Merge branch 'develop' into feature-settings-tab

1 files changed, 0 insertions, 1991 deletions

diff --git a/src/org/unitConverter/unit/UnitDatabase.java b/src/org/unitConverter/unit/UnitDatabase.java
deleted file mode 100644
index 000acf5..0000000
--- a/src/org/unitConverter/unit/UnitDatabase.java
+++ /dev/null
@@ -1,1991 +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.unit;
-
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.math.BigDecimal;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.AbstractSet;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.NoSuchElementException;
-import java.util.Objects;
-import java.util.Set;
-import java.util.function.BiFunction;
-import java.util.function.Function;
-import java.util.function.Predicate;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-import org.unitConverter.math.ConditionalExistenceCollections;
-import org.unitConverter.math.DecimalComparison;
-import org.unitConverter.math.ExpressionParser;
-import org.unitConverter.math.ObjectProduct;
-import org.unitConverter.math.UncertainDouble;
-
-/**
- * A database of units, prefixes and dimensions, and their names.
- * 
- * @author Adrien Hopkins
- * @since 2019-01-07
- * @since v0.1.0
- */
-public final class UnitDatabase {
-	/**
-	 * A map for units that allows the use of prefixes.
-	 * <p>
-	 * As this map implementation is intended to be used as a sort of "augmented
-	 * view" of a unit and prefix map, it is unmodifiable but instead reflects
-	 * the changes to the maps passed into it. Do not edit this map, instead edit
-	 * the maps that were passed in during construction.
-	 * </p>
-	 * <p>
-	 * The rules for applying prefixes onto units are the following:
-	 * <ul>
-	 * <li>Prefixes can only be applied to linear units.</li>
-	 * <li>Before attempting to search for prefixes in a unit name, this map will
-	 * first search for a unit name. So, if there are two units, "B" and "AB",
-	 * and a prefix "A", this map will favour the unit "AB" over the unit "B"
-	 * with the prefix "A", even though they have the same string.</li>
-	 * <li>Longer prefixes are preferred to shorter prefixes. So, if you have
-	 * units "BC" and "C", and prefixes "AB" and "A", inputting "ABC" will return
-	 * the unit "C" with the prefix "AB", not "BC" with the prefix "A".</li>
-	 * </ul>
-	 * </p>
-	 * <p>
-	 * This map is infinite in size if there is at least one unit and at least
-	 * one prefix. If it is infinite, some operations that only work with finite
-	 * collections, like converting name/entry sets to arrays, will throw an
-	 * {@code IllegalStateException}.
-	 * </p>
-	 * <p>
-	 * Because of ambiguities between prefixes (i.e. kilokilo = mega),
-	 * {@link #containsValue} and {@link #values()} currently ignore prefixes.
-	 * </p>
-	 * 
-	 * @author Adrien Hopkins
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	private static final class PrefixedUnitMap implements Map<String, Unit> {
-		/**
-		 * The class used for entry sets.
-		 * 
-		 * <p>
-		 * If the map that created this set is infinite in size (has at least one
-		 * unit and at least one prefix), this set is infinite as well. If this
-		 * set is infinite in size, {@link #toArray} will fail with a
-		 * {@code IllegalStateException} instead of creating an infinite-sized
-		 * array.
-		 * </p>
-		 * 
-		 * @author Adrien Hopkins
-		 * @since 2019-04-13
-		 * @since v0.2.0
-		 */
-		private static final class PrefixedUnitEntrySet
-				extends AbstractSet<Map.Entry<String, Unit>> {
-			/**
-			 * The entry for this set.
-			 * 
-			 * @author Adrien Hopkins
-			 * @since 2019-04-14
-			 * @since v0.2.0
-			 */
-			private static final class PrefixedUnitEntry
-					implements Entry<String, Unit> {
-				private final String key;
-				private final Unit value;
-				
-				/**
-				 * Creates the {@code PrefixedUnitEntry}.
-				 * 
-				 * @param key   key
-				 * @param value value
-				 * @since 2019-04-14
-				 * @since v0.2.0
-				 */
-				public PrefixedUnitEntry(final String key, final Unit value) {
-					this.key = key;
-					this.value = value;
-				}
-				
-				/**
-				 * @since 2019-05-03
-				 */
-				@Override
-				public boolean equals(final Object o) {
-					if (!(o instanceof Map.Entry))
-						return false;
-					final Map.Entry<?, ?> other = (Map.Entry<?, ?>) o;
-					return Objects.equals(this.getKey(), other.getKey())
-							&& Objects.equals(this.getValue(), other.getValue());
-				}
-				
-				@Override
-				public String getKey() {
-					return this.key;
-				}
-				
-				@Override
-				public Unit getValue() {
-					return this.value;
-				}
-				
-				/**
-				 * @since 2019-05-03
-				 */
-				@Override
-				public int hashCode() {
-					return (this.getKey() == null ? 0 : this.getKey().hashCode())
-							^ (this.getValue() == null ? 0
-									: this.getValue().hashCode());
-				}
-				
-				@Override
-				public Unit setValue(final Unit value) {
-					throw new UnsupportedOperationException(
-							"Cannot set value in an immutable entry");
-				}
-				
-				/**
-				 * Returns a string representation of the entry. The format of the
-				 * string is the string representation of the key, then the equals
-				 * ({@code =}) character, then the string representation of the
-				 * value.
-				 * 
-				 * @since 2019-05-03
-				 */
-				@Override
-				public String toString() {
-					return this.getKey() + "=" + this.getValue();
-				}
-			}
-			
-			/**
-			 * An iterator that iterates over the units of a
-			 * {@code PrefixedUnitNameSet}.
-			 * 
-			 * @author Adrien Hopkins
-			 * @since 2019-04-14
-			 * @since v0.2.0
-			 */
-			private static final class PrefixedUnitEntryIterator
-					implements Iterator<Entry<String, Unit>> {
-				// position in the unit list
-				private int unitNamePosition = 0;
-				// the indices of the prefixes attached to the current unit
-				private final List<Integer> prefixCoordinates = new ArrayList<>();
-				
-				// values from the unit entry set
-				private final Map<String, Unit> map;
-				private transient final List<String> unitNames;
-				private transient final List<String> prefixNames;
-				
-				/**
-				 * Creates the
-				 * {@code UnitsDatabase.PrefixedUnitMap.PrefixedUnitNameSet.PrefixedUnitNameIterator}.
-				 * 
-				 * @since 2019-04-14
-				 * @since v0.2.0
-				 */
-				public PrefixedUnitEntryIterator(final PrefixedUnitMap map) {
-					this.map = map;
-					this.unitNames = new ArrayList<>(map.units.keySet());
-					this.prefixNames = new ArrayList<>(map.prefixes.keySet());
-				}
-				
-				/**
-				 * @return current unit name
-				 * @since 2019-04-14
-				 * @since v0.2.0
-				 */
-				private String getCurrentUnitName() {
-					final StringBuilder unitName = new StringBuilder();
-					for (final int i : this.prefixCoordinates) {
-						unitName.append(this.prefixNames.get(i));
-					}
-					unitName.append(this.unitNames.get(this.unitNamePosition));
-					
-					return unitName.toString();
-				}
-				
-				@Override
-				public boolean hasNext() {
-					if (this.unitNames.isEmpty())
-						return false;
-					else {
-						if (this.prefixNames.isEmpty())
-							return this.unitNamePosition >= this.unitNames.size() - 1;
-						else
-							return true;
-					}
-				}
-				
-				/**
-				 * Changes this iterator's position to the next available one.
