[英]Groovy DSL: How to hide closure parameter?
I am trying to implement a mini DSL with Groovy: 我正在尝试使用Groovy实现一个迷你DSL:
def parent(closure){
def container = new ArrayList<>()
closure.call(container)
container
}
def child(element, parent) {
println "add child$element to parent"
parent.add(element)
}
parent{ it->
child(1, it)
child(2, it)
}
But I want to remove the it
parameter to make it looks better, like this: 但是我想删除it
参数以使其看起来更好,如下所示:
parent{
child(1)
child(2)
}
Is it possible to do it this way? 有可能这样做吗? Many thanks in advance. 提前谢谢了。
It's not a full solution, only example, but I think, you should do it this way: 这不是一个完整的解决方案,只是一个例子,但我想,你应该这样做:
class Parent{
def container = new ArrayList<>()
def child(element) {
println "add child$element to parent"
container.add(element)
}
def parent(Closure closure){
closure.delegate = this
closure.resolveStrategy = Closure.DELEGATE_FIRST
closure.call()
container
}
}
new Parent().parent {
child(1) // Here we are trying to resolve child method in our delegate, then owner.
child(2)
}
Of course, you can remove new Parent in future, it's only quick example, to show you delegate magic. 当然,你可以在将来删除新的Parent,这只是一个快速的例子,向你展示委托魔法。
You can use @Field
AST in the script if you do not want to create a whole separate class for it: 如果您不想为它创建一个完整的单独类,可以在脚本中使用@Field
AST:
import groovy.transform.Field
@Field ArrayList container = new ArrayList<>()
//or just list
//@Field def container = []
def parent(Closure closure){
closure.call()
container
}
def child(element) {
println "add child$element to parent"
container << element
}
parent {
child(1)
child(2)
}
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