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Alloy:一个紧凑的Java程序,用于执行不同的运行命令范围

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假设我想创建一个Java程序来执行几个Alloy运行,为每个循环更改它们的范围值(从0到9的整数),以检查哪个将花费更少的时间用于解决方案 .

请注意,命令实际上是相同的,我的意思是,只有范围的值(以及保留字“完全”的存在/不存在)会有所不同 .

这是一个数字示例:

1st run → command: run MyPred for 3 but 5 Int, exactly 1 Sig_Scope1, 1 Sig_Scope2, exactly 1 Sig_Scope3
2nd run → command: run MyPred for 4 but 5 Int, 2 Sig_Scope1, exactly 2 Sig_Scope2, exactly 2 Sig_Scope3
3rd run → command: run MyPred for 4 but 5 Int, 2 Sig_Scope1, exactly 1 Sig_Scope2, 1 Sig_Scope3

依此类推,直到达到最大迭代次数(假设为10) .

10th run → command: run MyPred for 4 but 5 Int, 0 Sig_Scope1, exactly 2 Sig_Scope2, 0 Sig_Scope3

程序输出将是这样的:

1st run. Found solution: Yes. Spent time: 17 seconds
2nd run. Found solution: No. Spent time: [it may take a time until the Alloy analyzer is going to return no solution]
3nd run. Found solution: No. Spent time: [it may take a time until the Alloy analyzer is going to return no solution]
...
9th run. Found solution: Yes. Spent time: 21 seconds
10th run. Found solution: Yes. Spent time: 10 seconds

这里是我试图通过的伪代码,但有很多部分(文本问题)我不知道如何实现它或如何找到更多的学习材料:

...
A4Reporter rep = new A4Reporter() {...}
...
Module world = CompUtil.parseEverything_fromFile(rep, null, filename); //reading Alloy filename.
...
A4Options options = new A4Options(); //Analyzer’s options.
...
Command command: world.getAllCommands(); //I’am looking for Alloy’s ‘run’ commands, for instance, the first run command would be: run MyPred for 3 but 3 Int, exactly 1 Sig_Scope1, 1 Sig_Scope2, exactly 1 Sig_Scope3
...
Int max_number_of_runs = 10;
for(i = 0; i < max_number_of_runs; i++) {
    A4Solution ans = TranslateAlloyToKodkod.execute_command(rep, world.getAllReachableSigs(), command, options); //get all Signatures, fine :)
    System.out.println(ans); //printing the whole command.
    if (ans.satisfiable()) {
        //How can I get the amount of time (in seconds) to found a solution as an integer or String?
        //Getting the label of the Sigs. I have got this way, however I do not know if it is the right one.
        SafeList<Sig> sigs = ans.getAllReachableSigs();
            for (Sig sig : sigs) {
                System.out.println(sig.shortLabel());
            }
        //For each Sig how can I get their values?
        //How can I build a new command (Command new_built_command) for the next run? The values of scope Sig will come from a list or they will be generated through Java Random class (I mean a know how to generate random integers).
        command = new_built_command;
    } else {
        //A message that the current command did not find a solution as a String!
    }
}

你能帮我解决一下吗?

1 Answer

  • 1

    我如何构建新命令

    您可以参阅ExampleUsingTheAPI以获取使用Alloy API构建Alloy模型的示例 . 使用该API,您可以以编程方式构造 Command 以运行 . 或者,您可以从文本形式的Alloy模型开始,使用CompUtil.parseEverything_fromString解析它,然后在原始Alloy模型上执行字符串find-replace以更新命令,并重新开始 .

    对于每个Sig,我如何获得他们的 Value 观?

    请参阅ExampleCompilingFromSource,第44行 . 基本上,一旦获得 A4Solution 对象,就可以在其上调用 eval 方法来针对找到的解决方案评估任何表达式(如果传递 Sig 对象,则会在解决方案中获得其值) .

    如何获得以整数或字符串形式找到解决方案的时间(以秒为单位)?

    我不确定 A4Solution 是否包含有关解决时间的任何信息,所以在这种情况下你必须自己测量时间 .

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