每次触发Jess规则时增加或更改变量 [英] Increment or change variable each time Jess rule fires

问题描述

每次触发规则时，是否可以增加或更改某些变量的值? 我需要在每次规则触发时引入插槽的新值，因为在以下示例中，我将使用此值进行连接: 我有一个将三角洲转换为恒星的电路和规则.对于每个变换产品，都是一个附加节点.对于简单网络，我将其命名为T，但是对于更复杂的网络，我最终得到的是充满T节点的网络，因为每次触发另一个增量的规则时，我都会得到一个T节点.

Is there a way to increment or change value of some variable each time rule fires? I need that for every time rule fires introduce new value of the slot, since I will use this value for connectivity in the following example: I have an electric circuit and rule that transforms delta to star. For every transform product is additional node. For simple network I have named it T, but for more complicated network I end up with network that is full of T nodes, since every time rule is triggered for another delta, I get a T node.

推荐答案

Jess具有一种特殊的变量:全局变量.它们在程序的所有部分(包括规则的RHS)中都是可见的.要创建，请使用defglobal，例如

Jess has a special kind of variables: global variable. They are visible in all parts of a program, including the RHSs of the rules. To create, use defglobal, e.g.

(defglobal ?*firecount* = 0)

请注意，星号是必需的.

Note that the asterisks are mandatory.

您可以像使用其他任何变量一样使用它们:

You use them just like any other variable:

(++ ?*firecount*)
(printout t "fire counter = " ?*firecount* crlf)

请注意，甚至reset都不会清除全局变量. -有关其他详细信息，请参阅Jess手册.

Note that not even reset clears a global. - Refer to the Jess manual for additional details.

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