Online PHP editor | output for qkvvr

<?php $tokenStream = []; // [tokenName, lexeme] pairs $input = <<<'end' $a = 3; // variable initialisation end; // Pre PHP 7 code preg_replace_callback( [ '~\$[a-z_][a-z\d_]*~i', '~=~', '~[\d]+~', '~;~', '~//.*~' ], function ($match) use (&$tokenStream) { if (strpos($match[0], '$') === 0) { $tokenStream[] = ['T_VARIABLE', $match[0]]; } elseif (strpos($match[0], '=') === 0) { $tokenStream[] = ['T_ASSIGN', $match[0]]; } elseif (ctype_digit($match[0])) { $tokenStream[] = ['T_NUM', $match[0]]; } elseif (strpos($match[0], ';') === 0) { $tokenStream[] = ['T_TERMINATE_STMT', $match[0]]; } elseif (strpos($match[0], '//') === 0) { $tokenStream[] = ['T_COMMENT', $match[0]]; } }, $input ); // PHP 7+ code preg_replace_callback_array( [ '~\$[a-z_][a-z\d_]*~i' => function ($match) use (&$tokenStream) { $tokenStream[] = ['T_VARIABLE', $match[0]]; }, '~=~' => function ($match) use (&$tokenStream) { $tokenStream[] = ['T_ASSIGN', $match[0]]; }, '~[\d]+~' => function ($match) use (&$tokenStream) { $tokenStream[] = ['T_NUM', $match[0]]; }, '~;~' => function ($match) use (&$tokenStream) { $tokenStream[] = ['T_TERMINATE_STMT', $match[0]]; }, '~//.*~' => function ($match) use (&$tokenStream) { $tokenStream[] = ['T_COMMENT', $match[0]]; } ], $input );