bento (empty) → 0.1.0

raw patch · 7 files changed

+194/−0 lines, 7 filesdep +basesetup-changed

Dependencies added: base

Files

• CHANGELOG.markdown +7/−0
• README.markdown +12/−0
• Setup.hs +4/−0
• bento.cabal +35/−0
• library/Bento.hs +115/−0
• package.yaml +18/−0
• stack.yaml +3/−0

@@ -0,0 +1,7 @@+# Change log++Bento uses [Semantic Versioning][].+The change log is available through the [releases on GitHub][].++[Semantic Versioning]: http://semver.org/spec/v2.0.0.html+[releases on GitHub]: https://github.com/tfausak/bento/releases

@@ -0,0 +1,12 @@+# 🍱 [Bento][]++[![Version badge][]][version]+[![Build badge][]][build]++Bento manages stateful components.++[Bento]: https://github.com/tfausak/bento+[Version badge]: https://www.stackage.org/package/bento/badge/nightly?label=version+[version]: https://www.stackage.org/package/bento+[Build badge]: https://travis-ci.org/tfausak/bento.svg?branch=main+[build]: https://travis-ci.org/tfausak/bento

@@ -0,0 +1,4 @@+import Distribution.Simple++main :: IO ()+main = defaultMain

@@ -0,0 +1,35 @@+-- This file has been generated from package.yaml by hpack version 0.9.0.+--+-- see: https://github.com/sol/hpack++name:           bento+version:        0.1.0+synopsis:       🍱 Manage stateful components.+description:    Bento manages stateful components.+category:       Utility+homepage:       https://github.com/tfausak/bento#readme+bug-reports:    https://github.com/tfausak/bento/issues+maintainer:     Taylor Fausak+license:        MIT+build-type:     Simple+cabal-version:  >= 1.10++extra-source-files:+    CHANGELOG.markdown+    package.yaml+    README.markdown+    stack.yaml++source-repository head+  type: git+  location: https://github.com/tfausak/bento++library+  hs-source-dirs:+      library+  ghc-options: -Wall+  build-depends:+      base >=4 && <5+  exposed-modules:+      Bento+  default-language: Haskell2010

@@ -0,0 +1,115 @@+{-# LANGUAGE TypeFamilies #-}++-- | Bento manages stateful components. It is inspired by+-- <https://github.com/stuartsierra/component Stuart Sierra's Component>+-- library for Clojure.+module Bento where++-- | A stateful component. Usually you will define an instance of this class to+-- a data type that contains all of its runtime state.+--+-- @data Example = Example { handle :: 'System.IO.Handle' }+--instance 'Component' Example where+--    -- To be defined...@+class Component component where+    -- | Everything necessary to start the component. Typically this is a+    -- tuple, but you are free to use whichever data structure you want. If+    -- your component does not have any dependencies, use @()@, the empty+    -- tuple.+    --+    -- @type 'Dependencies' Example = ('FilePath', 'System.IO.IOMode')@+    type Dependencies component :: *++    -- | Starts the component. This is where you should do things like open+    -- file handles, set up connections, and generally acquire resources. If+    -- anything goes wrong, just throw an exception, preferrably with+    -- 'Control.Exception.throwIO'.+    --+    -- This function should not block forever. If you need to start something+    -- that should keep running, like a server, put it on another thread with+    -- 'Control.Concurrent.forkIO'.+    --+    -- @'start' (path, mode) = do+    --    h <- 'System.IO.openFile' path mode+    --    let component = Example { handle = h }+    --    'return' component@+    start :: Dependencies component -> IO component++    -- | Stops the component. Generally this will do the opposite of whatever+    -- you did in 'start'. The default implementation does nothing, which can+    -- be enough if you want the garbage collector to handle everything.+    --+    -- @'stop' component = do+    --    'System.IO.hClose' (handle component)@+    stop :: component -> IO ()+    stop _component = return ()++-- * Complete example++-- $+-- The follow is a complete example of using 'Component's to build a larger+-- system, which is itself a 'Component'.+--+-- For this simple example, we will be starting a web server. The only piece of+-- configuration we need is the port to listen on. We will get that from the+-- environment. If it's not available, we'll fall back to a default.+--+-- @data Config = Config { port :: Int }+--instance 'Component' Config where+--    type 'Dependencies' Config = ()+--    'start' () = do+--        p <- 'System.Environment.lookupEnv' \"PORT\"+--        let config = Config { port = 'Data.Maybe.fromMaybe' 8080 p }+--        'return' config@+--+-- Now that we have the config, we can go ahead and set up the server. It+-- doesn't have to care how the config gets the port. We just have to list the+-- config as a dependency. We'll also need the 'Network.Wai.Application' we+-- want to run on the server.+--+-- Since 'start' shouldn't block forever, we fire up the server on a separate+-- thread. We keep track of the thread ID so that we can shut down the server+-- when we 'stop' by killing the thread.+--+-- @data Server = Server { threadId :: 'Control.Concurrent.ThreadId' }+--instance 'Component' Server where+--    type 'Dependencies' Server = (Config, 'Network.Wai.Application')+--    'start' (config, application) = do+--        tid <- 'Control.Concurrent.forkIO' ('Network.Wai.Handler.Warp.run' (port config) application)+--        let server = Server { threadId = tid }+--        return server+--    'stop' server = do+--        'Control.Concurrent.killThread' (threadId server)@+--+-- With the config and server in hand, we can combine them into a larger+-- system. The system will need the 'Network.Wai.Application' we want to run,+-- but it will handle 'start'ing the config and passing it to the server.+--+-- To 'stop' the system, we 'stop' each 'Component' in the reverse order that+-- we 'start'ed them.+--+-- @data System = System { config :: Config, server :: Server }+--instance 'Component' System where+--    type 'Dependencies' System = ('Network.Wai.Application')+--    'start' (application) = do+--        c <- 'start' ()+--        s <- 'start' (c, application)+--        let system = System { config = c, server = s }+--        'return' system+--    'stop' system = do+--        'stop' (server system)+--        'stop' (config system)@+--+-- To actually run the system, we 'start' it just like the other 'Component's.+-- Once it's started, we want to wait forever until something sends us a+-- @SIGINT@. Then we 'stop' the system.+--+-- @main :: 'IO' ()+--main = do+--    let application _request respond = respond ('Network.Wai.responseLBS' 'Network.HTTP.Types.ok200' [] 'Data.ByteString.Lazy.empty')+--    system <- 'start' (application)+--    sentinel <- 'Control.Concurrent.newEmptyMVar'+--    let handler _signal = 'Control.Concurrent.putMVar' sentinel ()+--    'System.Signal.installHandler' 'System.Signal.sigINT' handler+--    'Control.Concurrent.takeMVar' sentinel+--    'stop' (system :: System)@

@@ -0,0 +1,18 @@+category: Utility+description: Bento manages stateful components.+extra-source-files:+- CHANGELOG.markdown+- package.yaml+- README.markdown+- stack.yaml+ghc-options: -Wall+github: tfausak/bento+library:+  dependencies: base >=4 && <5+  source-dirs: library+license: MIT+license-file: LICENSE.markdown+maintainer: Taylor Fausak+name: bento+synopsis: ! "\U0001F371 Manage stateful components."+version: '0.1.0'

@@ -0,0 +1,3 @@+install-ghc: true+require-stack-version: ! '>=1.0.4'+resolver: nightly-2016-04-16