From de5be50b2d5a67dd1f969fc8f451ea7a74debac7 Mon Sep 17 00:00:00 2001
From: Michael Raskin <7c6f434c@mail.ru>
Date: Thu, 13 Sep 2012 13:59:23 +0400
Subject: [PATCH] Adding a function capable of extracting the name with version
 out of url/file path

---
 pkgs/lib/strings.nix | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/pkgs/lib/strings.nix b/pkgs/lib/strings.nix
index fb2752d97c19..4bd7a5bebde3 100644
--- a/pkgs/lib/strings.nix
+++ b/pkgs/lib/strings.nix
@@ -155,4 +155,14 @@ rec {
   # Return true iff string v1 denotes a version older than v2.
   versionOlder = v1: v2: builtins.compareVersions v2 v1 == 1;
 
+  # Extract name with version from URL. Ask for separator which is 
+  # supposed to start extension
+  nameFromURL = url: sep: let
+    components = splitString "/" url;
+    filename = lib.last components;
+    name = builtins.head (splitString sep filename);
+  in
+  assert ! eqStrings name filename;
+  name;
+
 }