Hi, > I realize that this problem can be coded around, sometimes > with better data > structures, or by the double reversing approach (which is > what I used to use) > but my own sense of programming language aesthetics is that > this is a flaw, or > at least a hole in the language that should be filled one day. There is an implementation of VLists for OCaml. VLists are - like single linked lists - persistent, but have better performance, require less memory and are GC friendlier. Here is the announcement and a link to the paper: http://sourceforge.net/mailarchive/forum.php?thread_id=6740097&forum_id=2988 0 Stack overflow problems should be solved. Unfortunatly you loose the ability of pattern matching and List contruction with the bracket notation. The paper is quite nice. Christoph Bauer