Curryer - Fast Haskell-to-Haskell RPC

Curryer (pun intended) is a fast, Haskell-exclusive RPC (remote procedure call) library. By using the latest Haskell serialization and streaming libraries, curryer aims to be the fastest and easiest means of communicating between Haskell-based processes.

Curryer is inspired by the now unmaintained distributed-process library, but is lighter-weight and uses a higher-performance serialization package.

Features

• blocking and non-blocking remote function calls
• asynchronous server-to-client callbacks (for server-initiated notifications)
• timeouts
• leverages winery for high-performance serialization

Requirements

• GHC 9.0+

Code Example

Server:

data SetKey = SetKey String String deriving (Generic, Show) deriving Serialise via WineryVariant SetKey data GetKey = GetKey String deriving (Generic, Show) deriving Serialise via WineryVariant GetKey main :: IO () main = do kvmap <- M.newIO void $ serve kvRequestHandlers kvmap localHostAddr 8765 Nothing kvRequestHandlers :: RequestHandlers (M.Map String String) kvRequestHandlers = [ RequestHandler $ \state (SetKey k v) -> atomically $ M.insert v k (connectionServerState state) , RequestHandler $ \state (GetKey k) -> atomically $ M.lookup k (connectionServerState state) ] 

Client:

data SetKey = SetKey String String deriving (Generic, Show) deriving Serialise via WineryVariant SetKey data GetKey = GetKey String deriving (Generic, Show) deriving Serialise via WineryVariant GetKey data CommandOptions = Get {name :: String} | Set {name :: String, value :: String} deriving (Generic, Show) instance ParseRecord CommandOptions main :: IO () main = do opts <- getRecord "SimpleKeyValueClient" conn <- connect [] localHostAddr 8765 case opts of Get k -> do eRet <- call conn (GetKey k) case eRet of Left err -> error (show err) Right (Just val) -> putStrLn val Right Nothing -> error "no such key" Set k v -> do eRet <- call conn (SetKey k v) case eRet of Left err -> error (show err) Right () -> pure ()