class Gem::PathSupport


to the rest of RubyGems.
Gem::PathSupport facilitates the GEM_HOME and GEM_PATH environment settings
#

def default_path

Return the default Gem path 
def default_path
  Gem.default_path + [@home]
end

def expand(path) 

def expand(path)
  if File.directory?(path)
    File.realpath(path)
  else
    path
  end
end

def initialize(env)


hashtable, or defaults to ENV, the system environment.
Constructor. Takes a single argument which is to be treated like a

# 
def initialize(env)
  @home = normalize_home_dir(env["GEM_HOME"] || Gem.default_dir)
  @path = split_gem_path env["GEM_PATH"], @home
  @spec_cache_dir = env["GEM_SPEC_CACHE"] || Gem.default_spec_cache_dir
end

def normalize_home_dir(home) 

def normalize_home_dir(home)
  if File::ALT_SEPARATOR
    home = home.gsub(File::ALT_SEPARATOR, File::SEPARATOR)
  end
  expand(home)
end

def split_gem_path(gpaths, home) 

def split_gem_path(gpaths, home)
  # FIX: it should be [home, *path], not [*path, home]
  gem_path = []
  if gpaths
    gem_path = gpaths.split(Gem.path_separator)
    # Handle the path_separator being set to a regexp, which will cause
    # end_with? to error
    if /#{Gem.path_separator}\z/.match?(gpaths)
      gem_path += default_path
    end
    if File::ALT_SEPARATOR
      gem_path.map! do |this_path|
        this_path.gsub File::ALT_SEPARATOR, File::SEPARATOR
      end
    end
    gem_path << home
  else
    gem_path = default_path
  end
  gem_path.map {|path| expand(path) }.uniq
end