Haanga_Compiler_Parser::yy_get_expected_tokens PHP Method

    function yy_get_expected_tokens($token)
    {
        $state = $this->yystack[$this->yyidx]->stateno;
        $expected = self::$yyExpectedTokens[$state];
        if (in_array($token, self::$yyExpectedTokens[$state], true)) {
            return $expected;
        }
        $stack = $this->yystack;
        $yyidx = $this->yyidx;
        do {
            $yyact = $this->yy_find_shift_action($token);
            if ($yyact >= self::YYNSTATE && $yyact < self::YYNSTATE + self::YYNRULE) {
                // reduce action
                $done = 0;
                do {
                    if ($done++ == 100) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        // too much recursion prevents proper detection
                        // so give up
                        return array_unique($expected);
                    }
                    $yyruleno = $yyact - self::YYNSTATE;
                    $this->yyidx -= self::$yyRuleInfo[$yyruleno]['rhs'];
                    $nextstate = $this->yy_find_reduce_action($this->yystack[$this->yyidx]->stateno, self::$yyRuleInfo[$yyruleno]['lhs']);
                    if (isset(self::$yyExpectedTokens[$nextstate])) {
                        $expected += self::$yyExpectedTokens[$nextstate];
                        if (in_array($token, self::$yyExpectedTokens[$nextstate], true)) {
                            $this->yyidx = $yyidx;
                            $this->yystack = $stack;
                            return array_unique($expected);
                        }
                    }
                    if ($nextstate < self::YYNSTATE) {
                        // we need to shift a non-terminal
                        $this->yyidx++;
                        $x = new Haanga_yyStackEntry();
                        $x->stateno = $nextstate;
                        $x->major = self::$yyRuleInfo[$yyruleno]['lhs'];
                        $this->yystack[$this->yyidx] = $x;
                        continue 2;
                    } elseif ($nextstate == self::YYNSTATE + self::YYNRULE + 1) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        // the last token was just ignored, we can't accept
                        // by ignoring input, this is in essence ignoring a
                        // syntax error!
                        return array_unique($expected);
                    } elseif ($nextstate === self::YY_NO_ACTION) {
                        $this->yyidx = $yyidx;
                        $this->yystack = $stack;
                        // input accepted, but not shifted (I guess)
                        return $expected;
                    } else {
                        $yyact = $nextstate;
                    }
                } while (true);
            }
            break;
        } while (true);
        return array_unique($expected);
    }