RND in Python

import re
RND_MATCHER = re.compile(r'%\[(?P<name>[A-Za-z0-9_|.])\]')
def RND(tmpl, ns):
    def convert(mo):
        sp = mo.group('name').split('|')
        name = sp[0]
        filters = sp[1:]
        if ns.has_key(name):
            cnt = ns[name]
            for f in filters:
                cnt = ns[f](cnt)
        else:
            cnt = mo.group(0)
        return str(cnt)
    return RND_MATCHER.sub(convert, tmpl)

text = '<a href="%[link]">%[value|parseInt]</a>'
ns = {'link': 'http://amix.dk', 'value': 5.5,
      'parseInt': lambda x: int(x)}
print RND(text, ns)

function RND(tmpl, ns, scope) {
  scope = scope || window;
  var fn = function(w, g) {
    g = g.split("|");
    var cnt = ns[g[0]];
    for(var i=1; i < g.length; i++)
      cnt = scope[g[i]](cnt);
    if(cnt == 0 || cnt == -1)
      cnt += '';
    return cnt || w;
  };
  return tmpl.replace(/%\(([A-Za-z0-9_|.])\)/g, fn);
}