如何在Dart中传递常见的论点？ [英] How to pass common arguments in Dart?

问题描述

说，我有：

callback.orderBy('foo', reverse: true).localToThis();
callback.orderBy('foo', reverse: true);

您可以在两个回调函数中看到，我传递的参数相同，

You can see in both callbacks, I am passing same arguments,

'foo', reverse: true

有什么方法可以使它们成为某种东西（变量或方法），以便可以使用类似这样的东西：

Is there any way I can make them something (a variable or a method) so that I can use something like this:

callback.orderBy(common).localToThis();
callback.orderBy(common);

推荐答案

callback.orderBy('foo', reverse: true).localToThis();
callback.orderBy('foo', reverse: true);

如果您要使用一组相同的函数来调用相同的函数参数，如果函数没有副作用，则最好保存结果并避免再次调用该函数。

If you're calling the same function with the same set of arguments, if the function has no side-effects, you might as well just save the result and avoid calling the function again.

如果函数确实具有副作用或如果要仅使用某些参数调用该函数，则可以使用部分函数应用程序绑定参数：

If the function does have side-effects or if you want to call the function with only some of its arguments the same, you could use a partial function application to bind arguments:

final orderBy = () => callback.orderBy('foo', reverse: true);
orderBy().localToThis();
orderBy();

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