Applies discount to given number of unit of given item using.

Checks if given item can be used to fulfill discounts conditions.

Checks if given item can be discounted using given discount.

Evaluates given discounts and applies matching ones to corresponding cart items.

Finds items satisfying given discounts conditions.

Finds items to be discounted with given discount based on given items. Returns true when at least one item was found.

Returns the number of unit not used as base for any discount nor discounted.

Ensures that PrioritizedItems list is ready for application of given discount.

Remembers that given items in given number of units were used for given discount.

Resets evaluator to its initial state.