用匿名函数替换 create_function

Question

我在发布问题之前检查了this。

这是使用create_function的代码的一小部分

$lambda_functions[$code_hash] = create_function('$action, &$self, $text', 'if ($action == "encrypt") { '.$encrypt.' } else { '.$decrypt.' }');

试过用这种方法

$lambda_functions[$code_hash] = function ( $action, &$self, $text ) use ( $encrypt, $decrypt ) {
                if ($action == "encrypt") {
                    return $encrypt;
                } else {
                    return $decrypt;
                }
            };

但不能按预期工作 $encrypt 或 $decrypt 将包含看起来像这样的代码

$encrypt = $init_encryptBlock . '
           $ciphertext = "";
           $text = $self->_pad($text);
           $plaintext_len = strlen($text);

           $in = $self->encryptIV;

             for ($i = 0; $i < $plaintext_len; $i+= '.$block_size.') {
              $in = substr($text, $i, '.$block_size.') ^ $in;
                        '.$_encryptBlock.'
                        $ciphertext.= $in;
             }

             if ($self->continuousBuffer) {
               $self->encryptIV = $in;
             }

             return $ciphertext;
             ';

create_function 工作正常，但anonymous 函数不知道我哪里出错了？

Answer 1

不同之处在于，对于create_function()，您的代码被提交为字符串并被解释为代码，但对于匿名函数，字符串被解释为字符串，而不是它包含的代码。

您可以从$encrypt 和$decrypt 中的字符串中提取代码。这看起来像这样：

/*
 * Removed the "use ($encrypt, $decrypt)" part, 
 * because those were the strings that contained the code, 
 * but now the code itself is part of the anonymous function.
 * 
 * Instead, i added "use ($block_size)", because this is a vairable,
 * which is not defined inside of your function, but still used in it.
 * The other code containing variables might include such variables as
 * well, which you need to provide in the use block, too.
 */
$lambda_functions[$code_hash] = function ( $action, &$self, $text ) use ($block_size) {
    if ($action == "encrypt") {
        //Extract $init_encryptBlock here
        $ciphertext = "";
        $text = $self->_pad($text);
        $plaintext_len = strlen($text);

        $in = $self->encryptIV;

        for ($i = 0; $i < $plaintext_len; $i+= $block_size) {
            $in = substr($text, $i, $block_size) ^ $in;
            // Extract $_encryptBlock here
            $ciphertext.= $in;
        }

        if ($self->continuousBuffer) {
            $self->encryptIV = $in;
        }

         return $ciphertext;
    } else {
        //Extract $decrypt here
    }
};

请记住，这不是一个完整的答案。您会在代码中找到许多 // Extract $variable here cmets，它们代表包含变量的每个代码，您在代码中拥有这些变量，并且需要顺便提取这些变量，其中我从 $encrypt 提取代码。