0.16.0.0

• Updated to work with GHC 9.2.x. In particular:
  • The generated code now enables the FlexibleContexts extension since it is no longer implied by UndecidableInstances
  • The IsPtr type alias now includes an additional constraint, which GHC seems to no longer be able to derive from the others.
  • Internals have been updated to deal with a breaking change to template-haskell.
• Fixed an error building the documentation.

0.15.0.0

• There is now a per-connection limit on the total size of incoming Call messages that are being serviced, which can be used to limit memory usage and provide backpressure. ConnConfig has a new maxCallWords field to configure this.
• Some bugs in the RPC layer have been fixed.
• tracingTransport now provides an option to omit call & return bodies from the logged messages.

0.14.0.0

• Significant performance improvements.
• The Data.Mutable module and its Thaw class have been replaced by Capnp.Mutability and a class MaybeMutable, which serves the same function but is easier to work with. Notably, thaw and freeze can now be used on Raw` values directly.
• Mutability is now defined in Capnp.Mutability instead of Capnp.Message, though the latter still re-exports it for compatibility (for now).
• The parameters to the Raw type constructor have been flipped; the new ordering makes it possible to implement thaw/freeze on Raw a
  • The Untyped type family has seen similar treatment.
• HasMessage and MessageDefault are now defined on a type of kind * -> Mutability, which keeps the mutability out of constraints.
  • This has the unfortunate side-effect of making type inference for these classes not work very well :(. Hopefully a better solution will be found in the future.

0.13.0.0

This release drops support for the old API. To upgrade to the new API, Users should first upgrade to the latest 0.12.x version, switch their code to use the new API, and then upgrade to this version.

0.12.1.0

This release backports some fixes and minor features in the new API.

0.12.0.0

• The 0.12.x series is the last major version that will support the old API; the next release will not generate code for the old API, and some low level interfaces will be removed. See https://zenhack.net/2021/07/30/new-haskell-capnp-release-reworked-apis.html for details.
• For the new API, there is a new HasTypeId class, with instances defined for all generated types.
• The new API now supports implementing RPC servers. Capnp.Tutorial discusses this, and the examples have been updated to use the new API.

0.11.0.0

• This release introduces some experimental new APIs; see the blog post for details: https://zenhack.net/2021/07/30/new-haskell-capnp-release-reworked-apis.html
  • The new APIs include support for RPC pipelining, which is not possible with the old APIs.
• The traversal limit is tracked at a coarser granularity. This results in a modest performance improvement, and may result in slightly different (but similar) amounts of the limit being used for a given computation than with the old implementation.
• Bounds on pointers are checked a bit earlier (when the pointer is read, rather than when its referent is accessed). As a result, some malformed messages may trigger bounds check errors which did not previously, because the offending portion of the message was not read.
• The limit on how many capabilities can be attached to a single message has been increased.
• LimitT m now has an instance of MonadCatch if m has an instance.
• Some harmless warnings triggered by the generated code are now silenced.
• Capnp.Rpc.Promise exposes a new function newReadyPromise, which can be used to create an already-fulfilled promise.
• Fixed a race condition where if the supervisor for a client is killed before the server has finished spawning, the shutdown method might not be run.
• Capnp.Rpc.Server.runServer no longer calls handleStop on exit. Most users of the library will not be affected, as this function is mostly a low-level implementation detail that is called by higher level functionality.
• In Capnp.Message some uses of the type Int in the API have been strengthened to type WordCount.

0.10.0.1

• Fix a bug causing spurious exceptions when creating very large messages.

0.10.0.0

• The parametrization of messages has been reworked. Most things that were parametrized over a message type are now parametrized over a type parameter of kind Mutability (defined in Capnp.Message).
  • The Message type class has been replaced with a type Message of kind Mutability -> *, and a type class MonadReadMessage for operations that can work on any Message.
• Message.fromByteString/toByteString:
  • are now stand-alone functions, rather than methods on the class
  • only operate on immutable segments.
  • are pure functions, rather than monadic ones.
• Some functions that were derivative of toByteString/fromByteString, e.g. Untyped.rawBytes, also only work on immutable messages now, and may be pure functions where before they were monadic.
• The types defined in Capnp.Basics now have Thaw instances.

0.9.0.0

• Significant performance improvements. A few low level APIs have been changed to support this work.

0.8.0.0

Serialization

• The code generator now supports type parameters in schema; previously the code generator would treat these the same as AnyPointer, but now the generated Haskell has corresponding type parameters.
• The Cerialize and Marshal type classes now take the state token s as a parameter, which was necessary to support type parameters.

Misc

• Some of the multi-parameter type classes in Capnp.Classes now have functional dependencies between their parameters. This should generally improve type inference.

