31 lines
975 B
Ruby
31 lines
975 B
Ruby
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module Virtual
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# the first instruction we need is to stop. Off course in a real machine this would be a syscall, but that is just
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# an implementation (in a programm it would be a function). But in a virtual machine, not only do we need this instruction,
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# it is indeed the first instruction as just this instruction is the smallest possible programm for the machine.
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# As such it is the next instruction for any first instruction that we generate.
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class Halt < Instruction
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end
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class MethodReturn < Instruction
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end
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# a branch must branch to a block. This is an abstract class, names indicate the actual test
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class Branch < Instruction
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def initialize to
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@to = to
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end
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attr_reader :to
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end
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# implicit means there is no explcit test involved.
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# normal ruby rules are false and nil are false, EVERYTHING else is true (and that includes 0)
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class ImplicitBranch < Branch
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end
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class UnconditionalBranch < Branch
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end
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end
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