fcn fasta(data){ // a lazy cruise through a FASTA file
   fcn(w){      // one string at a time, -->False garbage at front of file
      line:=w.next().strip();
      if(line[0]==">") w.pump(line[1,*]+": ",'wrap(l){
         if(l[0]==">") { w.push(l); Void.Stop } else l.strip()
      })
   }.fp(data.walker()) : Utils.Helpers.wap(_);
}