Case Class

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kshalle edited this page Apr 15, 2018 · 4 revisions

Description

A case class represents a special type of class in Scala that has the features:

external access to the class parameters,
eliminates the need to use new when instantiating the class
automatically creates an unapply method that supplies access to all of the class Parameters,
cannot be subclassed from.

It's often used to essentially create a data structure.

Examples

From RocketTiles.scala line 15:

case class RocketTileParams(
    core: RocketCoreParams = RocketCoreParams(),
    icache: Option[ICacheParams] = Some(ICacheParams()),
    dcache: Option[DCacheParams] = Some(DCacheParams()),
    rocc: Seq[RoCCParams] = Nil,
    btb: Option[BTBParams] = Some(BTBParams()),
    dataScratchpadBytes: Int = 0) extends TileParams {
    ...

Which is used this way:

class RocketTile(val rocketParams: RocketTileParams, val hartid: Int)(implicit p: Parameters) extends BaseTile(rocketParams)(p)
    ...
      val m = if (rocketParams.core.mulDiv.nonEmpty) "m" else ""
    ...