0.7.0.0

Serialization

• The library now supports canonicalization via Capnp.canonicalize
• There is a new function Capnp.Message.singleSegment for constructing a ConstMsg from an (unframed) Segment ConstMsg.

RPC

• Some signatures in Capnp.Rpc.Untyped have changed to facilitate a future release supporting promise pipelining.

Misc

• The included schema now match those in version 0.8 of the reference implementation

0.6.0.3

• Fix a race condition [(#74)][issue74] causing remote objects to very occasionally be released too early.

0.6.0.2

• Fix a bug (#71) which sometimes caused the code generator to crash.

0.6.0.1

• Fix a bug in the code generator (#72) which sometimes resulted in build failures of the generated code.

0.6.0.0

RPC

• Fix a serious bug in newPromiseClient, resulting in dropped calls made on the promise before it is resolved.
• There is now a Server class, which all RPC servers must implement. All of its methods have default implementations, so adding an instance to existing servers is straightforward.
• It is now possible to "unwrap" clients that point to a local server using the new 'Capnp.Rpc.unwrapServer' function, if the server implements support for it with the new 'Server' type class.
• Servers can now specify a hook to be run when the server is shut down, using the server class's 'shutdown' method.

0.5.0.0

Serialization

In Capnp.Untyped, The dataSection and ptrSection APIs have been removed. structDataSize has been replaced with structWordCount, and new functions structByteCount and structPtrCount` have been added.

RPC

This release brings some improvements to the RPC API:

• Add newPromiseClient for creating a promise-based client that can be fulfilled later.

• Make Client an instance of IsClient.

• Previously, there were a number of functions that had two variants:

  • foo, which ran in IO
  • fooSTM, which ran in STM.

  Now there is just one variant, foo, which is polymorphic over MonadSTM, defined by the monad-stm package. There are instances of this class for IO, STM, and any monad transformer applied to an instance.

  Note that previously some of the foo variants were polymorphic over MonadIO. Unfortunately it is not possible to define a general instance MonadIO m => MonadSTM m, but for a particular mtl stack that has an instance of MonadIO, you can fix the problem by defining:

  instance MonadSTM MyStack where
      liftSTM = liftIO . liftSTM
  

  Or, you can add liftIO/liftSTM to the appropriate call sites.

0.4.0.0

• RPC support! This should be considered alpha quality for now. The API will likely change substantially.
• Many bug fixes; users are strongly encouraged to upgrade.
• Reorganization of the module hierarchy:
  • Generated code is now placed under Capnp.Gen, rather than Capnp.
  • The Data prefix has been removed from the Data.Capnp hierarchy.
• The included generated modules for the core schema have been updated to those shipped with version 0.7 of the reference implementation.
• Other miscellaneous API Changes:
  • createPure can now be used with any instance of MonadThrow, not just Either SomeException.
  • LimitT m is now an instance of MonadIO, provided that m is an instance.
  • More type class instances from elsewhere in the library are re-exported via the Capnp module.
  • The IsPtr type class has been split into FromPtr and ToPtr. Most user code should not care about this.
  • Generated high-level types no longer have Read instances; interfaces make this problematic.
  • Getters for anonymous unions are now get_Foo' instead of get_Foo'union'.
  • newMessage now accepts an optional size hint.
  • Instances of Cerialize now exist/are generated for (Vector (Vector (Vector ...))) up to a reasonable depth.
• Other improvements not directly reflected in the API:
  • The allocation strategy has changed to reduce unnecessary copying.
  • It is now possible to create messages with a size > 2GiB. Note that individual segments are still limited.

0.3.0.0

• Instances of some type classes are no longer generated for "second class" types (i.e. types which cannot appear as stand-alone definitions in schema files -- groups and unions).
• has_* functions are now only generated for pointer fields.
• Various non-functional changes in the output of the code generator.
• We now generate constants for (most) pointer types; previously constants defined in a schema would not result in any generated code (#41).
• The set_* functions now check if the arguments are in the same message, and copy if need be (#34).
• MutMsg is now an instance of Eq.
• The HasMessage class from Data.Capnp.Untyped is now a type family, rather than a multi-parameter type class. This improves inference and removes some superfluous generalization.
• The module Data.Capnp.Pure has been folded into Data.Capnp. If you were previously using the Text and Data type aliases it exported, you should instead use Text from Data.Text and ByteString from Data.ByteString; the Text and Data exported by Data.Capnp are types from the low-level API.

0.2.0.0

• Redesign the 'Mutable' type class's API.
• Provide helpers for doing zero-copy message creation in pure code.
• General improvements to the documentation.

0.1.0.0

• First release; basic read & write support, serialization only.