stack (idea)

One of the basic, canonical data structures.

Logically resembling a stack of items, you can only affect the top. Putting another object on, taking it off, or viewing it.

(Some purists may argue that viewing the top object is not part of the traditional stack data structure, but I would say that it is enough used in practice that it may as well be.)

Common user interface:

• pop:  Take the top object off the stack, and pass it back to the caller.
• push:  Take an object from the caller, put it on the top of the stack.
• peek:  Allow caller to view the top object, without changing it.

Uses include:

• Mathematical evaluation
• Simple action rollback
• Goal seeking