commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ted Dunning <>
Subject Re: (MATH-608) Remove methods from RealMatrix Interface
Date Sat, 02 Jul 2011 16:45:43 GMT
Marker methods is what we did in Mahout.  Marker interfaces is what I think
we perhaps should have done.

My rationale is that you can always introduce new marker interfaces without
changing the API but if you introduce a new marker method and aren't
hard-core about never using interfaces where abstract classes will do, then
you are in a world of API-change hurt.

I don't know if there is a performance difference.  Presumably the cost of
even a simple matrix operation will swamp any potential difference.

On Sat, Jul 2, 2011 at 9:39 AM, Luc Maisonobe <> wrote:

> Le 02/07/2011 18:20, Ted Dunning a écrit :
>  That won't work.
>> That only works for statically declared matrix types, not run-time matrix
>> types.  To be usable, the suggested mechanism must work against runtime
>> data-types.
> I agree with this need to work with runtime data-types.
> In one of your messages, you wrote about marker predicated like
> isSymmetric() or the like. In another message, you wrote about using
> instanceof. What would be the better approach ?

  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message