🚀 go-pugleaf

As someone already pointed out, the "reverse diff arrays" are really
an old idea.  Besides the Prolog paper, Adrienne Bloss and I described
the technique (we called it "trailers") in our 1985 POPL paper [1].
Since then Adrienne implemented several versions of array updating,
and came up with some interesting results.  For example, besides the
obvious fact that "multiply-threaded arrays" don't work well with
trailers, she found that in certain cases trailers performed worse
than outright copying!  See her FPCA paper [2] or better yet her
thesis [3] for more details.

  -Paul


[1] @InProceedings{
    ,author={Hudak, P. and Bloss, A.}
    ,title={The aggregate update problem in functional programming systems}
    ,booktitle={12th ACM Symposium on Principles of Programming Languages}
    ,organization={ACM}
    ,year=1985
    ,pages={300-314}
    }

[2] @inproceedings{
    ,author={Bloss, A.}
    ,title={Update Analysis and the Efficient Implementation of
            Functional Aggregates}
    ,booktitle={Proceedings of 4th Int'l Conference on Functional
                Programming Languages and Computer Architecture}
    ,organization={ACM, IFIP}
    ,year=1989
    ,pages={26-38}
    }

[3] @phdthesis{
    ,author={Bloss, A.}
    ,title={Path Analysis: Using Order-of-Evaluation Information to
            Optimize Lazy Functional Languages}
    ,school={Yale University, Department of Computer Science}
    ,year=1988
    }