XQueryP: An XML Application Development Language

Presentation:

XQueryP: An XML Application Development Language

Presenter: Daniela Florescu, Senior Consultant, Oracle Corporation

XML 2006 Tues. 10:30

XQuery semantics were carefully specified to side-effect free

AND and OR are distributable
order of evaluation is irrelevant

New additions to XQuery for updates: insert, delete, rename, etc.

These are not fully-composable with the rest of the language.

XQueryP Overview

• - A small language extension
• - Supported by Oracle, BEA, DataDirect, etc.
• - Proposed to W3C
• - Details:

• 
  
• * A well-defined evaluation order for XQuery expressions ("sequential order") [this is a big change!!!]
• * adds new expressions: block, set, while, break, continue

• * error handling (try/catch)

• * added a way to model graphs in XML
• * a way of mapping XQueryp <-> Web services (optional)

New Expression Types:

Block Expressions

{ block-decl;... expr;... }

Assignment expressions

set $varName := exprSingle

Functions and blocks

declare updating function local:prune($d as xs:integer) as xs:integer {
declare $count as xs:inteer := 0;
for $m in /mail/message[date lt $d]
return { do delete $m;
set $count :- $count + 1
};
$count;
};

While

while ( condition ) {
expr;...
break;
continue;
}

posted by Unknown @ 10:27 AM