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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

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

% start by loading the example:

| ?- logtalk_load(parvars(loader)). ...

% some queries using the list parametric object:

| ?- [1, 2, 3]::member(X).

X = 1 ; X = 2 ; X = 3 ; no

| ?- [1, 2, 3]::last(X).

X = 3 yes

| ?- [1, 2, 3]::nextto(2, Y).

Y = 3 yes

| ?- []::member(X).

no

% some queries using the time and date parametric objects:

| ?- date(Year, Month, Day)::today.

Year = 2000 Month = 8 Day = 15 yes

| ?- date(Year, _, _)::today, \+ date(Year, _, _)::leap_year.

Year = 2002 yes

| ?- time(Hours, Mins, Secs)::now.

Hours = 13 Mins = 52 Secs = 42 yes

| ?- rectangle(W, H, X, Y)::init, rectangle(W, H, X, Y)::move(3, 4, NR), NR::position(X2, Y2).

W = 2 H = 1 X = 0 Y = 0 NR = rectangle(2, 1, 3, 4) X2 = 3 Y2 = 4 yes

% some queries with parametric objects that define "setter" % methods that return updated object identifiers:

| ?- person(sally, 20)::grow_older(NewId).

NewId = person(sally, 21) yes

| ?- employee(sally, 21, 1200)::give_raise(250, NewId).

NewId = employee(sally, 21, 1450) yes

% some queries with parametric categories:

| ?- speech(winter, wedding)::advice.

Clothes: [pants, sleeves, heavy] Speech: [happy, jokes] yes