findPattern example

class NumberHandler implements HandlerInterface
{
    private TokenizerPatterns $patterns;

    public function __construct(TokenizerPatterns $patterns)
    {
        $this->patterns = $patterns;
    }

    public function handle(Reader $reader, TokenStream $stream): bool
    {
        $match = $reader->findPattern($this->patterns->getNumberPattern());

        if (!$match) {
            return false;
        }

        $stream->push(new Token(Token::TYPE_NUMBER, $match[0], $reader->getPosition()));
        $reader->moveForward(\strlen($match[0]));

        return true;
    }
}

class WhitespaceHandler implements HandlerInterface
{
    public function handle(Reader $reader, TokenStream $stream): bool
    {
        $match = $reader->findPattern('~^[ \t\r\n\f]+~');

        if (false === $match) {
            return false;
        }

        $stream->push(new Token(Token::TYPE_WHITESPACE, $match[0], $reader->getPosition()));
        $reader->moveForward(\strlen($match[0]));

        return true;
    }
}

$this->assertFalse($reader->getOffset('w'));

        $this->assignPosition($reader, 2);
        $this->assertEquals(0, $reader->getOffset('ll'));
        $this->assertFalse($reader->getOffset('he'));
    }

    public function testFindPattern()
    {
        $reader = new Reader('hello');

        $this->assertFalse($reader->findPattern('/world/'));
        $this->assertEquals(['hello', 'h'], $reader->findPattern('/^([a-z]).*/'));

        $this->assignPosition($reader, 2);
        $this->assertFalse($reader->findPattern('/^h.*/'));
        $this->assertEquals(['llo'], $reader->findPattern('/^llo$/'));
    }

    public function testMoveForward()
    {
        $reader = new Reader('hello');
        $this->assertEquals(0, $reader->getPosition());

        

private TokenizerPatterns $patterns;
    private TokenizerEscaping $escaping;

    public function __construct(TokenizerPatterns $patterns, TokenizerEscaping $escaping)
    {
        $this->patterns = $patterns;
        $this->escaping = $escaping;
    }

    public function handle(Reader $reader, TokenStream $stream): bool
    {
        $match = $reader->findPattern($this->patterns->getHashPattern());

        if (!$match) {
            return false;
        }

        $value = $this->escaping->escapeUnicode($match[1]);
        $stream->push(new Token(Token::TYPE_HASH, $value, $reader->getPosition()));
        $reader->moveForward(\strlen($match[0]));

        return true;
    }
}

    public function handle(Reader $reader, TokenStream $stream): bool
    {
        $quote = $reader->getSubstring(1);

        if (!\in_array($quote, ["'", '"'])) {
            return false;
        }

        $reader->moveForward(1);
        $match = $reader->findPattern($this->patterns->getQuotedStringPattern($quote));

        if (!$match) {
            throw new InternalErrorException(sprintf('Should have found at least an empty match at %d.', $reader->getPosition()));
        }

        // check unclosed strings         if (\strlen($match[0]) === $reader->getRemainingLength()) {
            throw SyntaxErrorException::unclosedString($reader->getPosition() - 1);
        }

        // check quotes pairs validity

private TokenizerPatterns $patterns;
    private TokenizerEscaping $escaping;

    public function __construct(TokenizerPatterns $patterns, TokenizerEscaping $escaping)
    {
        $this->patterns = $patterns;
        $this->escaping = $escaping;
    }

    public function handle(Reader $reader, TokenStream $stream): bool
    {
        $match = $reader->findPattern($this->patterns->getIdentifierPattern());

        if (!$match) {
            return false;
        }

        $value = $this->escaping->escapeUnicode($match[0]);
        $stream->push(new Token(Token::TYPE_IDENTIFIER, $value, $reader->getPosition()));
        $reader->moveForward(\strlen($match[0]));

        return true;
    }
}