local SkeletonData = {}
function SkeletonData.new (attachmentResolver)
	if not attachmentResolver then error("attachmentResolver cannot be nil", 2) end

	local self = {
		attachmentResolver = attachmentResolver,
		bones = {},
		slots = {},
		skins = {}
	}

	function self:findBone (boneName)
		if not boneName then error("boneName cannot be nil.", 2) end
		for i,bone in ipairs(self.bones) do
			if bone.name == boneName then return bone end
		end
		return nil
	end

	function self:findBoneIndex (boneName)
		if not boneName then error("boneName cannot be nil.", 2) end
		for i,bone in ipairs(self.bones) do
			if bone.name == boneName then return i end
		end
		return -1
	end

	function self:findSlot (slotName)
		if not slotName then error("slotName cannot be nil.", 2) end
		for i,slot in ipairs(self.slots) do
			if slot.name == slotName then return slot end
		end
		return nil
	end

	function self:findSlotIndex (slotName)
		if not slotName then error("slotName cannot be nil.", 2) end
		for i,slot in ipairs(self.slots) do
			if slot.name == slotName then return i end
		end
		return -1
	end

	function self:findSkin (skinName)
		if not skinName then error("skinName cannot be nil.", 2) end
		for i,skin in ipairs(self.skins) do
			if skin.name == skinName then return skin end
		end
		return nil
	end

	return self
end
return SkeletonData