Right... Aside from adding libgmp support, a change from j903 is that
j903 had an extended precision infinity which was used in parsing
numeric constants, but j904 does not.

And, when I was rewriting the bit that handles rational constants, I
overlooked some of the ways of representing rational infinity.

I'm testing a fix for this problem right now. It should be ready soon.

Thanks,

-- 
Raul

On Tue, Jan 24, 2023 at 10:18 PM Henry Rich <[email protected]> wrote:
>
> Decision, decisions.  How /should/ you specify an extended infinity?  I say
>
>     _x
> |ill-formed number
>
> There could be alternatives. _r(any finite) and (any non0)r0 are both
> reasonable.
>
> NOTE that the GMP library that we have moved to has no way to represent
> extended infinity.  Raul has chosen 1r0 as our internal representation
> of extended infinity, so infinity will always have rational precision,
> not extended integer.
>
> For display, we get it right:
>
>     1r0
> _
>
> It seems that _r(any) should be converted to infinity - and _x and __x
> too I think.  This is in Raul's area.
>
> If you have a dependency on the internal representation of infinity it
> will be on you to update it.
>
> Henry Rich
>
>
>
>
>
>
>
> On 1/24/2023 9:00 PM, Ian Clark wrote:
> > j903 accepts -- but j904 rejects -- this way of defining rational infinity:
> >
> > _r1
> >
> > |ill-formed number
> >
> > | _r1
> >
> > | ^
> >
> > JVERSION
> >
> > Engine: j904/j64arm/darwin
> >
> > Beta-k: commercial/2023-01-24T04:42:28
> >
> > Library: 9.04.10
> >
> > Qt IDE: 2.0.3/6.2.4(6.2.4)
> >
> > Platform: Darwin 64
> >
> > Installer: J904 install
> >
> > InstallPath: /applications/j904
> >
> > Contact: www.jsoftware.com
> >
> > A workaround is to use 1r0 instead:
> >
> >
> > 1r0
> >
> > _
> >
> > datatype 1r0
> >
> > rational
> >
> >
> > Not a lot of j-ers willl have a use for rational [minus] infinity, but IMO
> > a beginner might find it more intuitive to define it as _r1 rather than 1r0
> > . Maybe it's no big deal in itself, but it breaks 3 addons, viz: math/cal,
> > math/uu -- and in consequence math/tabula:
> >
> >
> >     load'math/uu' NB. Launch UU only
> > |ill-formed number in script, executing monad 0!: 0
> > |any word beginning with a digit or _ must be a valid number
> > |   BADRAT=: __r1
> > |            ^
> > |[-33] /applications/j904/addons/math/uu/uu.ijs
> >
> >     load'math/cal'
> > |ill-formed number in script, executing monad 0!: 0
> > |any word beginning with a digit or _ must be a valid number
> > |   BAD_EXE_VALUE=: __r1
> > |                   ^
> > |[-92] /applications/j904/addons/math/cal/cal.ijs
> >
> >
> > So I'd call it a bug.
> >
> >
> > There's been plenty of time to discover this. Sorry it's taken me so long.
> >
> >
> > Ian Clark
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to