var reserved = require('reserved-words');
var parse = require('messageformat-parser').parse;
/** Creates a new message compiler. Called internally from {@link MessageFormat#compile}.
*
* @class
* @param {MessageFormat} mf - A MessageFormat instance
* @property {object} locales - The locale identifiers that are used by the compiled functions
* @property {object} runtime - Names of the core runtime functions that are used by the compiled functions
* @property {object} formatters - The formatter functions that are used by the compiled functions
*/
function Compiler(mf) {
this.mf = mf;
this.lc = null;
this.locales = {};
this.runtime = {};
this.formatters = {};
}
module.exports = Compiler;
/** Utility function for quoting an Object's key value if required
*
* Quotes the key if it contains invalid characters or is an
* ECMAScript 3rd Edition reserved word (for IE8).
*/
Compiler.propname = function(key, obj) {
if (/^[A-Z_$][0-9A-Z_$]*$/i.test(key) &&
['break', 'continue', 'delete', 'else', 'for', 'function', 'if', 'in', 'new',
'return', 'this', 'typeof', 'var', 'void', 'while', 'with', 'case', 'catch',
'default', 'do', 'finally', 'instanceof', 'switch', 'throw', 'try'].indexOf(key) < 0) {
return obj ? obj + '.' + key : key;
} else {
var jkey = JSON.stringify(key);
return obj ? obj + '[' + jkey + ']' : jkey;
}
}
/** Utility function for escaping a function name if required
*/
Compiler.funcname = function(key) {
var fn = key.trim().replace(/\W+/g, '_');
return reserved.check(fn, 'es2015', true) || /^\d/.test(fn) ? '_' + fn : fn;
}
/** Utility formatter function for enforcing Bidi Structured Text by using UCC
*
* List inlined from data extracted from CLDR v27 & v28
* To verify/recreate, use the following:
*
* git clone https://github.com/unicode-cldr/cldr-misc-full.git
* cd cldr-misc-full/main/
* grep characterOrder -r . | tr '"/' '\t' | cut -f2,6 | grep -C4 right-to-left
*/
Compiler.bidiMarkText = function(text, locale) {
function isLocaleRTL(locale) {
var rtlLanguages = ['ar', 'ckb', 'fa', 'he', 'ks($|[^bfh])', 'lrc', 'mzn',
'pa-Arab', 'ps', 'ug', 'ur', 'uz-Arab', 'yi'];
return new RegExp('^' + rtlLanguages.join('|^')).test(locale);
}
var mark = JSON.stringify(isLocaleRTL(locale) ? '\u200F' : '\u200E');
return mark + ' + ' + text + ' + ' + mark;
}
/** @private */
Compiler.prototype.cases = function(token, plural) {
var needOther = token.type === 'select' || !this.mf.hasCustomPluralFuncs;
var r = token.cases.map(function(c) {
if (c.key === 'other') needOther = false;
var s = c.tokens.map(function(tok) { return this.token(tok, plural); }, this);
return Compiler.propname(c.key) + ': ' + (s.join(' + ') || '""');
}, this);
if (needOther) throw new Error("No 'other' form found in " + JSON.stringify(token));
return '{ ' + r.join(', ') + ' }';
}
/** @private */
Compiler.prototype.token = function(token, plural) {
if (typeof token == 'string') return JSON.stringify(token);
var fn, args = [ Compiler.propname(token.arg, 'd') ];
switch (token.type) {
case 'argument':
return this.mf.bidiSupport ? Compiler.bidiMarkText(args[0], this.lc) : args[0];
case 'select':
fn = 'select';
args.push(this.cases(token, this.mf.strictNumberSign ? null : plural));
this.runtime.select = true;
break;
case 'selectordinal':
fn = 'plural';
args.push(0, Compiler.funcname(this.lc), this.cases(token, token), 1);
this.locales[this.lc] = true;
this.runtime.plural = true;
break;
case 'plural':
fn = 'plural';
args.push(token.offset || 0, Compiler.funcname(this.lc), this.cases(token, token));
this.locales[this.lc] = true;
this.runtime.plural = true;
break;
case 'function':
if (!(token.key in this.mf.fmt) && (token.key in this.mf.constructor.formatters)) {
var fmt = this.mf.constructor.formatters[token.key];
this.mf.fmt[token.key] = fmt(this.mf);
}
if (!this.mf.fmt[token.key]) throw new Error('Formatting function ' + JSON.stringify(token.key) + ' not found!');
args.push(JSON.stringify(this.lc));
if (typeof token.param === 'string') {
args.push(JSON.stringify(token.param.trim()))
}
fn = Compiler.propname(token.key, 'fmt');
this.formatters[token.key] = true;
break;
case 'octothorpe':
if (!plural) return '"#"';
fn = 'number';
args = [ Compiler.propname(plural.arg, 'd'), JSON.stringify(plural.arg) ];
if (plural.offset) args.push(plural.offset);
this.runtime.number = true;
break;
}
if (!fn) throw new Error('Parser error for token ' + JSON.stringify(token));
return fn + '(' + args.join(', ') + ')';
};
/** Recursively compile a string or a tree of strings to JavaScript function sources
*
* If `src` is an object with a key that is also present in `plurals`, the key
* in question will be used as the locale identifier for its value. To disable
* the compile-time checks for plural & selectordinal keys while maintaining
* multi-locale support, use falsy values in `plurals`.
*
* @param {string|object} src - the source for which the JS code should be generated
* @param {string} lc - the default locale
* @param {object} plurals - a map of pluralization keys for all available locales
*/
Compiler.prototype.compile = function(src, lc, plurals) {
if (typeof src != 'object') {
this.lc = lc;
var pc = plurals[lc] || { cardinal: [], ordinal: [] };
pc.strictNumberSign = !!this.mf.strictNumberSign;
var r = parse(src, pc).map(function(token) { return this.token(token); }, this);
return 'function(d) { return ' + (r.join(' + ') || '""') + '; }';
} else {
var result = {};
for (var key in src) {
var lcKey = plurals.hasOwnProperty(key) ? key : lc;
result[key] = this.compile(src[key], lcKey, plurals);
}
return result;
}
}