Initial commit

16 files changed, 774 insertions, 0 deletions

diff --git a/.classpath b/.classpath
new file mode 100644
index 0000000..145a671
--- /dev/null
+++ b/.classpath
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/5"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..866d01d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+bin/
+*.class
+*~
\ No newline at end of file
diff --git a/.project b/.project
new file mode 100644
index 0000000..656186b
--- /dev/null
+++ b/.project
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>Unit Converter</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>
diff --git a/.settings/org.eclipse.jdt.core.prefs b/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..3a21537
--- /dev/null
+++ b/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,11 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.8
diff --git a/src/unitConverter/converter/package-info.java b/src/unitConverter/converter/package-info.java
new file mode 100644
index 0000000..6148784
--- /dev/null
+++ b/src/unitConverter/converter/package-info.java
@@ -0,0 +1,23 @@
+/**
+ * Copyright (C) 2019 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/>.
+ */
+/**
+ * All classes that work to convert units.
+ * 
+ * @author Adrien Hopkins
+ * @since 2019-01-25
+ */
+package unitConverter.converter;
\ No newline at end of file
diff --git a/src/unitConverter/dimension/BaseDimension.java b/src/unitConverter/dimension/BaseDimension.java
new file mode 100755
index 0000000..6a727a9
--- /dev/null
+++ b/src/unitConverter/dimension/BaseDimension.java
@@ -0,0 +1,37 @@
+/**
+ * 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 unitConverter.dimension;
+
+/**
+ * A base dimension that makes up {@code UnitDimension} objects.
+ * 
+ * @author Adrien Hopkins
+ * @since 2018-12-22
+ */
+public interface BaseDimension {
+	/**
+	 * @return the dimension's name
+	 * @since 2019-01-25
+	 */
+	String getName();
+
+	/**
+	 * @return a short string (usually one character) that represents this base dimension
+	 * @since 2018-12-22
+	 */
+	String getSymbol();
+}
diff --git a/src/unitConverter/dimension/OtherBaseDimension.java b/src/unitConverter/dimension/OtherBaseDimension.java
new file mode 100755
index 0000000..2ab19b3
--- /dev/null
+++ b/src/unitConverter/dimension/OtherBaseDimension.java
@@ -0,0 +1,53 @@
+/**
+ * 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 unitConverter.dimension;
+
+import java.util.Objects;
+
+/**
+ * Non-SI base dimensions.
+ * 
+ * @author Adrien Hopkins
+ * @since 2019-01-14
+ */
+public enum OtherBaseDimension implements BaseDimension {
+	INFORMATION("Info"), CURRENCY("$$");
+
+	/** The dimension's symbol */
+	private final String symbol;
+
+	/**
+	 * Creates the {@code SIBaseDimension}.
+	 * 
+	 * @param symbol
+	 *            dimension's symbol
+	 * @since 2018-12-11
+	 */
+	private OtherBaseDimension(final String symbol) {
+		this.symbol = Objects.requireNonNull(symbol, "symbol must not be null.");
+	}
+
+	@Override
+	public String getName() {
+		return this.toString();
+	}
+
+	@Override
+	public String getSymbol() {
+		return this.symbol;
+	}
+}
diff --git a/src/unitConverter/dimension/SIBaseDimension.java b/src/unitConverter/dimension/SIBaseDimension.java
new file mode 100755
index 0000000..b731b00
--- /dev/null
+++ b/src/unitConverter/dimension/SIBaseDimension.java
@@ -0,0 +1,55 @@
+/**

+ * 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 unitConverter.dimension;

+

+import java.util.Objects;

+

+/**

+ * The seven base dimensions that make up the SI.

+ * 

+ * @author Adrien Hopkins

+ * @since 2018-12-11

+ */

+public enum SIBaseDimension implements BaseDimension {

+	LENGTH("L"), MASS("M"), TIME("T"), ELECTRIC_CURRENT("I"), TEMPERATURE("\u0398"), // u0398 is the theta symbol

+	QUANTITY("N"), LUMINOUS_INTENSITY("J");

+

+	/** The dimension's symbol */

+	private final String symbol;

+

+	/**

+	 * Creates the {@code SIBaseDimension}.

