A query language for a Web-site management system
ACM SIGMOD Record
Typechecking for XML transformers
PODS '00 Proceedings of the nineteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
XML with data values: typechecking revisited
PODS '01 Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Programming Constructs for Unstructured Data
DBLP-5 Proceedings of the Fifth International Workshop on Database Programming Languages
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LICS '01 Proceedings of the 16th Annual IEEE Symposium on Logic in Computer Science
CDuce: an XML-centric general-purpose language
ICFP '03 Proceedings of the eighth ACM SIGPLAN international conference on Functional programming
An efficient algorithm for XML type projection
Proceedings of the 8th ACM SIGPLAN international conference on Principles and practice of declarative programming
VLDB '06 Proceedings of the 32nd international conference on Very large data bases
Static analysis for path correctness of XML queries
Journal of Functional Programming
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Journal of Functional Programming
Scrap your boilerplate with XPath-like combinators
Proceedings of the 34th annual ACM SIGPLAN-SIGACT symposium on Principles of programming languages
On deciding well-definedness for query languages on trees
Journal of the ACM (JACM)
CSchema: a downgrading policy language for XML access control
Journal of Computer Science and Technology
Detection of corrupted schema mappings in XML data integration systems
ACM Transactions on Internet Technology (TOIT)
Identifying query incompatibilities with evolving XML schemas
Proceedings of the 14th ACM SIGPLAN international conference on Functional programming
Impact of XML Schema Evolution
ACM Transactions on Internet Technology (TOIT)
Precision and complexity of XQuery type inference
Proceedings of the 13th international ACM SIGPLAN symposium on Principles and practices of declarative programming
Error mining for regular expression patterns
ICTCS'05 Proceedings of the 9th Italian conference on Theoretical Computer Science
Mapping maintenance in XML p2p databases
DBPL'05 Proceedings of the 10th international conference on Database Programming Languages
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If a subexpression in a query will never contribute data to the query answer, this should be regarded as an error. This principle has been recently accepted into mainstream XML query languages, but was still waiting for a complete treatment. We provide here a precise definition for this class of errors, and define a type system that is sound and complete, in its search for such errors, for a core language, under mild restrictions on the use of recursion in type definitions. In the process, we describe a dichotomy among existential and universal type systems, which is useful to understand some unusual features of our type system.