From ac14c2a4dbfd73533737df86da071f5949f6c4d9 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 27 Oct 2016 23:00:18 -0700
Subject: [PATCH] ircd::js: Add generator state class.

---
 include/ircd/js/generator.h | 90 +++++++++++++++++++++++++++++++++++++
 include/ircd/js/js.h        |  1 +
 ircd/js.cc                  |  5 +++
 3 files changed, 96 insertions(+)
 create mode 100644 include/ircd/js/generator.h

diff --git a/include/ircd/js/generator.h b/include/ircd/js/generator.h
new file mode 100644
index 000000000..89f8e0d40
--- /dev/null
+++ b/include/ircd/js/generator.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2016 Charybdis Development Team
+ * Copyright (C) 2016 Jason Volk <jason@zemos.net>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+#define HAVE_IRCD_JS_GENERATOR_H
+
+namespace ircd {
+namespace js   {
+
+struct generator
+{
+	heap_object state;
+	heap_object last;
+
+	bool done() const;
+	template<class... args> value next(args&&...);
+	template<class... args> value _throw(args&&...);
+	template<class... args> value _return(args&&...);
+
+	generator(object::handle state);
+	generator(object state);
+	generator() = default;
+};
+
+inline
+generator::generator(object state)
+:state{state}
+{
+}
+
+inline
+generator::generator(object::handle state)
+:state{state}
+{
+}
+
+template<class... args>
+value
+generator::_return(args&&... a)
+{
+	function func(get(state, "return"));
+	last = func(state, std::forward<args>(a)...);
+	return has(last, "value")? get(last, "value") : value{};
+}
+
+template<class... args>
+value
+generator::_throw(args&&... a)
+{
+	function func(get(state, "throw"));
+	last = func(state, std::forward<args>(a)...);
+	return has(last, "value")? get(last, "value") : value{};
+}
+
+template<class... args>
+value
+generator::next(args&&... a)
+{
+	function func(get(state, "next"));
+	last = func(state, std::forward<args>(a)...);
+	return has(last, "value")? get(last, "value") : value{};
+}
+
+inline bool
+generator::done()
+const
+{
+	return bool(get(last, "done"));
+}
+
+} // namespace js
+} // namespace ircd
diff --git a/include/ircd/js/js.h b/include/ircd/js/js.h
index 4f37ad318..bdb5daad3 100644
--- a/include/ircd/js/js.h
+++ b/include/ircd/js/js.h
@@ -86,3 +86,4 @@ inline JSVersion version(const char *const &v)   { return JS_StringToVersion(v);
 #include "args.h"
 #include "trap.h"
 #include "trap_function.h"
+#include "generator.h"
diff --git a/ircd/js.cc b/ircd/js.cc
index 31c9fb26a..921d0fee3 100644
--- a/ircd/js.cc
+++ b/ircd/js.cc
@@ -138,6 +138,11 @@ js::ReportOutOfMemory(ExclusiveContext *const c)
 // ircd/js/js.h - With 3rd party (JSAPI) symbols
 //
 
+///////////////////////////////////////////////////////////////////////////////
+//
+// ircd/js/generator.h
+//
+
 ///////////////////////////////////////////////////////////////////////////////
 //
 // ircd/js/trap_function.h