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() {
        return [
            '[a-z_\\\\][a-z0-9_\\:\\\\]*[a-z_][a-z0-9_]*',
            '(?:[+-]?[0-9]+(?:[\\.][0-9]+)*)(?:[eE][+-]?[0-9]+)?',
            '"(?:""|[^"])*+"',
        ];
    }
    
    /**
     * {@inheritDoc}
     */
    protected function getNonCatchablePatterns() {
        return [
            '\\s+',
            '\\*+',
            '(.)',
        ];
    }
    
    /**
     * {@inheritDoc}
     */
    protected function getType(&$value) {
        $type = self::T_NONE;
        if ($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;
    }

}