Multiple String Comparison in XSLT with tan:collate()

Abstract

In this article I introduce tan:collate(), an XSLT function for comparing three or more strings. Collated multiple string comparison is a difficult problem that merits experimentation with alternative methods. tan:collate() approaches the task in three different ways. Two of those methods involve a sequence of pairwise comparisons, with each comparison grafted into a guide tree. The third method applies the staggered-sample approach of tan:diff() to multiple strings, to detect a common superskeleton, before attempting to refine results. This paper situates the problem of multiple string comparison in the context of textual criticism, proposes a general output format and test suite, and presents measured results for the quality and performance of tan:collate() against an example test suite. Released as part of an open-source function library, tan:collate() enables developers to incorporate robust text comparison directly into XSLT applications.