populate: layer populate below krops

populate is a program of its own, with a Nix library, in pkgs/populate,
which krops uses, and which doesn't use krops:

- default.nix builds the program, with nix-build there or callPackage,
  as pkgs.populate-unwrapped.
- lib is populate's Nix library: the types of sources and the POSIX
  types they use, evalSource, flakeFollows, hasGeneratedFlake, and
  derivesFlake, taking nixpkgs' lib.  krops' lib takes them from there,
  so it provides them as before, and so does lib/types.

pkgs.populate, the function from populate's arguments to a script
running the program, is krops' own, in pkgs/krops/populate.nix, with
checks.nix next to it.  It takes the program as populate-unwrapped,
which callPackage passes from the overlay; the flake, whose nixpkgs
lacks it, passes its own.

1 files changed, 5 insertions, 55 deletions

diff --git a/lib/default.nix b/lib/default.nix
index 0ffdff2..4eb6438 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -4,60 +4,8 @@ let {
 
   lib = nixpkgs.lib // builtins // {
 
-    evalSource = let
-      eval = source: lib.evalModules {
-        modules = lib.singleton {
-          _file = toString ./.;
-          imports = map (source: { inherit source; }) (lib.toList source);
-          options.source = lib.mkOption {
-            default = {};
-            type = lib.types.attrsOf lib.types.source;
-          };
-        };
-      };
-      sanitize = x: lib.getAttr (lib.typeOf x) {
-        bool = x;
-        list = map sanitize x;
-        set = lib.mapAttrs
-                (lib.const sanitize)
-                (lib.filterAttrs
-                  (name: value: name != "_module" && value != null) x);
-        string = x;
-      };
-    in
-      # This function's return value can be used as pkgs.populate input.
-      source: sanitize (eval source).config.source;
-
-    # Inputs a source draws from other sources, as list of attribute sets like
-    # { path = [ "stockholm" "nixpkgs" ]; source = "nixpkgs"; }.
-    flakeFollows = source: let
-      flatten = prefix: inputs: lib.concatLists (lib.mapAttrsToList
-        (name: input:
-          lib.optional (input.follows or null != null) {
-            path = prefix ++ [ name ];
-            source = input.follows;
-          } ++
-          flatten (prefix ++ [ name ]) (input.inputs or {}))
-        inputs);
-    in
-      flatten [] (source.${source.type}.inputs or {});
-
-    # Tells whether a source's inputs get drawn from other sources by a
-    # generated flake in .populate/flakes, instead of by rewriting the lock
-    # file of the flake in the source.  Symlink sources point at other
-    # sources, whose lock files stay as they are.
-    hasGeneratedFlake = source:
-      lib.flakeFollows source != [] &&
-      (source.type == "symlink" || !(source.${source.type}.rewriteLock or true));
-
-    # Tells whether a flake or flake-input source gets delivered as a copy,
-    # which gets patched, gets its lock file rewritten, or is materialized.
-    derivesFlake = source: let
-      source' = source.${source.type};
-    in
-      lib.elem source.type [ "flake" "flake-input" ] &&
-      (source'.materialize or false || source'.patches or [] != [] ||
-       (source'.rewriteLock or true && lib.flakeFollows source != []));
+    # What populate's Nix library defines.
+    inherit (populate.lib) evalSource flakeFollows hasGeneratedFlake derivesFlake;
 
     maybeHostName = default: let
       # We're parsing /etc/hostname here because reading
@@ -153,9 +101,11 @@ let {
     test = re: x: lib.isString x && lib.testString re x;
     testString = re: x: lib.match re x != null;
 
-    types = nixpkgs.lib.types // import ./types { lib = body; };
+    types = nixpkgs.lib.types // populate.lib.types;
   };
 
   nixpkgs.lib = import <nixpkgs/lib>;
 
+  populate.lib = import ../pkgs/populate/lib { lib = nixpkgs.lib; };
+
 }