Chan package:base-prelude

Chan is an abstract type representing an unbounded FIFO channel.
Duplicate a Chan: the duplicate channel begins empty, but data written to either channel from then on will be available from both. Hence this creates a kind of broadcast channel, where data written by anyone is seen by everyone else. (Note that a duplicated channel is not equal to its original. So: fmap (c /=) $ dupChan c returns True for all c.)
Return a lazy list representing the contents of the supplied Chan, much like hGetContents.
Build and returns a new instance of Chan.
Read the next value from the Chan. Blocks when the channel is empty. Since the read end of a channel is an MVar, this operation inherits fairness guarantees of MVars (e.g. threads blocked in this operation are woken up in FIFO order). Throws BlockedIndefinitelyOnMVar when the channel is empty and no other thread holds a reference to the channel.
Write a value to a Chan.
Write an entire list of items to a Chan.