-				 * 
-				 * @since 2019-04-14
-				 * @since v0.2.0
-				 */
-				private void incrementPosition() {
-					this.unitNamePosition++;
-					
-					if (this.unitNamePosition >= this.unitNames.size()) {
-						// we have used all of our units, go to a different prefix
-						this.unitNamePosition = 0;
-						
-						// if the prefix coordinates are empty, then set it to [0]
-						if (this.prefixCoordinates.isEmpty()) {
-							this.prefixCoordinates.add(0, 0);
-						} else {
-							// get the prefix coordinate to increment, then increment
-							int i = this.prefixCoordinates.size() - 1;
-							this.prefixCoordinates.set(i,
-									this.prefixCoordinates.get(i) + 1);
-							
-							// fix any carrying errors
-							while (i >= 0 && this.prefixCoordinates
-									.get(i) >= this.prefixNames.size()) {
-								// carry over
-								this.prefixCoordinates.set(i--, 0); // null and
-																				// decrement at the
-																				// same time
-								
-								if (i < 0) { // we need to add a new coordinate
-									this.prefixCoordinates.add(0, 0);
-								} else { // increment an existing one
-									this.prefixCoordinates.set(i,
-											this.prefixCoordinates.get(i) + 1);
-								}
-							}
-						}
-					}
-				}
-				
-				@Override
-				public Entry<String, Unit> next() {
-					// get next element
-					final Entry<String, Unit> nextEntry = this.peek();
-					
-					// iterate to next position
-					this.incrementPosition();
-					
-					return nextEntry;
-				}
-				
-				/**
-				 * @return the next element in the iterator, without iterating over
-				 *         it
-				 * @since 2019-05-03
-				 */
-				private Entry<String, Unit> peek() {
-					if (!this.hasNext())
-						throw new NoSuchElementException("No units left!");
-						
-					// if I have prefixes, ensure I'm not using a nonlinear unit
-					// since all of the unprefixed stuff is done, just remove
-					// nonlinear units
-					if (!this.prefixCoordinates.isEmpty()) {
-						while (this.unitNamePosition < this.unitNames.size()
-								&& !(this.map.get(this.unitNames.get(
-										this.unitNamePosition)) instanceof LinearUnit)) {
-							this.unitNames.remove(this.unitNamePosition);
-						}
-					}
-					
-					final String nextName = this.getCurrentUnitName();
-					
-					return new PrefixedUnitEntry(nextName, this.map.get(nextName));
-				}
-				
-				/**
-				 * Returns a string representation of the object. The exact details
-				 * of the representation are unspecified and subject to change.
-				 * 
-				 * @since 2019-05-03
-				 */
-				@Override
-				public String toString() {
-					return String.format(
-							"Iterator iterating over name-unit entries; next value is \"%s\"",
-							this.peek());
-				}
-			}
-			
-			// the map that created this set
-			private final PrefixedUnitMap map;
-			
-			/**
-			 * Creates the {@code PrefixedUnitNameSet}.
-			 * 
-			 * @param map map that created this set
-			 * @since 2019-04-13
-			 * @since v0.2.0
-			 */
-			public PrefixedUnitEntrySet(final PrefixedUnitMap map) {
-				this.map = map;
-			}
-			
-			@Override
-			public boolean add(final Map.Entry<String, Unit> e) {
-				throw new UnsupportedOperationException(
-						"Cannot add to an immutable set");
-			}
-			
-			@Override
-			public boolean addAll(
-					final Collection<? extends Map.Entry<String, Unit>> c) {
-				throw new UnsupportedOperationException(
-						"Cannot add to an immutable set");
-			}
-			
-			@Override
-			public void clear() {
-				throw new UnsupportedOperationException(
-						"Cannot clear an immutable set");
-			}
-			
-			@Override
-			public boolean contains(final Object o) {
-				// get the entry
-				final Entry<String, Unit> entry;
-				
-				try {
-					// This is OK because I'm in a try-catch block, catching the
-					// exact exception that would be thrown.
-					@SuppressWarnings("unchecked")
-					final Entry<String, Unit> tempEntry = (Entry<String, Unit>) o;
-					entry = tempEntry;
-				} catch (final ClassCastException e) {
-					throw new IllegalArgumentException(
-							"Attempted to test for an entry using a non-entry.");
-				}
-				
-				return this.map.containsKey(entry.getKey())
-						&& this.map.get(entry.getKey()).equals(entry.getValue());
-			}
-			
-			@Override
-			public boolean containsAll(final Collection<?> c) {
-				for (final Object o : c)
-					if (!this.contains(o))
-						return false;
-				return true;
-			}
-			
-			@Override
-			public boolean isEmpty() {
-				return this.map.isEmpty();
-			}
-			
-			@Override
-			public Iterator<Entry<String, Unit>> iterator() {
-				return new PrefixedUnitEntryIterator(this.map);
-			}
-			
-			@Override
-			public boolean remove(final Object o) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public boolean removeAll(final Collection<?> c) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public boolean removeIf(
-					final Predicate<? super Entry<String, Unit>> filter) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public boolean retainAll(final Collection<?> c) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public int size() {
-				if (this.map.units.isEmpty())
-					return 0;
-				else {
-					if (this.map.prefixes.isEmpty())
-						return this.map.units.size();
-					else
-						// infinite set
-						return Integer.MAX_VALUE;
-				}
-			}
-			
-			/**
-			 * @throws IllegalStateException if the set is infinite in size
-			 */
-			@Override
-			public Object[] toArray() {
-				if (this.map.units.isEmpty() || this.map.prefixes.isEmpty())
-					return super.toArray();
-				else
-					// infinite set
-					throw new IllegalStateException(
-							"Cannot make an infinite set into an array.");
-			}
-			
-			/**
-			 * @throws IllegalStateException if the set is infinite in size
-			 */
-			@Override
-			public <T> T[] toArray(final T[] a) {
-				if (this.map.units.isEmpty() || this.map.prefixes.isEmpty())
-					return super.toArray(a);
-				else
-					// infinite set
-					throw new IllegalStateException(
-							"Cannot make an infinite set into an array.");
-			}
-			
-			@Override
-			public String toString() {
-				if (this.map.units.isEmpty() || this.map.prefixes.isEmpty())
-					return super.toString();
-				else
-					return String.format(
-							"Infinite set of name-unit entries created from units %s and prefixes %s",
-							this.map.units, this.map.prefixes);
-			}
-		}
-		
-		/**
-		 * The class used for unit name sets.
-		 * 
-		 * <p>
-		 * If the map that created this set is infinite in size (has at least one
-		 * unit and at least one prefix), this set is infinite as well. If this
-		 * set is infinite in size, {@link #toArray} will fail with a
-		 * {@code IllegalStateException} instead of creating an infinite-sized
-		 * array.
-		 * </p>
-		 * 
-		 * @author Adrien Hopkins
-		 * @since 2019-04-13
-		 * @since v0.2.0
-		 */
-		private static final class PrefixedUnitNameSet
-				extends AbstractSet<String> {
-			/**
-			 * An iterator that iterates over the units of a
-			 * {@code PrefixedUnitNameSet}.
-			 * 
-			 * @author Adrien Hopkins
-			 * @since 2019-04-14
-			 * @since v0.2.0
-			 */
-			private static final class PrefixedUnitNameIterator
-					implements Iterator<String> {
-				// position in the unit list
-				private int unitNamePosition = 0;
-				// the indices of the prefixes attached to the current unit
-				private final List<Integer> prefixCoordinates = new ArrayList<>();
-				
-				// values from the unit name set
-				private final Map<String, Unit> map;
-				private transient final List<String> unitNames;
-				private transient final List<String> prefixNames;
-				
-				/**
-				 * Creates the
-				 * {@code UnitsDatabase.PrefixedUnitMap.PrefixedUnitNameSet.PrefixedUnitNameIterator}.
-				 * 
-				 * @since 2019-04-14
-				 * @since v0.2.0
-				 */
-				public PrefixedUnitNameIterator(final PrefixedUnitMap map) {
-					this.map = map;
-					this.unitNames = new ArrayList<>(map.units.keySet());
-					this.prefixNames = new ArrayList<>(map.prefixes.keySet());
-				}
-				
-				/**
-				 * @return current unit name
-				 * @since 2019-04-14
-				 * @since v0.2.0
-				 */
-				private String getCurrentUnitName() {
-					final StringBuilder unitName = new StringBuilder();
-					for (final int i : this.prefixCoordinates) {
-						unitName.append(this.prefixNames.get(i));
-					}
-					unitName.append(this.unitNames.get(this.unitNamePosition));
-					
-					return unitName.toString();
-				}
-				
-				@Override
-				public boolean hasNext() {
-					if (this.unitNames.isEmpty())
-						return false;
-					else {
-						if (this.prefixNames.isEmpty())
-							return this.unitNamePosition >= this.unitNames.size() - 1;
-						else
-							return true;
-					}
-				}
-				
-				/**
-				 * Changes this iterator's position to the next available one.
