add pic_assoc

2013-12-07 06:30:21 -08:00
parent dcb5b448cd
commit aac2082991
2 changed files with 19 additions and 0 deletions
@@ -128,6 +128,24 @@ pic_assq(pic_state *pic, pic_value key, pic_value assoc)
  goto enter;
 }

+pic_value
+pic_assoc(pic_state *pic, pic_value key, pic_value assoc)
+{
+  pic_value cell;
+
+ enter:
+
+  if (pic_nil_p(assoc))
+    return assoc;
+
+  cell = pic_car(pic, assoc);
+  if (pic_equal_p(pic, key, pic_car(pic, cell)))
+    return cell;
+
+  assoc = pic_cdr(pic, assoc);
+  goto enter;
+}
+
 pic_value
 pic_acons(pic_state *pic, pic_value key, pic_value val, pic_value assoc)
 {