janestreet/incremental: A library for incremental computations · GitHub

Incremental is a library that gives you a way of building complex
computations that can update efficiently in response to their inputs
changing, inspired by the work of Umut Acar et. al. on self-adjusting
computations. Incremental can be useful in a number of applications,
including:

• Building large calculations (of the kind you might build into a
  spreadsheet) that can react efficiently to changing data.
• Constructing views in GUI applications that can incorporate new data
  efficiently.
• Computing derived data while guaranteeing that the derived data
  stays in sync with the source data, for instance filtering or
  inversing a mapping.

You can find detailed documentation of the library and how to use
it in incremental/src/incremental_intf.ml. You can also find an
informal introduction to the library in this blog post
and this video.