[DFDL-WG] examples of decimal validation using pattern facet
Mike Beckerle
mbeckerle.dfdl at gmail.com
Fri May 24 08:47:09 EDT 2013
I believe it boils down to two issues
1) checking for leading zero padding - can you do this by saying
totalDigits is more than the number of non-zero digits? I think not,
because totaldigits/fractiondigits just translate into range checks on
decimal values created by filling up that precision with the digit "9".
I.e., totalDigits=6 fractionDigits=2 means the same thing (for a decimal)
as minInclusive=-9999.99 maxInclusive=9999.99.
Hmm. Do we allow total/fraction digits on non-decimal? I.e., on float or
double? If we do there is an issue here.
2) optional decimal point. I.e., wants the pattern so can be strict about
allowing 99.9 or 99 without decimal point, but not 99. as a variation.
I.e., the allowed format syntax is clearly either a decimal number with
specified fraction part, or it's an integer and has no decimal point.
In all these cases, I suggested this is modeled as a hidden or non-hidden
string carrying the pattern facet, and a decimal value computed from the
string using inputValueCalc.
On Fri, May 24, 2013 at 8:33 AM, Steve Hanson <smh at uk.ibm.com> wrote:
> I'd still like to know whether Roger had examples of logical xs:decimal
> values that he was unable to validate using the min/max inclusive/exclusive
> and total/fractional digits facets. That would be a justification for
> allowing pattern facets but only for validation (ie, same as how pattern
> facets are used for xs:string).
>
> Regards
>
> Steve Hanson
> Architect, IBM Data Format Description Language (DFDL)
> Co-Chair, *OGF DFDL Working Group* <http://www.ogf.org/dfdl/>
> IBM SWG, Hursley, UK*
> **smh at uk.ibm.com* <smh at uk.ibm.com>
> tel:+44-1962-815848
>
>
>
> From: Mike Beckerle <mbeckerle.dfdl at gmail.com>
> To: dfdl-wg at ogf.org,
> Date: 24/05/2013 13:22
> Subject: Re: [DFDL-WG] examples of decimal validation using
> pattern facet
> Sent by: dfdl-wg-bounces at ogf.org
> ------------------------------
>
>
>
>
> Forgot to distribute this to the WG.
>
> I now recall one of the discussions of patterns on numbers was this.
>
> XML has this characteristic that everything is both a string, and whatever
> type it's logical XML Schema type says it is.
>
> So a pattern that requires leading zeros makes sense on an integer because
> in XML, everything is a string; hence, we can talk about a pattern facet
> for the string-behavior of what XML-schema tells us is an integer.
>
> Not so in DFDL.
>
> In DFDL, the integer is converted to a pure conceptual number. Facet
> constraints can have to do only with the value of this logical type. The
> facets aren't about the representation. They are about the value only.
>
> Hence, talking about leading zeros on an integer simply doesn’t make
> sense. Leading zero is a representation concept.
>
> Here's the simplest way to think about it. If I had binary integers, would
> this same pattern facet requiring leading zeros make sense? --- no it
> would not; and therefore it isn't allowed in DFDL for any integers, binary
> nor textual representations. Facets must be about the logical value, not
> the representation. Hence, patterns aren't allowed on numbers, because
> patterns are fundamentally about strings.
>
>
> On Sat, May 18, 2013 at 2:42 PM, Mike Beckerle <*mbeckerle.dfdl at gmail.com*<mbeckerle.dfdl at gmail.com>>
> wrote:
>
> Roger costello of Mitre provides this example of using pattern facet.
>
> Basically, it expresses several different possible formats, all of which
> are some combination of digits and a optional decimal point. In terms of
> cobol-style patterns it is one of these formats:
>
> 99
> 99.9
> 99.99
> 99.999
> 99.9999
>
> I am not sure a textNumberPattern can handle the optionality of the
> decimal point. I know we can deal with the varying number of fraction
> digits, and the fixed number of integer digits, but conditional decimal
> point I am unsure about.
>
>
>
>
>
>
>
> ---------- Forwarded message ----------
> From: *Costello, Roger L.* <*costello at mitre.org* <costello at mitre.org>>
> Date: Fri, May 17, 2013 at 4:00 PM
> Subject: RE: examples of decimal validation using pattern facet
> To: Mike Beckerle <*mbeckerle.dfdl at gmail.com* <mbeckerle.dfdl at gmail.com>>
> Cc: "Cranford, Jonathan W." <*jcranford at mitre.org* <jcranford at mitre.org>>
>
> Hello Mike,
>
>
>
> Ø Can you send an example of the lat/lon validation
>
> Ø you mentioned on yesterday's Daffodil call?
>
>
>
> Here ya go:
>
>
> <xsd:simpleType name="foo">
> <xsd:restriction base="xsd:decimal">
>
> <xsd:minInclusive value="00"/>
> <xsd:maxInclusive value="59.9999"/>
> <xsd:pattern value=
> "[0-9]{2}|[0-9]{2}\.[0-9]{1}|[0-9]{2}\.[0-9]{2}|[0-9]{2}\.[0-9]{3}|[0-9]{2}\.[0-9]{4}"
> />
> </xsd:restriction>
> </xsd:simpleType>
>
>
>
> /Roger
>
>
>
> *From:* Mike Beckerle [mailto:*mbeckerle.dfdl at gmail.com*<mbeckerle.dfdl at gmail.com>]
> *
> Sent:* Thursday, May 16, 2013 8:15 AM*
> To:* Costello, Roger L.*
> Subject:* examples of decimal validation using pattern facet
>
>
>
> Roger,
>
> Can you send an example of the lat/lon validation you mentioned on
> yesterday's Daffodil call?
>
> The other members of the workgroup are wondering what can't be done via
> totalDigits/fractionDigits, etc.
>
> The rationale for why pattern facet is not supported on numbers in DFDL is
> that we already have a much more powerful mechanism for parsing and
> unparsing numbers called textNumberPattern. The pattern facet only allows
> pass/fail using a regex, and is considered redundant (and problematic) for
> numbers as a result.
>
> ...mike
>
> --
> Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | *
> www.tresys.com* <http://www.tresys.com/>
>
>
>
>
> --
> Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | *
> www.tresys.com* <http://www.tresys.com/>
>
>
>
>
> --
> Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | *
> www.tresys.com* <http://www.tresys.com/>
> --
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>
> Unless stated otherwise above:
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>
>
--
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology |
www.tresys.com
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