laminar.Seq[A] is what Laminar needs to render sequences of things. It is less powerful than real collection types, and that lets us abstract away their differences, such as the lack of Scala semantics in JsVector, or the need for ClassTag when mapping a scala.Array.

The purpose of this class is to allow users to provide arbitrary collection types to Laminar methods like children <--, including types that have better performance than native Scala collections, such as JsVector, or even a mutable js.Array.

As a Laminar user, you shouldn't need to instantiate this class yourself, Laminar takes care of that behind the scenes.

If you have a custom collection type that you want Laminar to understand, provide an implicit instance of com.raquo.laminar.modifiers.RenderableSeq for it.

Note: Internally, only one of seq / scalaArray / jsVector members contains a value, all the other ones are null. Note: Mapping over ChildrenSeq may internally translate the source collection to another collection type (see comments below).