text: ##############################################################################
  # Copyright (c) 2013-2017, Lawrence Livermore National Security, LLC.
  # Produced at the Lawrence Livermore National Laboratory.
  #
  # This file is part of Spack.
  # Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
  # LLNL-CODE-647188
  #
  # For details, see https://github.com/spack/spack
  # Please also see the NOTICE and LICENSE files for our notice and the LGPL.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU Lesser General Public License (as
  # published by the Free Software Foundation) version 2.1, February 1999.
  #
  # This program is distributed in the hope that it will be useful, but
  # WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
  # conditions of the GNU Lesser General Public License for more details.
  #
  # You should have received a copy of the GNU Lesser General Public
  # License along with this program; if not, write to the Free Software
  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ##############################################################################
  from spack import *
  
  
  class RXvector(RPackage):
      """Memory efficient S4 classes for storing sequences "externally" (behind
         an R external pointer, or on disk)."""
  
      homepage = "https://bioconductor.org/packages/XVector/"
      url      = "https://git.bioconductor.org/packages/XVector"
      list_url = homepage
  
      version('0.16.0', git='https://git.bioconductor.org/packages/XVector', commit='54615888e1a559da4a81de33e934fc0f1c3ad99f')
  
      depends_on('r-biocgenerics', type=('build', 'run'))
      depends_on('r-s4vectors', type=('build', 'run'))
      depends_on('r-iranges', type=('build', 'run'))
      depends_on('r-zlibbioc', type=('build', 'run'))
      depends_on('r@3.4.0:3.4.9', when='@0.16.0')
  