-				 * 
-				 * @since 2019-04-14
-				 * @since v0.2.0
-				 */
-				private void incrementPosition() {
-					this.unitNamePosition++;
-					
-					if (this.unitNamePosition >= this.unitNames.size()) {
-						// we have used all of our units, go to a different prefix
-						this.unitNamePosition = 0;
-						
-						// if the prefix coordinates are empty, then set it to [0]
-						if (this.prefixCoordinates.isEmpty()) {
-							this.prefixCoordinates.add(0, 0);
-						} else {
-							// get the prefix coordinate to increment, then increment
-							int i = this.prefixCoordinates.size() - 1;
-							this.prefixCoordinates.set(i,
-									this.prefixCoordinates.get(i) + 1);
-							
-							// fix any carrying errors
-							while (i >= 0 && this.prefixCoordinates
-									.get(i) >= this.prefixNames.size()) {
-								// carry over
-								this.prefixCoordinates.set(i--, 0); // null and
-																				// decrement at the
-																				// same time
-								
-								if (i < 0) { // we need to add a new coordinate
-									this.prefixCoordinates.add(0, 0);
-								} else { // increment an existing one
-									this.prefixCoordinates.set(i,
-											this.prefixCoordinates.get(i) + 1);
-								}
-							}
-						}
-					}
-				}
-				
-				@Override
-				public String next() {
-					final String nextName = this.peek();
-					
-					this.incrementPosition();
-					
-					return nextName;
-				}
-				
-				/**
-				 * @return the next element in the iterator, without iterating over
-				 *         it
-				 * @since 2019-05-03
-				 */
-				private String peek() {
-					if (!this.hasNext())
-						throw new NoSuchElementException("No units left!");
-					// if I have prefixes, ensure I'm not using a nonlinear unit
-					// since all of the unprefixed stuff is done, just remove
-					// nonlinear units
-					if (!this.prefixCoordinates.isEmpty()) {
-						while (this.unitNamePosition < this.unitNames.size()
-								&& !(this.map.get(this.unitNames.get(
-										this.unitNamePosition)) instanceof LinearUnit)) {
-							this.unitNames.remove(this.unitNamePosition);
-						}
-					}
-					
-					return this.getCurrentUnitName();
-				}
-				
-				/**
-				 * Returns a string representation of the object. The exact details
-				 * of the representation are unspecified and subject to change.
-				 * 
-				 * @since 2019-05-03
-				 */
-				@Override
-				public String toString() {
-					return String.format(
-							"Iterator iterating over unit names; next value is \"%s\"",
-							this.peek());
-				}
-			}
-			
-			// the map that created this set
-			private final PrefixedUnitMap map;
-			
-			/**
-			 * Creates the {@code PrefixedUnitNameSet}.
-			 * 
-			 * @param map map that created this set
-			 * @since 2019-04-13
-			 * @since v0.2.0
-			 */
-			public PrefixedUnitNameSet(final PrefixedUnitMap map) {
-				this.map = map;
-			}
-			
-			@Override
-			public boolean add(final String e) {
-				throw new UnsupportedOperationException(
-						"Cannot add to an immutable set");
-			}
-			
-			@Override
-			public boolean addAll(final Collection<? extends String> c) {
-				throw new UnsupportedOperationException(
-						"Cannot add to an immutable set");
-			}
-			
-			@Override
-			public void clear() {
-				throw new UnsupportedOperationException(
-						"Cannot clear an immutable set");
-			}
-			
-			@Override
-			public boolean contains(final Object o) {
-				return this.map.containsKey(o);
-			}
-			
-			@Override
-			public boolean containsAll(final Collection<?> c) {
-				for (final Object o : c)
-					if (!this.contains(o))
-						return false;
-				return true;
-			}
-			
-			@Override
-			public boolean isEmpty() {
-				return this.map.isEmpty();
-			}
-			
-			@Override
-			public Iterator<String> iterator() {
-				return new PrefixedUnitNameIterator(this.map);
-			}
-			
-			@Override
-			public boolean remove(final Object o) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public boolean removeAll(final Collection<?> c) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public boolean removeIf(final Predicate<? super String> filter) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public boolean retainAll(final Collection<?> c) {
-				throw new UnsupportedOperationException(
-						"Cannot remove from an immutable set");
-			}
-			
-			@Override
-			public int size() {
-				if (this.map.units.isEmpty())
-					return 0;
-				else {
-					if (this.map.prefixes.isEmpty())
-						return this.map.units.size();
-					else
-						// infinite set
-						return Integer.MAX_VALUE;
-				}
-			}
-			
-			/**
-			 * @throws IllegalStateException if the set is infinite in size
-			 */
-			@Override
-			public Object[] toArray() {
-				if (this.map.units.isEmpty() || this.map.prefixes.isEmpty())
-					return super.toArray();
-				else
-					// infinite set
-					throw new IllegalStateException(
-							"Cannot make an infinite set into an array.");
-				
-			}
-			
-			/**
-			 * @throws IllegalStateException if the set is infinite in size
-			 */
-			@Override
-			public <T> T[] toArray(final T[] a) {
-				if (this.map.units.isEmpty() || this.map.prefixes.isEmpty())
-					return super.toArray(a);
-				else
-					// infinite set
-					throw new IllegalStateException(
-							"Cannot make an infinite set into an array.");
-			}
-			
-			@Override
-			public String toString() {
-				if (this.map.units.isEmpty() || this.map.prefixes.isEmpty())
-					return super.toString();
-				else
-					return String.format(
-							"Infinite set of name-unit entries created from units %s and prefixes %s",
-							this.map.units, this.map.prefixes);
-			}
-		}
-		
-		/**
-		 * The units stored in this collection, without prefixes.
-		 * 
-		 * @since 2019-04-13
-		 * @since v0.2.0
-		 */
-		private final Map<String, Unit> units;
-		
-		/**
-		 * The available prefixes for use.
-		 * 
-		 * @since 2019-04-13
-		 * @since v0.2.0
-		 */
-		private final Map<String, UnitPrefix> prefixes;
-		
-		// caches
-		private transient Collection<Unit> values = null;
-		private transient Set<String> keySet = null;
-		private transient Set<Entry<String, Unit>> entrySet = null;
-		
-		/**
-		 * Creates the {@code PrefixedUnitMap}.
-		 * 
-		 * @param units    map mapping unit names to units
-		 * @param prefixes map mapping prefix names to prefixes
-		 * @since 2019-04-13
-		 * @since v0.2.0
-		 */
-		public PrefixedUnitMap(final Map<String, Unit> units,
-				final Map<String, UnitPrefix> prefixes) {
-			// I am making unmodifiable maps to ensure I don't accidentally make
-			// changes.
