/**
* Parse :-).
*
* @param string $text Text to parse.
* @param string $rule The axiom, i.e. root rule.
* @param bool $tree Whether build tree or not.
* @return mixed
* @throws \Hoa\Compiler\Exception\UnexpectedToken
*/
public function parse($text, $rule = null, $tree = true)
{
$lexer = new Lexer();
$this->_tokenSequence = $lexer->lexMe($text, $this->_tokens);
$this->_currentState = 0;
$this->_errorState = 0;
$this->_trace = [];
$this->_todo = [];
if (false === array_key_exists($rule, $this->_rules)) {
$rule = $this->getRootRule();
}
$closeRule = new Rule\Ekzit($rule, 0);
$openRule = new Rule\Entry($rule, 0, [$closeRule]);
$this->_todo = [$closeRule, $openRule];
do {
$out = $this->unfold();
if (null !== $out && 'EOF' === $this->getCurrentToken()) {
break;
}
if (false === $this->backtrack()) {
$token = $this->_tokenSequence[$this->_errorState];
$offset = $token['offset'];
$line = 1;
$column = 1;
if (!empty($text)) {
if (0 === $offset) {
$leftnl = 0;
} else {
$leftnl = strrpos($text, "\n", -(strlen($text) - $offset) - 1) ?: 0;
}
$rightnl = strpos($text, "\n", $offset);
$line = substr_count($text, "\n", 0, $leftnl + 1) + 1;
$column = $offset - $leftnl + (0 === $leftnl);
if (false !== $rightnl) {
$text = trim(substr($text, $leftnl, $rightnl - $leftnl), "\n");
}
}
throw new Compiler\Exception\UnexpectedToken('Unexpected token "%s" (%s) at line %d and column %d:' . "\n" . '%s' . "\n" . str_repeat(' ', $column - 1) . '↑', 0, [$token['value'], $token['token'], $line, $column, $text], $line, $column);
}
} while (true);
if (false === $tree) {
return true;
}
$tree = $this->_buildTree();
if (!$tree instanceof TreeNode) {
throw new Compiler\Exception('Parsing error: cannot build AST, the trace is corrupted.', 1);
}
return $this->_tree = $tree;
}
/**
* Build the analyzer of the rules (does not analyze the rules).
*
* @param array $rules Rule to be analyzed.
* @return void
* @throws \Hoa\Compiler\Exception
*/
public function analyzeRules(array $rules)
{
if (empty($rules)) {
throw new Compiler\Exception\Rule('No rules specified!', 0);
}
$tokens = ['default' => ['skip' => '\\s', 'or' => '\\|', 'zero_or_one' => '\\?', 'one_or_more' => '\\+', 'zero_or_more' => '\\*', 'n_to_m' => '\\{[0-9]+,[0-9]+\\}', 'zero_to_m' => '\\{,[0-9]+\\}', 'n_or_more' => '\\{[0-9]+,\\}', 'exactly_n' => '\\{[0-9]+\\}', 'skipped' => '::[a-zA-Z_][a-zA-Z0-9_]*(\\[\\d+\\])?::', 'kept' => '<[a-zA-Z_][a-zA-Z0-9_]*(\\[\\d+\\])?' . '>', 'named' => '[a-zA-Z_][a-zA-Z0-9_]*\\(\\)', 'node' => '#[a-zA-Z_][a-zA-Z0-9_]*(:[mM])?', 'capturing_' => '\\(', '_capturing' => '\\)']];
$this->_createdRules = [];
$this->_rules = $rules;
foreach ($rules as $key => $value) {
$lexer = new Compiler\Llk\Lexer();
$this->_tokenSequence = $lexer->lexMe($value, $tokens);
$this->_rule = $value;
$this->_currentState = 0;
$nodeId = null;
if ('#' === $key[0]) {
$nodeId = $key;
$key = substr($key, 1);
}
$pNodeId = $nodeId;
$rule = $this->rule($pNodeId);
if (null === $rule) {
throw new Compiler\Exception('Error while parsing rule %s.', 1, $key);
}
$zeRule = $this->_createdRules[$rule];
$zeRule->setName($key);
$zeRule->setPPRepresentation($value);
if (null !== $nodeId) {
$zeRule->setDefaultId($nodeId);
}
unset($this->_createdRules[$rule]);
$this->_createdRules[$key] = $zeRule;
}
return $this->_createdRules;
}