RosettaCodeData/Task/Rep-string/Zkl/rep-string-1.zkl

fcn repString(s){
   foreach n in ([s.len()/2+1..1,-1]){
      Walker.cycle(s[0,n]).pump(s.len(),String) :
      if(_==s and n*2<=s.len()) return(n);
   }
   return(False)
}