建立对象报错

function newAnimal(name)
    local animal={
        name="unknown",
        says="pffft",
        position={x=0,y=0}
    }
    animal.name=name;
    if name=="cat" then
        animal.says="meow"
    elseif name=="dog" then
        animal.says="bow bow"
    elseif name=="mouse" then
        animal.says="squeak"
    end
   
    function animal:speak()
        print(animal.says)
    end
   
    function animal:move(speed)
        animal.position.x=animal.position.x+speed
    end
   
    return animal
end

cat_01=animal.new("cat")
cat_01:speak()