Switch to fourmolu

.vscode/settings.json

@@ -1,5 +1,6 @@
 {
   "editor.formatOnType": true,
   "editor.formatOnSave": true,
-  "nixEnvSelector.nixFile": "${workspaceRoot}/shell.nix"
+  "nixEnvSelector.nixFile": "${workspaceRoot}/shell.nix",
+  "haskell.formattingProvider": "fourmolu"
 }

README.md

@@ -1,6 +1,6 @@
 # haskell-template
 
-Haskell project template optimized for a fully reproducible and friendly development environment. Based on [Nix](http://www.srid.ca/haskell-nix) + [Flakes](https://serokell.io/blog/practical-nix-flakes) + VSCode ([HLS](https://github.com/haskell/haskell-language-server)) + [ormolu](https://github.com/tweag/ormolu) autoformatting + [Relude](https://github.com/kowainik/relude#relude) as Prelude.
+Haskell project template optimized for a fully reproducible and friendly development environment. Based on [Nix](http://www.srid.ca/haskell-nix) + [Flakes](https://serokell.io/blog/practical-nix-flakes) + VSCode ([HLS](https://github.com/haskell/haskell-language-server)) + [fourmolu](https://github.com/fourmolu/fourmolu) autoformatting + [Relude](https://github.com/kowainik/relude#relude) as Prelude.
 
 ## Getting Started
 

bin/format

@@ -1,6 +1,6 @@
 #!/usr/bin/env nix-shell 
 #! nix-shell ../shell.nix -i bash
 set -xe
-find src -name \*.hs | xargs ormolu -m inplace -o -XImportQualifiedPost -o -XTypeApplications
+find src -name \*.hs | xargs fourmolu -m inplace -o -XImportQualifiedPost -o -XTypeApplications
 nixpkgs-fmt *.nix
 cabal-fmt -i *.cabal

flake.nix

@@ -39,7 +39,7 @@
                   cabal-install
                   ghcid
                   haskell-language-server
-                  ormolu
+                  fourmolu
                   hlint
                   pkgs.nixpkgs-fmt
                 ]);

fourmolu.yaml

@@ -0,0 +1,8 @@
+indentation: 2
+comma-style: leading
+record-brace-space: true 
+indent-wheres: true
+diff-friendly-import-export: true 
+respectful: true 
+haddock-style: multi-line 
+newlines-between-decls: 1 

src/Main.hs

@@ -2,6 +2,12 @@ module Main where
 
 import Main.Utf8 (withUtf8)
 
+{- |
+ Main entry point.
+
+ The `bin/run` script will invoke this function. See `.ghcid` file to change
+ that.
+-}
 main :: IO ()
 main = do
   -- For withUtf8, see https://serokell.io/blog/haskell-with-utf8