如何在 Scala 中将不可变 Seq 的不可变 Seq 转换为可变 Seq 的可变 Seq？

Question

设不可变序列的不可变序列为：

val content: Seq[Seq[Double]

我想将其转换为可变序列的可变序列：

val mutable_being_inversed_matrix:
  collection.mutable.Seq[collection.mutable.Seq[Double]] =
    content.to[collection.mutable.Seq[collection.mutable.Seq[Double]]

但这会产生以下错误：

Error:(79, 128)
  scala.collection.mutable.Seq[scala.collection.mutable.Seq[Double]]
    takes no type parameters, expected: one
  val mutable_being_inversed_matrix: collection.mutable.Seq[collection.mutable.Seq[Double]] = content.to[collection.mutable.Seq[collection.mutable.Seq[Double]]]

如何处理？

Answer 1

鉴于此不可变输入：

val immutableInput = Seq(Seq(1, 2), Seq(4))

您可以使用 varargs constructor:

切换到可变序列的可变序列

scala.collection.mutable.Seq(
  immutableInput.map(imseq => scala.collection.mutable.Seq(imseq:_*)):_*
)

产生：

res0: scala.collection.mutable.Seq[scala.collection.mutable.Seq[Int]] =
  ArrayBuffer(ArrayBuffer(1, 2), ArrayBuffer(4))

如何在 Scala 中将不可变 Seq 的不可变 Seq 转换为可变 Seq 的可变 Seq？

How to convert an inmutable Seq of immutable Seq into a mutable Seq of mutable Seq in Scala?

scala

mutable

immutability