如何在Scala中找到用于时间转换隐式的包？

Question

On the official API page, I've searched for "time", but can't find the class. I looked at all methods on RichLong and RichInt , but can't find the methods.

I'm specifically talking about the methods that convert between int/long to some kind of rich object:

2 hours + 12 seconds

Note I'm not asking what the package is, I want to know how to find it.

Answer 1

您可以使用-Xlog-implicits标志使编译器向您显示查找隐式转换的位置。

Answer 2

Those aren't in the standard Scala API. Are you using the scala-time wrapper for JodaTime? If so, that would tell you where to look. In general, if you know which import enables the capability, it helps a lot when trying to find documentation!

If you know a method name, you can click on the little letters at the top of the left panel, just below the search text field in ScalaDoc--this will bring up a list of everything in the docs with that name, including methods (and tell you how to find it).

If a class doesn't have a method itself, you can use Scala to tell you what class it's getting converted to:

def whoHasSize[A](a: A)(implicit ev: A => { def size: Int }) = ev(a).getClass.getName

scala> whoHasSize("fish")
res1: java.lang.String = scala.collection.immutable.StringOps

So here you see that the string "fish" does not itself have a size method; instead, that's been granted by the scala.collection.immutable.StringOps method. You could do the same thing to find out about seconds .

Finally, stew's answer is probably what you were really looking for!