Format with fourmolu and ch-hs-imports

default.nix

@@ -1,5 +1,5 @@
 let
-  haskellNix = import (import ./nix/sources.nix)."haskell.nix" {};
+  haskellNix = import (import ./nix/sources.nix)."haskell.nix" { };
 
   nixpkgsSrc = haskellNix.sources.nixpkgs-unstable;
 
@@ -21,7 +21,8 @@ pkgs.haskell-nix.project {
   };
 
   modules = [
-    { packages.rel8 = {
+    {
+      packages.rel8 = {
         preCheck = ''
           export PATH="${pkgs.postgresql}/bin:${"$PATH"}"
         '';

fourmolu.yaml

@@ -0,0 +1,10 @@
+indentation: 2
+comma-style: leading
+import-export-style: diff-friendly
+indent-wheres: true
+record-brace-space: false
+respectful: true
+haddock-style: multi-line
+newlines-between-decls: 2
+fixities: []
+single-constraint-parens: auto

nix/sources.json

@@ -1,4 +1,16 @@
 {
+    "ch-hs-imports": {
+        "branch": "master",
+        "description": null,
+        "homepage": null,
+        "owner": "circuithub",
+        "repo": "ch-hs-imports",
+        "rev": "e3dc32bb2e945334261b6d72dc5c3df490cebc2b",
+        "sha256": "08z7hishpp1j7nxwhap4c0ggwhpm15i5swy91r96jh70ql20j3yi",
+        "type": "tarball",
+        "url": "https://github.com/circuithub/ch-hs-imports/archive/e3dc32bb2e945334261b6d72dc5c3df490cebc2b.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "haskell.nix": {
         "branch": "master",
         "description": "Alternative Haskell Infrastructure for Nixpkgs",

nix/sources.nix

@@ -10,27 +10,27 @@ let
     let
       name' = sanitizeName name + "-src";
     in
-      if spec.builtin or true then
-        builtins_fetchurl { inherit (spec) url sha256; name = name'; }
-      else
-        pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
+    if spec.builtin or true then
+      builtins_fetchurl { inherit (spec) url sha256; name = name'; }
+    else
+      pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
 
   fetch_tarball = pkgs: name: spec:
     let
       name' = sanitizeName name + "-src";
     in
-      if spec.builtin or true then
-        builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
-      else
-        pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
+    if spec.builtin or true then
+      builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
+    else
+      pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
 
   fetch_git = name: spec:
     let
       ref =
         if spec ? ref then spec.ref else
-          if spec ? branch then "refs/heads/${spec.branch}" else
-            if spec ? tag then "refs/tags/${spec.tag}" else
-              abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
+        if spec ? branch then "refs/heads/${spec.branch}" else
+        if spec ? tag then "refs/tags/${spec.tag}" else
+        abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
       submodules = if spec ? submodules then spec.submodules else false;
       submoduleArg =
         let
@@ -44,15 +44,15 @@ let
                   + "but your nix's (${builtins.nixVersion}) builtins.fetchGit "
                   + "does not support them"
                 )
-                {}
-            else {};
+                { }
+            else { };
         in
-          if nixSupportsSubmodules
-          then { inherit submodules; }
-          else emptyArgWithWarning;
+        if nixSupportsSubmodules
+        then { inherit submodules; }
+        else emptyArgWithWarning;
     in
-      builtins.fetchGit
-        ({ url = spec.repo; inherit (spec) rev; inherit ref; } // submoduleArg);
+    builtins.fetchGit
+      ({ url = spec.repo; inherit (spec) rev; inherit ref; } // submoduleArg);
 
   fetch_local = spec: spec.path;
 
@@ -86,16 +86,16 @@ let
       hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
       hasThisAsNixpkgsPath = <nixpkgs> == ./.;
     in
-      if builtins.hasAttr "nixpkgs" sources
-      then sourcesNixpkgs
-      else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then
-        import <nixpkgs> {}
-      else
-        abort
-          ''
-            Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or
-            add a package called "nixpkgs" to your sources.json.
-          '';
+    if builtins.hasAttr "nixpkgs" sources
+    then sourcesNixpkgs
+    else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then
+      import <nixpkgs> { }
+    else
+      abort
+        ''
+          Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or
+          add a package called "nixpkgs" to your sources.json.
+        '';
 
   # The actual fetching function.
   fetch = pkgs: name: spec:
@@ -118,10 +118,10 @@ let
       saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
       ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
     in
-      if ersatz == "" then drv else
-        # this turns the string into an actual Nix path (for both absolute and
-        # relative paths)
-        if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";
+    if ersatz == "" then drv else
+      # this turns the string into an actual Nix path (for both absolute and
+      # relative paths)
+    if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";
 
   # Ports of functions for older nix versions
 
@@ -132,7 +132,7 @@ let
   );
 
   # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
-  range = first: last: if first > last then [] else builtins.genList (n: first + n) (last - first + 1);
+  range = first: last: if first > last then [ ] else builtins.genList (n: first + n) (last - first + 1);
 
   # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
   stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
@@ -143,43 +143,46 @@ let
   concatStrings = builtins.concatStringsSep "";
 
   # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
-  optionalAttrs = cond: as: if cond then as else {};
+  optionalAttrs = cond: as: if cond then as else { };
 
   # fetchTarball version that is compatible between all the versions of Nix
   builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
     let
       inherit (builtins) lessThan nixVersion fetchTarball;
     in
-      if lessThan nixVersion "1.12" then
-        fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-      else
-        fetchTarball attrs;
+    if lessThan nixVersion "1.12" then
+      fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
+    else
+      fetchTarball attrs;
 
   # fetchurl version that is compatible between all the versions of Nix
   builtins_fetchurl = { url, name ? null, sha256 }@attrs:
     let
       inherit (builtins) lessThan nixVersion fetchurl;
     in
-      if lessThan nixVersion "1.12" then
-        fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-      else
-        fetchurl attrs;
+    if lessThan nixVersion "1.12" then
+      fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
+    else
+      fetchurl attrs;
 
   # Create the final "sources" from the config
   mkSources = config:
-    mapAttrs (
-      name: spec:
-        if builtins.hasAttr "outPath" spec
-        then abort
-          "The values in sources.json should not have an 'outPath' attribute"
-        else
-          spec // { outPath = replace name (fetch config.pkgs name spec); }
-    ) config.sources;
+    mapAttrs
+      (
+        name: spec:
+          if builtins.hasAttr "outPath" spec
+          then
+            abort
+              "The values in sources.json should not have an 'outPath' attribute"
+          else
+            spec // { outPath = replace name (fetch config.pkgs name spec); }
+      )
+      config.sources;
 
   # The "config" used by the fetchers
   mkConfig =
     { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
-    , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
+    , sources ? if isNull sourcesFile then { } else builtins.fromJSON (builtins.readFile sourcesFile)
     , system ? builtins.currentSystem
     , pkgs ? mkPkgs sources system
     }: rec {
@@ -191,4 +194,4 @@ let
     };
 
 in
-mkSources (mkConfig {}) // { __functor = _: settings: mkSources (mkConfig settings); }
+mkSources (mkConfig { }) // { __functor = _: settings: mkSources (mkConfig settings); }