-			this.units = Collections.unmodifiableMap(units);
-			this.prefixes = Collections.unmodifiableMap(prefixes);
-		}
-		
-		@Override
-		public void clear() {
-			throw new UnsupportedOperationException(
-					"Cannot clear an immutable map");
-		}
-		
-		@Override
-		public Unit compute(final String key,
-				final BiFunction<? super String, ? super Unit, ? extends Unit> remappingFunction) {
-			throw new UnsupportedOperationException(
-					"Cannot edit an immutable map");
-		}
-		
-		@Override
-		public Unit computeIfAbsent(final String key,
-				final Function<? super String, ? extends Unit> mappingFunction) {
-			throw new UnsupportedOperationException(
-					"Cannot edit an immutable map");
-		}
-		
-		@Override
-		public Unit computeIfPresent(final String key,
-				final BiFunction<? super String, ? super Unit, ? extends Unit> remappingFunction) {
-			throw new UnsupportedOperationException(
-					"Cannot edit an immutable map");
-		}
-		
-		@Override
-		public boolean containsKey(final Object key) {
-			// First, test if there is a unit with the key
-			if (this.units.containsKey(key))
-				return true;
-			
-			// Next, try to cast it to String
-			if (!(key instanceof String))
-				throw new IllegalArgumentException(
-						"Attempted to test for a unit using a non-string name.");
-			final String unitName = (String) key;
-			
-			// Then, look for the longest prefix that is attached to a valid unit
-			String longestPrefix = null;
-			int longestLength = 0;
-			
-			for (final String prefixName : this.prefixes.keySet()) {
-				// a prefix name is valid if:
-				// - it is prefixed (i.e. the unit name starts with it)
-				// - it is longer than the existing largest prefix (since I am
-				// looking for the longest valid prefix)
-				// - the part after the prefix is a valid unit name
-				// - the unit described that name is a linear unit (since only
-				// linear units can have prefixes)
-				if (unitName.startsWith(prefixName)
-						&& prefixName.length() > longestLength) {
-					final String rest = unitName.substring(prefixName.length());
-					if (this.containsKey(rest)
-							&& this.get(rest) instanceof LinearUnit) {
-						longestPrefix = prefixName;
-						longestLength = prefixName.length();
-					}
-				}
-			}
-			
-			return longestPrefix != null;
-		}
-		
-		/**
-		 * {@inheritDoc}
-		 * 
-		 * <p>
-		 * Because of ambiguities between prefixes (i.e. kilokilo = mega), this
-		 * method only tests for prefixless units.
-		 * </p>
-		 */
-		@Override
-		public boolean containsValue(final Object value) {
-			return this.units.containsValue(value);
-		}
-		
-		@Override
-		public Set<Entry<String, Unit>> entrySet() {
-			if (this.entrySet == null) {
-				this.entrySet = new PrefixedUnitEntrySet(this);
-			}
-			return this.entrySet;
-		}
-		
-		@Override
-		public Unit get(final Object key) {
-			// First, test if there is a unit with the key
-			if (this.units.containsKey(key))
-				return this.units.get(key);
-			
-			// Next, try to cast it to String
-			if (!(key instanceof String))
-				throw new IllegalArgumentException(
-						"Attempted to obtain a unit using a non-string name.");
-			final String unitName = (String) key;
-			
-			// Then, look for the longest prefix that is attached to a valid unit
-			String longestPrefix = null;
-			int longestLength = 0;
-			
-			for (final String prefixName : this.prefixes.keySet()) {
-				// a prefix name is valid if:
-				// - it is prefixed (i.e. the unit name starts with it)
-				// - it is longer than the existing largest prefix (since I am
-				// looking for the longest valid prefix)
-				// - the part after the prefix is a valid unit name
-				// - the unit described that name is a linear unit (since only
-				// linear units can have prefixes)
-				if (unitName.startsWith(prefixName)
-						&& prefixName.length() > longestLength) {
-					final String rest = unitName.substring(prefixName.length());
-					if (this.containsKey(rest)
-							&& this.get(rest) instanceof LinearUnit) {
-						longestPrefix = prefixName;
-						longestLength = prefixName.length();
-					}
-				}
-			}
-			
-			// if none found, returns null
-			if (longestPrefix == null)
-				return null;
-			else {
-				// get necessary data
-				final String rest = unitName.substring(longestLength);
-				// this cast will not fail because I verified that it would work
-				// before selecting this prefix
-				final LinearUnit unit = (LinearUnit) this.get(rest);
-				final UnitPrefix prefix = this.prefixes.get(longestPrefix);
-				
-				return unit.withPrefix(prefix);
-			}
-		}
-		
-		@Override
-		public boolean isEmpty() {
-			return this.units.isEmpty();
-		}
-		
-		@Override
-		public Set<String> keySet() {
-			if (this.keySet == null) {
-				this.keySet = new PrefixedUnitNameSet(this);
-			}
-			return this.keySet;
-		}
-		
-		@Override
-		public Unit merge(final String key, final Unit value,
-				final BiFunction<? super Unit, ? super Unit, ? extends Unit> remappingFunction) {
-			throw new UnsupportedOperationException(
-					"Cannot merge into an immutable map");
-		}
-		
-		@Override
-		public Unit put(final String key, final Unit value) {
-			throw new UnsupportedOperationException(
-					"Cannot add entries to an immutable map");
-		}
-		
-		@Override
-		public void putAll(final Map<? extends String, ? extends Unit> m) {
-			throw new UnsupportedOperationException(
-					"Cannot add entries to an immutable map");
-		}
-		
-		@Override
-		public Unit putIfAbsent(final String key, final Unit value) {
-			throw new UnsupportedOperationException(
-					"Cannot add entries to an immutable map");
-		}
-		
-		@Override
-		public Unit remove(final Object key) {
-			throw new UnsupportedOperationException(
-					"Cannot remove entries from an immutable map");
-		}
-		
-		@Override
-		public boolean remove(final Object key, final Object value) {
-			throw new UnsupportedOperationException(
-					"Cannot remove entries from an immutable map");
-		}
-		
-		@Override
-		public Unit replace(final String key, final Unit value) {
-			throw new UnsupportedOperationException(
-					"Cannot replace entries in an immutable map");
-		}
-		
-		@Override
-		public boolean replace(final String key, final Unit oldValue,
-				final Unit newValue) {
-			throw new UnsupportedOperationException(
-					"Cannot replace entries in an immutable map");
-		}
-		
-		@Override
-		public void replaceAll(
-				final BiFunction<? super String, ? super Unit, ? extends Unit> function) {
-			throw new UnsupportedOperationException(
-					"Cannot replace entries in an immutable map");
-		}
-		
-		@Override
-		public int size() {
-			if (this.units.isEmpty())
-				return 0;
-			else {
-				if (this.prefixes.isEmpty())
-					return this.units.size();
-				else
-					// infinite set
-					return Integer.MAX_VALUE;
-			}
-		}
-		
-		@Override
-		public String toString() {
-			if (this.units.isEmpty() || this.prefixes.isEmpty())
-				return super.toString();
-			else
-				return String.format(
-						"Infinite map of name-unit entries created from units %s and prefixes %s",
-						this.units, this.prefixes);
-		}
-		
-		/**
-		 * {@inheritDoc}
-		 * 
-		 * <p>
-		 * Because of ambiguities between prefixes (i.e. kilokilo = mega), this
-		 * method ignores prefixes.
-		 * </p>
-		 */
-		@Override
-		public Collection<Unit> values() {
-			if (this.values == null) {
-				this.values = Collections
-						.unmodifiableCollection(this.units.values());
-			}
-			return this.values;
-		}
-	}
-	
-	/**
-	 * Replacements done to *all* expression types
-	 */
-	private static final Map<Pattern, String> EXPRESSION_REPLACEMENTS = new HashMap<>();
-	
-	// add data to expression replacements
-	static {
-		// add spaces around operators
-		for (final String operator : Arrays.asList("\\*", "/", "\\^")) {
-			EXPRESSION_REPLACEMENTS.put(Pattern.compile(operator),
-					" " + operator + " ");
-		}
-		
-		// replace multiple spaces with a single space
-		EXPRESSION_REPLACEMENTS.put(Pattern.compile(" +"), " ");
-		// place brackets around any expression of the form "number unit", with or
-		// without the space
-		EXPRESSION_REPLACEMENTS.put(Pattern.compile("((?:-?[1-9]\\d*|0)" // integer
-				+ "(?:\\.\\d+(?:[eE]\\d+))?)" // optional decimal point with numbers
-														// after it
-				+ "\\s*" // optional space(s)
-				+ "([a-zA-Z]+(?:\\^\\d+)?" // any string of letters
-				+ "(?:\\s+[a-zA-Z]+(?:\\^\\d+)?))" // optional other letters
-				+ "(?!-?\\d)" // no number directly afterwards (avoids matching
-									// "1e3")
-		), "\\($1 $2\\)");
-	}
-	
-	/**
-	 * A regular expression that separates names and expressions in unit files.
