devel/hs-async 2.2.5nb4 NetBSD

This package provides a higher-level interface over threads, in which an Async a is a concurrent thread that will eventually deliver a value of type a. The package provides ways to create Async computations, wait for their results, and cancel them.

Using Async is safer than using threads in two ways:

When waiting for a thread to return a result, if the thread dies
with an exception then the caller must either re-throw the
exception (wait) or handle it (waitCatch); the exception cannot be
ignored.

The API makes it possible to build a tree of threads that are
automatically killed when their parent dies (see withAsync).