Convert anonymous function in PHP 5.3 into PHP 5.2 equivalent - php

Question

I have error in line 2 and 13 in PHP 5.2, I have no idea to make the correction, I tried using create_function but not working, can anyone help with this?
function _process_special_keyword($str){
$callback = function($match){
$ret = $match[1] . '[' . $match[2] . ']';
if(!empty($match[3])){
$ret .= '.[' . $match[3] . ']';
}
$ret .= $match[4];
return $ret;
};
$strSQL = preg_replace_callback('/([\s\(\.,])(' . SPECIAL_KEYWORDS . ')(?:\.(' . SPECIAL_KEYWORDS . '))?([\s\)\.,])/i', $callback, $str);
$callback = function($match){
return 'CASE WHEN ' . $match[1] . ' THEN ' . $match[2] . ' ELSE ' . $match[3] . ' END';
};
$strSQL = preg_replace_callback('/if\s*\((.+),(.+),(.+)\)/i', $callback, $strSQL);
return $strSQL;
}
Thanks.
Error: Parse error: syntax error, unexpected T_FUNCTION

Answer 1

When using create_function(), the contents of the first argument should be a string representation of the PHP code that would fill the parentheses for the function declaration. The second argument should contain only the code inside the curly braces {} of the function declaration, the actual declaration itself should be omitted.
Try this code:
function _process_special_keyword($str){
$callback = create_function(
'$match',
'
$ret = $match[1] . "[" . $match[2] . "]";
if(!empty($match[3])){
$ret .= ".[" . $match[3] . "]";
}
$ret .= $match[4];
return $ret;
'
);
$strSQL = preg_replace_callback('/([\s\(\.,])(' . SPECIAL_KEYWORDS . ')(?:\.(' . SPECIAL_KEYWORDS . '))?([\s\)\.,])/i', $callback, $str);
$callback = create_function(
'$match',
'return "CASE WHEN " . $match[1] . " THEN " . $match[2] . " ELSE " . $match[3] . " END";'
);
$strSQL = preg_replace_callback('/if\s*\((.+),(.+),(.+)\)/i', $callback, $strSQL);
return $strSQL;
}

Answer 2

You can declare the callbacks outside of this function. Like this:
function _callback_one($match){
$ret = $match[1] . '[' . $match[2] . ']';
if(!empty($match[3])){
$ret .= '.[' . $match[3] . ']';
}
$ret .= $match[4];
return $ret;
}
function _callback_two($match){
return 'CASE WHEN ' . $match[1] . ' THEN ' . $match[2] . ' ELSE ' . $match[3] . ' END';
}
function _process_special_keyword($str){
$strSQL = preg_replace_callback('/([\s\(\.,])(' . SPECIAL_KEYWORDS . ')(?:\.(' . SPECIAL_KEYWORDS . '))?([\s\)\.,])/i', '_callback_one', $str);
$strSQL = preg_replace_callback('/if\s*\((.+),(.+),(.+)\)/i', '_callback_two', $strSQL);
return $strSQL;
}
Note: If these functions are in a class (meaning the function would be need to called like $this->_callback_one), pass an array as the "callback" parameter.
function _process_special_keyword($str){
$strSQL = preg_replace_callback('/([\s\(\.,])(' . SPECIAL_KEYWORDS . ')(?:\.(' . SPECIAL_KEYWORDS . '))?([\s\)\.,])/i', array($this, '_callback_one'), $str);
$strSQL = preg_replace_callback('/if\s*\((.+),(.+),(.+)\)/i', array($this, '_callback_two'), $strSQL);
return $strSQL;
}

Answer 3

according with object question, the faster way I think is something like so,
$f = <<<myfunc
\$ret = \$match[1] . '[' . \$match[2] . ']';
if(!empty(\$match[3])){
\$ret .= '.[' . \$match[3] . ']';
}
\$ret .= \$match[4];
return \$ret;
myfunc;
$callback = create_function('$match',$f);
note backslashes before $ and <<< FLAG FLAG; construct. In practice the answer of Rocket is more simple.