Section: New Results

A Core Calculus for XQuery 3.0: Combining Navigational and Pattern Matching Approaches

XML processing languages can be classified according to whether they extract XML data by paths or patterns. The strengths of one category correspond to the weaknesses of the other. In this work, we propose to bridge the gap between these two classes by considering two languages, one in each class: XQuery (for path-based extraction) and CDuce (for pattern-based extraction). To this end, we extend CDuce so as it can be seen as a succinct core $\lambda$-calculus that captures XQuery 3.0. The extensions we consider essentially allow CDuce to implement XPath-like navigational expressions by pattern matching and precisely type them. The elaboration of XQuery 3.0 into the extended CDuce provides a formal semantics and a sound static type system for XQuery 3.0 programs [18] .