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Diffstat (limited to 'devtools/shared/plural-form.js')
| -rw-r--r-- | devtools/shared/plural-form.js | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/devtools/shared/plural-form.js b/devtools/shared/plural-form.js new file mode 100644 index 0000000000..1d89ad9961 --- /dev/null +++ b/devtools/shared/plural-form.js @@ -0,0 +1,203 @@ +/* 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/. */ + +/* + * The code below is mostly is a slight modification of intl/locale/PluralForm.jsm that + * removes dependencies on chrome privileged APIs. To make maintenance easier, this file + * is kept as close as possible to the original in terms of implementation. + * The modified methods here are + * - makeGetter (remove code adding the caller name to the log) + * - get ruleNum() (rely on LocalizationHelper instead of String.services) + * - log() (rely on console.log) + * + * Disable eslint warnings to preserve original code style. + */ + +/* eslint-disable */ + +/** + * 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 { LocalizationHelper } = require("resource://devtools/shared/l10n.js"); +const L10N = new LocalizationHelper("toolkit/locales/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. +const gFunctions = [ + // 0: Chinese + [1, (n) => 0], + // 1: English + [2, (n) => n!=1?1:0], + // 2: French + [2, (n) => n>1?1:0], + // 3: Latvian + [3, (n) => n%10==1&&n%100!=11?1:n%10==0?0:2], + // 4: Scottish Gaelic + [4, (n) => n==1||n==11?0:n==2||n==12?1:n>0&&n<20?2:3], + // 5: Romanian + [3, (n) => n==1?0:n==0||n%100>0&&n%100<20?1:2], + // 6: Lithuanian + [3, (n) => n%10==1&&n%100!=11?0:n%10>=2&&(n%100<10||n%100>=20)?2:1], + // 7: Russian + [3, (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, (n) => n==1?0:n>=2&&n<=4?1:2], + // 9: Polish + [3, (n) => n==1?0:n%10>=2&&n%10<=4&&(n%100<10||n%100>=20)?1:2], + // 10: Slovenian + [4, (n) => n%100==1?0:n%100==2?1:n%100==3||n%100==4?2:3], + // 11: Irish Gaeilge + [5, (n) => n==1?0:n==2?1:n>=3&&n<=6?2:n>=7&&n<=10?3:4], + // 12: Arabic + [6, (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, (n) => n==1?0:n==0||n%100>0&&n%100<=10?1:n%100>10&&n%100<20?2:3], + // 14: Unused + [3, (n) => n%10==1?0:n%10==2?1:2], + // 15: Icelandic, Macedonian + [2, (n) => n%10==1&&n%100!=11?0:1], + // 16: Breton + [5, (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], + // 17: Shuar + [2, (n) => n!=0?1:0], + // 18: Welsh + [6, (n) => n==0?0:n==1?1:n==2?2:n==3?3:n==6?4:5], + // 19: Bosnian, Croatian, Serbian + [3, (n) => n % 10 == 1 && n % 100 != 11 ? 0 : n % 10 >= 2 && n % 10 <= 4 && (n % 100 < 10 || n % 100 >= 20) ? 1 : 2], +]; + +const 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 this.numForms; + delete this.get; + + // Make the plural form get function and set it as the default get + [this.get, this.numForms] = this.makeGetter(this.ruleNum); + return this.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 == "")) { + // Display a message in the error console + log(["Index #", index, " of '", aWords, "' for value ", aNum, + " is invalid -- plural rule #", aRuleNum, ";"]); + + // Default to the first entry (which might be empty, but not undefined) + ret = words[0]; + } + + return ret; + }, () => 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() + this.get(); + return this.numForms; + }, + + /** + * Get the plural rule number from the intl stringbundle + * + * @return The plural rule number + */ + get ruleNum() + { + try { + return parseInt(L10N.getStr("pluralRule"), 10); + } catch (e) { + // Fallback to English if the pluralRule property is not available. + return 1; + } + } +}; + +/** + * 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 = "plural-form.js: " + (aMsg.join ? aMsg.join("") : aMsg); + console.log(msg + "\n"); +} + +exports.PluralForm = PluralForm; +exports.get = PluralForm.get; + +/* eslint-enable */ |