Yeah I'd be happy with that approach. Sounds good, I'll have to take a lot
whether we can read random indices in OPC-UA.
On Sat, Oct 29, 2022 at 3:35 PM Christofer Dutz <christofer.d...@c-ware.de>
wrote:
> Don’t know if you followed that discussion on LinkedIn, where I asked
> about the array notation.
>
> Turned out that you can generally do all sorts of crazy stuff … such as
> define Arrays that start at 6 and go to 12 … in general you can let your
> first element be whatever you like.
>
> I guess if we interpret just one number as array size and if the array is
> defined as [6..12] and I read a [3], then it should probably return the
> elements 6,7,8 … but if I do a [0..3] it should probably fail and if I do
> [7..10] then it should return 7, 8, 9 and 10.
>
> Would that interpretation make more sense? Then on PLCs where the first
> element has the index 1 I can continue to use the same semantics as in one
> where 0 is the default. However the user would have to know which is the
> first index when using the X..Y notation.
>
> Chris
>
>
> From: Christofer Dutz <christofer.d...@c-ware.de>
> Date: Saturday, 29. October 2022 at 20:15
> To: dev@plc4x.apache.org <dev@plc4x.apache.org>
> Subject: Re: Change the array-notation in fields?
> Hi Ben,
>
> in general we currently have no option to read partial arrays starting
> with anything else than the first element.
> That’s generally what I’m currently trying to add.
>
> Chris
>
> From: Ben Hutcheson <ben.hut...@gmail.com>
> Date: Saturday, 29. October 2022 at 18:35
> To: dev@plc4x.apache.org <dev@plc4x.apache.org>
> Subject: Re: Change the array-notation in fields?
> As long as the original notation is kept, Im sure no one will mind.
> Changing the wording in the original from numElements to endIndex seems to
> have very little effect except to force the user to think about the start
> index as starting at 1.
>
> In practise do we have the ability to read partial arrays in any of the
> drivers?
>
>
>
> On Sat, 29 Oct 2022 at 9:35 am, Lukas Ott <ott.lukas...@gmail.com> wrote:
>
> > The question for me is why not startIndex = 0
> > Instead of 1.
> >
> > In general this proposal sound reasonable to me and a I opt +1.
> > Luk
> >
> > Am Sa., 29. Okt. 2022 um 17:30 Uhr schrieb Christofer Dutz <
> > christofer.d...@c-ware.de>:
> >
> > > Hi all
> > >
> > > currently in most drivers we support an array notation like:
> > > XYZ{numElements}]
> > > In order to support reading arrays.
> > >
> > > Now in order to support reading partial arrays, I think it would be
> good
> > > to generally change that to:
> > >
> > > XYZ[{startIndex}..{endIndex}]
> > >
> > > And the ordinary version:
> > >
> > > XYZ[{endIndex}]
> > >
> > > This would imply starting at the first element.
> > > However, we should probably start with index “1”, as this seems to be
> > what
> > > most seem to use.
> > >
> > > So:
> > > XYZ
> > > Would be the same as:
> > > XYZ[1]
> > > Would be the same as:
> > > XYZ[1..1]
> > >
> > > What do you think?
> > >
> > > Chris
> > >
> >
>
