require_ext.rb

module Kernel

  # Settiing this global variable to +false+ will disable rubygems from
  # being loaded at all.
  $use_rubygems = true

  # call-seq:
  #    require!( string )
  #    require!( string, gem_version )
  #    require!( string, gem_name, gem_version )
  #
  # Attempt to the load the library named _string_ using the standard
  # Kernel#require method. If the library cannot be loaded then require
  # rubygems and retry the original require of the library.
  #
  # Raises a LoadError if the library cannot be loaded.
  #
  # If a _gem_version_ is given, then the rubygems +gem+ command is used to
  # load the specific version of the gem. The library _string_ is used for
  # the _gem_name_ if one is omitted.
  #
  def require!( string, *args )
    return require(string) if args.empty?

    name, version = *args
    version, name = name, string if name =~ %r/^[0-9<>=~]/

    gem name, version
    require(string)
  rescue LoadError, NoMethodError
    retry if $use_rubygems and require('rubygems')
    raise
  end

  # call-seq:
  #    require?( string )
  #    require?( string, gem_version )
  #    require?( string, gem_name, gem_version )
  #
  # Attempt to the load the library named _string_ using the standard
  # Kernel#require method. If the library cannot be loaded then require
  # rubygems and retry the original require of the library.
  #
  # Returns +true+ if the library was successfully loaded. Returns +false+
  # if the library could not be loaded. This method will never raise an
  # exception.
  #
  # If a _gem_version_ is given, then the rubygems +gem+ command is used to
  # load the specific version of the gem. The library _string_ is used for
  # the _gem_name_ if one is omitted.
  #
  def require?( string, *args )
    require!(string, *args)
    return true
  rescue LoadError
    return false
  end

end  # module Kernel