let {

body = lib;

lib = nixpkgs.lib // builtins // {

evalSource = let
  eval = source: lib.evalModules {
    modules = lib.singleton {
      _file = toString ./.;
      imports = map (source: { inherit source; }) (lib.toList source);
      options.source = lib.mkOption {
        default = {};
        type = lib.types.attrsOf lib.types.source;
      };
    };
  };
  sanitize = x: lib.getAttr (lib.typeOf x) {
    bool = x;
    list = map sanitize x;
    set = lib.mapAttrs
            (lib.const sanitize)
            (lib.filterAttrs
              (name: value: name != "_module" && value != null) x);
    string = x;
  };
in
  # This function's return value can be used as pkgs.populate input.
  source: sanitize (eval source).config.source;

maybeHostName = default: let
  # We're parsing /etc/hostname here because reading
  # /proc/sys/kernel/hostname yields ""
  path = "/etc/hostname";
  lines = lib.splitString "\n" (lib.readFile path);
  hostNames = lib.filter lib.types.label.check lines;
in
  if lib.pathExists path then
    if lib.length hostNames == 1 then
      lib.head hostNames
    else
      lib.trace "malformed ${path}" default
  else
    default;

firstWord = s:
  lib.head (lib.match "^([^[:space:]]*).*" s);

isLocalTarget = let
  origin = lib.mkTarget "";
in target:
  target.user == origin.user &&
  lib.elem target.host [origin.host "localhost"];

mkTarget = s: let
  parse = lib.match "(([^@]*)@)?(([^:/]+))?(:([^/]+))?(/.*)?" s;
  elemAt' = xs: i: if lib.length xs > i then lib.elemAt xs i else null;
  filterNull = lib.filterAttrs (n: v: v != null);
in {
  user = lib.maybeEnv "LOGNAME" null;
  host = lib.maybeEnv "HOSTNAME" (lib.maybeHostName "localhost");
  port = null;
  path = "/var/src";
  sudo = false;
  extraOptions = [];
} // (if lib.isString s then filterNull {
  user = elemAt' parse 1;
  host = elemAt' parse 3;
  port = elemAt' parse 5;
  path = elemAt' parse 6;
} else s);

mkUserPortSSHOpts = target:
  (lib.optionals (target.user != null) ["-l" target.user]) ++
  (lib.optionals (target.port != null) ["-p" target.port]);

shell = let
  isSafeChar = lib.testString "[-+./0-9:=A-Z_a-z]";
  quoteChar = c:
    if isSafeChar c then c
    else if c == "\n" then "'\n'"
    else "\\${c}";
in {
  quote = x: if x == "" then "''" else lib.stringAsChars quoteChar x;
};

test = re: x: lib.isString x && lib.testString re x;
testString = re: x: lib.match re x != null;

types = nixpkgs.lib.types // import ./types { lib = body; };

};

nixpkgs.lib = import ;

}