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Diffstat (limited to 'src/org/unitConverter/math/ObjectProduct.java')
| -rw-r--r-- | src/org/unitConverter/math/ObjectProduct.java | 284 |
1 files changed, 0 insertions, 284 deletions
diff --git a/src/org/unitConverter/math/ObjectProduct.java b/src/org/unitConverter/math/ObjectProduct.java deleted file mode 100644 index bf00647..0000000 --- a/src/org/unitConverter/math/ObjectProduct.java +++ /dev/null @@ -1,284 +0,0 @@ -/**
- * Copyright (C) 2018 Adrien Hopkins
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <https://www.gnu.org/licenses/>.
- */
-package org.unitConverter.math;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-import java.util.function.Function;
-
-/**
- * An immutable product of multiple objects of a type, such as base units. The objects can be multiplied and
- * exponentiated.
- *
- * @author Adrien Hopkins
- * @since 2019-10-16
- */
-public final class ObjectProduct<T> {
- /**
- * Returns an empty ObjectProduct of a certain type
- *
- * @param <T>
- * type of objects that can be multiplied
- * @return empty product
- * @since 2019-10-16
- */
- public static final <T> ObjectProduct<T> empty() {
- return new ObjectProduct<>(new HashMap<>());
- }
-
- /**
- * Gets an {@code ObjectProduct} from an object-to-integer mapping
- *
- * @param <T>
- * type of object in product
- * @param map
- * map mapping objects to exponents
- * @return object product
- * @since 2019-10-16
- */
- public static final <T> ObjectProduct<T> fromExponentMapping(final Map<T, Integer> map) {
- return new ObjectProduct<>(new HashMap<>(map));
- }
-
- /**
- * Gets an ObjectProduct that has one of the inputted argument, and nothing else.
- *
- * @param object
- * object that will be in the product
- * @return product
- * @since 2019-10-16
- * @throws NullPointerException
- * if object is null
- */
- public static final <T> ObjectProduct<T> oneOf(final T object) {
- Objects.requireNonNull(object, "object must not be null.");
- final Map<T, Integer> map = new HashMap<>();
- map.put(object, 1);
- return new ObjectProduct<>(map);
- }
-
- /**
- * The objects that make up the product, mapped to their exponents. This map treats zero as null, and is immutable.
- *
- * @since 2019-10-16
- */
- final Map<T, Integer> exponents;
-
- /**
- * Creates the {@code ObjectProduct}.
- *
- * @param exponents
- * objects that make up this product
- * @since 2019-10-16
- */
- private ObjectProduct(final Map<T, Integer> exponents) {
- this.exponents = Collections.unmodifiableMap(ConditionalExistenceCollections.conditionalExistenceMap(exponents,
- e -> !Integer.valueOf(0).equals(e.getValue())));
- }
-
- /**
- * Calculates the quotient of two products
- *
- * @param other
- * other product
- * @return quotient of two products
- * @since 2019-10-16
- * @throws NullPointerException
- * if other is null
- */
- public ObjectProduct<T> dividedBy(final ObjectProduct<T> other) {
- Objects.requireNonNull(other, "other must not be null.");
- // get a list of all objects in both sets
- final Set<T> objects = new HashSet<>();
- objects.addAll(this.getBaseSet());
- objects.addAll(other.getBaseSet());
-
- // get a list of all exponents
- final Map<T, Integer> map = new HashMap<>(objects.size());
- for (final T key : objects) {
- map.put(key, this.getExponent(key) - other.getExponent(key));
- }
-
- // create the product
- return new ObjectProduct<>(map);
- }
-
- // this method relies on the use of ZeroIsNullMap
- @Override
- public boolean equals(final Object obj) {
- if (this == obj)
- return true;
- if (!(obj instanceof ObjectProduct))
- return false;
- final ObjectProduct<?> other = (ObjectProduct<?>) obj;
- return Objects.equals(this.exponents, other.exponents);
- }
-
- /**
- * @return immutable map mapping objects to exponents
- * @since 2019-10-16
- */
- public Map<T, Integer> exponentMap() {
- return this.exponents;
- }
-
- /**
- * @return a set of all of the base objects with non-zero exponents that make up this dimension.
