phpcallable

php print callable function

I'm trying to solve a problem : 

function f($callable_function){
   print_r($callable_function);// doesn't work at all, of course
}

f(function(){echo "hello World"});

I get the Closure Object element with my print_r function. Is there a way to get : 

//OUTPUT RESULT
echo "hello World";

EDIT

The purpose of this is to get the function declaration inside a String (for database later). The f function can be used by any developer so the idea is to make this as simple as possible, that means I don't want the developer to declare his function inside of a String.

Solution

  • Never closed this question but I have the answer since 2014 : 

     $reflFunc = new ReflectionFunction($callable);
 $filename = $reflFunc->getFileName()); 
 $startline = $reflFunc->getStartLine(); 
 $endline = $reflFunc->getEndLine();

    And using preg_match, I can extract what I need. (as suggested by the first answer)