Re: [xsl] Are XPath expressions parsed using compiler parsing techniques?

["Adam Retter adam.retter@xxxxxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hi Roger,

Due to the complexity they are typically parsed using one of the
traditional compiler parsing algorithms, either through a manually
coded parser such as the ones in Saxon and the experimental parser for
FusionDB, or through a parser compiler compiler toolkit such as Antlr,
Yacc, etc.

I gave a talk on some aspects of our new Hand-rolled Recursive Descent
approach here (you might recognise "the book" in the background at the
beginning of the video) at Declarative Amsterdam 2020 -
https://www.youtube.com/watch?v=nxLqE_7ZO2A and the slides:
https://declarative.amsterdam/resources/da/slides/da.2020.retter.slides.pdf

There are also various pre-baked Open Source XPath and XQuery parsers
in Java and Scala using Antlr and various other toolkits kicking
around my various GitHubs - let me know if you want links to them.

Kind regards. Adam.

On Sun, 8 May 2022 at 23:19, Roger L Costello costello@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hi Folks,
>
> I dug out my old compiler "Dragon book" and started rereading it.
>
> Chapter 1 lists some of the tools that employ compiler techniques. This one caught my attention:
>
> Query interpreters: A query interpreter translates a predicate containing relational and boolean operators into commands to search a database of records satisfying that predicate.
>
> An XPath expression is a query. Not against a database, but against an XML document. Are XPath expressions parsed using compiler parsing algorithms? Is a syntax tree constructed for an XPath expression? Is the syntax tree traversed?
>
> /Roger
> 
>


-- 
Adam Retter

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http://www.adamretter.org.uk