Web Optimisation: Formal Methods and Cascading Style Sheets

Abstract

Cascading Style Sheets are a pervasive web technology which control the layout and appearance of the majority of the world's web pages. They also form part of the bloat that large scale websites are keen to avoid.  As such, many minification technologies exist to compress and remove redundancies in these style sheets.

However, much of these tools are developed without a formal understanding of CSS semantics.  This leads to unsafe transformations which can not only affect the appearance of a web page, but also its functionality.

In this talk I will describe two of our recent attempts to minimise, remove redundancies, and generally understand cascading style sheets based on formal analysis and semantics.

This is joint work with Chih-Duo Hong, Anthony Lin, and C.-H. Luke Ong.