The class of collections whose keys are consecutive integers starting from zero.
Sequences must be stable under iteration, and the iteration order must match the order of keys. Thus, the key associated with a sequence’s iteration state can be determined by keeping a counter in parallel with the iteration state.
The default methods for add, add-new, remove, choose, choose-by, intersection, union, remove-duplicates, copy-sequence, concatenate, reverse, and sort all return new sequences that are instances of the type-for-copy of their primary sequence argument.
abstract free open