module Vm # Our virtual machine has a number of registers of a given size and uses a stack # So much so standard # But our machine is oo, meaning that the register contents is typed. # Off course current hardware does not have that (a perceived issue), but for our machine we pretend. # So internally we have at least 8 word registers, one of which is used to keep track of types* # and any number of scratch registers # but externally it's all Values (see there) # * Note that register content is typed externally. Not as in mri, where int's are tagged. Floats can's # be tagged and lambda should be it's own type, so tagging does not work # Note: subclasses should/will be used once we have the basic architecture clear and working class Machine attr_reader :registers attr_reader :scratch attr_reader :pc attr_reader :stack # is often a pseudo register (ie doesn't support move or other operations). # Still, using if to express tests makes sense, not just for # consistency in this code, but also because that is what is actually done attr_reader :status end end