esx_core/client/entityiter.lua

--[[The MIT License (MIT)

Copyright (c) 2017 IllidanS4

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
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copies of the Software, and to permit persons to whom the
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conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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OTHER DEALINGS IN THE SOFTWARE.
]]

local entityEnumerator = {
	__gc = function(enum)
		if enum.destructor and enum.handle then
			enum.destructor(enum.handle)
		end

		enum.destructor = nil
		enum.handle = nil
	end
}

local function EnumerateEntities(initFunc, moveFunc, disposeFunc)
	return coroutine.wrap(function()
		local iter, id = initFunc()
		if not id or id == 0 then
			disposeFunc(iter)
			return
		end

		local enum = {handle = iter, destructor = disposeFunc}
		setmetatable(enum, entityEnumerator)
		local next = true

		repeat
			coroutine.yield(id)
			next, id = moveFunc(iter)
		until not next

		enum.destructor, enum.handle = nil, nil
		disposeFunc(iter)
	end)
end

function EnumerateEntitiesWithinDistance(entities, isPlayerEntities, coords, maxDistance)
	local nearbyEntities = {}

	if coords then
		coords = vector3(coords.x, coords.y, coords.z)
	else
		local playerPed = PlayerPedId()
		coords = GetEntityCoords(playerPed)
	end

	for k,entity in pairs(entities) do
		local distance = #(coords - GetEntityCoords(entity))

		if distance <= maxDistance then
			table.insert(nearbyEntities, isPlayerEntities and k or entity)
		end
	end

	return nearbyEntities
end

function EnumerateObjects()
	return EnumerateEntities(FindFirstObject, FindNextObject, EndFindObject)
end

function EnumeratePeds()
	return EnumerateEntities(FindFirstPed, FindNextPed, EndFindPed)
end

function EnumerateVehicles()
	return EnumerateEntities(FindFirstVehicle, FindNextVehicle, EndFindVehicle)
end

function EnumeratePickups()
	return EnumerateEntities(FindFirstPickup, FindNextPickup, EndFindPickup)
end