Deprecate List module, introduce LinkedLists

[benharsh]

This PR adds a deprecation warning to the "List" module and introduces a new "LinkedLists" module to take its place, and likewise renames the type from "list" to "LinkedList". We expect to eventually use the name "list" (along with "deque") for a type to replace some of the array-as-vector operations.

Modules and tests have been updated to use the new LinkedList type, and a deprecation test has been added.

Testing:

• local
• gasnet

[ben-albrecht]

Thanks!

[vasslitvinov]

My preference is to make the name capitalized: LinkedList.

I think this is our convention for library types that are not all-lowercase like bigint or date.

To me linkedList looks more like the name of a variable.

To avoid the potential conflict with the module name, we could follow the lead of the Barrier type, whose module is plural Barriers. In this case, the module name would be LinkedLists. Allowing us to add a doulbly-linked list to it easily later.

[ben-albrecht]

@vasslitvinov makes a good point.

The closest thing to documented guidelines on this is in #6698 :

Types should be CamelCase or lowercase. User-defined types should generally start with an uppercase letter and be CamelCase (e.g. RandomStream,Timer). Internal types can be lowercase (e.g. int, domain,bigint)

I don't think a linked list counts as an internal type, so I agree that LinkedList type and LinkedLists.chpl is more consistent.

[benharsh]

I've pushed some commits that use LinkedList/LinkedLists and will re-test.

@bradcray : do you have a preference?

Edit: If we end up preferring "linkedList" for now, I can just revert the commits.

[bradcray]

No particular preference on naming here.