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This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2023 Paulo Moura <pmoura@logtalk.org> SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

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% start by loading the design pattern sample implementations:

| ?- logtalk_load(design_patterns('structural/flyweight/loader')). ...

% add cheese brands and respective cost to the flyweight object % using any of the shops:

| ?- shop1::(stock_cheese(white, 1.25), stock_cheese(blue, 3.75)).

yes

% all shops now have white and blue cheese at the same cost:

| ?- shop2::cheese(Brand, Cost).

Brand = white, Cost = 1.25 ; Brand = blue, Cost = 3.75 yes

% both shops can sell cheese but the units sold are stored per-shop:

| ?- shop1::sell_cheese(blue, 3), shop2::sell_cheese(blue, 8).

yes

% check cheese units sold and income for each shop:

| ?- shop1::(total_units_sold(Units), total_income(Income)).

Total = 3 Income = 11.25 yes

| ?- shop2::(total_units_sold(Units), total_income(Income)).

Total = 8 Income = 30.0 yes