A new type constraint was added to the sort cache to make indexes
type safe. The types are limited to `comparable` so the indexes can
be used as map keys internally. The primary motivation for the
change is to leverage the compiler to prevent using indexes which
are not valid for a given cache.
While it's still technically possible to use a string literal as
the index if the type index is constrained to `~string` it should
be avoided to ensure the compiler can catch invalid indexes.
- Adds (SortCache) Clear to allow resetting an existing cache
- Converts (SortCache) Ascend and (SortCache) Descend to return
an iter.Seq[T] instead of taking an iteration function
- Removes (SortCache) AscendPaginated and (SortCache) DescendPaginated
Leveraging iterates aligns the API with the direction that Go is
heading in regards to iteration. Removing of the paginated functions
does put the onus on callers to paginate, however, in the only
cases these were used there are now fewer allocations. AscendPaginated
was unused and DescendPaginated was only used in two places - both
of which would benefit from migrating away from using streams in
favor of iter.Seq.
The new Clear API makes it easier for callers to reset an existing
cache. Without this change the only way to reset a cache would be
to replace the entire cache with a new one. This places the burden
on callers to apply locking and handle concurrent read/write/deletes
and swapping out the cache entirely. That all is eliminated by
Clear handling the internal locking to reset the cache state.
rosstimothy