var_dump()在Scala中

Scala (console) has a very useful feature to inspect or dump variables / object values :

scala> def b = Map("name" -> "Yudha","age" -> 27)
b: scala.collection.immutable.Map[java.lang.String,Any]

scala> b
res1: scala.collection.immutable.Map[java.lang.String,Any] = Map((name,Yudha),(age,27))

但是如果你想要更多的细节,你可以试试REPL Scala Utils,以获得一个“Easier object inspection in the Scala REPL”

So I’ve written a utility for use on the Scala REPL that will print out all of the “attributes” of an object.

(注：“我”在这里：Erik Engbrecht,还有on BitBucket)

Here’s some sample usage:

scala> import replutils._
import replutils._

scala> case class Test(a: CharSequence,b: Int)
defined class Test

scala> val t = Test("hello",1)
t: Test = Test(hello,1)

scala> printAttrValues(t)
hashCode: int = -229308731
b: int = 1
a: CharSequence (String) = hello
productArity: int = 2
getClass: Class = class line0$object$$iw$$iw$Test

That looks fairly anti-climatic,but after spending hours typing objName to see what’s there,and poking at methods,it seems like a miracle. Also,one neat feature of it is that if the class of the object returned is different from the class declared on the method,it prints both the declared class and the actual returned class.