start detangling lib

nodes/1_lib/source/default.nix

@@ -4,32 +4,38 @@
  * for new functions in `./tests.nix`.
  */
 let
-  loadStatic = (folder:
-    {
-      setup        = builtins.fromTOML ( builtins.readFile  "${folder}/static/setup.toml"         );
-      meta         = builtins.fromTOML ( builtins.readFile  "${folder}/static/meta.toml"          );
-    }
-  );
-  static = loadStatic ../.;
-  untangledLib = {
+  foundation = import ./detangled/1_foundation.nix;
+  fixedPoints = import ./detangled/2_fixed-points.nix;
+in
+  let
+    static = foundation.loadStatic ../.;
+    untangledBase = {
       # constants
       sourceTypes  = static.setup.sourceTypes;
       licenses     = static.setup.licenses;
       maintainers  = static.setup.maintainers;
       teams        = static.setup.teams;
       
-    builtins = builtins;# just to be overridable
-    loadStatic = loadStatic;
+      # just to be overridable
+      builtins = builtins;
+      
+      # top level helpers
+      loadStatic = foundation.loadStatic;
+      foldr      = foundation.foldr;
+      
+      # namespaces
+      fixedPoints = fixedPoints;
     };
     
-  inherit (import ./fixed-points.nix { inherit lib; }) makeExtensible;
-
-  lib = makeExtensible (self: let
+    #   
+    # legacy lib
+    #   
+    lib = fixedPoints.makeExtensible (self: let
       callLibs = file: import file { lib = self; };
-  in untangledLib // {
+    in untangledBase // {
+      fixedPoints = fixedPoints;
       # often used, or depending on very little
       trivial = callLibs ./trivial.nix;
-    fixedPoints = callLibs ./fixed-points.nix;
   
       # datatypes
       attrsets = callLibs ./attrsets.nix;
@@ -169,4 +175,4 @@ let
       inherit (self.versions)
         splitVersion;
     });
-in lib
+  in lib

nodes/1_lib/source/detangled/1_foundation.nix

@@ -0,0 +1,22 @@
+# 
+# foundation contains functions that only depend on builtins
+# 
+{
+    loadStatic = (folder:
+        {
+        setup        = builtins.fromTOML ( builtins.readFile  "${folder}/static/setup.toml"         );
+        meta         = builtins.fromTOML ( builtins.readFile  "${folder}/static/meta.toml"          );
+        }
+    );
+    foldr = (
+        op: nul: list:
+          let
+            len = builtins.length list;
+            fold' = n:
+              if n == len
+              then nul
+              else op (builtins.elemAt list n) (fold' (n + 1));
+          in
+            fold' 0
+    );
+}

nodes/1_lib/source/detangled/2_fixed-points.nix

@@ -1,4 +1,6 @@
-{ foldr }:
+let # internal lib dependencies
+  foundation = import ./1_foundation.nix;
+in
   let
     /*
       `fix f` computes the fixed point of the given function `f`. In other words, the return value is `x` in `x = f x`.
@@ -274,7 +276,7 @@
       ```
     */
     composeManyExtensions =
-      foldr (x: y: composeExtensions x y) (final: prev: {});
+      foundation.foldr (x: y: composeExtensions x y) (final: prev: {});
   
     /*
       Same as `makeExtensible` but the name of the extending attribute is