From c7829122123f9f6385b59b26172567291a513bad Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 25 Oct 2013 00:37:08 +0900
Subject: [PATCH] add pair?

---
 src/pair.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/pair.c b/src/pair.c
index 072cb97e..2f522891 100644
--- a/src/pair.c
+++ b/src/pair.c
@@ -115,6 +115,16 @@ pic_acons(pic_state *pic, pic_value key, pic_value val, pic_value assoc)
   return pic_cons(pic, pic_cons(pic, key, val), assoc);
 }
 
+static pic_value
+pic_pair_pair_p(pic_state *pic)
+{
+  pic_value v;
+
+  pic_get_args(pic, "o", &v);
+
+  return pic_bool_value(pic_pair_p(v));
+}
+
 static pic_value
 pic_pair_set_car(pic_state *pic)
 {
@@ -146,6 +156,7 @@ pic_pair_set_cdr(pic_state *pic)
 void
 pic_init_pair(pic_state *pic)
 {
+  pic_defun(pic, "pair?", pic_pair_pair_p);
   pic_defun(pic, "set-car!", pic_pair_set_car);
   pic_defun(pic, "set-cdr!", pic_pair_set_cdr);
 }