Groovysh 在循环中使用自定义命令

Question

我有一个 groovysh 问题，我注意到您不能在循环上下文或函数内部使用 goovysh 命令。似乎命令在解析时而不是运行时进行评估。

是否有一些神奇的语法可以解决这个问题？

这是一个例子：

import org.codehaus.groovy.tools.shell.CommandSupport
import org.codehaus.groovy.tools.shell.Groovysh

class Rand extends CommandSupport {
    private Random random = new Random()

    protected Rand(final Groovysh shell) {
        super(shell, 'rand', 'r')
    }

    public Integer execute(List args) {
        random.nextInt()
    }

}

:register Rand

(1..3).each {
    println "number ${it}"
    rand
    foo = _
    println "Random number is ${foo}"
}

执行时，您会看到随机数没有改变，您会看到它在我将代码粘贴到控制台时进行了评估，但在它进入循环之前：

Groovy Shell (2.4.11, JVM: 1.8.0_51)
Type ':help' or ':h' for help.
-----------------------------------------------------------------------------------------------------------------------
groovy:000> import org.codehaus.groovy.tools.shell.CommandSupport
===> org.codehaus.groovy.tools.shell.CommandSupport
groovy:000> import org.codehaus.groovy.tools.shell.Groovysh
===> org.codehaus.groovy.tools.shell.CommandSupport, org.codehaus.groovy.tools.shell.Groovysh
groovy:000>
groovy:000> class Rand extends CommandSupport {
groovy:001>     private Random random = new Random()
groovy:002>
groovy:002>     protected Rand(final Groovysh shell) {
groovy:003>         super(shell, 'rand', 'r')
groovy:004>     }
groovy:005>
groovy:005>     public Integer execute(List args) {
groovy:006>         random.nextInt()
groovy:007>     }
groovy:008>
groovy:008> }
===> true
groovy:000>
groovy:000> :register Rand
===> true
groovy:000>
groovy:000> (1..3).each {
groovy:001>     println "number ${it}"
groovy:002>     rand
===> -1321819102
groovy:002>     foo = _
groovy:003>     println "Random number is ${foo}"
groovy:004> }
number 1
Random number is -1321819102
number 2
Random number is -1321819102
number 3
Random number is -1321819102
===> [1, 2, 3]
groovy:000>

我希望有一些方法可以通过直接引用 shell 或其他语法的其他语法来引用自定义命令。

Answer 1

好的，我只是想出了一个有点老套的解决方案。掌握 Groovysh 实例意味着我可以在需要时进行评估：

import org.codehaus.groovy.tools.shell.CommandSupport
import org.codehaus.groovy.tools.shell.Groovysh

class Rand extends CommandSupport {
    private Random random = new Random()

    protected Rand(final Groovysh shell) {
        super(shell, 'rand', 'r')
    }

    public Integer execute(List args) {
        random.nextInt()
    }

}

:register Rand

class Shell extends CommandSupport {

    private Groovysh shellint

    protected Shell(final Groovysh shell) {
        super(shell, 'shell', 's')
        shellint = shell
    }

    public Groovysh execute(List args) {
        shellint
    }

}

:register Shell

shell
myshell = _

(1..3).each {
    println "number ${it}"
    foo = myshell.execute("rand")
    println "Random number is ${foo}"
}

输出为：

Groovy Shell (2.4.11, JVM: 1.8.0_51)
Type ':help' or ':h' for help.
-----------------------------------------------------------------------------------------------------------------------
groovy:000> import org.codehaus.groovy.tools.shell.CommandSupport
===> org.codehaus.groovy.tools.shell.CommandSupport
groovy:000> import org.codehaus.groovy.tools.shell.Groovysh
===> org.codehaus.groovy.tools.shell.CommandSupport, org.codehaus.groovy.tools.shell.Groovysh
groovy:000>
groovy:000> class Rand extends CommandSupport {
groovy:001>     private Random random = new Random()
groovy:002>
groovy:002>     protected Rand(final Groovysh shell) {
groovy:003>         super(shell, 'rand', 'r')
groovy:004>     }
groovy:005>
groovy:005>     public Integer execute(List args) {
groovy:006>         random.nextInt()
groovy:007>     }
groovy:008>
groovy:008> }
===> true
groovy:000>
groovy:000> :register Rand
===> true
groovy:000>
groovy:000> class Shell extends CommandSupport {
groovy:001>
groovy:001>     private Groovysh shellint
groovy:002>
groovy:002>     protected Shell(final Groovysh shell) {
groovy:003>         super(shell, 'shell', 's')
groovy:004>         shellint = shell
groovy:005>     }
groovy:006>
groovy:006>     public Groovysh execute(List args) {
groovy:007>         shellint
groovy:008>     }
groovy:009>
groovy:009> }
===> true
groovy:000>
groovy:000> :register Shell
===> true
groovy:000>
groovy:000> shell
===> org.codehaus.groovy.tools.shell.Groovysh@16ec132
groovy:000> myshell = _
===> org.codehaus.groovy.tools.shell.Groovysh@16ec132
groovy:000>
groovy:000> (1..3).each {
groovy:001>     println "number ${it}"
groovy:002>     foo = myshell.execute("rand")
groovy:003>     println "Random number is ${foo}"
groovy:004> }
number 1
===> -666149132
Random number is -666149132
number 2
===> -1675600826
Random number is -1675600826
number 3
===> 412144734
Random number is 412144734
===> [1, 2, 3]

~~还有其他方法吗？在我需要这个的上下文中，groovysh 是一个自定义的，删除了 :register~~

我修改了 groovysh jar 文件以重新添加 :register 命令，然后我可以使用上述解决方案。我通过查看 https://github.com/groovy/groovy-core/blob/master/subprojects/groovy-groovysh/src/main/groovy/org/codehaus/groovy/tools/shell/Groovysh.groovy 并看到 org/codehaus/groovy/tools/shell/commands.xml 包含命令列表来做到这一点，然后我将 <command>org.codehaus.groovy.tools.shell.commands.RegisterCommand</command> 添加到列表中。

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