Function peek

jsonpath.js:1387–1397

()

    }

    function peek() {
        var pos, line, start;

        pos = index;
        line = lineNumber;
        start = lineStart;
        lookahead = (typeof extra.tokens !== 'undefined') ? collectToken() : advance();
        index = pos;
        lineNumber = line;
        lineStart = start;
    }

    function Position(line, column) {
        this.line = line;