[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: File output performance

If there are a lot of rows/columns, this line will hurt you fairly badly:
    (format FILE-STREAM "~S"

Both nth and cdr are O(n) operations, where n is the # of elements in
the list being traversed.  It looks to me like you should be using 2
dimensional arrays and hash tables for optimal performance from LISP.

Aside from that, I/O is still blindingly slow in MCL.  Just for
comparison sake, I wrote some I/O stuff in C that I had already done in
MCL.  It took about 1/50 the time (no kidding).