stack

function newStack()
	return {sz = 0}
end

function pop(st)
	if(st.sz == 0) then
		return nil
    end
	retval = st[st.sz]
	st[st.sz] = nil
	st.sz = st.sz - 1
	os.loadAPI("tableApi")
	print(tableApi.dump(st))
	return retval
end

function push(st, x)
	st.sz = st.sz + 1
	st[st.sz] = x
	os.loadAPI("tableApi")
	print(tableApi.dump(st))
end