async-2.0.2: Run IO operations asynchronously and wait for their results

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).

Changes in 2.0.2:

• Add a Monad instance for Concurrently
• Bump base dependency to allow 4.9

Changes in 2.0.1.6:

• Add workaround to waitCatch for #14

Changes in 2.0.1.5:

• Bump base dependencies for GHC 7.8

Changes in 2.0.1.4:

• Bump base dependency of test suite

Changes in 2.0.1.3:

• Bump base dependency to allow 4.6

Changes in 2.0.1.2:

• Bump stm dependency to 2.4

Changes in 2.0.1.1:

• Safe Haskell support: Control.Concurrent.Async is now Trustworthy

Changes in 2.0.1.0:

• Added a Functor instance for Async
• Added asyncBound, asyncOn, asyncWithUnmask, asyncOnWithUnmask, withAsyncBound, withAsyncOn, withAsyncWithUnmask, withAsyncOnWithUnmask.
• Added mapConcurrently
• Added Concurrently (with Applicative and Alternative instances)