grouping by custom tags

1 files changed, 8 insertions, 6 deletions

diff --git a/misc.py b/misc.py
index 8b93326..329238e 100644
--- a/misc.py
+++ b/misc.py
@@ -29,15 +29,17 @@ def unique(seq):
 	seen = []
 	return t(c for c in seq if not (c in seen or seen.append(c)))
 
-def format(string, song=None, xtra_tags={}):
+def format(string, song=None, overwrite={}, ensure={}):
 	"""Replace all tags in $str with their respective value."""
 	# what tags are available?
+	tags={}
+	for tag in ensure:
+		tags[tag]=ensure[tag]
 	if song:
-		tags=song._data
-	else:
-		tags={}
-	for tag in xtra_tags:
-		tags[tag]=xtra_tags[tag]
+		for tag in song._data:
+			tags[tag]=song._data[tag]
+	for tag in overwrite:
+		tags[tag]=overwrite[tag]
 	
 	ret=string
 	# first perform some functions: $name(value)