XL (XML programming language)
XL is an XML - programming language for implementing Web services . It was developed in 2001 by Daniela Florescu (XQRL Inc.), Andreas Grünhagen and Donald Kossmann ( ETH Zurich ). XL is still in development and is based on the XML data model . It supports the W3C standards and uses a. XQuery as the query language, SOAP for communication with other network services and WSDL for specifying the interfaces .
XL is to a high degree declarative, which means that recurring functions are already implemented in the language for network services. These functions can be called up by specifying key words, so-called Declarative Web Service Clauses . These include:
- Saving entries from clients (logging)
- Automatic new request if the request to another service fails (retry of action)
- Distribution across multiple systems (workload management)
- Automatic optimization of the code (performance tuning)
By concentrating solely on XML as the data model, conversions between type systems that require intensive computing time can be avoided. These conversions are necessary for common implementations in an object-oriented or procedural programming language in combination with a relational database .
XL integrates XML processing, storage and communication in a modular, scalable system. The current runtime environment was implemented in Java . XL is not freely available. Comparable programming languages are for example: WS-BPEL or (C-omega).
