* Move some functions for manipulating meta and name attributes out of

all-packages.nix and into lib.

svn path=/nixpkgs/trunk/; revision=14778

pkgs/lib/default.nix

@@ -6,12 +6,13 @@ let
   attrsets = import ./attrsets.nix;
   sources = import ./sources.nix;
   options = import ./options.nix;
+  meta = import ./meta.nix;
   debug = import ./debug.nix;
   misc = import ./misc.nix;
 
 in
-  { inherit trivial lists strings attrsets sources options debug; }
+  { inherit trivial lists strings attrsets sources options meta debug; }
   # !!! don't include everything at top-level; perhaps only the most
   # commonly used functions.
   // trivial // lists // strings // attrsets // sources // options
-  // debug // misc
+  // meta // debug // misc

pkgs/lib/meta.nix

@@ -0,0 +1,44 @@
+/* Some functions for manipulating meta attributes, as well as the
+   name attribute. */
+
+rec {
+
+
+  /* Add to or override the meta attributes of the given
+     derivation.
+
+     Example:
+       addMetaAttrs {description = "Bla blah";} somePkg
+  */
+  addMetaAttrs = newAttrs: drv:
+    drv // { meta = (if drv ? meta then drv.meta else {}) // newAttrs; };
+
+
+  /* Change the symbolic name of a package for presentation purposes
+     (i.e., so that nix-env users can tell them apart).
+  */
+  setName = name: drv: drv // {inherit name;};
+
+
+  /* Like `setName', but takes the previous name as an argument.
+
+     Example:
+       updateName (oldName: oldName + "-experimental") somePkg
+  */
+  updateName = updater: drv: drv // {name = updater (drv.name);};
+
+
+  /* Append a suffix to the name of a package.  !!! the suffix should
+     really be appended *before* the version, at least most of the
+     time.
+  */
+  appendToName = suffix: updateName (name: "${name}-${suffix}");
+
+
+  /* Decrease the nix-env priority of the package, i.e., other
+     versions/variants of the package will be preferred.
+  */
+  lowPrio = drv: addMetaAttrs { priority = "10"; } drv;
+
+  
+}

pkgs/stdenv/adapters.nix

@@ -107,5 +107,18 @@ rec {
       isStatic = true;
     } // {inherit fetchurl;};
 
-      
-}
+
+  /* Modify a stdenv so that the specified attributes are added to
+     every derivation returned by its mkDerivation function.
+
+     Example:
+       stdenvNoOptimise =
+         addAttrsToDerivation
+           { NIX_CFLAGS_COMPILE = "-O0"; }
+           stdenv;
+  */
+  addAttrsToDerivation = extraAttrs: stdenv: stdenv //
+    { mkDerivation = args: stdenv.mkDerivation (args // extraAttrs); };
+
+
+}