On 08 October 2004 13:36, Robert Dockins wrote:

BTW can you give some references to these known techniques?

Hmm, well here's some folklorish ideas. I'm sure there are references for most of these, but I don't know them off hand. - Have another list constructor that has 2 (or more) elements. Prelude funnctions can take advantage of this, but the constructor can magically transform itself into ordinary cons cells when it is examined by an ordinary pattern match. - take this further and have list cells with 2 (or more) unboxed characters, or even a full buffer. - use space-saving techniques for storing list cells: eg. remove the tail pointer when cells appear next to each other in the heap, or have a memory page just for list cells and omit the info pointers. Or just improve cache behaviour by trying to store list cells adjacent in the heap. Cheers, Simon