/**
* The bounded-exhaustive algorithm.
*
* @param \Hoa\Compiler\Llk\Rule $rule Rule to cover.
* @param int $next Next rule.
* @return bool
*/
protected function boundedExhaustive(Compiler\Llk\Rule $rule, $next)
{
$content = $rule->getContent();
if ($rule instanceof Compiler\Llk\Rule\Repetition) {
if (0 === $next) {
$this->_trace[] = new Compiler\Llk\Rule\Entry($rule->getName(), $rule->getMin());
array_pop($this->_todo);
$this->_todo[] = new Compiler\Llk\Rule\Ekzit($rule->getName(), $rule->getMin(), $this->_todo);
for ($i = 0, $min = $rule->getMin(); $i < $min; ++$i) {
$this->_todo[] = new Compiler\Llk\Rule\Ekzit($content, 0);
$this->_todo[] = new Compiler\Llk\Rule\Entry($content, 0);
}
} else {
$nbToken = 0;
foreach ($this->_trace as $trace) {
if ($trace instanceof Compiler\Llk\Rule\Token) {
++$nbToken;
}
}
$max = $rule->getMax();
if (-1 != $max && $next > $max) {
return false;
}
$this->_todo[] = new Compiler\Llk\Rule\Ekzit($rule->getName(), $next, $this->_todo);
$this->_todo[] = new Compiler\Llk\Rule\Ekzit($content, 0);
$this->_todo[] = new Compiler\Llk\Rule\Entry($content, 0);
}
return true;
} elseif ($rule instanceof Compiler\Llk\Rule\Choice) {
if (count($content) <= $next) {
return false;
}
$this->_trace[] = new Compiler\Llk\Rule\Entry($rule->getName(), $next, $this->_todo);
$nextRule = $content[$next];
$this->_todo[] = new Compiler\Llk\Rule\Ekzit($nextRule, 0);
$this->_todo[] = new Compiler\Llk\Rule\Entry($nextRule, 0);
return true;
} elseif ($rule instanceof Compiler\Llk\Rule\Concatenation) {
$this->_trace[] = new Compiler\Llk\Rule\Entry($rule->getName(), $next);
for ($i = count($content) - 1; $i >= 0; --$i) {
$nextRule = $content[$i];
$this->_todo[] = new Compiler\Llk\Rule\Ekzit($nextRule, 0);
$this->_todo[] = new Compiler\Llk\Rule\Entry($nextRule, 0);
}
return true;
} elseif ($rule instanceof Compiler\Llk\Rule\Token) {
$nbToken = 0;
foreach ($this->_trace as $trace) {
if ($trace instanceof Compiler\Llk\Rule\Token) {
++$nbToken;
}
}
if ($nbToken >= $this->getLength()) {
return false;
}
$this->_trace[] = $rule;
array_pop($this->_todo);
return true;
}
return false;
}
