- take this further and have list cells with 2 (or more) unboxed characters, or even a full buffer.
This sounds like the best idea to me... with each list cell being a full buffer you could effectively write nieve [Char] code and have it implemented in about as fast a way as possible... A little improvement on this would be to do a bit of read ahead, so that the filesystem latency can be hidden. (ie one thread reads the next buffer, whilst the application thread processes the previous buffer)... This would also benefit string processing... Imagine: test = "aaaa" ++ "bbbb" This could be implented as two list cells, one for each string, anf the cost of the "++" becomes the same as the cost of ":" test = 'a' : "bbbb" could be implemented in exactly the same way (a cell of size one and a cell of size 4) In this way with the cell size dependant on the source, lists generated by prepending characters would remain exactly as they are. The only slight complexity would be allowing 'next' pointers to point halfway through a cell, so that if you start with "dddd" remove the first character and prepend 'c' the original list "dddd" could still be in scope. Keean.