const self = {

    /**
     * Finds and replaces stings formatted: <%KEY%> by a value with the same key
    */

    engine: function (tpl, data) {
        // set the RegEx pattern
        var re = /<%([^%>]+)?%>/g, match;
        // Get the results of the expression
        while (match = re.exec(tpl)) {
            // Replace the string var with the designated value
            tpl = tpl.replace(match[0], data[match[1]])
        }

        // Check if there are more variables to replace
        if (re.exec(tpl) !== null) {
            // if so, return an instance of itself.
            return self.engine(tpl, data);
        } else {
            // otherwise, return the string
            return tpl;
        }
    }
}

module.exports = self;