alternative version of state monad
alternative version of state monad

xnning/fcore,hkuplg/fcore,zhiyuanshi/fcore,zhiyuanshi/fcore,bixuanzju/fcore,zhiyuanshi/fcore,xnning/fcore,xnning/fcore,wxzh/fcore,hkuplg/fcore,bixuanzju/fcore,wxzh/fcore,hkuplg/fcore,bixuanzju/fcore,wxzh/fcore