Split interfaces and base/abstract classes into more sensible pieces

src/Monolog/Handler/ProcessableHandlerInterface.php

@@ -0,0 +1,35 @@
+<?php
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (c) Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Monolog\Handler;
+
+/**
+ * Interface to describe loggers that have processors
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+interface ProcessableHandlerInterface
+{
+    /**
+     * Adds a processor in the stack.
+     *
+     * @param  callable $callback
+     * @return self
+     */
+    public function pushProcessor(callable $callback);
+
+    /**
+     * Removes the processor on top of the stack and returns it.
+     *
+     * @return callable
+     */
+    public function popProcessor();
+}