class DocLexer

final class DocLexer extends AbstractLexer {
  public const T_NONE = 1;
  public const T_INTEGER = 2;
  public const T_STRING = 3;
  public const T_FLOAT = 4;
  // All tokens that are also identifiers should be >= 100
  public const T_IDENTIFIER = 100;
  public const T_AT = 101;
  public const T_CLOSE_CURLY_BRACES = 102;
  public const T_CLOSE_PARENTHESIS = 103;
  public const T_COMMA = 104;
  public const T_EQUALS = 105;
  public const T_FALSE = 106;
  public const T_NAMESPACE_SEPARATOR = 107;
  public const T_OPEN_CURLY_BRACES = 108;
  public const T_OPEN_PARENTHESIS = 109;
  public const T_TRUE = 110;
  public const T_NULL = 111;
  public const T_COLON = 112;
  public const T_MINUS = 113;
  /** @var array<string, self::T*> */
  protected $noCase = [
    '@' => self::T_AT,
    ',' => self::T_COMMA,
    '(' => self::T_OPEN_PARENTHESIS,
    ')' => self::T_CLOSE_PARENTHESIS,
    '{' => self::T_OPEN_CURLY_BRACES,
    '}' => self::T_CLOSE_CURLY_BRACES,
    '=' => self::T_EQUALS,
    ':' => self::T_COLON,
    '-' => self::T_MINUS,
    '\\' => self::T_NAMESPACE_SEPARATOR,
  ];
  /** @var array<string, self::T*> */
  protected $withCase = [
    'true' => self::T_TRUE,
    'false' => self::T_FALSE,
    'null' => self::T_NULL,
  ];
  
  /**
   * Whether the next token starts immediately, or if there were
   * non-captured symbols before that
   */
  public function nextTokenIsAdjacent() : bool {
    return $this->token === null || $this->lookahead !== null && $this->lookahead->position - $this->token->position === strlen($this->token->value);
  }
  
  /**
   * {@inheritDoc}
   */
  protected function getCatchablePatterns() : array {
    return [
      '[a-z_\\\\][a-z0-9_\\:\\\\]*[a-z_][a-z0-9_]*',
      '(?:[+-]?[0-9]+(?:[\\.][0-9]+)*)(?:[eE][+-]?[0-9]+)?',
      '"(?:""|[^"])*+"',
    ];
  }
  
  /**
   * {@inheritDoc}
   */
  protected function getNonCatchablePatterns() : array {
    return [
      '\\s+',
      '\\*+',
      '(.)',
    ];
  }
  
  /**
   * {@inheritDoc}
   */
  protected function getType(&$value) : int {
    $type = self::T_NONE;
    if ($value[0] === '"') {
      $value = str_replace('""', '"', substr($value, 1, strlen($value) - 2));
      return self::T_STRING;
    }
    if (isset($this->noCase[$value])) {
      return $this->noCase[$value];
    }
    if ($value[0] === '_' || $value[0] === '\\' || ctype_alpha($value[0])) {
      return self::T_IDENTIFIER;
    }
    $lowerValue = strtolower($value);
    if (isset($this->withCase[$lowerValue])) {
      return $this->withCase[$lowerValue];
    }
    // Checking numeric value
    if (is_numeric($value)) {
      return strpos($value, '.') !== false || stripos($value, 'e') !== false ? self::T_FLOAT : self::T_INTEGER;
    }
    return $type;
  }

}