rubyx/lib/virtual/instruction.rb
2014-07-15 10:35:29 +03:00

78 lines
2.0 KiB
Ruby

require_relative "object"
module Virtual
# Instruction is an abstract for all the code of the object-machine. Derived classe make up the actual functionality
# of the machine.
# All functions on the machine are captured as instances of instructions
#
# It is actully the point of the virtual machine layer to express oo functionality in the set of instructions, thus
# defining a minimal set of instructions needed to implement oo.
# This is partly because jumping over this layer and doing in straight in assember was too big a step
class Instruction < Virtual::Object
attr_accessor :next
def attributes
[:next]
end
def initialize nex = nil
@next = nex
end
end
# the first instruction we need is to stop. Off course in a real machine this would be a syscall, but that is just
# an implementation (in a programm it would be a function). But in a virtual machine, not only do we need this instruction,
# it is indeed the first instruction as just this instruction is the smallest possible programm for the machine.
# As such it is the next instruction for any first instruction that we generate.
class Halt < Instruction
end
# following classes are stubs. currently in brainstorming mode, so anything may change anytime
class MethodEnter < Instruction
end
class FrameGet < Instruction
def initialize name
@name = name
end
attr_reader :name
def attributes
[:name]
end
end
class FrameSend < Instruction
def initialize name , args = []
@name = name.to_sym
@args = args
end
attr_reader :name , :args
def attributes
[:name , :args]
end
end
class FrameSet < Instruction
def initialize name , val
@name = name.to_sym
@value = val
end
attr_reader :name , :value
def attributes
[:name , :value]
end
end
class ObjectGet < Instruction
def initialize name
@name = name
end
attr_reader :name
def attributes
[:name]
end
end
end