If you would like me to list a single concrete technical idea, I am pleased to oblige. The idea is: universal gaps. Our syntactic-semantic documents can have holes in them, places where we know some content is missing. That allows a document to behave like a template which lets us fill in the blanks. In a text-editor-based IDE there is no equivalent, which means that when I go to make a new sticky regex in Javascript I type //y and the IDE thinks I meant to comment out the rest of the line. It has no way of expressing the concept that between those two slashes something is known to be missing, which is exactly what I want to be able to tell it so that it can understand the difference between the state when I'm about to write a regex body and the state where I'm about to write a comment body