-	 */
-	private static final Pattern NAME_EXPRESSION = Pattern
-			.compile("(\\S+)\\s+(\\S.*)");
-	
-	/**
-	 * The exponent operator
-	 * 
-	 * @param base         base of exponentiation
-	 * @param exponentUnit exponent
-	 * @return result
-	 * @since 2019-04-10
-	 * @since v0.2.0
-	 */
-	private static final LinearUnit exponentiateUnits(final LinearUnit base,
-			final LinearUnit exponentUnit) {
-		// exponent function - first check if o2 is a number,
-		if (exponentUnit.getBase().equals(SI.ONE.getBase())) {
-			// then check if it is an integer,
-			final double exponent = exponentUnit.getConversionFactor();
-			if (DecimalComparison.equals(exponent % 1, 0))
-				// then exponentiate
-				return base.toExponent((int) (exponent + 0.5));
-			else
-				// not an integer
-				throw new UnsupportedOperationException(
-						"Decimal exponents are currently not supported.");
-		} else
-			// not a number
-			throw new IllegalArgumentException("Exponents must be numbers.");
-	}
-	
-	/**
-	 * The exponent operator
-	 * 
-	 * @param base         base of exponentiation
-	 * @param exponentUnit exponent
-	 * @return result
-	 * @since 2020-08-04
-	 */
-	private static final LinearUnitValue exponentiateUnitValues(
-			final LinearUnitValue base, final LinearUnitValue exponentValue) {
-		// exponent function - first check if o2 is a number,
-		if (exponentValue.canConvertTo(SI.ONE)) {
-			// then check if it is an integer,
-			final double exponent = exponentValue.getValueExact();
-			if (DecimalComparison.equals(exponent % 1, 0))
-				// then exponentiate
-				return base.toExponent((int) (exponent + 0.5));
-			else
-				// not an integer
-				throw new UnsupportedOperationException(
-						"Decimal exponents are currently not supported.");
-		} else
-			// not a number
-			throw new IllegalArgumentException("Exponents must be numbers.");
-	}
-	
-	/**
-	 * The units in this system, excluding prefixes.
-	 * 
-	 * @since 2019-01-07
-	 * @since v0.1.0
-	 */
-	private final Map<String, Unit> prefixlessUnits;
-	
-	/**
-	 * The unit prefixes in this system.
-	 * 
-	 * @since 2019-01-14
-	 * @since v0.1.0
-	 */
-	private final Map<String, UnitPrefix> prefixes;
-	
-	/**
-	 * The dimensions in this system.
-	 * 
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private final Map<String, ObjectProduct<BaseDimension>> dimensions;
-	
-	/**
-	 * A map mapping strings to units (including prefixes)
-	 * 
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	private final Map<String, Unit> units;
-	
-	/**
-	 * The rule that specifies when prefix repetition is allowed. It takes in one
-	 * argument: a list of the prefixes being applied to the unit
-	 * <p>
-	 * The prefixes are inputted in <em>application order</em>. This means that
-	 * testing whether "kilomegagigametre" is a valid unit is equivalent to
-	 * running the following code (assuming all variables are defined correctly):
-	 * <br>
-	 * {@code prefixRepetitionRule.test(Arrays.asList(giga, mega, kilo))}
-	 */
-	private Predicate<List<UnitPrefix>> prefixRepetitionRule;
-	
-	/**
-	 * A parser that can parse unit expressions.
-	 * 
-	 * @since 2019-03-22
-	 * @since v0.2.0
-	 */
-	private final ExpressionParser<LinearUnit> unitExpressionParser = new ExpressionParser.Builder<>(
-			this::getLinearUnit).addBinaryOperator("+", (o1, o2) -> o1.plus(o2), 0)
-					.addBinaryOperator("-", (o1, o2) -> o1.minus(o2), 0)
-					.addBinaryOperator("*", (o1, o2) -> o1.times(o2), 1)
-					.addSpaceFunction("*")
-					.addBinaryOperator("/", (o1, o2) -> o1.dividedBy(o2), 1)
-					.addBinaryOperator("^", UnitDatabase::exponentiateUnits, 2)
-					.build();
-	
-	/**
-	 * A parser that can parse unit value expressions.
-	 * 
-	 * @since 2020-08-04
-	 */
-	private final ExpressionParser<LinearUnitValue> unitValueExpressionParser = new ExpressionParser.Builder<>(
-			this::getLinearUnitValue)
-					.addBinaryOperator("+", (o1, o2) -> o1.plus(o2), 0)
-					.addBinaryOperator("-", (o1, o2) -> o1.minus(o2), 0)
-					.addBinaryOperator("*", (o1, o2) -> o1.times(o2), 1)
-					.addSpaceFunction("*")
-					.addBinaryOperator("/", (o1, o2) -> o1.dividedBy(o2), 1)
-					.addBinaryOperator("^", UnitDatabase::exponentiateUnitValues, 2)
-					.build();
-	
-	/**
-	 * A parser that can parse unit prefix expressions
-	 * 
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	private final ExpressionParser<UnitPrefix> prefixExpressionParser = new ExpressionParser.Builder<>(
-			this::getPrefix).addBinaryOperator("*", (o1, o2) -> o1.times(o2), 0)
-					.addSpaceFunction("*")
-					.addBinaryOperator("/", (o1, o2) -> o1.dividedBy(o2), 0)
-					.addBinaryOperator("^",
-							(o1, o2) -> o1.toExponent(o2.getMultiplier()), 1)
-					.build();
-	
-	/**
-	 * A parser that can parse unit dimension expressions.
-	 * 
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	private final ExpressionParser<ObjectProduct<BaseDimension>> unitDimensionParser = new ExpressionParser.Builder<>(
-			this::getDimension).addBinaryOperator("*", (o1, o2) -> o1.times(o2), 0)
-					.addSpaceFunction("*")
-					.addBinaryOperator("/", (o1, o2) -> o1.dividedBy(o2), 0).build();
-	
-	/**
-	 * Creates the {@code UnitsDatabase}.
-	 * 
-	 * @since 2019-01-10
-	 * @since v0.1.0
-	 */
-	public UnitDatabase() {
-		this(prefixes -> true);
-	}
-	
-	/**
-	 * Creates the {@code UnitsDatabase}
-	 * 
-	 * @param prefixRepetitionRule the rule that determines when prefix
-	 *                             repetition is allowed
-	 * @since 2020-08-26
-	 */
-	public UnitDatabase(Predicate<List<UnitPrefix>> prefixRepetitionRule) {
-		this.prefixlessUnits = new HashMap<>();
-		this.prefixes = new HashMap<>();
-		this.dimensions = new HashMap<>();
-		this.prefixRepetitionRule = prefixRepetitionRule;
-		this.units = ConditionalExistenceCollections.conditionalExistenceMap(
-				new PrefixedUnitMap(this.prefixlessUnits, this.prefixes),
-				entry -> this.prefixRepetitionRule
-						.test(this.getPrefixesFromName(entry.getKey())));
-	}
-	
-	/**
-	 * Adds a unit dimension to the database.
-	 * 
-	 * @param name      dimension's name
-	 * @param dimension dimension to add
-	 * @throws NullPointerException if name or dimension is null
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	public void addDimension(final String name,
-			final ObjectProduct<BaseDimension> dimension) {
-		this.dimensions.put(
-				Objects.requireNonNull(name, "name must not be null."),
-				Objects.requireNonNull(dimension, "dimension must not be null."));
-	}
-	
-	/**
-	 * Adds to the list from a line in a unit dimension file.
