(PECL runkit >= 0.7.0)
runkit_method_redefine — Dynamically changes the code of the given method
$classname
   , string $methodname
   , string $args
   , string $code
   [, int $flags = RUNKIT_ACC_PUBLIC
   [, string $doc_comment = NULL
  ]] ) : bool$classname
   , string $methodname
   , Closure $closure
   [, int $flags = RUNKIT_ACC_PUBLIC
   [, string $doc_comment = NULL
  ]] ) : boolNote: This function cannot be used to manipulate the currently running (or chained) method.
classnameThe class in which to redefine the method
methodnameThe name of the method to redefine
argsComma-delimited list of arguments for the redefined method
code
       The new code to be evaluated when methodname
       is called
      
closureA closure that defines the method.
flags
       The redefined method can be
       RUNKIT_ACC_PUBLIC,
       RUNKIT_ACC_PROTECTED or
       RUNKIT_ACC_PRIVATE optionally combined via bitwise OR with
       RUNKIT_ACC_STATIC (since 1.0.1)
      
doc_commentThe doc comment of the function.
   Returns TRUE on success or FALSE on failure.
  
| Version | Description | 
|---|---|
| runkit 1.0.4 | An alternative syntax expecting a closurehas been added. | 
| runkit 1.0.4 | The optional parameter doc_commenthas been added. | 
Example #1 runkit_method_redefine() example
<?php
class Example {
    function foo() {
        return "foo!\n";
    }
}
// create an Example object
$e = new Example();
// output Example::foo() (before redefine)
echo "Before: " . $e->foo();
// Redefine the 'foo' method
runkit_method_redefine(
    'Example',
    'foo',
    '',
    'return "bar!\n";',
    RUNKIT_ACC_PUBLIC
);
// output Example::foo() (after redefine)
echo "After: " . $e->foo();
?>
The above example will output:
Before: foo! After: bar!