fix insert method. it wouldn't insert in empty sets, grmbl

trunk/ripnews/set/intspan.rb

@@ -598,11 +598,14 @@ def member(n)
 end
 
 def insert(n)
-	n or return
-
 	inSet = @set["negInf"]
 	edge = @set["edges"]
 
+	if (edge.length == 0)
+		@set["edges"] = [n-1, n]
+		return
+	end
+
 	if n > edge[-1]+1
 		@set["edges"] += [n-1, n]
 		return
@@ -907,7 +910,7 @@ end	# module
 # [x] infinite
 # [ ] universal
 # [x] member
-# [x] insert
+# [x] insert		# way to much code i think
 # [x] remove
 # [x] min
 # [x] max