Split out MIT code

closure.nix

@@ -0,0 +1,86 @@
+# MIT license, see below
+#
+# These are helper functions for determining buildtime closures.
+# Sources:
+# - https://github.com/NixOS/bundlers/blob/00762a03a3d862a2ca6272a21fdc50bda5d36c42/report/default.nix
+# - https://nmattia.com/posts/2019-10-08-runtime-dependencies.html
+
+{ pkgs, ... }:
+let
+  inherit (builtins)
+    genericClosure
+    hasAttr
+    map
+    ;
+  inherit (pkgs.lib)
+    concatLists
+    concatMap
+    filter
+    isDerivation
+    isList
+    mapAttrsToList
+    ;
+
+  # Map a drv or list of drvs to a list of output drvs
+  drvOutputs = drv:
+    if isList drv then
+      concatMap drvOutputs drv
+    else if hasAttr "outputs" drv then
+      map (out: drv.${out}) drv.outputs
+    else [ drv ];
+
+  # Map a drv or list of drvs to the outputs of referenced derivations
+  drvDeps =
+    drv:
+    if isList drv then
+      concatMap drvDeps drv
+    else
+      mapAttrsToList (
+        k: v:
+        if isDerivation v then
+          (drvOutputs v)
+        else if isList v then
+          concatMap drvOutputs (filter isDerivation v)
+        else
+          [ ]
+      ) drv;
+in
+{
+  # Get the reference closure of a derivation or list of derivations
+  # This may miss dependencies that are only in-closure from string context
+  drvClosure =
+    let
+      wrap = drv: {
+        key = drv.outPath;
+        inherit drv;
+      };
+    in
+    drv:
+    map (obj: obj.drv) (genericClosure {
+      startSet = map wrap (drvOutputs drv);
+      operator = obj: map wrap (concatLists (drvDeps obj.drv.drvAttrs));
+    });
+}
+
+# MIT License
+#
+# Copyright (c) 2021 Nicolas Mattia, Tim Van Baak
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#

flake.nix

@@ -4,7 +4,7 @@
     let
       system = "x86_64-linux";
       pkgs = nixpkgs.legacyPackages.${system};
-      lib = import ./default.nix { inherit pkgs; };
+      lib = import ./lib.nix { inherit pkgs; };
       inherit (lib)
         allMaintainers
         expandInput

lib.nix

@@ -20,47 +20,9 @@ let
     isList
     mapAttrsToList
     ;
+  inherit (import ./closure.nix { inherit pkgs; }) drvClosure;
 in
 rec {
-  # Map a drv or list of drvs to a list of output drvs
-  drvOutputs = drv:
-    if isList drv then
-      concatMap drvOutputs drv
-    else if hasAttr "outputs" drv then
-      map (out: drv.${out}) drv.outputs
-    else [ drv ];
-
-  # Map a drv or list of drvs to the outputs of referenced derivations
-  drvDeps =
-    drv:
-    if isList drv then
-      concatMap drvDeps drv
-    else
-      mapAttrsToList (
-        k: v:
-        if isDerivation v then
-          (drvOutputs v)
-        else if isList v then
-          concatMap drvOutputs (filter isDerivation v)
-        else
-          [ ]
-      ) drv;
-
-  # Get the reference closure of a derivation or list of derivations
-  # This may miss dependencies that are only in-closure from string context
-  drvClosure =
-    let
-      wrap = drv: {
-        key = drv.outPath;
-        inherit drv;
-      };
-    in
-    drv:
-    map (obj: obj.drv) (genericClosure {
-      startSet = map wrap (drvOutputs drv);
-      operator = obj: map wrap (concatLists (drvDeps obj.drv.drvAttrs));
-    });
-
   maintainable = drv: hasAttr "meta" drv && hasAttr "maintainers" drv.meta;
   drvMaintainers = drv: if maintainable drv then drv.meta.maintainers else [ ];