module SlotMachine # A base class for conditions in SlotMachine # Checks (if in code, compare in assm) jump or not, depending # The logic we choose is closer to the code logic (the asm is reversed) # When we write an if, the true is the next code, so the Check logic is # that if the check passes, no jump happens # This means you need to pass the false label, where to jump to if the # check does not pass # Note: In assembler a branch on 0 does just that, it branches if the condition # is met. This means that the asm implementation is somewhat the reverse # of the SlotMachine names. But it's easier to understand (imho) class Check < Instruction attr_reader :false_label def initialize(false_label) set_label(false_label) end def set_label(false_label) @false_label = false_label raise "Jump target must be a label #{false_label}" unless false_label.is_a?(Label) end end end