From 813ce064f3eb5ab56b80b0560c2c06138084ccf3 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Tue, 9 Sep 2014 02:12:51 +0900
Subject: [PATCH] add port-open?

---
 port.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/port.c b/port.c
index f53832f5..1b217873 100644
--- a/port.c
+++ b/port.c
@@ -206,6 +206,16 @@ pic_port_eof_object(pic_state *pic)
   return pic_eof_object();
 }
 
+static pic_value
+pic_port_port_open_p(pic_state *pic)
+{
+  struct pic_port *port;
+
+  pic_get_args(pic, "p", &port);
+
+  return pic_bool_value(port->status == PIC_PORT_OPEN);
+}
+
 static pic_value
 pic_port_close_port(pic_state *pic)
 {
@@ -665,6 +675,8 @@ pic_init_port(pic_state *pic)
   pic_defun(pic, "textual-port?", pic_port_textual_port_p);
   pic_defun(pic, "binary-port?", pic_port_binary_port_p);
   pic_defun(pic, "port?", pic_port_port_p);
+
+  pic_defun(pic, "port-open?", pic_port_port_open_p);
   pic_defun(pic, "close-port", pic_port_close_port);
 
   /* string I/O */