In the previous article, I showed an example of a simple DSL for formula calculation and query filter. More complex scenarios require extended syntax, certain optimization techniques, and a lightweight VM. That’s what this article covers.
Some time ago there was an article about how to implement a formula interpreter in Formula Interpreter (DSL). When implementing tekBlueprint.frame, there was a need to make a universal query language for the REST API to obtain tabular data for the UI. Actually this is what we will talk about.
Quite often projects require the ability to customize some formulas or scripts available to the user. The main idea is to change the behavior of parts of the application without having to go through the entire development cycle with delivery of a new release. There are different options for how to do this, this will be discussed below.