scala: How to pass an expanded list as varargs into a method?

scala map variadic-functions
dsg picture dsg · Mar 31, 2011 · Viewed 24.1k times · Source

When creating a Map in scala, I call Map(entities.map{e => e.id -> e}), and I get:

found   : scala.collection.mutable.IndexedSeq[(Int, Entity)]
required: (Int, Entity)

This is because the signature for Map.apply is: def apply[A, B](elems: (A, B)*): CC[A, B], which requires a varargs style argument.

Is there a way to convert the IndexedSeq so that it can be accepted via Map.apply?

Answer

dsg picture dsg · Mar 31, 2011

Try this: Map(entities.map{e => e.id -> e}:_*)

Explicitly typing it as a varargs using :_* seems to work.

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