anchor.diff:  
     meta = with stdenv.lib; {
       description = "J programming language, an ASCII-based APL successor";
  -    maintainers = with maintainers; [ raskin ];
  -    platforms = platforms.linux;
  +    maintainers = with maintainers; [ raskin synthetica ];
  +    platforms = with platforms; linux ++ darwin;
       license = licenses.gpl3Plus;
       homepage = http://jsoftware.com/;
     };
  
positive.code: 
      # Now run the real tests
      cd $SOURCE_DIR/test
      # for f in *.ijs
      # do
      #   echo $f
      #   $JBIN/jconsole < $f
      # done
    '';
  
    installPhase = ''
      mkdir -p "$out"
      cp -r $JBIN "$out/bin"
  
      mkdir -p "$out/share/j"
      cp -r $JLIB/{addons,system} "$out/share/j"
  
negative.code: { stdenv, fetchFromGitHub, readline, libedit, bc }:
  
  stdenv.mkDerivation rec {
    name = "j-${version}";
    version = "807";
    jtype = "release";
    src = fetchFromGitHub {
      owner = "jsoftware";
      repo = "jsource";
      rev = "j${version}-${jtype}";
      sha256 = "1qciw2yg9x996zglvj2461qby038x89xcmfb3qyrh3myn8m1nq2n";
    };
  
    buildInputs = [ readline libedit bc ];
    bits = if stdenv.is64bit then "64" else "32";
    platform =
      if (stdenv.isAarch32 || stdenv.isAarch64) then "raspberry" else
      if stdenv.isLinux then "linux" else
      if stdenv.isDarwin then "darwin" else
      "unknown";
  