define[订单]   //简单化，假设一个订单只能订一份，那么可以暂时不需要数量
//whether[defined[订单] ]

define[订单编号, Link:Integer]  
whether[defined[Link:订单编号]]

define[客户, Link:String]

define[品种, Link:String]
whether[defined[Link:品种]]

define[数量, Link:Integer]
whether[defined[Link:数量]]

define[payed, State]
whether[defined[State:payed]]

define[已发货, State]
whether[defined[State:已发货]]

define[已结单, State]
whether[defined[State:已结单]]

define[下单时间, Link:String]
whether[defined[Link:下单时间]]

create[订单{订单编号:=2000,品种:="木桶饭", 数量:=2, 下单时间:=now.toString, payed::false}]
create[订单{订单编号:=2001,品种:="盖浇饭", 数量:=1, 下单时间:=now.toString, payed::false}]

ask[订单.all]

ask[订单.select{订单编号=2000}]

订单.select{订单编号=2000}#turn[payed, true]
whether[订单.select{订单编号=2000}$payed]
whether[订单.select{订单编号=2000}!payed]

ask[订单.select{payed}]   //已付款订单
ask[订单.select{!payed}]  //未付款订单

define[编号生成器,Object:create[Object]]
define[lastSeq, Link:Integer]
define[nextSeq, Link:Integer]
编号生成器#assign[lastSeq,0]
//ask[编号生成器.lastSeq]
编号生成器#declare[Calculation:nextSeq,{assign[lastSeq, lastSeq+1],return[lastSeq]}] ask[编号生成器.nextSeq]   //1
ask[编号生成器.nextSeq]   //2，每次加1

register("Rose", "111111")
hasUser("Rose")  //whether[hasUser("Rose")]
register("Jack", "111111")

login[Rose,"111111"]
login[Jack,"111111"]
ask[me]
ask[me.userid]
logout

//下单的前提是客户已登录
define[newOrder(String, Integer), Action]
declare[Action:newOrder(String x, Integer y) ,create[订单{订单编号:=编号生成器.nextSeq,品种:=x, 数量:=y, 客户:=me.userid,下单时间:=now.toString, payed::false}] ]
newOrder("盖浇饭", 3)

ask[订单.select{订单编号=4, 客户=me.userid}]

//前提：客户已登录
define[pay(Integer), Action]
declare[Action:pay(Integer x), 订单.select{订单编号=x}#turn[payed, true]]

define[send(Integer), Action]
declare[Action:send(Integer x), 订单.select{订单编号=x}#turn[已发货, true]]

define[deal(Integer), Action]
declare[Action:deal(Integer x), 订单.select{订单编号=x}#turn[已结单, true]]
ask[订单.select{订单编号=3}]