template.ts

let cache: Object = new Object();

export function tmpl(str: string, data ?: Object): string {
    let fn = !/\W/.test(str) ?
        cache[str] = cache[str] ||
        tmpl(document.getElementById(str).innerHTML) :

        //
        // Generate a reusable function that will serve as a template
        // generator (and which will be cached).
        //
        new Function("obj",
            "var p=[],print=function(){p.push.apply(p,arguments);};" +

            // Introduce the data as local variables using with
            "with(obj){p.push('" +

            // Convert the template into pure JavaScript
            str
                .replace(/[\r\t\n]/g, " ")
                .split("<%").join("\t")
                .replace(/((^|%>)[^\t]*)'/g, "$1\r")
                .replace(/\t=(.*?)%>/g, "',$1,'")
                .split("\t").join("');")
                .split("%>").join("p.push('")
                .split("\r").join("\\'")
            + "');}return p.join('');");

    // Provide some basic currying to the user
    return data ? fn(data) : fn;
}