inline-java: Call any JVM function from Haskell

The Haskell standard includes a native foreign function interface (FFI). It can be a pain to use and in any case only C support is implemented in GHC. inline-java lets you call any JVM function directly, from Haskell, without the need to write your own foreign import declarations using the FFI. In the style of inline-c for C and inline-r for calling R, inline-java lets you name any function to call inline in your code.

This is an early tech preview, not production ready.

Quasiquotation to make inline calls in Java syntax not yet implemented. But calls in Haskell syntax supported.

Example

Graphical Hello World using Java Swing:

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}

import Data.Text (Text)
import Language.Java

newtype JOptionPane = JOptionPane (J ('Class "javax.swing.JOptionPane"))
instance Coercible JOptionPane ('Class "javax.swing.JOptionPane")

main :: IO ()
main = withJVM [] $ do
    message <- reflect ("Hello World!" :: Text)
    callStatic
      (classOf (undefined :: JOptionPane))
      "showMessageDialog"
      [JObject nullComponent, JObject (upcast message)]
  where
    nullComponent :: J ('Class "java.awt.Component")
    nullComponent = jnull

License

Copyright (c) 2015-2016 EURL Tweag.

All rights reserved.

Sparkle is free software, and may be redistributed under the terms specified in the LICENSE file.

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