lib: attrs: add renaming functions

lib/attrs.nix

@@ -1,6 +1,6 @@
 { lib, ... }:
 let
-  inherit (lib) filterAttrs listToAttrs mapAttrs';
+  inherit (lib) filterAttrs listToAttrs mapAttrs' nameValuePair;
 in
 {
   # Filter a generated set of attrs using a predicate function.
@@ -18,4 +18,19 @@ in
   #   (value -> { name = any; value = any; })
   #   attrs
   genAttrs' = values: f: listToAttrs (map f values);
+
+  # Rename each of the attributes in an attribute set using the mapping function
+  #
+  # renameAttrs ::
+  #   (name -> new name)
+  #   attrs
+  renameAttrs = f: mapAttrs' (name: value: nameValuePair (f name) value);
+
+  # Rename each of the attributes in an attribute set using a function which
+  # takes the attribute's name and value as inputs.
+  #
+  # renameAttrs' ::
+  #   (name -> value -> new name)
+  #   attrs
+  renameAttrs' = f: mapAttrs' (name: value: nameValuePair (f name value) value);
 }