Carried over form IRC to placeholder the conversation as I saw it:
We define the following in S06 as immutable types:
List Lazy Perl list (composed of Seq and Range parts)
Seq Completely evaluated (hence immutable) sequence
Range Incrementally generated (hence lazy) sequence
Set Unordered Seqs that allow no duplicates
Junction Sets with additional behaviours
Pair Seq of two elements that serves as a one-element Mapping
Mapping Pairs with no duplicate keys
It seems to me that there are three core attributes, each of which has
Mutability: true, false
Laziness: true, false
Ordered: true, false
There are, thus, eight types of containers, but two (unordered, mutable,
lazy/eager) don't really work very well, so let's say 6:
Ordered, Immutable, Eager: Seq
Ordered, Immutable, Lazy: Range and/or Seq of Range?
Ordered, Mutable, Eager: ?
Ordered, Mutable, Lazy: Array
Unordered, Immutable, Eager: Set
Unordered, Immutable, Lazy: x and/or Set of x?
In that last example, x is "an unordered range", though we don't have
such a type. Basically, this is something like any(a..b).
The real question in my mind, though is this: do we need to call
something Lazy (as we currently do in S29), or should we just call it
List or Array depending on its mutability?