms;

     delete PluralForm.get;

     // Get the plural rule number from the intl stringbundle

     let ruleNum = Number(Cc["@mozilla.org/intl/stringbundle;1"].

       getService(Ci.nsIStringBundleService).createBundle(kIntlProperties).

       GetStringFromName("pluralRule"));

     // Make the plural form get function and set it as the default get

     [PluralForm.get, PluralForm.numForms] = PluralForm.makeGetter(ruleNum);

     return PluralForm.get;

   },

   /**

    * Create a pair of plural form functions for the given plural rule number.

    *

    * @param aRuleNum

    *        The plural rule number to create functions

    * @return A pair: [function that gets the right plural form,

    *                  function that returns the number of plural forms]

    */

   makeGetter: function(aRuleNum)

   {

     // Default to "all plural" if the value is out of bounds or invalid

     if (aRuleNum < 0 || aRuleNum >= gFunctions.length || isNaN(aRuleNum)) {

       log(["Invalid rule number: ", aRuleNum, " -- defaulting to 0"]);

       aRuleNum = 0;

     }

     // Get the desired pluralRule function

     let [numForms, pluralFunc] = gFunctions[aRuleNum];

     // Return functions that give 1) the number of forms and 2) gets the right

     // plural form

     return [function(aNum, aWords) {

       // Figure out which index to use for the semi-colon separated words

       let index = pluralFunc(aNum ? Number(aNum) : 0);

       let words = aWords ? aWords.split(/;/) : [""];

       // Explicitly check bounds to avoid strict warnings

       let ret = index < words.length ? words[index] : undefined;

       // Check for array out of bounds or empty strings

       if ((ret == undefined) || (ret == "")) {

         // Report the caller to help figure out who is causing badness

         let caller = PluralForm.get.caller ? PluralForm.get.caller.name : "top";

         // Display a message in the error console

         log(["Index #", index, " of '", aWords, "' for value ", aNum,

             " is invalid -- plural rule #", aRuleNum, "; called by ", caller]);

         // Default to the first entry (which might be empty, but not undefined)

         ret = words[0];

       }

       return ret;

     }, function() numForms];

   },

   /**

    * Get the number of forms for the current plural rule

    *

    * @return The number of forms

    */

   get numForms()

   {

     // We lazily load numForms, so trigger the init logic with get()

     PluralForm.get();

     return PluralForm.numForms;

   },

 };

 /**

  * Private helper function to log errors to the error console and command line

  *

  * @param aMsg

  *        Error message to log or an array of strings to concat

  */

 function log(aMsg)

 {

   let msg = "PluralForm.jsm: " + (aMsg.join ? aMsg.join("") : aMsg);

   Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService).

     logStringMessage(msg);

   dump(msg + "\n");

 }