class Op(object):
    __slots__ = ["name"]

    def __init__(self, name):
        self.name = name

    def __str__(self):
        return self.name

    def __repr__(self):
        return "<Tag: %s>" % self


Op.ADD      = Op("ADD") # x = y + z   -> y z x
Op.SUB      = Op("SUB") # x = y - z   -> y z x
Op.MUL      = Op("MUL") # x = y * z   -> y z x
Op.DIV      = Op("DIV") # x = y / z   -> y z x
Op.MOD      = Op("MOD") # x = y % z   -> y z x
Op.AND      = Op("AND") # x = y AND z -> y z x
Op.OR       = Op("OR")  # x = y OR z  -> y z x

Op.NOT      = Op("NOT") # x = !y      -> y None x
Op.MINUS    = Op("MINUS") # x = - y   -> y None x

Op.ASSIGN   = Op("ASSIGN") # x = y    -> y None x

Op.JMP      = Op("JMP") # "goto" x           -> x
Op.BEQ      = Op("BEQ") # "if y == z" goto x -> y z x
Op.BNE      = Op("BNE") # "if y != z" goto x -> y z x
Op.BLE      = Op("BLE") # ...
Op.BGE      = Op("BGE")
Op.BLT      = Op("BLT")
Op.BGT      = Op("BGT")

Op.PARAM    = Op("PARAM") # param x -> x
Op.CALL     = Op("CALL")  # fun y (z-args..) -> y z
Op.RETURN   = Op("RETURN") # return x -> x

Op.ARRAYGET = Op("ARRAYGET") # x = y[i] -> y i x
Op.ARRAYSET = Op("ARRAYSET") # x[i] = y -> y i x


class ThreeAddressCode:

    def __init__(self,op,arg1=None,arg2=None,result=None):
        self.op = op
        self.arg1 = arg1
        self.arg2 = arg2
        self.result = result