buildNimPackage: refactor to use overlay-style overrideAttrs

Make buildNimPackage cleaner and more efficient. Also encourage
the use of a "buildNimPackage (finalAttrs: {…})" pattern.

doc/languages-frameworks/nim.section.md

@@ -15,32 +15,23 @@ case of packages not containing exported library code the attribute
 The following example shows a Nim program that depends only on Nim libraries:
 
 ```nix
-{ lib, nimPackages, fetchurl }:
-
-nimPackages.buildNimPackage rec {
-  pname = "hottext";
-  version = "1.4";
+{ lib, nimPackages, fetchFromGitHub }:
 
+nimPackages.buildNimPackage (finalAttrs: {
+  pname = "ttop";
+  version = "1.0.1";
   nimBinOnly = true;
 
-  src = fetchurl {
-    url = "https://git.sr.ht/~ehmry/hottext/archive/v${version}.tar.gz";
-    hash = "sha256-hIUofi81zowSMbt1lUsxCnVzfJGN3FEiTtN8CEFpwzY=";
+  src = fetchFromGitHub {
+    owner = "inv2004";
+    repo = "ttop";
+    rev = "v${finalAttrs.version}";
+    hash = "sha256-x4Uczksh6p3XX/IMrOFtBxIleVHdAPX9e8n32VAUTC4=";
   };
 
-  buildInputs = with nimPackages; [
-    bumpy
-    chroma
-    flatty
-    nimsimd
-    pixie
-    sdl2
-    typography
-    vmath
-    zippy
-  ];
-}
+  buildInputs = with nimPackages; [ asciigraph illwill parsetoml zippy ];
 
+})
 ```
 
 ## Nim library packages in Nixpkgs {#nim-library-packages-in-nixpkgs}
@@ -60,15 +51,16 @@ non-Nim package:
 ```nix
 { lib, buildNimPackage, fetchNimble, SDL2 }:
 
-buildNimPackage rec {
+buildNimPackage (finalAttrs: {
   pname = "sdl2";
   version = "2.0.4";
   src = fetchNimble {
-    inherit pname version;
-    hash = "sha256-qDtVSnf+7rTq36WAxgsUZ8XoUk4sKwHyt8EJcY5WP+o=";
+    inherit (finalAttrs) pname version;
+    hash = "sha256-Vtcj8goI4zZPQs2TbFoBFlcR5UqDtOldaXSH/+/xULk=";
   };
   propagatedBuildInputs = [ SDL2 ];
-}
+  doCheck = true;
+})
 ```
 
 ## `buildNimPackage` parameters {#buildnimpackage-parameters}

pkgs/development/nim-packages/build-nim-package/default.nix

@@ -1,45 +1,44 @@
 { lib, stdenv, nim, nim_builder }:
+pkgArgs:
 
-{ strictDeps ? true, depsBuildBuild ? [ ], nativeBuildInputs ? [ ]
-, configurePhase ? null, buildPhase ? null, checkPhase ? null
-, installPhase ? null, enableParallelBuilding ? true, meta ? { }, ... }@attrs:
-
-stdenv.mkDerivation (attrs // {
-  inherit strictDeps enableParallelBuilding;
-  depsBuildBuild = [ nim_builder ] ++ depsBuildBuild;
-  nativeBuildInputs = [ nim ] ++ nativeBuildInputs;
-
-  configurePhase = if (configurePhase == null) then ''
-    runHook preConfigure
-    export NIX_NIM_BUILD_INPUTS=''${pkgsHostTarget[@]} $NIX_NIM_BUILD_INPUTS
-    nim_builder --phase:configure
-    runHook postConfigure
-  '' else
-    configurePhase;
-
-  buildPhase = if (buildPhase == null) then ''
-    runHook preBuild
-    nim_builder --phase:build
-    runHook postBuild
-  '' else
-    buildPhase;
-
-  checkPhase = if (checkPhase == null) then ''
-    runHook preCheck
-    nim_builder --phase:check
-    runHook postCheck
-  '' else
-    checkPhase;
-
-  installPhase = if (installPhase == null) then ''
-    runHook preInstall
-    nim_builder --phase:install
-    runHook postInstall
-  '' else
-    installPhase;
-
-  meta = meta // {
-    platforms = meta.platforms or nim.meta.platforms;
-    maintainers = (meta.maintainers or [ ]) ++ [ lib.maintainers.ehmry ];
+let
+  baseAttrs = {
+    strictDeps = true;
+    enableParallelBuilding = true;
+    configurePhase = ''
+      runHook preConfigure
+      export NIX_NIM_BUILD_INPUTS=''${pkgsHostTarget[@]} $NIX_NIM_BUILD_INPUTS
+      nim_builder --phase:configure
+      runHook postConfigure
+    '';
+    buildPhase = ''
+      runHook preBuild
+      nim_builder --phase:build
+      runHook postBuild
+    '';
+    checkPhase = ''
+      runHook preCheck
+      nim_builder --phase:check
+      runHook postCheck
+    '';
+    installPhase = ''
+      runHook preInstall
+      nim_builder --phase:install
+      runHook postInstall
+    '';
+    meta = { inherit (nim.meta) maintainers platforms; };
   };
-})
+
+  inputsOverride =
+    { depsBuildBuild ? [ ], nativeBuildInputs ? [ ], meta, ... }: {
+      depsBuildBuild = [ nim_builder ] ++ depsBuildBuild;
+      nativeBuildInputs = [ nim ] ++ nativeBuildInputs;
+    };
+
+  composition = finalAttrs:
+    let
+      asFunc = x: if builtins.isFunction x then x else (_: x);
+      prev = baseAttrs // (asFunc ((asFunc pkgArgs) finalAttrs)) baseAttrs;
+    in prev // inputsOverride prev;
+
+in stdenv.mkDerivation composition

pkgs/development/nim-packages/sdl2/default.nix

@@ -1,10 +1,10 @@
 { lib, buildNimPackage, fetchNimble, SDL2 }:
 
-buildNimPackage rec {
+buildNimPackage (finalAttrs: {
   pname = "sdl2";
   version = "2.0.4";
   src = fetchNimble {
-    inherit pname version;
+    inherit (finalAttrs) pname version;
     hash = "sha256-Vtcj8goI4zZPQs2TbFoBFlcR5UqDtOldaXSH/+/xULk=";
   };
   propagatedBuildInputs = [ SDL2 ];
@@ -14,4 +14,4 @@ buildNimPackage rec {
     platforms = lib.platforms.linux; # Problems with Darwin.
     license = [ lib.licenses.mit ];
   };
-}
+})

pkgs/tools/system/ttop/default.nix

@@ -1,6 +1,6 @@
 { lib, nimPackages, fetchFromGitHub }:
 
-nimPackages.buildNimPackage rec {
+nimPackages.buildNimPackage (finalAttrs: {
   pname = "ttop";
   version = "1.0.1";
   nimBinOnly = true;
@@ -8,17 +8,17 @@ nimPackages.buildNimPackage rec {
   src = fetchFromGitHub {
     owner = "inv2004";
     repo = "ttop";
-    rev = "v${version}";
+    rev = "v${finalAttrs.version}";
     hash = "sha256-x4Uczksh6p3XX/IMrOFtBxIleVHdAPX9e8n32VAUTC4=";
   };
 
   buildInputs = with nimPackages; [ asciigraph illwill parsetoml zippy ];
 
   meta = with lib;
-    src.meta // {
+    finalAttrs.src.meta // {
       description = "Top-like system monitoring tool";
       license = licenses.mit;
       platforms = platforms.linux;
       maintainers = with maintainers; [ sikmir ];
     };
-}
+})