1 files changed, 259 insertions, 136 deletions
diff --git a/src/org/unitConverter/UnitsDatabase.java b/src/org/unitConverter/UnitsDatabase.java
index 901c6ef..959c151 100755
--- a/src/org/unitConverter/UnitsDatabase.java
+++ b/src/org/unitConverter/UnitsDatabase.java
@@ -30,6 +30,7 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.NoSuchElementException;
 import java.util.Objects;
 import java.util.Set;
 import java.util.function.BiFunction;
@@ -83,6 +84,153 @@ public final class UnitsDatabase {
 		 * @since 2019-04-13
 		 */
 		private static final class PrefixedUnitEntrySet extends AbstractSet<Map.Entry<String, Unit>> {
+			/**
+			 * The entry for this set.
+			 * 
+			 * @author Adrien Hopkins
+			 * @since 2019-04-14
+			 */
+			private static final class PrefixedUnitEntry implements Entry<String, Unit> {
+				private final String key;
+				private final Unit value;
+
+				/**
+				 * Creates the {@code PrefixedUnitEntry}.
+				 * 
+				 * @param key
+				 * @param value
+				 * @since 2019-04-14
+				 */
+				public PrefixedUnitEntry(final String key, final Unit value) {
+					this.key = key;
+					this.value = value;
+				}
+
+				@Override
+				public String getKey() {
+					return this.key;
+				}
+
+				@Override
+				public Unit getValue() {
+					return this.value;
+				}
+
+				@Override
+				public Unit setValue(final Unit value) {
+					throw new UnsupportedOperationException();
+				}
+			}
+
+			/**
+			 * An iterator that iterates over the units of a {@code PrefixedUnitNameSet}.
+			 * 
+			 * @author Adrien Hopkins
+			 * @since 2019-04-14
+			 */
+			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<>();
+
+				private final Map<String, Unit> map;
+				private final List<String> unitNames;
+				private final List<String> prefixNames;
+
+				/**
+				 * Creates the {@code UnitsDatabase.PrefixedUnitMap.PrefixedUnitNameSet.PrefixedUnitNameIterator}.
+				 * 
+				 * @since 2019-04-14
+				 */
+				public PrefixedUnitEntryIterator(final PrefixedUnitEntrySet set) {
+					this.map = set.map;
+					this.unitNames = new ArrayList<>(set.map.units.keySet());
+					this.prefixNames = new ArrayList<>(set.map.prefixes.keySet());
+				}
+
+				/**
+				 * @return current unit name
+				 * @since 2019-04-14
+				 */
+				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
+				 */
+				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() {
+					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();
+
+					this.incrementPosition();
+
+					return new PrefixedUnitEntry(nextName, this.map.get(nextName));
+				}
+			}
+
 			// the map that created this set
 			private final PrefixedUnitMap map;
 