- * @since 2018-12-12
- * @since v0.1.0
- */
- public final Set<T> getBaseSet() {
- final Set<T> dimensions = new HashSet<>();
-
- // add all dimensions with a nonzero exponent - zero exponents shouldn't be there in the first place
- for (final T dimension : this.exponents.keySet()) {
- if (!this.exponents.get(dimension).equals(0)) {
- dimensions.add(dimension);
- }
- }
-
- return dimensions;
- }
-
- /**
- * Gets the exponent for a specific dimension.
- *
- * @param dimension
- * dimension to check
- * @return exponent for that dimension
- * @since 2018-12-12
- * @since v0.1.0
- */
- public int getExponent(final T dimension) {
- return this.exponents.getOrDefault(dimension, 0);
- }
-
- @Override
- public int hashCode() {
- return Objects.hash(this.exponents);
- }
-
- /**
- * @return true if this product is a single object, i.e. it has one exponent of one and no other nonzero exponents
- * @since 2019-10-16
- */
- public boolean isSingleObject() {
- int oneCount = 0;
- boolean twoOrMore = false; // has exponents of 2 or more
- for (final T b : this.getBaseSet()) {
- if (this.getExponent(b) == 1) {
- oneCount++;
- } else if (this.getExponent(b) != 0) {
- twoOrMore = true;
- }
- }
- return oneCount == 1 && !twoOrMore;
- }
-
- /**
- * Multiplies this product by another
- *
- * @param other
- * other product
- * @return product of two products
- * @since 2019-10-16
- * @throws NullPointerException
- * if other is null
- */
- public ObjectProduct<T> times(final ObjectProduct<T> other) {
- Objects.requireNonNull(other, "other must not be null.");
- // get a list of all objects in both sets
- final Set<T> objects = new HashSet<>();
- objects.addAll(this.getBaseSet());
- objects.addAll(other.getBaseSet());
-
- // get a list of all exponents
- final Map<T, Integer> map = new HashMap<>(objects.size());
- for (final T key : objects) {
- map.put(key, this.getExponent(key) + other.getExponent(key));
- }
-
- // create the product
- return new ObjectProduct<>(map);
- }
-
- /**
- * Returns this product, but to an exponent
- *
- * @param exponent
- * exponent
- * @return result of exponentiation
- * @since 2019-10-16
- */
- public ObjectProduct<T> toExponent(final int exponent) {
- final Map<T, Integer> map = new HashMap<>(this.exponents);
- for (final T key : this.exponents.keySet()) {
- map.put(key, this.getExponent(key) * exponent);
- }
- return new ObjectProduct<>(map);
- }
-
- /**
- * Converts this product to a string using the objects' {@link Object#toString()} method. If objects have a long
- * toString representation, it is recommended to use {@link #toString(Function)} instead to shorten the returned
- * string.
- *
- * <p>
- * {@inheritDoc}
- */
- @Override
- public String toString() {
- return this.toString(Object::toString);
- }
-
- /**
- * Converts this product to a string. The objects that make up this product are represented by
- * {@code objectToString}
- *
- * @param objectToString
- * function to convert objects to strings
- * @return string representation of product
- * @since 2019-10-16
- */
- public String toString(final Function<T, String> objectToString) {
- final List<String> positiveStringComponents = new ArrayList<>();
- final List<String> negativeStringComponents = new ArrayList<>();
-
- // for each base object that makes up this object, add it and its exponent
- for (final T object : this.getBaseSet()) {
- final int exponent = this.exponents.get(object);
- if (exponent > 0) {
- positiveStringComponents.add(String.format("%s^%d", objectToString.apply(object), exponent));
- } else if (exponent < 0) {
- negativeStringComponents.add(String.format("%s^%d", objectToString.apply(object), -exponent));
- }
- }
-
- final String positiveString = positiveStringComponents.isEmpty() ? "1"
- : String.join(" * ", positiveStringComponents);
- final String negativeString = negativeStringComponents.isEmpty() ? ""
- : " / " + String.join(" * ", negativeStringComponents);
-
- return positiveString + negativeString;
- }
-}
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