#!/usr/bin/env ruby
# vim: set sw=4 sts=4 et tw=80 :

=begin description
This example demonstrates how to use EnvironmentFactory and the resultant
Environment.
=end

require 'Paludis'
require 'example_command_line'

include Paludis

exit_status = 0

# We use EnvironmentFactory to construct an environment from the user's
# --environment commandline choice. With an empty string, this uses the
# distribution-defined default environment. With a non-empty string, it
# is split into two parts upon the first colon (if there is no colon,
# the second part is considered empty). The first part is the name of
# the environment class to use (e.g. 'paludis', 'portage') and the
# second part is passed as parameters to be handled by that
# environment's constructor.
env = EnvironmentFactory.instance.create(ExampleCommandLine.instance.environment)

# A lot of the Environment members aren't very useful to clients. The mask
# related methods are used by PackageID, and shouldn't usually be called
# directly from clients. The system information and mirror functions are mostly
# for use by Repository subclasses. The [] operator is covered in other
# examples. That leaves the package database and sets. The package database has
# its own examples, so we'll start with sets:

world = env.set('world')
if (world)
    # see examples_dep_tree.rb for how to make use of this set
    puts "World set exists"
else
    puts "No world set defined"
end