fn: Improve readability of fn.lst function arguments.

fn.nix

@@ -32,31 +32,33 @@ rec {
   */
   cwd = builtins.getEnv "PWD";
 
-  # lst (string PATH) (string FILETYPE) (bool RETURNFULLPATH)
+  /**
+    lst (string PATH) (string FILETYPE) (bool RETURNFULLPATH)
+  */
   lst =
     {
-      p ? cwd,
-      t ? "regular",
-      b ? false,
+      path ? cwd,
+      fileType ? "regular",
+      fullPath ? false,
     }:
-    (lists.forEach (attrNames (filterAttrs (n: v: v == t) (readDir p))) (
-      v: ((optionalString b "${p}/") + v)
+    assert (builtins.isString path) || throw "Argument path needs to be a string.";
+    (lists.forEach (attrNames (filterAttrs (n: v: v == fileType) (readDir path))) (
+      v: ((optionalString fullPath "${path}/") + v)
     ));
-  lsf = p: (lst { inherit p; });
+  lsf = path: (lst { inherit path; });
   lsd =
-    p:
+    path:
     (lst {
-      inherit p;
-      t = "directory";
-      b = true;
+      inherit path;
+      fileType = "directory";
+      fullPath = true;
     });
   lsfRec =
-    p: b:
+    path: fullPath:
     flatten (
-      (map (np: lsfRec np b) (lsd p))
+      (map (nextPath: lsfRec nextPath fullPath) (lsd path))
       ++ (lst {
-        inherit p;
-        inherit b;
+        inherit path fullPath;
       })
     );
   hasAttrs = aList: d: (map (a: (ifelse (isList a) (hasAttrByPath a d) (hasAttr a d))) aList);