function extractLineFeeds(s) {
    return s.replace(/[^\n]+/g, '');
}

// input is the HanSON string to convert.
// if keepLineNumbers is set, toJSON() tried not to modify line numbers, so a JSON parser's
// line numbers in error messages will still make sense.
function toJSON(input, keepLineNumbers) {
    var UNESCAPE_MAP = { '\\"': '"', "\\`": "`", "\\'": "'" };
    var ML_ESCAPE_MAP = {'\n': '\\n', "\r": '\\r', "\t": '\\t', '"': '\\"'};
    function unescapeQuotes(r) { return UNESCAPE_MAP[r] || r; }

    return input.replace(/`(?:\\.|[^`])*`|'(?:\\.|[^'])*'|"(?:\\.|[^"])*"|\/\*[^]*?\*\/|\/\/.*\n?/g, // pass 1: remove comments
                         function(s) {
        if (s.charAt(0) == '/')
            return keepLineNumbers ? extractLineFeeds(s) : '';
        else
            return s;
    })
    .replace(/(?:true|false|null)(?=[^\w_$]|$)|([a-zA-Z_$][\w_\-$]*)|`((?:\\.|[^`])*)`|'((?:\\.|[^'])*)'|"(?:\\.|[^"])*"|(,)(?=\s*[}\]])/g, // pass 2: requote
                         function(s, identifier, multilineQuote, singleQuote, lonelyComma) {
        if (lonelyComma)
            return '';
        else if (identifier != null)
                return '"' + identifier + '"';
        else if (multilineQuote != null)
            return '"' + multilineQuote.replace(/\\./g, unescapeQuotes).replace(/[\n\r\t"]/g, function(r) { return ML_ESCAPE_MAP[r]; }) +
                   '"' + (keepLineNumbers ? extractLineFeeds(multilineQuote) : '');
        else if (singleQuote != null)
            return '"' + singleQuote.replace(/\\./g, unescapeQuotes).replace(/"/g, '\\"') + '"';
        else
            return s;
    });
}

export const parseRelaxedJson = (str : string) : object => {
    return JSON.parse(toJSON(str, false))
}