Ever thought "I really wish I could generate Javascript code from a QGIS expression string"? Well, this is the talk for you. We take a QGIS expression string, break it down to the AST (Abstract Syntax Tree), and generate us some sweet sweet Javascript code just for a bit of fun.
Ok maybe not just fun as this was also used as part of QGIS2Web plugin by Tom to export rules to OpenLayers and Leaflet maps, but also for fun.