CDuce is an XML

XML

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

-oriented functional language, which extends XDuce in a few directions.
It features XML regular expression

Regular expression

In computing, a regular expression provides a concise and flexible means for "matching" strings of text, such as particular characters, words, or patterns of characters. Abbreviations for "regular expression" include "regex" and "regexp"...

 types, XML

XML

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

 regular expression patterns,
XML iterators. CDuce is not strictly speaking an XML transformation language

XML transformation language

An XML transformation language is a programming language designed specifically to transform an input XML document into an output XML document which satisfies some specific goal.There are two special cases of transformation:...

 since
it can be used for general-purpose programming.

CDuce conforms to basic standards: Unicode

Unicode

Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

, XML

XML

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

, DTD

Document Type Definition

Document Type Definition is a set of markup declarations that define a document type for SGML-family markup languages...

, Namespaces

Namespace (computer science)

A namespace is an abstract container or environment created to hold a logical grouping of unique identifiers or symbols . An identifier defined in a namespace is associated only with that namespace. The same identifier can be independently defined in multiple namespaces...

 are fully supported, XML Schema is partially supported.

Benefits of CDuce

• static verifications (e.g.: ensure that a transformation produces a valid document);
• in particular, we aim at smooth and safe compositions of XML transformations, and incremental programming;
• static optimizations and efficient execution model (knowing the type of a document is crucial to extract information efficiently).

Features particular to CDuce

• XML objects can be manipulated as first-class citizen values: elements, sequences, tags, characters and strings, attribute sets; sequences of XML elements can be specified by regular expressions, which also apply to characters strings;
• functions themselves are first-class values, they can be manipulated, stored in data structure, returned by a function,...
• a powerful pattern matching operation can perform complex extractions from sequences of XML elements;
• a rich type algebra
  Algebra
  Algebra is the branch of mathematics concerning the study of the rules of operations and relations, and the constructions and concepts arising from them, including terms, polynomials, equations and algebraic structures...
  
  , with recursive type
  Recursive type
  In computer programming languages, a recursive data type is a data type for values that may contain other values of the same type...
  
  s and arbitrary boolean
  Boolean operation
  Boolean operation or Boolean operator may refer to one of the following related meanings.*Boolean function*an operation in a Boolean algebra; in particular:**operations over the algebra of sets: union , intersection , etc....
  
   combinations (union, intersection, complement) allows precise definitions of data structures and XML types; general purpose types and types constructors are taken seriously (products, extensible records, arbitrary precision integers with interval constraints, Unicode characters);
• polymorphism
  Type polymorphism
  In computer science, polymorphism is a programming language feature that allows values of different data types to be handled using a uniform interface. The concept of parametric polymorphism applies to both data types and functions...
  
  through a natural notion of subtyping, and overloaded functions with dynamic dispatch;
• a highly-effective type-driven compilation schema.