+	 * 

+	 * @param symbol

+	 *            dimension's symbol

+	 * @since 2018-12-11

+	 */

+	private SIBaseDimension(final String symbol) {

+		this.symbol = Objects.requireNonNull(symbol, "symbol must not be null.");

+	}

+

+	@Override

+	public String getName() {

+		return this.toString();

+	}

+

+	@Override

+	public String getSymbol() {

+		return this.symbol;

+	}

+

+}

diff --git a/src/unitConverter/dimension/StandardDimensions.java b/src/unitConverter/dimension/StandardDimensions.java
new file mode 100755
index 0000000..c830f00
--- /dev/null
+++ b/src/unitConverter/dimension/StandardDimensions.java
@@ -0,0 +1,79 @@
+/**

+ * 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 unitConverter.dimension;

+

+/**

+ * All of the dimensions that are used by the SI.

+ * 

+ * @author Adrien Hopkins

+ * @since 2018-12-11

+ */

+public final class StandardDimensions {

+	// base dimensions

+	public static final UnitDimension EMPTY = UnitDimension.EMPTY;

+	public static final UnitDimension LENGTH = UnitDimension.getBase(SIBaseDimension.LENGTH);

+	public static final UnitDimension MASS = UnitDimension.getBase(SIBaseDimension.MASS);

+	public static final UnitDimension TIME = UnitDimension.getBase(SIBaseDimension.TIME);

+	public static final UnitDimension ELECTRIC_CURRENT = UnitDimension.getBase(SIBaseDimension.ELECTRIC_CURRENT);

+	public static final UnitDimension TEMPERATURE = UnitDimension.getBase(SIBaseDimension.TEMPERATURE);

+	public static final UnitDimension QUANTITY = UnitDimension.getBase(SIBaseDimension.QUANTITY);

+	public static final UnitDimension LUMINOUS_INTENSITY = UnitDimension.getBase(SIBaseDimension.LUMINOUS_INTENSITY);

+	public static final UnitDimension INFORMATION = UnitDimension.getBase(OtherBaseDimension.INFORMATION);

+	public static final UnitDimension CURRENCY = UnitDimension.getBase(OtherBaseDimension.CURRENCY);

+	// derived dimensions without named SI units

+	public static final UnitDimension AREA = LENGTH.times(LENGTH);

+

+	public static final UnitDimension VOLUME = AREA.times(LENGTH);

+	public static final UnitDimension VELOCITY = LENGTH.dividedBy(TIME);

+	public static final UnitDimension ACCELERATION = VELOCITY.dividedBy(TIME);

+	public static final UnitDimension WAVENUMBER = EMPTY.dividedBy(LENGTH);

+	public static final UnitDimension MASS_DENSITY = MASS.dividedBy(VOLUME);

+	public static final UnitDimension SURFACE_DENSITY = MASS.dividedBy(AREA);

+	public static final UnitDimension SPECIFIC_VOLUME = VOLUME.dividedBy(MASS);

+	public static final UnitDimension CURRENT_DENSITY = ELECTRIC_CURRENT.dividedBy(AREA);

+	public static final UnitDimension MAGNETIC_FIELD_STRENGTH = ELECTRIC_CURRENT.dividedBy(LENGTH);

+	public static final UnitDimension CONCENTRATION = QUANTITY.dividedBy(VOLUME);

+	public static final UnitDimension MASS_CONCENTRATION = CONCENTRATION.times(MASS);

+	public static final UnitDimension LUMINANCE = LUMINOUS_INTENSITY.dividedBy(AREA);

+	public static final UnitDimension REFRACTIVE_INDEX = VELOCITY.dividedBy(VELOCITY);

+	public static final UnitDimension REFLACTIVE_PERMEABILITY = EMPTY.times(EMPTY);

