Using scala list in java

Question

In scala, I can add to the end of list by,

val list = List[Integer](1,2,3,4)
val addEndList  = list:::List[Integer](101) //now this list has 1,2,3,4,101

I am trying to do it from java now,

scala.collection.immutable.List<Integer> list =  perform.getScalaListofSize(4); //1,2,3,4
scala.collection.immutable.List<Integer> list2 =  perform.getScalaListofSize(1); //1
scala.collection.immutable.List<Integer> list1 = list2.$colon$colon$colon(list);//1,2,3,4,1

Shouldn't the last line in java be:

list.$colon$colon$colon(list2)

its giving me output as

//1,1,2,3,4

Ben Jackson · Accepted Answer · 2011-07-07 21:42:33Z

5

Scala methods that end with : are right-associative when used with infix notation: If you do a ::: b in Scala it invokes b.:::(a). In your manual Java invocation you have to transpose the arguments yourself, as you discovered.

edited Jul 7, 2011 at 21:42

answered Jul 7, 2011 at 3:38

Ben Jackson

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2 Comments

Jörg W Mittag Over a year ago

Actually, he means methods. It's not a function, and Scala doesn't really have operators.

Daniel C. Sobral Over a year ago

You might say "right-associative when used in infix notation".

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