Simple Lexer in PHP

lexer.php

<?php

class Lexer
{
    protected static $tokens = [
        'T_PHRASE' => '/\s*"(([^"\\\\]|\\\\\\\\|\\\\"|\\\\)+)"?(\s+|$)/',
        'T_OR' => '/\s*(or)(\s+|$)/',
        'T_AND' => '/\s*(and)(\s+|$)/',
        'T_WILDCARD' => '/\s*(\*)/',
        'T_WORD' => '/\s*([^ \t\r\n\v\f\*]+)(\s*|$)/',
    ];

    public function tokenize($subject)
    {
        $tokens = [];

        $offset = 0;
        while ($offset < strlen($subject)) {
            $token = $this->match(substr($subject, $offset));
            if (false === $token) {
                throw new Exception(sprintf('Unable to parse subject "%s"', $subject));
            }
            $offset += $token['size'];
            $tokens[] = [$token['token'] => $token['match']];
        }

        return $tokens;
    }

    public function match($subject)
    {
        foreach (self::$tokens as $name => $pattern) {
            $matches = [];
            if (1 === preg_match($pattern.'A', $subject, $matches)) {
                return [
                    'size' => strlen($matches[0]),
                    'match' => $matches[1],
                    'token' => $name,
                ];
            }
        }

        return false;
    }

    public function debug(array $tokens)
    {
        $res = [];
        foreach ($tokens as $token) {
            $tokens[] = $token['token'];
        }

        return implode(', ', $res);
    }
}

$tests = [
    '"salut les amis' => [
        ['T_PHRASE' => 'salut les amis'],
    ],
    '"salut les" amis' => [
        ['T_PHRASE' => 'salut les'],
        ['T_WORD' => 'amis'],
    ],
    'coo "salut les" amis' => [
        ['T_WORD' => 'coo'],
        ['T_PHRASE' => 'salut les'],
        ['T_WORD' => 'amis'],
    ],
    'bob or marley' => [
        ['T_WORD' => 'bob'],
        ['T_OR' => 'or'],
        ['T_WORD' => 'marley'],
    ],
    '"bob or" marley' => [
        ['T_PHRASE' => 'bob or'],
        ['T_WORD' => 'marley'],
    ],
    '"bob marley" or "bob dylan"' => [
        ['T_PHRASE' => 'bob marley'],
        ['T_OR' => 'or'],
        ['T_PHRASE' => 'bob dylan'],
    ],
    'symfon* or zf' => [
        ['T_WORD' => 'symfon'],
        ['T_WILDCARD' => '*'],
        ['T_OR' => 'or'],
        ['T_WORD' => 'zf'],
    ],
    'su*er co*ol   and   bob' => [
        ['T_WORD' => 'su'],
        ['T_WILDCARD' => '*'],
        ['T_WORD' => 'er'],
        ['T_WORD' => 'co'],
        ['T_WILDCARD' => '*'],
        ['T_WORD' => 'ol'],
        ['T_AND' => 'and'],
        ['T_WORD' => 'bob'],

    ],
];

$lexer = new Lexer();
foreach ($tests as $subject => $expected) {
    echo "Testing: ".$subject."\n";
    if ($expected !== ($res = $lexer->tokenize($subject))) {
        echo "---> Error, expected\n";
        print_r($expected);
        echo "get\n";
        print_r($res);
    }
}

@see https://nitschinger.at/Writing-a-simple-lexer-in-PHP/