70 lines
2.5 KiB
Ruby
70 lines
2.5 KiB
Ruby
module Vool
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class SendStatement < Statement
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attr_reader :name , :receiver , :arguments
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def initialize(name , receiver , arguments )
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@name , @receiver , @arguments = name , receiver , arguments
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@arguments ||= []
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end
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def collect(arr)
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@receiver.collect(arr)
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@arguments.each do |arg|
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arg.collect(arr)
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end
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super
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end
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# Sending in a dynamic language is off course not as simple as just calling.
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# The function that needs to be called depends after all on the receiver,
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# and no guarantees can be made on what that is.
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#
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# It helps to know that usually (>99%) the class of the receiver does not change.
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# Our stategy then is to cache the functions and only dynamically determine it in
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# case of a miss (the 1%, and first invocation)
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#
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# As cache key we must use the type of the object (which is the first word of _every_ object)
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# as that is constant, and function implementations depend on the type (not class)
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#
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# A Send breaks down to 2 steps:
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# - Setting up the next message, with receiver, arguments, and (importantly) return address
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# - a CachedCall , or a SimpleCall, depending on weather the receiver type can be determined
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#
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# FIXME: we now presume direct (assignable) values for the arguments and receiver.
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# in a not so distant future, temporary variables will have to be created
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# and complex statements hoisted to assign to them. pps: same as in conditions
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def to_mom( method )
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if(@receiver.ct_type)
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simple_call(method)
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else
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cached_call(method)
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end
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end
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def message_setup(method)
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setup = [Mom::MessageSetup.new(method)]
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receiver = @receiver.slot_class.new([:message , :next_message , :receiver] , @receiver)
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arg_target = [:message , :next_message , :arguments]
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args = []
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@arguments.each_with_index do |arg , index|
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args << arg.slot_class.new( arg_target + [index] , arg)
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end
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setup << Mom::ArgumentTransfer.new( receiver , args )
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end
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def simple_call(method)
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type = @receiver.ct_type
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method = type.resolve_method(@name)
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raise "No method #{@name} for #{type}" unless method
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Mom::Statements.new( message_setup(method) << Mom::SimpleCall.new( method) )
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end
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def cached_call(method)
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raise "Not implemented #{method}"
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Mom::Statements.new( message_setup + call_instruction )
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[@receiver.slot_class.new([:message , :next_message , :receiver] , @receiver) ]
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end
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end
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end
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