Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Once per turn, when the battle position of a Rock monster you control is changed: You can target 1 Spell/Trap your opponent controls; destroy that target.
--ムーン・スクレイパー
--Attack the Moon!
local s,id=GetID()
function s.initial_effect(c)
	--activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--destroy
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_DESTROY)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e2:SetCode(EVENT_CHANGE_POS)
	e2:SetProperty(EFFECT_FLAG_CARD_TARGET)
	e2:SetRange(LOCATION_SZONE)
	e2:SetCountLimit(1)
	e2:SetCondition(s.descon)
	e2:SetTarget(s.destg)
	e2:SetOperation(s.desop)
	c:RegisterEffect(e2)
end
function s.cfilter(c,tp)
	local np=c:GetPosition()
	local pp=c:GetPreviousPosition()
	return c:IsControler(tp) and c:IsRace(RACE_ROCK) and not c:IsStatus(STATUS_CONTINUOUS_POS) and ((np<3 and pp>3) or (pp<3 and np>3))
end
function s.descon(e,tp,eg,ep,ev,re,r,rp)
	return eg:IsExists(s.cfilter,1,nil,tp)
end
function s.desfilter(c)
	return c:IsSpellTrap()
end
function s.destg(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chkc then return chkc:IsControler(1-tp) and chkc:IsOnField() and s.desfilter(chkc) end
	if chk==0 then return e:GetHandler():IsRelateToEffect(e) and not e:GetHandler():IsStatus(STATUS_CHAINING)
		and Duel.IsExistingTarget(s.desfilter,tp,0,LOCATION_ONFIELD,1,nil) end
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DESTROY)
	local g=Duel.SelectTarget(tp,s.desfilter,tp,0,LOCATION_ONFIELD,1,1,nil)
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,g,1,0,0)
end
function s.desop(e,tp,eg,ep,ev,re,r,rp)
	if not e:GetHandler():IsRelateToEffect(e) then return end
	local tc=Duel.GetFirstTarget()
	if tc:IsRelateToEffect(e) then
		Duel.Destroy(tc,REASON_EFFECT)
	end
end