-	 * 
-	 * @param line        line to look at
-	 * @param lineCounter number of line, for error messages
-	 * @since 2019-04-10
-	 * @since v0.2.0
-	 */
-	private void addDimensionFromLine(final String line,
-			final long lineCounter) {
-		// ignore lines that start with a # sign - they're comments
-		if (line.isEmpty())
-			return;
-		if (line.contains("#")) {
-			this.addDimensionFromLine(line.substring(0, line.indexOf("#")),
-					lineCounter);
-			return;
-		}
-		
-		// divide line into name and expression
-		final Matcher lineMatcher = NAME_EXPRESSION.matcher(line);
-		if (!lineMatcher.matches())
-			throw new IllegalArgumentException(String.format(
-					"Error at line %d: Lines of a dimension file must consist of a dimension name, then spaces or tabs, then a dimension expression.",
-					lineCounter));
-		final String name = lineMatcher.group(1);
-		final String expression = lineMatcher.group(2);
-		
-		if (name.endsWith(" ")) {
-			System.err.printf("Warning - line %d's dimension name ends in a space",
-					lineCounter);
-		}
-		
-		// if expression is "!", search for an existing dimension
-		// if no unit found, throw an error
-		if (expression.equals("!")) {
-			if (!this.containsDimensionName(name))
-				throw new IllegalArgumentException(String.format(
-						"! used but no dimension found (line %d).", lineCounter));
-		} else {
-			// it's a unit, get the unit
-			final ObjectProduct<BaseDimension> dimension;
-			try {
-				dimension = this.getDimensionFromExpression(expression);
-			} catch (final IllegalArgumentException e) {
-				System.err.printf("Parsing error on line %d:%n", lineCounter);
-				throw e;
-			}
-			
-			this.addDimension(name, dimension);
-		}
-	}
-	
-	/**
-	 * Adds a unit prefix to the database.
-	 * 
-	 * @param name   prefix's name
-	 * @param prefix prefix to add
-	 * @throws NullPointerException if name or prefix is null
-	 * @since 2019-01-14
-	 * @since v0.1.0
-	 */
-	public void addPrefix(final String name, final UnitPrefix prefix) {
-		this.prefixes.put(Objects.requireNonNull(name, "name must not be null."),
-				Objects.requireNonNull(prefix, "prefix must not be null."));
-	}
-	
-	/**
-	 * Adds a unit to the database.
-	 * 
-	 * @param name unit's name
-	 * @param unit unit to add
-	 * @throws NullPointerException if unit is null
-	 * @since 2019-01-10
-	 * @since v0.1.0
-	 */
-	public void addUnit(final String name, final Unit unit) {
-		this.prefixlessUnits.put(
-				Objects.requireNonNull(name, "name must not be null."),
-				Objects.requireNonNull(unit, "unit must not be null."));
-	}
-	
-	/**
-	 * Adds to the list from a line in a unit file.
-	 * 
-	 * @param line        line to look at
-	 * @param lineCounter number of line, for error messages
-	 * @since 2019-04-10
-	 * @since v0.2.0
-	 */
-	private void addUnitOrPrefixFromLine(final String line,
-			final long lineCounter) {
-		// ignore lines that start with a # sign - they're comments
-		if (line.isEmpty())
-			return;
-		if (line.contains("#")) {
-			this.addUnitOrPrefixFromLine(line.substring(0, line.indexOf("#")),
-					lineCounter);
-			return;
-		}
-		
-		// divide line into name and expression
-		final Matcher lineMatcher = NAME_EXPRESSION.matcher(line);
-		if (!lineMatcher.matches())
-			throw new IllegalArgumentException(String.format(
-					"Error at line %d: Lines of a unit file must consist of a unit name, then spaces or tabs, then a unit expression.",
-					lineCounter));
-		final String name = lineMatcher.group(1);
-		
-		final String expression = lineMatcher.group(2);
-		
-		if (name.endsWith(" ")) {
-			System.err.printf("Warning - line %d's unit name ends in a space",
-					lineCounter);
-		}
-		
-		// if expression is "!", search for an existing unit
-		// if no unit found, throw an error
-		if (expression.equals("!")) {
-			if (!this.containsUnitName(name))
-				throw new IllegalArgumentException(String
-						.format("! used but no unit found (line %d).", lineCounter));
-		} else {
-			if (name.endsWith("-")) {
-				final UnitPrefix prefix;
-				try {
-					prefix = this.getPrefixFromExpression(expression);
-				} catch (final IllegalArgumentException e) {
-					System.err.printf("Parsing error on line %d:%n", lineCounter);
-					throw e;
-				}
-				this.addPrefix(name.substring(0, name.length() - 1), prefix);
-			} else {
-				// it's a unit, get the unit
-				final Unit unit;
-				try {
-					unit = this.getUnitFromExpression(expression);
-				} catch (final IllegalArgumentException e) {
-					System.err.printf("Parsing error on line %d:%n", lineCounter);
-					throw e;
-				}
-				
-				this.addUnit(name, unit);
-			}
-		}
-	}
-	
-	/**
-	 * Tests if the database has a unit dimension with this name.
-	 * 
-	 * @param name name to test
-	 * @return if database contains name
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	public boolean containsDimensionName(final String name) {
-		return this.dimensions.containsKey(name);
-	}
-	
-	/**
-	 * Tests if the database has a unit prefix with this name.
-	 * 
-	 * @param name name to test
-	 * @return if database contains name
-	 * @since 2019-01-13
-	 * @since v0.1.0
-	 */
-	public boolean containsPrefixName(final String name) {
-		return this.prefixes.containsKey(name);
-	}
-	
-	/**
-	 * Tests if the database has a unit with this name, taking prefixes into
-	 * consideration
-	 * 
-	 * @param name name to test
-	 * @return if database contains name
-	 * @since 2019-01-13
-	 * @since v0.1.0
-	 */
-	public boolean containsUnitName(final String name) {
-		return this.units.containsKey(name);
-	}
-	
-	/**
-	 * @return a map mapping dimension names to dimensions
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	public Map<String, ObjectProduct<BaseDimension>> dimensionMap() {
-		return Collections.unmodifiableMap(this.dimensions);
-	}
-	
-	/**
-	 * Evaluates a unit expression, following the same rules as
-	 * {@link #getUnitFromExpression}.
-	 * 
-	 * @param expression expression to parse
-	 * @return {@code LinearUnitValue} representing value of expression
-	 * @since 2020-08-04
-	 */
-	public LinearUnitValue evaluateUnitExpression(final String expression) {
-		Objects.requireNonNull(expression, "expression must not be null.");
-		
-		// attempt to get a unit as an alias, or a number with precision first
-		if (this.containsUnitName(expression))
-			return this.getLinearUnitValue(expression);
-		
-		// force operators to have spaces
-		String modifiedExpression = expression;
-		modifiedExpression = modifiedExpression.replaceAll("\\+", " \\+ ");
-		modifiedExpression = modifiedExpression.replaceAll("-", " - ");
-		
-		// format expression
-		for (final Entry<Pattern, String> replacement : EXPRESSION_REPLACEMENTS
-				.entrySet()) {
-			modifiedExpression = replacement.getKey().matcher(modifiedExpression)
-					.replaceAll(replacement.getValue());
-		}
-		
-		// the previous operation breaks negative numbers, fix them!
-		// (i.e. -2 becomes - 2)
-		// FIXME the previous operaton also breaks stuff like "1e-5"
-		for (int i = 0; i < modifiedExpression.length(); i++) {
-			if (modifiedExpression.charAt(i) == '-'
-					&& (i < 2 || Arrays.asList('+', '-', '*', '/', '^')
-							.contains(modifiedExpression.charAt(i - 2)))) {
-				// found a broken negative number
-				modifiedExpression = modifiedExpression.substring(0, i + 1)
-						+ modifiedExpression.substring(i + 2);
-			}
-		}
-		
-		return this.unitValueExpressionParser.parseExpression(modifiedExpression);
-	}
-	
-	/**
-	 * Gets a unit dimension from the database using its name.
