Update to GHC 8.8.4 and switch to haskell.nix for nix builds

.gitignore

@@ -1,3 +1,4 @@
 .stack-work/
 *~
 .envrc
+result

default.nix

@@ -1,2 +1,21 @@
-{ pkgs ? import <nixpkgs> {}}:
-pkgs.haskell.packages.ghc865.callPackage ./prefmanager.nix { }
+{ # Fetch the latest haskell.nix and import its default.nix
+  haskellNix ? import (import nix/sources.nix)."haskell.nix" {}
+
+# haskell.nix provides access to the nixpkgs pins which are used by our CI,
+# hence you will be more likely to get cache hits when using these.
+# But you can also just use your own, e.g. '<nixpkgs>'.
+, nixpkgsSrc ? haskellNix.sources.nixpkgs-2009
+
+# haskell.nix provides some arguments to be passed to nixpkgs, including some
+# patches and also the haskell.nix functionality itself as an overlay.
+, nixpkgsArgs ? haskellNix.nixpkgsArgs
+
+# import nixpkgs with overlays
+, pkgs ? import nixpkgsSrc nixpkgsArgs
+}: pkgs.haskell-nix.project {
+  # 'cleanGit' cleans a source directory based on the files known by git
+  src = pkgs.haskell-nix.haskellLib.cleanGit {
+    name = "prefmanager";
+    src = ./.;
+  };
+}

nix/sources.json

@@ -1,14 +1,26 @@
 {
+    "haskell.nix": {
+        "branch": "master",
+        "description": "Alternative Haskell Infrastructure for Nixpkgs",
+        "homepage": "https://input-output-hk.github.io/haskell.nix",
+        "owner": "input-output-hk",
+        "repo": "haskell.nix",
+        "rev": "6134e66e1decf2155ba500dd5de00adb06e2cdee",
+        "sha256": "1w6mvlblszl3spx46m3a4bz13xah18gkznzpk0fzkmfizasv7lgi",
+        "type": "tarball",
+        "url": "https://github.com/input-output-hk/haskell.nix/archive/6134e66e1decf2155ba500dd5de00adb06e2cdee.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "nixpkgs": {
         "branch": "nixpkgs-unstable",
         "description": "Nix Packages collection",
         "homepage": null,
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "fcd447bfed52b95d8e63314c0e8ab3c01649dfdc",
-        "sha256": "013gvrhxvn3qpfjf0vjb3nymw8h4zmdgnvz46dvfp8cgvv0603s4",
+        "rev": "502845c3e31ef3de0e424f3fcb09217df2ce6df6",
+        "sha256": "0fcqpsy6y7dgn0y0wgpa56gsg0b0p8avlpjrd79fp4mp9bl18nda",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/fcd447bfed52b95d8e63314c0e8ab3c01649dfdc.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/502845c3e31ef3de0e424f3fcb09217df2ce6df6.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }

nix/sources.nix

@@ -6,25 +6,33 @@ let
   # The fetchers. fetch_<type> fetches specs of type <type>.
   #
 
-  fetch_file = pkgs: spec:
+  fetch_file = pkgs: name: spec:
+    let
+      name' = sanitizeName name + "-src";
+    in
       if spec.builtin or true then
-      builtins_fetchurl { inherit (spec) url sha256; }
+        builtins_fetchurl { inherit (spec) url sha256; name = name'; }
       else
-      pkgs.fetchurl { inherit (spec) url sha256; };
+        pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
 
   fetch_tarball = pkgs: name: spec:
     let
-      ok = str: ! builtins.isNull (builtins.match "[a-zA-Z0-9+-._?=]" str);
-      # sanitize the name, though nix will still fail if name starts with period
-      name' = stringAsChars (x: if ! ok x then "-" else x) "${name}-src";
+      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; };
 
-  fetch_git = spec:
-    builtins.fetchGit { url = spec.repo; inherit (spec) rev ref; };
+  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`!";
+    in
+      builtins.fetchGit { url = spec.repo; inherit (spec) rev; inherit ref; };
 
   fetch_local = spec: spec.path;
 
@@ -40,11 +48,21 @@ let
   # Various helpers
   #
 
+  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
+  sanitizeName = name:
+    (
+      concatMapStrings (s: if builtins.isList s then "-" else s)
+        (
+          builtins.split "[^[:alnum:]+._?=-]+"
+            ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)
+        )
+    );
+
   # The set of packages used when specs are fetched using non-builtins.
-  mkPkgs = sources:
+  mkPkgs = sources: system:
     let
       sourcesNixpkgs =
-        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) {};
+        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };
       hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
       hasThisAsNixpkgsPath = <nixpkgs> == ./.;
     in
@@ -64,9 +82,9 @@ let
 
     if ! builtins.hasAttr "type" spec then
       abort "ERROR: niv spec ${name} does not have a 'type' attribute"
-    else if spec.type == "file" then fetch_file pkgs spec
+    else if spec.type == "file" then fetch_file pkgs name spec
     else if spec.type == "tarball" then fetch_tarball pkgs name spec
-    else if spec.type == "git" then fetch_git spec
+    else if spec.type == "git" then fetch_git name spec
     else if spec.type == "local" then fetch_local spec
     else if spec.type == "builtin-tarball" then fetch_builtin-tarball name
     else if spec.type == "builtin-url" then fetch_builtin-url name
@@ -98,25 +116,29 @@ let
 
   # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
   stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
+  concatMapStrings = f: list: concatStrings (map f list);
   concatStrings = builtins.concatStringsSep "";
 
+  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
+  optionalAttrs = cond: as: if cond then as else {};
+
   # fetchTarball version that is compatible between all the versions of Nix
-  builtins_fetchTarball = { url, name, sha256 }@attrs:
+  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
     let
       inherit (builtins) lessThan nixVersion fetchTarball;
     in
       if lessThan nixVersion "1.12" then
-        fetchTarball { inherit name url; }
+        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, sha256 }@attrs:
+  builtins_fetchurl = { url, name ? null, sha256 }@attrs:
     let
       inherit (builtins) lessThan nixVersion fetchurl;
     in
       if lessThan nixVersion "1.12" then
-        fetchurl { inherit url; }
+        fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
       else
         fetchurl attrs;
 
@@ -135,7 +157,8 @@ let
   mkConfig =
     { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
     , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
-    , pkgs ? mkPkgs sources
+    , system ? builtins.currentSystem
+    , pkgs ? mkPkgs sources system
     }: rec {
       # The sources, i.e. the attribute set of spec name to spec
       inherit sources;

prefmanager.nix

@@ -1,27 +0,0 @@
-{ mkDerivation, async, base, containers, diffmap, hpack, hxt
-, optparse-applicative, plist, pretty-show, process, stdenv
-}:
-mkDerivation {
-  pname = "prefmanager";
-  version = "0.1.0.0";
-  src = ./.;
-  isLibrary = true;
-  isExecutable = true;
-  libraryHaskellDepends = [
-    async base containers diffmap hxt optparse-applicative plist
-    pretty-show process
-  ];
-  libraryToolDepends = [ hpack ];
-  executableHaskellDepends = [
-    async base containers diffmap hxt optparse-applicative plist
-    pretty-show process
-  ];
-  testHaskellDepends = [
-    async base containers diffmap hxt optparse-applicative plist
-    pretty-show process
-  ];
-  prePatch = "hpack";
-  homepage = "https://github.com/malob/prefmanager#readme";
-  description = "A CLI utility for managing macOS preferences";
-  license = stdenv.lib.licenses.bsd3;
-}

shell.nix

@@ -3,7 +3,7 @@
 with pkgs;
 mkShell {
   buildInputs = [
-    haskell.packages.ghc865.haskell-language-server
+    haskell.packages.ghc884.haskell-language-server
     cabal2nix
     stack
     niv

stack.yaml

@@ -1,9 +1,14 @@
-# GHC 8.6.5
-resolver: lts-14.21
+# GHC 8.8.4
+resolver: lts-16.17
 
 packages:
 - .
 
 extra-deps:
-- plist-0.0.6
 - diffmap-0.1.0.0
+# Use fork of plist package that supports MonadFail
+- github: malob/plist
+  commit: 4103af23b364c101e44da115367800a2f90cc7c3
+  # nix-sha256: 126c52498c89gd015p40hg671dg58j8xq8ggdqfywnkw2c8cjxxr
+
+allow-newer: true

stack.yaml.lock

@@ -4,13 +4,6 @@
 #   https://docs.haskellstack.org/en/stable/lock_files
 
 packages:
-- completed:
-    hackage: plist-0.0.6@sha256:2c25ca88b99581ef0fe44f9d7dc636f24026603624be9c43631d2b03752886b3,1702
-    pantry-tree:
-      size: 463
-      sha256: 92af2902f8f62e95ec57a5671267e2882cbe5092eaa36fce82172bbdb768cd7f
-  original:
-    hackage: plist-0.0.6
 - completed:
     hackage: diffmap-0.1.0.0@sha256:27ea8c315b5dbfb243b2c3b61eab2164534e1d02887a05392dda65995cd36c3e,727
     pantry-tree:
@@ -18,9 +11,20 @@ packages:
       sha256: 76ea9b9ad91d113addadf58cb19e289e84347ab667aa5c7feed0a1ccfa4ed613
   original:
     hackage: diffmap-0.1.0.0
+- completed:
+    size: 4384
+    url: https://github.com/malob/plist/archive/4103af23b364c101e44da115367800a2f90cc7c3.tar.gz
+    name: plist
+    version: 0.0.6
+    sha256: fcc0a7f0dcdb81d379329f5be2af2a566431ed66cbe37e9a1f4101e49b80d4c6
+    pantry-tree:
+      size: 512
+      sha256: 0ede20c4e670e906987a171721f05c3a3337ed936d5ff84e6fe77c13e2c7fbdf
+  original:
+    url: https://github.com/malob/plist/archive/4103af23b364c101e44da115367800a2f90cc7c3.tar.gz
 snapshots:
 - completed:
-    size: 524162
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/14/21.yaml
-    sha256: 9a55dd75853718f2bbbe951872b36a3b7802fcd71796e0f25b8664f24e34c666
-  original: lts-14.21
+    size: 532386
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/16/17.yaml
+    sha256: d3ee1ae797cf63189c95cf27f00700304946c5cb3c1e6a82001cd6584a221e1b
+  original: lts-16.17