rf-web/vendor/bundle/gems/eventmachine-1.2.7/lib/em/future.rb

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#--
#
# Author:: Francis Cianfrocca (gmail: blackhedd)
# Homepage:: http://rubyeventmachine.com
# Date:: 16 Jul 2006
#
# See EventMachine and EventMachine::Connection for documentation and
# usage examples.
#
#----------------------------------------------------------------------------
#
# Copyright (C) 2006-07 by Francis Cianfrocca. All Rights Reserved.
# Gmail: blackhedd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of either: 1) the GNU General Public License
# as published by the Free Software Foundation; either version 2 of the
# License, or (at your option) any later version; or 2) Ruby's License.
#
# See the file COPYING for complete licensing information.
#
#---------------------------------------------------------------------------
#
#
#--
# This defines EventMachine::Deferrable#future, which requires
# that the rest of EventMachine::Deferrable has already been seen.
# (It's in deferrable.rb.)
module EventMachine
module Deferrable
# A future is a sugaring of a typical deferrable usage.
#--
# Evaluate arg (which may be an expression or a block).
# What's the class of arg?
# If arg is an ordinary expression, then return it.
# If arg is deferrable (responds to :set_deferred_status),
# then look at the arguments. If either callback or errback
# are defined, then use them. If neither are defined, then
# use the supplied block (if any) as the callback.
# Then return arg.
def self.future arg, cb=nil, eb=nil, &blk
arg = arg.call if arg.respond_to?(:call)
if arg.respond_to?(:set_deferred_status)
if cb || eb
arg.callback(&cb) if cb
arg.errback(&eb) if eb
else
arg.callback(&blk) if blk
end
end
arg
end
end
end