Define container behavior

[xandkar]

Goal: swappable implementations

[xandkar]

Some common operations for a vague notion of a container could be:

• empty
• add
• remove
• find
• length
• is_empty
• is_element

These are suitable for at least: list, set, stack, queue, heap, dictionary.

Being that each implementation defines a particular order, our collection is also a sequence, so ordered access can also make sense:

• first
• last
• nth

There is a semantic conflict for a remove operation between a set and a queue/stack, since set removes a specific item and queue/stack remove whatever is at the top of the order. Can we come-up with an abstraction to accommodate both?

A heap is probably less of a problem, since it can be viewed as just an extension to the regular queue/stack interface.