A core calculus for XQuery 3.0 combining navigational and pattern matching approaches

초록

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: X Query (for path-based extraction) and ℂ Duce (for pattern-based extraction). To this end, we extend ℂ Duce so as it can be seen as a succinct core λ-calculus that captures XQuery 3.0. The extensions we consider essentially allow ℂ Duce to implement XPath-like navigational expressions by pattern matching and precisely type them. The elaboration of XQuery 3.0 into the extended ℂ Duce provides a formal semantics and a sound static type system for XQuery 3.0 programs. © Springer-Verlag Berlin Heidelberg 2015.