This library provides Haskell bindings to 0MQ 3.x (http://zeromq.org).
This software currently has beta status, i.e. it had seen limited testing.
Version 0.2 - Add additional functionality from 3.2 stable release, e.g. zmq_proxy support, new socket options, socket monitoring etc. API Change: withContext no longer accepts the number of I/O threads as first argument.
Version 0.1.4 - Expose 'waitRead' and 'waitWrite'.
Version 0.1.3 - Deprecated 'Xreq', 'XRep' in favour of 'Dealer' and 'Router' as in libzmq. Fixes to compile and run with GHC 7.4.1.
Version 0.1.2 - Add 'sendMulti' and 'receiveMulti'. Rename 'SndMore' to 'SendMore'.
Version 0.1.1 - Include better error message when trying to build against invalid 0MQ version.
Version 0.1 - First release to provide bindings against 0MQ 3.1.0
As usual for Haskell packages this software is installed best via Cabal (http://www.haskell.org/cabal). In addition to GHC it depends on 0MQ 3.1.x of course.
zeromq3-haskell mostly follows 0MQ's API. One difference though is that sockets
are parameterized types, i.e. there is not one single socket type but when
creating a socket the desired socket type has to be specified, e.g.
the resulting socket is of type
This additional type information is used to ensure that only options applicable
to the socket type can be set.
Other differences are mostly for convenience. Also one does not deal directly with 0MQ messages, instead these are created internally as needed.
Finally note that
receive is already non-blocking internally.
GHC's I/O manager is used to wait for data to be available, so from a client's
receive appears to be blocking.
Differences to the 0MQ 2.x binding
This library is based on the zeromq-haskell binding for 0MQ 2.x. Socket types
and options have been aligned with 0MQ 3.x and instead of using a big
SocketOption datatype, this library provides separate get and set functions for
each available option, e.g.
setAffinity. For details, please refer
to the module's haddock documentation.
The examples folder contains some simple tests mostly mimicking the ones that come with 0MQ.