Re: [xsl] In the field of programming, where does xsl:apply-templates reside?

["steve.majewski@xxxxxxxxx" <steve.majewski@xxxxxxxxx>]

I would call this programming paradigm "pattern matching" : besides  
SQL, other
examples would be prolog, regular expressions in general, and  
especially how
they are used in languages like awk and sed: If the input matches this  
pattern,
apply this rule. ( Whether the rule is implemented as a function or  
not is secondary
to the pattern matching paradigm. ) Some AI systems mixed the pattern  
matching
and Object-Oriented/agent paradigms by having agents send output  
messages to a common
"blackboard" area which the agents also monitor for an activating/ 
triggering pattern.

It doesn't really map into a either a pure procedural, functional or  
Obj.Oriented language.

-- Steve Majewski



On May 8, 2010, at 10:24 AM, cknell@xxxxxxxxxx wrote:

> XSLT has more in common with SQL than Java. Consider how a SQL  
> SELECT statement would map to any Java statement. Give up? Now  
> compare a SQL SELECT to an XSLT xsl:template.
>
> SELECT FName, LName, MobilePhone
> FROM ContactInfo
> WHERE ZipCode IN ('02853', '58741','32574');
>
> <xsl:template match="\ContactInfo\Contact[ZipCode  
> =('02853','58741','32574')]\Name">
>    <xsl:value-of select="FName"/>
>    <xsl:value-of select="LName"/>
>    <xsl:value-of select="MobilePhone "/>
> </xsl:template>
>
> In both cases you will get the first and last names, and the mobile  
> phone number of any persons in your database (xml file) whose  
> address has a Zip Code matching one of the three listed.
>
> Unlike Java (or C, or Basic, etc.) you tell the program what to do,  
> not how to do it.
>
> I know that the underlying programs that run a SQL SELECT statement  
> and the XSLT stylesheet are written in procedural languages, but if  
> you try to map the procedural onto the declarative, you will end up  
> with inapt comparisons which are likely to produce either  
> misapprehension or confusion.
> --
> Charles Knell
> cknell@xxxxxxxxxx - email
>
>
>
> -----Original Message-----
> From:     Costello, Roger L. <costello@xxxxxxxxx>
> Sent:     Sat, 8 May 2010 07:48:25 -0400
> To:       "xsl-list@xxxxxxxxxxxxxxxxxxxxxx" <xsl-list@xxxxxxxxxxxxxxxxxxxxxx 
> >
> Subject:  [xsl] In the field of programming, where does xsl:apply- 
> templates reside?
>
> Hi Folks,
>
> Introductory textbooks on programming identify  constructs common  
> among programming languages:
>
>   - looping constructs
>   - branching constructs
>   - sequencing constructs
>
> And others.
>
> Where does xsl:apply-templates reside within the field of programming?
>
> For example, if you were to map an XSLT program to, say, a Java  
> program, what Java construct would you map xsl:apply-templates to?
>
> Perhaps asking how an XSLT construct maps to a Java construct is  
> wrong, since XSLT is a rule-based language and Java is not. Do you  
> agree?
>
> Perhaps a better question is, how does xsl:apply-templates map to  
> constructs in other rule-based languages? (I confess ignorance of  
> other rule-based languages).
>
>    "xsl:apply-templates falls within the general category
>     of _____________ constructs for rule-based languages."
>
> Would you fill in the blank please?
>
> /Roger