Function Parser

clients/web/embed/less/less.js:3110–4906

(context, imports, fileInfo)

//`
//
var Parser = function Parser(context, imports, fileInfo) {
    var parsers,
        parserInput = getParserInput();

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

    function expect(arg, msg, index) {
        // some older browsers return typeof 'function' for RegExp
        var 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)) {
            return arg;
        }
        error(msg || "expected '" + arg + "' got '" + parserInput.currentChar() + "'");
    }

    function getDebugInfo(index) {
        var filename = fileInfo.filename;

        return {
            lineNumber: utils.getLocation(index, parserInput.getInput()).line + 1,
            fileName: filename
        };
    }

    //
    // The Parser
    //
    return {

        //
        // Parse an input string into an abstract syntax tree,
        // @param str A string containing 'less' markup
        // @param callback call `callback` when done.
        // @param [additionalData] An optional map which can contains vars - a map (key, value) of variables to apply
        //
        parse: function (str, callback, additionalData) {
            var root, error = null, globalVars, modifyVars, ignored, preText = "";

            globalVars = (additionalData && additionalData.globalVars) ? Parser.serializeVars(additionalData.globalVars) + '\n' : '';