io-sim
IOSim
is a simulator monad that supports:
forkIO
as well as async
styleTVar
, TMVar
s, etc.TVar
's, etc.io-classes:io-classes
provides an interface, which allows writing code that
can be run in both real IO
and IOSim
. It is a drop-in replacement for
IO
, and supports interfaces commonly known from base
, exceptions
, stm
,
async
, or time
packages.
One of the principles of io-classes:io-classes
was to stay as close to IO
as possible, thus most of the IO
instances are directly referring to base
or async
API. However, we made some distinctions, which are reported below.
io-classes:io-classes
supports a novel hierarchy for error-handling monads
as well as more familiar exception
style. The new hierarchy provides
bracket
and finally
functions in the MonadThrow
class, while catch
style operators are provided by a super-class MonadCatch
. Both bracket
and
finally
are the most common functions used to write code with robust
exception handling, exposing them through the more basic MonadThrow
class
informs the reader / reviewer that no tricky error handling is done in that
section of the code base.
IOSim
exposes a detailed trace, which can be enhanced by labeling threads, or
mutable variables, tracing Dynamic
values (which can be recovered from the
trace), or simple String
based tracing. Although it's agnostic concerning
the logging framework, it worked for us particularly well using
contra-tracer. It has been used to develop, test, and debug
a complex, highly concurrent, distributed system
(ouroboros-network), in particular
io-sim
: provides two simulator interpreters: IOSim
and
IOSimPOR
- an enhanced IOSim
version with schedule discovery
capabilities.io-classes:io-classes
: class bases interface, which allows to to abstract over the
monadio-classes:strict-stm
: strict STM operationsio-classes:si-timers
: non-standard timers APINew issues should be reported in this repository.