How to pad a Scala collection for minimum size?

Question

How to make sure a Seq is of certain minimum length, in Scala?

The below code does what I want (adds empty strings until arr has three entries), but it feels clumsy.

scala> val arr = Seq("a")
arr: Seq[String] = List(a)

scala> arr ++ Seq.fill(3-arr.size)("")
res2: Seq[String] = List(a, "", "")

A way to fulfill this would be a merger of two sequences: take from first, but if it runs out, continue from second. What was such method called...?

Answer 1

I find this slightly better:

scala> (arr ++ Seq.fill(3)("")).take(3)
res4: Seq[String] = List(a, "", "")

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And even better, thanks @thomas-böhm

scala> arr.toArray.padTo(3,"")
res5: Array[String] = Array(a, "", "")