+	public static final UnitDimension ANGLE = LENGTH.dividedBy(LENGTH);

+	public static final UnitDimension SOLID_ANGLE = AREA.dividedBy(AREA);

+	// derived dimensions with named SI units

+	public static final UnitDimension FREQUENCY = EMPTY.dividedBy(TIME);

+

+	public static final UnitDimension FORCE = MASS.times(ACCELERATION);

+	public static final UnitDimension ENERGY = FORCE.times(LENGTH);

+	public static final UnitDimension POWER = ENERGY.dividedBy(TIME);

+	public static final UnitDimension ELECTRIC_CHARGE = ELECTRIC_CURRENT.times(TIME);

+	public static final UnitDimension VOLTAGE = ENERGY.dividedBy(ELECTRIC_CHARGE);

+	public static final UnitDimension CAPACITANCE = ELECTRIC_CHARGE.dividedBy(VOLTAGE);

+	public static final UnitDimension ELECTRIC_RESISTANCE = VOLTAGE.dividedBy(ELECTRIC_CURRENT);

+	public static final UnitDimension ELECTRIC_CONDUCTANCE = ELECTRIC_CURRENT.dividedBy(VOLTAGE);

+	public static final UnitDimension MAGNETIC_FLUX = VOLTAGE.times(TIME);

+	public static final UnitDimension MAGNETIC_FLUX_DENSITY = MAGNETIC_FLUX.dividedBy(AREA);

+	public static final UnitDimension INDUCTANCE = MAGNETIC_FLUX.dividedBy(ELECTRIC_CURRENT);

+	public static final UnitDimension LUMINOUS_FLUX = LUMINOUS_INTENSITY.times(SOLID_ANGLE);

+	public static final UnitDimension ILLUMINANCE = LUMINOUS_FLUX.dividedBy(AREA);

+	public static final UnitDimension SPECIFIC_ENERGY = ENERGY.dividedBy(MASS);

+	public static final UnitDimension CATALYTIC_ACTIVITY = QUANTITY.dividedBy(TIME);

+

+	// You may NOT get StandardDimensions instances!

+	private StandardDimensions() {

+		throw new AssertionError();

+	}

+}

diff --git a/src/unitConverter/dimension/UnitDimension.java b/src/unitConverter/dimension/UnitDimension.java
new file mode 100755
index 0000000..ba2a750
--- /dev/null
+++ b/src/unitConverter/dimension/UnitDimension.java
@@ -0,0 +1,230 @@
+/**

+ * 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 unitConverter.dimension;

+

+import java.util.ArrayList;

+import java.util.HashMap;

+import java.util.HashSet;

+import java.util.List;

+import java.util.Map;

+import java.util.Objects;

+import java.util.Set;

+

+/**

+ * An object that represents what a unit measures, like length, mass, area, energy, etc.

+ * 

+ * @author Adrien Hopkins

+ * @since 2018-12-11

+ */

+public final class UnitDimension {

+	/**

+	 * The unit dimension where every exponent is zero

+	 * 

+	 * @since 2018-12-12

+	 */

+	public static final UnitDimension EMPTY = new UnitDimension(new HashMap<>());

+

+	/**

+	 * Gets an UnitDimension that has 1 of a certain dimension and nothing else

+	 * 

+	 * @param dimension

+	 *            dimension to get

+	 * @return unit dimension

+	 * @since 2018-12-11

+	 */

+	public static final UnitDimension getBase(final BaseDimension dimension) {

+		final Map<BaseDimension, Integer> map = new HashMap<>();

+		map.put(dimension, 1);

+		return new UnitDimension(map);

+	}

+

+	/**

+	 * The base dimensions that make up this dimension.

+	 * 

+	 * @since 2018-12-11

+	 */

+	final Map<BaseDimension, Integer> exponents;

+

+	/**

+	 * Creates the {@code UnitDimension}.

