I used ANTLR to build a query language parser and interpreter for a past employer. They had a specialized use case. ANTLR was pretty pleasant to use. The soluti

I used ANTLR to build a query language parser and interpreter for a past employer. They had a specialized use case. ANTLR was pretty pleasant to use. The solution ended up being a pretty small amount of code and enabled much more powerful searching in their internal data viewing tool. I still think fondly about the project from time to time, partly because it was the one project where my fellow devs were just as happy with the tool as the non-dev users were (this was a very common tool for both devs and non-devs to use).