Identity<T> implements Functor<T>
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45
src/main/java/net/kemitix/mon/Identity.java
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src/main/java/net/kemitix/mon/Identity.java
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/**
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* The MIT License (MIT)
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*
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* Copyright (c) 2017 Paul Campbell
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
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* and associated documentation files (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all copies
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* or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
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* AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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package net.kemitix.mon;
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import lombok.RequiredArgsConstructor;
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import java.util.function.Function;
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/**
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* Identity.
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*
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* @param <T> the type of the identity content
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*
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* @author Paul Campbell (pcampbell@kemitix.net)
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*/
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@RequiredArgsConstructor
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class Identity<T> implements Functor<T> {
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private final T value;
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@Override
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public <R> Identity<R> map(final Function<T, R> f) {
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return new Identity<>(f.apply(value));
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}
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}
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39
src/test/java/net/kemitix/mon/Address.java
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src/test/java/net/kemitix/mon/Address.java
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/**
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* The MIT License (MIT)
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*
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* Copyright (c) 2017 Paul Campbell
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
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* and associated documentation files (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all copies
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* or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
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* AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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package net.kemitix.mon;
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import lombok.RequiredArgsConstructor;
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/**
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* .
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*
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* @author Paul Campbell (pcampbell@kemitix.net)
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*/
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@RequiredArgsConstructor
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class Address {
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private final String street;
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String getStreet() {
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return street;
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}
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}
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40
src/test/java/net/kemitix/mon/Customer.java
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src/test/java/net/kemitix/mon/Customer.java
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/**
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* The MIT License (MIT)
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*
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* Copyright (c) 2017 Paul Campbell
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
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* and associated documentation files (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all copies
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* or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
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* AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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package net.kemitix.mon;
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import lombok.RequiredArgsConstructor;
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/**
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* .
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*
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* @author Paul Campbell (pcampbell@kemitix.net)
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*/
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@RequiredArgsConstructor
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class Customer {
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private final Address address;
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Address getAddress() {
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return address;
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}
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}
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37
src/test/java/net/kemitix/mon/IdentityTest.java
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src/test/java/net/kemitix/mon/IdentityTest.java
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package net.kemitix.mon;
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import org.assertj.core.api.WithAssertions;
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import org.junit.Test;
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/**
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* Tests for {@link Identity}.
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*
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* @author Paul Campbell (pcampbell@kemitix.net)
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*/
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public class IdentityTest implements WithAssertions {
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@Test
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public void canMapIdentityFromStringToInteger() {
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//given
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final Identity<String> idString = new Identity<>("abc");
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//when
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final Identity<Integer> idInt = idString.map(String::length);
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//then
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idInt.map(id -> assertThat(id).isEqualTo(3));
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}
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@Test
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public void canFluentlyComposeFunctions() {
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//given
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final Customer customer = new Customer(new Address("Park Place"));
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//when
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final Identity<byte[]> idBytes = new Identity<>(customer).map(Customer::getAddress)
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.map(Address::getStreet)
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.map((String s) -> s.substring(0, 3))
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.map(String::toLowerCase)
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.map(String::getBytes);
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//then
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idBytes.map(bytes -> assertThat(bytes).isEqualTo("par".getBytes()));
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}
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}
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