Oh, oh.  If com.vividsolutions.jts.geom.LineSegment.setCoordinates()
is any indication, JTS  is probably going to prevent making this
policy retroactive.  There seem to be several places where Coordinate
values are passed into methods and have their x,y values modified.

regards,
Larry

On 6/25/07, Larry Becker <[EMAIL PROTECTED]> wrote:
> I agree with Martin.  Modifying Coordinate values in-place is probably
> a bad idea, however I'm pretty sure I've been guilty.  What I'm trying
> to figure out now, is a good way to find out where and how many times.
>
> regards,
> Larry Becker
>
> On 6/25/07, Martin Davis <[EMAIL PROTECTED]> wrote:
> >
> >
> > Michaël Michaud wrote:
> > >
> > > @Martin : Please, can you explain what immutability means for
> > > coordinates. I see that x,y,z are public fields (and I remember I often
> > > changed them via small scripts, especially the z value). But may be I
> > > have no clear idea about immutability and its advantages.
> > >
> > >
> >
> > Well, it's pretty simple. If you have a tool that works by altering the
> > ordinate values in a Coordinate, and you are using the "interned
> > Coordinate" strategy, you are going to get bugs, since Geometrys will
> > change unexpectedly when their shared Coordinate values are changed by
> > someone else.
> >
> > The public x,y,z in Coordinate were originally there for efficiency
> > reasons.  Probably a bad idea. In fact, Coordinate should have simply
> > been an interface.  But too late to change now!  However, an application
> > like JUMP should make it a blanket policy that Coordinate values should
> > never by changed.  Any other policy leads to insanity, IMO.
> >
> > HTH - Martin
> >
> > --
> > Martin Davis
> > Senior Technical Architect
> > Refractions Research, Inc.
> > (250) 383-3022
> >
> >
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>
>
> --
> http://amusingprogrammer.blogspot.com/
>


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