garnet/exe/Main.hs

module Main (main) where

import Data.Vector.Storable qualified as V
import GarnetRs.Wrapped
import System.IO

main :: IO ()
main = do
    hello "Haskell"
    helloStruct T{a = True, b = 42}
    helloStruct T{a = False, b = maxBound}
    helloEnum E1
    helloEnum E3
    helloShape $ Circle 3.14
    helloShape $ Rectangle 10.0 5.0
    putStrLn $ "3 + 4 = " <> show (add 3 4)
    putStrLn $ "Tree sum: " <> show (sumTree (Fork (Fork (Leaf 1) (Fork (Leaf 2) (Leaf 3))) (Leaf 4)))
    putStrLn $ "Slice sum: " <> show (sumSlice $ V.fromList [0 .. 5])
    putStrLn "Nothing." >> printOptional Nothing
    putStr "Something: " >> hFlush stdout >> printOptional (Just 67)
Initial 2026-02-17 14:57:34 +00:00			`module Main (main) where`

Add vector/slice example 2026-03-25 01:09:10 +00:00			`import Data.Vector.Storable qualified as V`
Create manual high level wrapper 2026-02-19 13:44:16 +00:00			`import GarnetRs.Wrapped`
Add maybe/optional example 2026-03-25 01:57:56 +00:00			`import System.IO`
Call Rust from Haskell with `cargo-cabal` and `hs-bindgen` See https://sraka.xyz/posts/hs-bindgen-introduction.html. For now, this is a shell-based workflow, rather than using Nix to build everything, i.e. `nix develop` works but `nix build` doesn't. And `cargo build` has to be called manually to create the C library, rather than `cabal` being clever enough to invoke it itself. We ran `cargo cabal init` from the `rust` directory (`nix shell github:yvan-sraka/cargo-cabal`), which generated `hsbindgen.toml` (which we use), and `Setup.lhs` (which just added `extra-lib-dirs`, and with the wrong paths, so we dspecify those statically instead in `garnet.cabal`). We also follow its advice to use `staticlib`. Also, after we ran the first `cargo build` (requiring a `mkdir rust/src` before it would run), we took the generated the Haskell file, and moved the main contents in to `Main.hs` manually. 2026-02-18 15:49:08 +00:00
Initial 2026-02-17 14:57:34 +00:00			`main :: IO ()`
Expose explicit C interface We drop the tools specifically designed for Haskell and Rust together, in favour of general tools for using each with C. Namely, we use Mozilla's `cbindgen` for generating header files from the Rust source, and Well-Typed's new `hs-bindgen` tool for generating Haskell from those header files. The Rust code here is essentially the result of expanding the old macro, then inlining and renaming internals. The most important thing here is that we're now relying solely on robust well-maintained tools. 2026-02-19 11:08:20 +00:00			`main = do`
Create manual high level wrapper 2026-02-19 13:44:16 +00:00			`hello "Haskell"`
			`helloStruct T{a = True, b = 42}`
Call struct function with different arguments 2026-02-19 14:09:30 +00:00			`helloStruct T{a = False, b = maxBound}`
basic enum example 2026-04-14 00:42:17 +01:00			`helloEnum E1`
			`helloEnum E3`
Create manual high level wrapper 2026-02-19 13:44:16 +00:00			`helloShape $ Circle 3.14`
			`helloShape $ Rectangle 10.0 5.0`
Mark pure function 2026-02-19 15:56:55 +00:00			`putStrLn $ "3 + 4 = " <> show (add 3 4)`
Avoid IO for tree sum 2026-02-19 21:35:35 +00:00			`putStrLn $ "Tree sum: " <> show (sumTree (Fork (Fork (Leaf 1) (Fork (Leaf 2) (Leaf 3))) (Leaf 4)))`
Add vector/slice example 2026-03-25 01:09:10 +00:00			`putStrLn $ "Slice sum: " <> show (sumSlice $ V.fromList [0 .. 5])`
Add maybe/optional example 2026-03-25 01:57:56 +00:00			`putStrLn "Nothing." >> printOptional Nothing`
			`putStr "Something: " >> hFlush stdout >> printOptional (Just 67)`