The Filter-Map-Reduce programming model is a data-processing construct coming from the world of 'functional programming' - and has recently made serious headway into languages such as Java or C#. This triad of higher-order functions combined offer a powerful tool for manipulating sequences of data.
But that triad doesn't cover all use-cases, so we add a fourth concept to the mix.
Of course you can already do these things manually in LiveCode, especially with the 'repeat for each' construct as a speedy way to iterate over a sequence of data. So why would you need a library? One good reason is to cut down on typing and prevent subtle logic errors ; but far more important is that code becomes easier to understand and maintain as you make abstraction of the iterative process.
As an open source project, the scripts are available for review and modification - and you can help it grow by contributing your enhancements to the community.
If you have questions, don't hesitate to look at the FAQ. But more importantly: download the full version with the sample scripts, so you can see for yourself how remarkably powerful data-processing with LiveCode can be.