# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1509135970 -7200
# Node ID 683059dc2e7bdd2d32cf98ff4048ba9d35c4617e
# Parent  b4544a1a80c1cf277763c46fc1fa242039d03aac
Handle null inputs to URI conversion functions.

diff -r b4544a1a80c1 -r 683059dc2e7b imiptools/data.py
--- a/imiptools/data.py	Wed Oct 25 00:18:24 2017 +0200
+++ b/imiptools/data.py	Fri Oct 27 22:26:10 2017 +0200
@@ -1007,7 +1007,7 @@
 uri_value = get_uri
 
 def uri_values(values):
-    return map(get_uri, values)
+    return values and map(get_uri, values)
 
 def uri_dict(d):
     return dict([(get_uri(key), value) for key, value in d.items()])
@@ -1016,7 +1016,7 @@
     return get_uri(item[0]), item[1]
 
 def uri_items(items):
-    return [(get_uri(value), attr) for value, attr in items]
+    return items and [(get_uri(value), attr) for value, attr in items]
 
 # Operations on structure data.