[fdo-internals] New RFC posted

Tue Aug 21 17:53:44 EDT 2007

Thanks.

Sounds like there is some ambiguity on what you would expect MOD or
REMAINDER to return.  Can we just specify that for FDO the sign of the
return value must always be positive?  Or that it must follow some other
rule?  I'd hate to leave it up to the client to guess what will be
returned, based on the provider.

I'm not sure what I was talking about with code pages.  Perhaps I
misread the intention of the Translate function, thinking that it would
be used to translate a string from one character set to another, rather
than being a string replacement function.

Couple other minor picky questions:

- For the function Sign, what would be the returned values?  0 or 1 for
positive or negative?  Something else?
- Is the Instr position 0 or 1 based?  What does it return if the value
doesn't exist?
- Would it be possible to add an integer DIV function as well?  Or is
this just assumed when dividing integer values?  Showing some ignorance
of FDO operations here...

Am I getting annoying yet? :)

Jason

________________________________

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas
Knoell
Sent: Tuesday, August 21, 2007 12:41
To: FDO Internals Mail List
Subject: RE: [fdo-internals] New RFC posted

Hi Jason

Sorry for the late response on this as I did not get to do it during my
vacation.

The issues with the geometric functions like area and length are with
coordinate system/projection support. It is expected that this will
result in some discussion within the group. FDO includes coordinate
system specification via spatial context, but FDO itself does not expose
any projection capabilities nor does it specify use of coordinate system
packages. Most providers do not have coordinate system packages
available internally. MapGuide for instance does all of its projection
work separately, outside of FDO. So, we should discuss what happens if
the data is lat/long for example.

Unlike the geometric functions, the functions documented in RFC 8 are
rather simple. The idea was to keep those separated from the geometric
functions to ensure nothing gets overlooked and allow progress on
implementing the basic functions while discussion on geometric functions
goes ahead.

As for the functions MOD and REMAINDER, although the basically perform a
similar kind of operation, they are defined differently. The distinction
is with the sign of the return value: in case of the function MOD, it
corresponds to the sign of the divisor, in case of the function
REMAINDER, it corresponds to the sign of the dividend. Usually, in
number theory, the remainder (independent of the functions) is always a
positive number. However, with software products this might not be the
case.

As for the math operators with date functions, there was no intent to
support such operators other than on months. 

As for the code page question, I am not sure where you are heading here.

Thanks

  Thomas

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas
Knoell
Sent: Friday, August 03, 2007 6:39 PM
To: fdo-internals at lists.osgeo.org
Subject: Re: [fdo-internals] New RFC posted

Hi Jason

I will see what I can do. I am just leaving for my vacation and have to
get back to you on this next week (although being on vacation, I'll
still try to answer mails). I hope it can wait until then.

Thanks

  Thomas

--------------------------
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----- Original Message -----
From: fdo-internals-bounces at lists.osgeo.org
<fdo-internals-bounces at lists.osgeo.org>
To: FDO Internals Mail List <fdo-internals at lists.osgeo.org>
Sent: Fri Aug 03 18:06:32 2007
Subject: RE: [fdo-internals] New RFC posted

Could you maybe outline those issues? 

It would be helpful if we could all have an idea of what is coming up
and see how it fits together, rather than being fed RFCs / problems
piecemeal.

I was able to read the PDF version, btw, and it answers most of my
questions.  I still don't know what the difference between Mod and
Remainder is though :)

A couple functions raise questions for me

- the date functions have month math operators, but none for other
units?
- is there a common way of specifying code pages that all providers
should understand?  I don't know much about this area.

Jason

  _____ 

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas
Knoell
Sent: Friday, August 03, 2007 14:53
To: fdo-internals at lists.osgeo.org
Subject: Re: [fdo-internals] New RFC posted

For the geometry functions, there are different issues to address which
we thought is better suited to be outlined separately.

Thanks

  Thomas

--------------------------
Sent from my BlackBerry Wireless Handheld (www.BlackBerry.net)

----- Original Message -----
From: fdo-internals-bounces at lists.osgeo.org
<fdo-internals-bounces at lists.osgeo.org>
To: FDO Internals Mail List <fdo-internals at lists.osgeo.org>
Sent: Fri Aug 03 17:45:04 2007
Subject: RE: [fdo-internals] New RFC posted

Is there any specific reason for that ?

 Haris

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas
Knoell
Sent: Friday, August 03, 2007 11:40 PM
To: fdo-internals at lists.osgeo.org
Subject: Re: [fdo-internals] New RFC posted

Spatial functions will be handled separately.

--------------------------
Sent from my BlackBerry Wireless Handheld (www.BlackBerry.net)

----- Original Message -----
From: fdo-internals-bounces at lists.osgeo.org
<fdo-internals-bounces at lists.osgeo.org>
To: FDO Internals Mail List <fdo-internals at lists.osgeo.org>
Sent: Fri Aug 03 17:35:42 2007
Subject: RE: [fdo-internals] New RFC posted

I've noticed there is no any Spatial Functions. What is a reason for
that?

Thank you,

Haris

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas
Knoell
Sent: Friday, August 03, 2007 9:35 PM
To: FDO Internals Mail List
Subject: [fdo-internals] New RFC posted

Hi,

A new RFC (http://trac.osgeo.org/fdo/wiki/FDORfc8) has been posted. The
RFC addresses the enhancement of the FDO well known (expression)
function list to include additional, commonly used functions.

Please review the RFC. Any comments/suggestions and questions are
welcome. All feedback is expected by the end-of-day August 10th 2007. If
no changes are required it is my intent to motion that a vote for the
acceptance of the RFC be made and subsequently voted on by the PSC.

Thanks

  Thomas

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