Esempio n. 1
0
 function parse_factor()
 {
     switch ($this->peek()) {
         case 'leftparen':
             $this->next();
             $a = $this->parse_alternates();
             $this->parse_terminal('rightparen');
             return $a;
         case 'token':
             $t = $this->parse_terminal('token');
             $n = new enfa();
             $n->recognize($t);
             return $n;
         case 'epsilon':
             $t = $this->parse_terminal('epsilon');
             $n = new enfa();
             $n->add_epsilon($n->initial, $n->final);
             return $n;
     }
     die('CFG/PG got stuck parsing factors.');
 }
Esempio n. 2
0
function nfa_concat($nfa_list)
{
    $out = new enfa();
    $last_state = $out->initial;
    foreach ($nfa_list as $nfa) {
        $out->copy_in($nfa);
        $out->add_epsilon($last_state, $nfa->initial);
        $last_state = $nfa->final;
    }
    $out->add_epsilon($last_state, $out->final);
    return $out;
}