key=#Definitions+1,
end
	})
	Viewport.x = Spawn_point.x-30
	Viewport.y = Spawn_point.y-30
	Cursor_node = Definitions[#Definitions]
	Cursor_node.show_cursor = true

maybe_update_key_in_definitions = function(old_definition_name, definition_name, node)
		if old_definition_name == nil or Definitions[old_definition_name] ~= node then
			local pos = array.find(Definitions, node)
			for i,n in ipairs(Definitions) do n.key = i end
		elseif Definitions[old_definition_name] == node then
		-- at this point we're sure node is no longer in Definitions
		node.key = nil
			Definitions[definition_name] = node
			table.insert(Definitions, node)
end
			node.key = #Definitions
		end
		--print('-- definition keys')
		--for k in pairs(Definitions) do
			--print(k)
		--end
	end
			node.key = definition_name
		elseif definition_name == nil or Definitions[definition_name] then
			-- temporary collision; try again later
			-- deleting and reinserting is inefficient, but hopefully rare
			--print('moving to index', #Definitions+1)
		if definition_name and Definitions[definition_name] == nil then
			--print('moving to key', definition_name)
			--print('found at key', old_definition_name)
			Definitions[old_definition_name] = nil
		end
			--print('found at index', pos)
			assert(pos)
			table.remove(Definitions, pos)
	--print(old_definition_name, definition_name)
	if old_definition_name ~= definition_name then