34 lines
1.1 KiB
Ruby
34 lines
1.1 KiB
Ruby
module Mom
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# The funny thing about the ruby truth is that it is anything but false or nil
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#
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# To implement the normal ruby logic, we check for false or nil and jump
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# to the false branch. true_block follows implicitly
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#
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class TruthCheck < Check
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attr_reader :condition
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def initialize(condition , false_jump)
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super(false_jump)
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@condition = condition
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raise "condition must be slot_definition #{condition}" unless condition.is_a?(SlotDefinition)
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end
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def to_risc(compiler)
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false_label = @false_jump.to_risc(compiler)
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left = @condition.to_register(compiler,self)
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false_load = SlotDefinition.new( FalseConstant.new , [] ).to_register(compiler,self)
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left << false_load
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left << Risc.op( self , :- , left.register , false_load.register)
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left << Risc::IsNotZero.new( self, false_label)
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nil_load = SlotDefinition.new( NilConstant.new , [] ).to_register(compiler,self)
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left << nil_load
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left << Risc.op( self , :- , left.register , nil_load.register)
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left << Risc::IsNotZero.new( self, false_label)
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left
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end
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end
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end
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