better clustering

default.nix

@@ -16,6 +16,14 @@
     };
   };
 
+  packages = import ./nix/packages {inherit sources;};
+
+  #
+  #
+  # Module graph generation experiment below
+  #
+  #
+
   inherit (nixosConfigurations.vanadium) options;
 
   /*
@@ -27,21 +35,28 @@
   We could draw out file -> option, and cluster each option in a file rectangle
   */
 
+  traceShowId = x: builtins.trace x x;
+
   # Drop those that fail to eval
-  filtered = let
-    drop = path: {
-      inherit path;
-      update = _: {};
-    };
-  in
-    lib.updateManyAttrsByPath
-    (map drop [
-      ["_module"]
-      ["services" "immich"] # caused by option referencing a config value
-      ["services" "nagios"]
-      ["hardware" "nvidia"]
-    ])
-    options;
+  filtered =
+    let
+      drop = path: {
+        inherit path;
+        update = _: {};
+      };
+    in
+      lib.updateManyAttrsByPath
+      (map drop [
+        ["_module"]
+        ["services" "immich"] # caused by option referencing a config value
+        ["services" "nagios"]
+        ["hardware" "nvidia"]
+      ])
+      # options
+    # Use this for a smaller example
+    # {inherit (options.programs) vim less;}
+    { inherit (options) programs; }
+    ;
 
   # Transform each option to its path and call site
   mapped =
@@ -55,7 +70,9 @@
           _type = "result";
           optionPath = v.loc;
           definedBy = definedBy.value;
-          declaredAt = map (x: x.file) v.declarationPositions;
+          declaredAt =
+            # There can only be one
+            (builtins.head v.declarationPositions).file;
         }
     )
     filtered;
@@ -70,13 +87,62 @@
 
   # Run `nix eval --json -f ./. 'asList' | jq >asList.json` to generate
   asList = let
-    untag = map (lib.flip lib.removeAttrs ["_type"]);
+    untag = lib.flip lib.removeAttrs ["_type"];
   in
-    untag (
+    map untag (
       attrValuesRecursiveCond
       (as: !(as ? _type && as._type == "result"))
       mapped
     );
 
-  packages = import ./nix/packages {inherit sources;};
+  # TODO: Improve the granularity by checking the prefix
+  #
+  # Each attribute is a list of nodes in the same file
+  clusterized =
+    builtins.foldl' (
+      acc: elem:
+        acc
+        // {
+          ${elem.declaredAt} =
+            acc.${elem.declaredAt} or []
+            ++ [elem];
+        }
+    )
+    {}
+    asList;
+
+  subgraphs =
+    lib.mapAttrsToList (
+      declaredAt: elems: let
+        entries =
+          lib.concatMapStrings (
+            elem:
+              lib.concatMapStrings (
+                def:
+                  lib.optionalString (
+                    def != elem.declaredAt # remove loops
+                  )
+                  ''
+                    "${def}" -> "${builtins.concatStringsSep "." elem.optionPath}";
+                  ''
+              )
+              elem.definedBy
+          )
+          elems;
+      in ''
+        subgraph "cluster_${declaredAt}" {
+          ${entries}
+          label = "${declaredAt}";
+        }
+      ''
+    )
+    clusterized;
+
+  graphvizOutput = ''
+    digraph {
+      // compound=true;
+      rankdir="TB";
+      ${builtins.concatStringsSep "\n" subgraphs}
+    }
+  '';
 }