Dart类中的静态调用方法（使类可调用） [英] Static call method in Dart Classes (make Classes callable)

问题描述

对于嵌入式DSL，我希望类的行为像一个函数。这似乎很容易实例（ https://www.dartlang.org/articles/emulating-functions/ ），但我不能让类发生。我试着创建一个静态调用一个方法，但这也没有工作。

For an embedded DSL I want classes to behave like a function. It seems easy for instances (https://www.dartlang.org/articles/emulating-functions/) but I couldn't make it happen for classes. I tried creating a static call a method but this didn't work either.

有没有办法或者我必须给类另外一个名字，并使Pconst函数，调用构造函数？

Is there a way or do I have to give the class another name and make Pconst a function, calling the constructor?

class Pconst {
  final value;
  Pconst(this.value);
  static Pconst call(value) => new Pconst(value);

  String toString() => "Pconst($value)";
}

void main() {
  var test = Pconst(10);
  // Breaking on exception: Class '_Type' has no instance method 'call'.

  print("Hello, $test");
}

推荐答案

这个：

class _PConst{
    final value;
    _Pconst(this.value);

    String toString() => "Pconst($value)";
}

PConst(value){
    return new _PConst(value);
}

void main() {
    var test = Pconst(10);

    print("Hello, $test"); //should work ok
}

所以你基本上只是隐藏/包装你的类构造函数bog标准函数。

so your basically just hiding/wrapping your classes constructor behind a bog standard function.

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