harpocrates / inline-rust

Use snippets of Rust inline in your Haskell programs

inline-rust

This package allows you to write Rust inline in your Haskell source using quasiquotes. Here is a short example. For more examples, check out the examples folder.

-- examples/Hello.hs
{-# LANGUAGE TemplateHaskell, QuasiQuotes #-}

module Main where

import Language.Rust.Inline
import Data.Int

extendContext basic
setCrateRoot []

main = do
  putStrLn "Haskell: Hello. Enter a number:"
  x <- readLn
  y <- [rustIO| i32 {
    let x = $(x: i32);
    println!("Rust: Your number is {}", x);
    x + 1
  } |]
  putStrLn $ "Haskell: Rust says number plus 1 is " ++ show y

If you want to use this with GHCi, make sure to pass in -fobject-code.

Building

This currently depends on a GHC feature that will be available in GHC 8.6. Until then, you'll have to build GHC yourself or get a binary. For the latter, you can install one of GHC's nightly builds.

$ curl https://ghc-artifacts.s3.amazonaws.com/nightly/validate-x86_64-darwin/latest/bindist.tar.xz | tar xz
$ cd ghc-*
$ ./configure && make install

With that installed, something like the following should work

$ cabal new-build -w /usr/local/bin/ghc-8.5.20180423
$ cabal new-test  -w /usr/local/bin/ghc-8.5.20180423

Running the examples is only a matter of threading through the right package databases. With a new enough Cabal, new-exec does this for you.

$ cabal new-exec -w /usr/local/bin/ghc-8.5.20180423 ghc -- -threaded -package inline-rust examples/Hello.hs
[1 of 1] Compiling Main             ( examples/Hello.hs, examples/Hello.o )
Linking examples/Hello ...
$ ./examples/Hello
Haskell: Hello. Enter a number:
42
Rust: Your number is 42
Haskell: Rust says number plus 1 is 43

Bugs

Please report bugs to the issue tracker