JavaSript backend (early stage)

vlib/builtin/js/option.v

@@ -0,0 +1,31 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module builtin
+
+struct Option {
+	data [255]byte
+	error string
+	ok    bool
+}
+
+// `fn foo() ?Foo { return foo }` => `fn foo() ?Foo { return opt_ok(foo); }`
+fn opt_ok(data voidptr, size int) Option {
+	if size >= 255 {
+		panic('option size too big')
+	}
+	res := Option {
+		ok: true
+	}
+	C.memcpy(res.data, data, size)
+	return res
+}
+
+pub fn error(s string) Option {
+	return Option {
+		error: s
+	}
+}
+
+