-	 * 
-	 * <p>
-	 * This method accepts exponents, like "L^3"
-	 * </p>
-	 * 
-	 * @param name dimension's name
-	 * @return dimension
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	public ObjectProduct<BaseDimension> getDimension(final String name) {
-		Objects.requireNonNull(name, "name must not be null.");
-		if (name.contains("^")) {
-			final String[] baseAndExponent = name.split("\\^");
-			
-			final ObjectProduct<BaseDimension> base = this
-					.getDimension(baseAndExponent[0]);
-			
-			final int exponent;
-			try {
-				exponent = Integer
-						.parseInt(baseAndExponent[baseAndExponent.length - 1]);
-			} catch (final NumberFormatException e2) {
-				throw new IllegalArgumentException("Exponent must be an integer.");
-			}
-			
-			return base.toExponent(exponent);
-		}
-		return this.dimensions.get(name);
-	}
-	
-	/**
-	 * Uses the database's data to parse an expression into a unit dimension
-	 * <p>
-	 * The expression is a series of any of the following:
-	 * <ul>
-	 * <li>The name of a unit dimension, which multiplies or divides the result
-	 * based on preceding operators</li>
-	 * <li>The operators '*' and '/', which multiply and divide (note that just
-	 * putting two unit dimensions next to each other is equivalent to
-	 * multiplication)</li>
-	 * <li>The operator '^' which exponentiates. Exponents must be integers.</li>
-	 * </ul>
-	 * 
-	 * @param expression expression to parse
-	 * @throws IllegalArgumentException if the expression cannot be parsed
-	 * @throws NullPointerException     if expression is null
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	public ObjectProduct<BaseDimension> getDimensionFromExpression(
-			final String expression) {
-		Objects.requireNonNull(expression, "expression must not be null.");
-		
-		// attempt to get a dimension as an alias first
-		if (this.containsDimensionName(expression))
-			return this.getDimension(expression);
-		
-		// force operators to have spaces
-		String modifiedExpression = expression;
-		
-		// format expression
-		for (final Entry<Pattern, String> replacement : EXPRESSION_REPLACEMENTS
-				.entrySet()) {
-			modifiedExpression = replacement.getKey().matcher(modifiedExpression)
-					.replaceAll(replacement.getValue());
-		}
-		modifiedExpression = modifiedExpression.replaceAll(" *\\^ *", "\\^");
-		
-		return this.unitDimensionParser.parseExpression(modifiedExpression);
-	}
-	
-	/**
-	 * Gets a unit. If it is linear, cast it to a LinearUnit and return it.
-	 * Otherwise, throw an {@code IllegalArgumentException}.
-	 * 
-	 * @param name unit's name
-	 * @return unit
-	 * @since 2019-03-22
-	 * @since v0.2.0
-	 */
-	private LinearUnit getLinearUnit(final String name) {
-		// see if I am using a function-unit like tempC(100)
-		Objects.requireNonNull(name, "name may not be null");
-		if (name.contains("(") && name.contains(")")) {
-			// break it into function name and value
-			final List<String> parts = Arrays.asList(name.split("\\("));
-			if (parts.size() != 2)
-				throw new IllegalArgumentException(
-						"Format nonlinear units like: unit(value).");
-			
-			// solve the function
-			final Unit unit = this.getUnit(parts.get(0));
-			final double value = Double.parseDouble(
-					parts.get(1).substring(0, parts.get(1).length() - 1));
-			return LinearUnit.fromUnitValue(unit, value);
-		} else {
-			// get a linear unit
-			final Unit unit = this.getUnit(name);
-			
-			if (unit instanceof LinearUnit)
-				return (LinearUnit) unit;
-			else
-				throw new IllegalArgumentException(
-						String.format("%s is not a linear unit.", name));
-		}
-	}
-	
-	/**
-	 * Gets a {@code LinearUnitValue} from a unit name. Nonlinear units will be
-	 * converted to their base units.
-	 * 
-	 * @param name name of unit
-	 * @return {@code LinearUnitValue} instance
-	 * @since 2020-08-04
-	 */
-	private LinearUnitValue getLinearUnitValue(final String name) {
-		try {
-			// try to parse it as a number - otherwise it is not a number!
-			final BigDecimal number = new BigDecimal(name);
-			
-			final double uncertainty = Math.pow(10, -number.scale());
-			return LinearUnitValue.of(SI.ONE,
-					UncertainDouble.of(number.doubleValue(), uncertainty));
-		} catch (final NumberFormatException e) {
-			return LinearUnitValue.getExact(this.getLinearUnit(name), 1);
-		}
-	}
-	
-	/**
-	 * Gets a unit prefix from the database from its name
-	 * 
-	 * @param name prefix's name
-	 * @return prefix
-	 * @since 2019-01-10
-	 * @since v0.1.0
-	 */
-	public UnitPrefix getPrefix(final String name) {
-		try {
-			return UnitPrefix.valueOf(Double.parseDouble(name));
-		} catch (final NumberFormatException e) {
-			return this.prefixes.get(name);
-		}
-	}
-	
-	/**
-	 * Gets all of the prefixes that are on a unit name, in application order.
-	 * 
-	 * @param unitName name of unit
-	 * @return prefixes
-	 * @since 2020-08-26
-	 */
-	List<UnitPrefix> getPrefixesFromName(final String unitName) {
-		final List<UnitPrefix> prefixes = new ArrayList<>();
-		String name = unitName;
-		
-		while (!this.prefixlessUnits.containsKey(name)) {
-			// find the longest prefix
-			String longestPrefixName = null;
-			int longestLength = name.length();
-			
-			while (longestPrefixName == null) {
-				longestLength--;
-				if (longestLength <= 0)
-					throw new AssertionError(
-							"No prefix found in " + name + ", but it is not a unit!");
-				if (this.prefixes.containsKey(name.substring(0, longestLength))) {
-					longestPrefixName = name.substring(0, longestLength);
-				}
-			}
-			
-			// longest prefix found!
-			final UnitPrefix prefix = this.getPrefix(longestPrefixName);
-			prefixes.add(0, prefix);
-			name = name.substring(longestLength);
-		}
-		return prefixes;
-	}
-	
-	/**
-	 * Gets a unit prefix from a prefix expression
-	 * <p>
-	 * Currently, prefix expressions are much simpler than unit expressions: They
-	 * are either a number or the name of another prefix
-	 * </p>
-	 * 
-	 * @param expression expression to input
-	 * @return prefix
-	 * @throws IllegalArgumentException if expression cannot be parsed
-	 * @throws NullPointerException     if any argument is null
-	 * @since 2019-01-14
-	 * @since v0.1.0
-	 */
-	public UnitPrefix getPrefixFromExpression(final String expression) {
-		Objects.requireNonNull(expression, "expression must not be null.");
-		
-		// attempt to get a unit as an alias first
-		if (this.containsUnitName(expression))
-			return this.getPrefix(expression);
-		
-		// force operators to have spaces
-		String modifiedExpression = expression;
-		
-		// format expression
-		for (final Entry<Pattern, String> replacement : EXPRESSION_REPLACEMENTS
-				.entrySet()) {
-			modifiedExpression = replacement.getKey().matcher(modifiedExpression)
-					.replaceAll(replacement.getValue());
-		}
-		
-		return this.prefixExpressionParser.parseExpression(modifiedExpression);
-	}
-	
-	/**
-	 * @return the prefixRepetitionRule
-	 * @since 2020-08-26
-	 */
-	public final Predicate<List<UnitPrefix>> getPrefixRepetitionRule() {
-		return this.prefixRepetitionRule;
-	}
-	
-	/**
-	 * Gets a unit from the database from its name, looking for prefixes.
-	 * 
-	 * @param name unit's name
-	 * @return unit
-	 * @since 2019-01-10
-	 * @since v0.1.0
-	 */
-	public Unit getUnit(final String name) {
-		try {
-			final double value = Double.parseDouble(name);
-			return SI.ONE.times(value);
-		} catch (final NumberFormatException e) {
-			final Unit unit = this.units.get(name);
-			if (unit == null)
-				throw new NoSuchElementException("No unit " + name);
-			else if (unit.getPrimaryName().isEmpty())
-				return unit.withName(NameSymbol.ofName(name));
-			else if (!unit.getPrimaryName().get().equals(name)) {
-				final Set<String> otherNames = new HashSet<>(unit.getOtherNames());
-				otherNames.add(unit.getPrimaryName().get());
-				return unit.withName(NameSymbol.ofNullable(name,
-						unit.getSymbol().orElse(null), otherNames));
-			} else if (!unit.getOtherNames().contains(name)) {
-				final Set<String> otherNames = new HashSet<>(unit.getOtherNames());
-				otherNames.add(name);
-				return unit.withName(
-						NameSymbol.ofNullable(unit.getPrimaryName().orElse(null),
-								unit.getSymbol().orElse(null), otherNames));
-			} else
-				return unit;
-		}
-		
-	}
-	
-	/**
-	 * Uses the database's unit data to parse an expression into a unit
-	 * <p>
-	 * The expression is a series of any of the following:
-	 * <ul>
-	 * <li>The name of a unit, which multiplies or divides the result based on
-	 * preceding operators</li>
-	 * <li>The operators '*' and '/', which multiply and divide (note that just
-	 * putting two units or values next to each other is equivalent to
-	 * multiplication)</li>
-	 * <li>The operator '^' which exponentiates. Exponents must be integers.</li>
-	 * <li>A number which is multiplied or divided</li>
-	 * </ul>
-	 * This method only works with linear units.
