Function Parser

packages/less/lib/less/parser/parser.js:46–2699

(context, imports, fileInfo, currentIndex)

//

const Parser = function Parser(context, imports, fileInfo, currentIndex) {
    currentIndex = currentIndex || 0;
    let parsers;
    const parserInput = getParserInput();

    function error(msg, type) {
        throw new LessError(
            {
                index: parserInput.i,
                filename: fileInfo.filename,
                type: type || 'Syntax',
                message: msg
            },
            imports
        );
    }

    const deprecationHandler = new DeprecationHandler();

    /**
     * @param {string} msg
     * @param {number} index
     * @param {string} type
     * @param {string} [deprecationId] - stable deprecation ID for repetition limiting
     */
    function warn(msg, index, type, deprecationId) {
        if (context.quiet) { return; }
        if (deprecationId && context.quietDeprecations) { return; }
        if (deprecationId && !deprecationHandler.shouldWarn(deprecationId)) { return; }

        logger.warn(
            (new LessError(
                {
                    index: index ?? parserInput.i,
                    filename: fileInfo.filename,
                    type: type ? `${type.toUpperCase()} WARNING` : 'WARNING',
                    message: msg
                },
                imports
            )).toString()
        );
    }

    function expect(arg, msg) {
        // some older browsers return typeof 'function' for RegExp
        const result = (arg instanceof Function) ? arg.call(parsers) : parserInput.$re(arg);
        if (result) {
            return result;
        }

        error(msg || (typeof arg === 'string'
            ? `expected '${arg}' got '${parserInput.currentChar()}'`
            : 'unexpected token'));
    }

    // Specialization of expect()
    function expectChar(arg, msg) {
        if (parserInput.$char(arg)) {