Show HN: Tiny and CSP-safe expression language for JavaScript

Robin van der Vleuten released xprsn, a 1.2 KB gzipped expression language library for JavaScript that is CSP-safe and designed for runtime evaluation of business logic. The package, extracted from a closed-source project, supports custom function extensions and uses a precedence climbing parser.

For a feature on project I was working on, I needed a simple way to have some business logic like "expressions" evaluated at runtime. I only found a handfull packages either very old e.g. expr-eval or very Math oriented e.g. Mathjs . I wanted a way to have a very simple core "compile then evaluate" package that I could easily extend with custom functions needed for the project so in theory I could support a full Math suite . The result is this tiny xprsn package, and is somewhere around 1.2kb gzipped, extracted from the closed-source project. See https://github.com/robinvdvleuten/xprsn https://github.com/robinvdvleuten/xprsn . Not gonna lie here, as it is mostly Fable5 effort you probably will notice by the terse, not very human-readable precedence climbing parser. But the point was to get a tiny working package, not some heavy brain exercise of myself : Despite some anti AI-slop people on HN, I wanted to share it here as I still think it would be useful to others. Comments URL: https://news.ycombinator.com/item?id=48945983 https://news.ycombinator.com/item?id=48945983 Points: 1 Comments: 0