-	 * 
-	 * @param expression expression to parse
-	 * @throws IllegalArgumentException if the expression cannot be parsed
-	 * @throws NullPointerException     if expression is null
-	 * @since 2019-01-07
-	 * @since v0.1.0
-	 */
-	public Unit getUnitFromExpression(final String expression) {
-		Objects.requireNonNull(expression, "expression must not be null.");
-		
-		// attempt to get a unit as an alias first
-		if (this.containsUnitName(expression))
-			return this.getUnit(expression);
-		
-		// force operators to have spaces
-		String modifiedExpression = expression;
-		modifiedExpression = modifiedExpression.replaceAll("\\+", " \\+ ");
-		modifiedExpression = modifiedExpression.replaceAll("-", " - ");
-		
-		// format expression
-		for (final Entry<Pattern, String> replacement : EXPRESSION_REPLACEMENTS
-				.entrySet()) {
-			modifiedExpression = replacement.getKey().matcher(modifiedExpression)
-					.replaceAll(replacement.getValue());
-		}
-		
-		// the previous operation breaks negative numbers, fix them!
-		// (i.e. -2 becomes - 2)
-		for (int i = 0; i < modifiedExpression.length(); i++) {
-			if (modifiedExpression.charAt(i) == '-'
-					&& (i < 2 || Arrays.asList('+', '-', '*', '/', '^')
-							.contains(modifiedExpression.charAt(i - 2)))) {
-				// found a broken negative number
-				modifiedExpression = modifiedExpression.substring(0, i + 1)
-						+ modifiedExpression.substring(i + 2);
-			}
-		}
-		
-		return this.unitExpressionParser.parseExpression(modifiedExpression);
-	}
-	
-	/**
-	 * Adds all dimensions from a file, using data from the database to parse
-	 * them.
-	 * <p>
-	 * Each line in the file should consist of a name and an expression (parsed
-	 * by getDimensionFromExpression) separated by any number of tab characters.
-	 * <p>
-	 * <p>
-	 * Allowed exceptions:
-	 * <ul>
-	 * <li>Anything after a '#' character is considered a comment and
-	 * ignored.</li>
-	 * <li>Blank lines are also ignored</li>
-	 * <li>If an expression consists of a single exclamation point, instead of
-	 * parsing it, this method will search the database for an existing unit. If
-	 * no unit is found, an IllegalArgumentException is thrown. This is used to
-	 * define initial units and ensure that the database contains them.</li>
-	 * </ul>
-	 * 
-	 * @param file file to read
-	 * @throws IllegalArgumentException if the file cannot be parsed, found or
-	 *                                  read
-	 * @throws NullPointerException     if file is null
-	 * @since 2019-01-13
-	 * @since v0.1.0
-	 */
-	public void loadDimensionFile(final Path file) {
-		Objects.requireNonNull(file, "file must not be null.");
-		try {
-			long lineCounter = 0;
-			for (final String line : Files.readAllLines(file)) {
-				this.addDimensionFromLine(line, ++lineCounter);
-			}
-		} catch (final FileNotFoundException e) {
-			throw new IllegalArgumentException("Could not find file " + file, e);
-		} catch (final IOException e) {
-			throw new IllegalArgumentException("Could not read file " + file, e);
-		}
-	}
-	
-	/**
-	 * Adds all units from a file, using data from the database to parse them.
-	 * <p>
-	 * Each line in the file should consist of a name and an expression (parsed
-	 * by getUnitFromExpression) separated by any number of tab characters.
-	 * <p>
-	 * <p>
-	 * Allowed exceptions:
-	 * <ul>
-	 * <li>Anything after a '#' character is considered a comment and
-	 * ignored.</li>
-	 * <li>Blank lines are also ignored</li>
-	 * <li>If an expression consists of a single exclamation point, instead of
-	 * parsing it, this method will search the database for an existing unit. If
-	 * no unit is found, an IllegalArgumentException is thrown. This is used to
-	 * define initial units and ensure that the database contains them.</li>
-	 * </ul>
-	 * 
-	 * @param file file to read
-	 * @throws IllegalArgumentException if the file cannot be parsed, found or
-	 *                                  read
-	 * @throws NullPointerException     if file is null
-	 * @since 2019-01-13
-	 * @since v0.1.0
-	 */
-	public void loadUnitsFile(final Path file) {
-		Objects.requireNonNull(file, "file must not be null.");
-		try {
-			long lineCounter = 0;
-			for (final String line : Files.readAllLines(file)) {
-				this.addUnitOrPrefixFromLine(line, ++lineCounter);
-			}
-		} catch (final FileNotFoundException e) {
-			throw new IllegalArgumentException("Could not find file " + file, e);
-		} catch (final IOException e) {
-			throw new IllegalArgumentException("Could not read file " + file, e);
-		}
-	}
-	
-	/**
-	 * @return a map mapping prefix names to prefixes
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	public Map<String, UnitPrefix> prefixMap() {
-		return Collections.unmodifiableMap(this.prefixes);
-	}
-	
-	/**
-	 * @param prefixRepetitionRule the prefixRepetitionRule to set
-	 * @since 2020-08-26
-	 */
-	public final void setPrefixRepetitionRule(
-			Predicate<List<UnitPrefix>> prefixRepetitionRule) {
-		this.prefixRepetitionRule = prefixRepetitionRule;
-	}
-	
-	/**
-	 * @return a string stating the number of units, prefixes and dimensions in
-	 *         the database
-	 */
-	@Override
-	public String toString() {
-		return String.format(
-				"Unit Database with %d units, %d unit prefixes and %d dimensions",
-				this.prefixlessUnits.size(), this.prefixes.size(),
-				this.dimensions.size());
-	}
-	
-	/**
-	 * Returns a map mapping unit names to units, including units with prefixes.
-	 * <p>
-	 * The returned map is infinite in size if there is at least one unit and at
-	 * least one prefix. If it is infinite, some operations that only work with
-	 * finite collections, like converting name/entry sets to arrays, will throw
-	 * an {@code IllegalStateException}.
-	 * </p>
-	 * <p>
-	 * Specifically, the operations that will throw an IllegalStateException if
-	 * the map is infinite in size are:
-	 * <ul>
-	 * <li>{@code unitMap.entrySet().toArray()} (either overloading)</li>
-	 * <li>{@code unitMap.keySet().toArray()} (either overloading)</li>
-	 * </ul>
-	 * </p>
-	 * <p>
-	 * Because of ambiguities between prefixes (i.e. kilokilo = mega), the map's
-	 * {@link PrefixedUnitMap#containsValue containsValue} and
-	 * {@link PrefixedUnitMap#values() values()} methods currently ignore
-	 * prefixes.
-	 * </p>
-	 * 
-	 * @return a map mapping unit names to units, including prefixed names
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	public Map<String, Unit> unitMap() {
-		return this.units; // PrefixedUnitMap is immutable so I don't need to make
-									// an unmodifiable map.
-	}
-	
-	/**
-	 * @return a map mapping unit names to units, ignoring prefixes
-	 * @since 2019-04-13
-	 * @since v0.2.0
-	 */
-	public Map<String, Unit> unitMapPrefixless() {
-		return Collections.unmodifiableMap(this.prefixlessUnits);
-	}
-}