factor

Author	SHA1	Message	Date
Slava Pestov	3f4eb5a09a	Add changed-nth combinator: like change-nth but for persistent sequences	2008-11-13 00:10:55 -06:00
Slava Pestov	52f586877f	More data structure cleanups	2008-08-06 19:01:17 -05:00
Slava Pestov	bbcc4c2384	Builder fixes	2008-08-06 17:51:01 -05:00
Slava Pestov	efb6c73f28	Move persistent collections to basis	2008-08-06 04:59:58 -05:00