On 4/11/12 4:42 AM, Rémi Forax wrote:
On 04/07/2012 02:35 AM, Stuart Marks wrote:
In order to program effectively with generics, I think you have to understand
erasure and its implications. It may have been an unfortunate choice, but
erasure is part of the language and we have to deal with it and in some cases
rely on it. I don't think it's merely an "implementation glitch."
Erased casts are an implementation glitch, not the erasure by itself.
The difficulty I have with reification is that while there are proposals
floating around for how it could be done, nobody really knows how it will
eventually turn out, nor whether it will actually be done. If it is
eventually done, there will legal and illegal constructs, constructs that
generate warnings, and perhaps a style guide for how to use reified generics
properly.
Right now, we can *imagine* what these future rules might be, but it seems
untenable to me to try to make today's code conform to those imaginary future
rules, especially in the absence of tools to help support those rules.
There are several implementations that exist,
here is the publicly available papers.
M. Cimadamore and M. Viroli.
Reifying wildcards in Java using the EGO approach.
In SAC '07: Proceedings of the 2007 ACM symposium on
Applied computing, pages 1315{1322, New York, NY, USA,
2007. ACM.
M. Cimadamore and M. Viroli.
On Rei cation of Java Wildcards.
Science of Computer Programming, 2008
There's also Neal Gafter's blog post on the subject [1].
I haven't read these papers. Maybe I should just ask Maurizio about them. :-) I
guess, is there enough commonality among all of these, and enough confidence
that future-Java's generics reification will be similar to these, that today we
should make coding style decisions based on future-Java?
I can sort-of see it if there's a choice to be made in circumstances like the
following. Suppose we need to choose between a code fragments A and B where
they're more-or-less equivalent in an erased world but B is clearly better in
some future-Java world. Sure, we could choose B, I don't see the harm in it.
I'm just not convinced that we know enough about future-Java to make a strong
case for B.
s'marks
[1] http://gafter.blogspot.com/2006/11/reified-generics-for-java.html
