--- /dev/null
+<?php
+
+/*
+ * This file is part of Psy Shell.
+ *
+ * (c) 2012-2018 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Psy;
+
+/**
+ * The Psy Shell's execution scope.
+ */
+class ExecutionClosure
+{
+ const NOOP_INPUT = 'return null;';
+
+ private $closure;
+
+ /**
+ * @param Shell $__psysh__
+ */
+ public function __construct(Shell $__psysh__)
+ {
+ $exec = function () use ($__psysh__) {
+ try {
+ // Restore execution scope variables
+ extract($__psysh__->getScopeVariables(false));
+
+ // Buffer stdout; we'll need it later
+ ob_start([$__psysh__, 'writeStdout'], 1);
+
+ // Convert all errors to exceptions
+ set_error_handler([$__psysh__, 'handleError']);
+
+ // Evaluate the current code buffer
+ $_ = eval($__psysh__->onExecute($__psysh__->flushCode() ?: ExecutionClosure::NOOP_INPUT));
+ } catch (\Throwable $_e) {
+ // Clean up on our way out.
+ restore_error_handler();
+ if (ob_get_level() > 0) {
+ ob_end_clean();
+ }
+
+ throw $_e;
+ } catch (\Exception $_e) {
+ // Clean up on our way out.
+ restore_error_handler();
+ if (ob_get_level() > 0) {
+ ob_end_clean();
+ }
+
+ throw $_e;
+ }
+
+ // Won't be needing this anymore
+ restore_error_handler();
+
+ // Flush stdout (write to shell output, plus save to magic variable)
+ ob_end_flush();
+
+ // Save execution scope variables for next time
+ $__psysh__->setScopeVariables(get_defined_vars());
+
+ return $_;
+ };
+
+ if (self::shouldBindClosure()) {
+ $that = $__psysh__->getBoundObject();
+ if (is_object($that)) {
+ $this->closure = $exec->bindTo($that, get_class($that));
+ } else {
+ $this->closure = $exec->bindTo(null, null);
+ }
+
+ return;
+ }
+
+ $this->closure = $exec;
+ }
+
+ /**
+ * Go go gadget closure.
+ *
+ * @return mixed
+ */
+ public function execute()
+ {
+ $closure = $this->closure;
+
+ return $closure();
+ }
+
+ /**
+ * Decide whether to bind the execution closure.
+ *
+ * @return bool
+ */
+ protected static function shouldBindClosure()
+ {
+ // skip binding on HHVM < 3.5.0
+ // see https://github.com/facebook/hhvm/issues/1203
+ if (defined('HHVM_VERSION')) {
+ return version_compare(HHVM_VERSION, '3.5.0', '>=');
+ }
+
+ return true;
+ }
+}