A simple user-space PHP `with` implementation that mimics Python context managers.

context_manager.php

<?php

class Context {
  private $args = array();
  private $func = NULL;

  public function __construct() {
    $args = func_get_args();
    $func = array_pop($args);

    $this->args = $args;
    $this->func = $func;
  }

  public function execute() {
    $this->enter();

    try {
      call_user_func_array($this->func, $this->args);
      $this->leave();
    } catch (Exception $e) {
      $exception_handled = $this->leave($e);
      if (!$exception_handled) {
        throw $e;
      }
    }
  }

  private function enter() {
    foreach ($this->args as $arg) {
      if (method_exists($arg, "__enter")) {
        call_user_func(array($arg, "__enter"));
      }
    }
  }

  private function leave($error=NULL) {
    $exceptions_handled = TRUE;
    foreach (array_reverse($this->args) as $arg) {
      if (method_exists($arg, "__exit")) {
        $result = call_user_func(array($arg, "__exit"), $error);
        if (!$result) {
          $exceptions_handled = FALSE;
        }
      }
    }

    return $exceptions_handled;
  }
}

function with() {
  $class = new ReflectionClass("Context");
  $manager = $class->newInstanceArgs(func_get_args());
  $manager->execute();
}

/** Demo **/

class Box {
  private $var;

  public function __construct($value) {
    $this->var = $value;
  }

  public function __toString() {
    return (string)$this->var;
  }

  public function __enter() {
    echo "enter ". (string)$this ."\n";
  }

  public function __exit($e) {
    echo "exit ". (string)$this ."\n";
    if ($e != NULL) {
      echo "\t$e\n";
      return FALSE;
    }
  }
}

with(new Box(1), new Box(2), function($a, $b) {
  echo $a ."\n";
  throw new Exception();
  echo $b ."\n";
});