Also BPEL - https://en.wikipedia.org/wiki/Business_Process_Execution_Language
Michael Kay
Saxonica
> On 20 Aug 2022, at 17:54, Stephen D Green <stephengreenubl@gmail.com> wrote:
>
> http://docs.oasis-open.org/tamie/xtemp/v1.0/xtemp-v1.0.html
> ----
> Stephen D Green
>
> On Sat, 20 Aug 2022 at 17:30, Roger L Costello <costello@mitre.org> wrote:
>>
>> Hi Folks,
>>
>> Before I get to my question, please allow me to share a short story.
>>
>> Early versions of Fortran did not have high-level programming language constructs such as while-loops, so some smart person came along and created RATFOR (Rational Fortran), which extended Fortran with several high-level constructs. That person then created a preprocessor which converted programs expressed in RATFOR into equivalent Fortran programs. For example, here is a RATFOR program that uses the high-level while-loop construct:
>>
>> while (getc(c) != EOF)
>> call putc(c)
>>
>> The RATFOR preprocessor converts it to this equivalent Fortran code:
>>
>> 10 if (getc(c) .eq. EOF goto 20
>> call putc(c)
>> goto 10
>> 20 continue
>>
>> Now for my question.
>>
>> Question: How to represent step-by-step procedures in XML? The XML representation must be:
>>
>> Sufficiently detailed and precise that a program could input it and carry out the procedure being described. Alternatively, a preprocessor could take the description and convert it into an existing programming language which may then be executed.
>> The XML representation must be high-level enough that it is understandable by managers.
>>
>> What follows is a real-world example to illustrate my question.
>>
>> I have a file named ARPT.xml which contains a list of records for all the airports in the world. Each record contains data about an airport.
>>
>> I have another file named NAV.xml which contains a list of records for all the navigation aids (navaids) in the world. Each record contains data about a navaid.
>>
>> Some navaids are placed in locations to help airplanes fly between airports. Other navaids are placed in locations to help airplanes fly in and out of airports.
>>
>> Some airports are close to each other, so some navaids are used by more than one airport. In some cases, the same navaid is used by airports in different countries; for example, at the US-Canada border there might be a navaid that is shared between airports in the US and Canada.
>>
>> Since a navaid may be used by more than one airport, there is a file named ANAV.xml that is intermediary between ARPT.xml and NAV.xml; it maps a nav ID and country ID to the navaid records for the airport. In other words, there is a level of indirection to obtaining the navaid records for an airport. We use the airport ID from ARPT.xml as a foreign key into ANAV.xml to obtain a set of ANAV records, and for each ANAV record, we use its nav ID and country ID as a composite foreign key into NAV.xml. The selected NAV records are the airport’s navaids.
>>
>> How to represent in XML the procedure for obtaining the navaid records for an airport?
>>
>> You might wonder, “Why create an XML representation of a procedure?”
>>
>> The answer is threefold:
>>
>> An XML representation will provide a precise description of how to obtain the navaid records for an airport.
>> With that precise, machine-processable description, I can then use it as input into a program that performs the procedure. The program simply, blindly follows the description in the XML. Alternatively, a preprocessor could take the XML description and convert it into an existing programming language that may then be executed.
>> The procedure I just described is one of many procedures that I need to capture. Many of the procedures are more complicated than the one I described above. A standard, machine-processable way to express all procedures will prove invaluable.
>>
>> Here is one possible XML representation of the procedure:
>>
>> <Procedure>
>> <variable name="ARPT.XML" select="doc('ARPT.xml')"/>
>> <variable name="ANAV.XML" select="doc('ANAV.xml')"/>
>> <variable name="NAV.XML" select="doc('NAV.xml')"/>
>> <airports>
>> <for-each select="$ARPT.XML/record">
>> <airport>
>> <variable name="airport-ID" select="child::airport-ID" />
>> <for-each select="child::*">
>> <copy-of select="."/>
>> </for-each>
>> <for-each select="$ANAV.XML/record[child::airport-ID eq $airport-ID]">
>> <variable name="country-ID" select="child::country-ID']" />
>> <variable name="nav-ID" select="child::nav-ID" />
>> <for-each select="$NAV.XML/record[child::nav-ID eq $nav-ID][child::country-ID eq $country-ID">
>> <navaid>
>> <for-each select="child::*">
>> <copy-of select="."/>
>> </for-each>
>> </navaid>
>> </for-each>
>> </for-each>
>> </airport>
>> </for-each>
>> </airports>
>> </Procedure>
>>
>> Readers may recognize that as XSLT code, minus the xsl namespace prefix.
>>
>> That XML representation is simply not acceptable. It probably can be understood by a developer who knows XSLT, but to most developers and to most managers it is pure gibberish. It is analogous to the Fortran shown about.
>>
>> I am seeking a high-level XML representation, one that is understandable by a manager and at the same time is sufficiently detailed that it can be executed, or I can write a preprocessor which converts it into equivalent lower-level programming language code (analogous to how the RATFOR preprocessor converts programs written in the high-level RATFOR into equivalent low-level Fortran).
>>
>> I seek your suggestions on a high-level XML representation of the airport/navaid procedure I described.
>>
>> /Roger
>>
>>
>
> _______________________________________________________________________
>
> XML-DEV is a publicly archived, unmoderated list hosted by OASIS
> to support XML implementation and development. To minimize
> spam in the archives, you must subscribe before posting.
>
> [Un]Subscribe/change address: http://www.oasis-open.org/mlmanage/
> Or unsubscribe: xml-dev-unsubscribe@lists.xml.org
> subscribe: xml-dev-subscribe@lists.xml.org
> List archive: http://lists.xml.org/archives/xml-dev/
> List Guidelines: http://www.oasis-open.org/maillists/guidelines.php
>
_______________________________________________________________________
XML-DEV is a publicly archived, unmoderated list hosted by OASIS
to support XML implementation and development. To minimize
spam in the archives, you must subscribe before posting.
[Un]Subscribe/change address: http://www.oasis-open.org/mlmanage/
Or unsubscribe: xml-dev-unsubscribe@lists.xml.org
subscribe: xml-dev-subscribe@lists.xml.org
List archive: http://lists.xml.org/archives/xml-dev/
List Guidelines: http://www.oasis-open.org/maillists/guidelines.php