Torsten Rüger
31c8a0aac5
That sort of removes the last horrible code. Surely can still be improved, but mostly oo now
53 lines
1.9 KiB
Ruby
53 lines
1.9 KiB
Ruby
module SlotMachine
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# A SlotDefinition defines a slot. A bit like a variable name but for objects.
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#
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# PS: for the interested: A "development" of Smalltalk was the
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# prototype based language (read: JavaScript equivalent)
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# called Self https://en.wikipedia.org/wiki/Self_(programming_language)
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#
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# SlotDefinitions are the instance names of objects. But since the language is dynamic
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# what is it that we can say about instance names at runtime?
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# Start with a known object like the Message (in register one), we know all it's
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# variables. But there is a Message in there, and for that we know the instances
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# too. And off course for _all_ objects we know where the type is.
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#
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# The definiion is an array of symbols that we can resolve to SlotLoad
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# Instructions. Or in the case of constants to ConstantLoad
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#
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class SlotDefinition
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# get the right definition, depending on the object
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def self.for(object , slots)
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case object
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when :message
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MessageDefinition.new(slots)
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when Constant
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ConstantDefinition.new(object , slots)
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when Parfait::Object , Risc::Label
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ObjectDefinition.new(object , slots)
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else
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raise "not supported type #{object}"
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end
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end
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attr_reader :known_object , :slots
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# is an array of symbols, that specifies the first the object, and then the Slot.
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# The first element is either a known type name (Capitalized symbol of the class name) ,
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# or the symbol :message
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# And subsequent symbols must be instance variables on the previous type.
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# Examples: [:message , :receiver] or [:Space , :next_message]
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def initialize( object , slots)
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raise "No slots #{object}" unless slots
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slots = [slots] unless slots.is_a?(Array)
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@known_object , @slots = object , slots
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raise "Not known #{slots}" unless object
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end
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def to_s
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names = [known_name] + @slots
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"[#{names.join(', ')}]"
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end
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end
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end
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