@@ -143,83 +291,7 @@ public final class UnitsDatabase {
 
 			@Override
 			public Iterator<Entry<String, Unit>> iterator() {
-				return new Iterator<Entry<String, Unit>>() {
-					// position in the unit list
-					int unitNamePosition = -1;
-					// the indices of the prefixes attached to the current unit
-					List<Integer> prefixCoordinates = new ArrayList<>();
-
-					List<String> unitNames = new ArrayList<>(PrefixedUnitEntrySet.this.map.units.keySet());
-					List<String> prefixNames = new ArrayList<>(PrefixedUnitEntrySet.this.map.prefixes.keySet());
-
-					@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;
-						}
-					}
-
-					@Override
-					public Entry<String, Unit> next() {
-						// increment unit name position
-						this.unitNamePosition++;
-
-						// 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 (!(PrefixedUnitEntrySet.this.map
-									.get(this.unitNames.get(this.unitNamePosition)) instanceof LinearUnit)) {
-								this.unitNames.remove(this.unitNamePosition);
-							}
-						}
-
-						// carry over
-						if (!this.prefixNames.isEmpty() && this.unitNamePosition >= this.unitNames.size() - 1) {
-							// handle prefix position
-							this.unitNamePosition = 0;
-							int i = this.prefixCoordinates.size() - 1;
-							this.prefixCoordinates.set(i, this.prefixCoordinates.get(i) + 1);
-
-							while (this.prefixCoordinates.get(i) >= this.prefixNames.size() - 1) {
-								this.prefixCoordinates.set(i, 0);
-								i--;
-								if (i < 0) {
-									this.prefixCoordinates.add(0, 0);
-								}
-							}
-						}
-
-						// create the unit name
-						final StringBuilder unitNameBuilder = new StringBuilder();
-						for (final int i : this.prefixCoordinates) {
-							unitNameBuilder.append(this.prefixNames.get(i));
-						}
-						unitNameBuilder.append(this.unitNames.get(this.unitNamePosition));
-
-						final String unitName = unitNameBuilder.toString();
-						return new Entry<String, Unit>() {
-							@Override
-							public String getKey() {
-								return unitName;
-							}
-
-							@Override
-							public Unit getValue() {
-								return PrefixedUnitEntrySet.this.map.get(unitName);
-							}
-
-							@Override
-							public Unit setValue(final Unit value) {
-								throw new UnsupportedOperationException();
-							}
-						};
-					}
-				};
+				return new PrefixedUnitEntryIterator(this);
 			}
 
 			@Override
@@ -282,6 +354,115 @@ public final class UnitsDatabase {
 		 * @since 2019-04-13
 		 */
 		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
+			 */
+			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<>();
+
+				private final Map<String, Unit> map;
+				private final List<String> unitNames;
+				private final List<String> prefixNames;
+
+				/**
+				 * Creates the {@code UnitsDatabase.PrefixedUnitMap.PrefixedUnitNameSet.PrefixedUnitNameIterator}.
+				 * 
+				 * @since 2019-04-14
+				 */
+				public PrefixedUnitNameIterator(final PrefixedUnitNameSet set) {
+					this.map = set.map;
+					this.unitNames = new ArrayList<>(set.map.units.keySet());
+					this.prefixNames = new ArrayList<>(set.map.prefixes.keySet());
+				}
+
+				/**
+				 * @return current unit name
+				 * @since 2019-04-14
+				 */
+				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
+				 */
+				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() {
+					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();
+
+					this.incrementPosition();
+
+					return nextName;
+				}
+			}
+
 			// the map that created this set
 			private final PrefixedUnitMap map;
 
@@ -330,65 +511,7 @@ public final class UnitsDatabase {
 
 			@Override
 			public Iterator<String> iterator() {
-				return new Iterator<String>() {
-					// position in the unit list
-					int unitNamePosition = -1;
-					// the indices of the prefixes attached to the current unit
-					List<Integer> prefixCoordinates = new ArrayList<>();
-
-					List<String> unitNames = new ArrayList<>(PrefixedUnitNameSet.this.map.units.keySet());
-					List<String> prefixNames = new ArrayList<>(PrefixedUnitNameSet.this.map.prefixes.keySet());
-
-					@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;
-						}
-					}
-
-					@Override
-					public String next() {
-						// increment unit name position
-						this.unitNamePosition++;
-
-						// 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 (!(PrefixedUnitNameSet.this.map
-									.get(this.unitNames.get(this.unitNamePosition)) instanceof LinearUnit)) {
-								this.unitNames.remove(this.unitNamePosition);
-							}
-						}
-
-						// carry over
-						if (!this.prefixNames.isEmpty() && this.unitNamePosition >= this.unitNames.size() - 1) {
-							// handle prefix position
-							this.unitNamePosition = 0;
-							int i = this.prefixCoordinates.size() - 1;
-							this.prefixCoordinates.set(i, this.prefixCoordinates.get(i) + 1);
-
-							while (this.prefixCoordinates.get(i) >= this.prefixNames.size() - 1) {
-								this.prefixCoordinates.set(i, 0);
-								i--;
-								if (i < 0) {
-									this.prefixCoordinates.add(0, 0);
-								}
-							}
-						}
-
-						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();
-					}
-				};
+				return new PrefixedUnitNameIterator(this);
 			}
 
 			@Override