+	 * 

+	 * @param exponents

+	 *            base dimensions that make up this dimension

+	 * @since 2018-12-11

+	 */

+	private UnitDimension(final Map<BaseDimension, Integer> exponents) {

+		this.exponents = new HashMap<>(exponents);

+	}

+

+	/**

+	 * Divides this dimension by another

+	 * 

+	 * @param other

+	 *            other dimension

+	 * @return quotient of two dimensions

+	 * @since 2018-12-11

+	 */

+	public UnitDimension dividedBy(final UnitDimension other) {

+		final Map<BaseDimension, Integer> map = new HashMap<>(this.exponents);

+

+		for (final BaseDimension key : other.exponents.keySet()) {

+			if (map.containsKey(key)) {

+				// add the dimensions

+				map.put(key, map.get(key) - other.exponents.get(key));

+			} else {

+				map.put(key, -other.exponents.get(key));

+			}

+		}

+		return new UnitDimension(map);

+	}

+

+	@Override

+	public boolean equals(final Object obj) {

+		if (this == obj)

+			return true;

+		if (obj == null)

+			return false;

+		if (!(obj instanceof UnitDimension))

+			return false;

+		final UnitDimension other = (UnitDimension) obj;

+

+		// anything with a value of 0 is equal to a nonexistent value

+		for (final BaseDimension b : this.getBaseSet()) {

+			if (this.exponents.get(b) != other.exponents.get(b))

+				if (!(this.exponents.get(b) == 0 && !other.exponents.containsKey(b)))

+					return false;

+		}

+		for (final BaseDimension b : other.getBaseSet()) {

+			if (this.exponents.get(b) != other.exponents.get(b))

+				if (!(other.exponents.get(b) == 0 && !this.exponents.containsKey(b)))

+					return false;

+		}

+		return true;

+	}

+

+	/**

+	 * @return a set of all of the base dimensions with non-zero exponents that make up this dimension.

+	 * @since 2018-12-12

+	 */

+	public final Set<BaseDimension> getBaseSet() {

+		final Set<BaseDimension> dimensions = new HashSet<>();

+

+		// add all dimensions with a nonzero exponent - they shouldn't be there in the first place

+		for (final BaseDimension 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

+	 */

+	public int getExponent(final BaseDimension dimension) {

+		return this.exponents.getOrDefault(dimension, 0);

+	}

+

+	@Override

+	public int hashCode() {

+		return Objects.hash(this.exponents);

+	}

+

+	/**

+	 * @return true if this dimension is a base, i.e. it has one exponent of one and no other nonzero exponents

+	 * @since 2019-01-15

+	 */

+	public boolean isBase() {

+		int oneCount = 0;

+		boolean twoOrMore = false; // has exponents of 2 or more

+		for (final BaseDimension b : this.getBaseSet()) {

+			if (this.exponents.get(b) == 1) {

+				oneCount++;

+			} else if (this.exponents.get(b) != 0) {

+				twoOrMore = true;

+			}

+		}

+		return (oneCount == 0 || oneCount == 1) && !twoOrMore;

+	}

+

+	/**

+	 * Multiplies this dimension by another

+	 * 

+	 * @param other

+	 *            other dimension

+	 * @return product of two dimensions

+	 * @since 2018-12-11

+	 */

+	public UnitDimension times(final UnitDimension other) {

+		final Map<BaseDimension, Integer> map = new HashMap<>(this.exponents);

+

+		for (final BaseDimension key : other.exponents.keySet()) {

+			if (map.containsKey(key)) {

+				// add the dimensions

+				map.put(key, map.get(key) + other.exponents.get(key));

+			} else {

+				map.put(key, other.exponents.get(key));

+			}

+		}

+		return new UnitDimension(map);

+	}

+

+	/**

+	 * Returns this dimension, but to an exponent

+	 * 

+	 * @param exp

+	 *            exponent

+	 * @return result of exponientation

+	 * @since 2019-01-15

+	 */

+	public UnitDimension toExponent(final int exp) {

+		final Map<BaseDimension, Integer> map = new HashMap<>(this.exponents);

+		for (final BaseDimension key : this.exponents.keySet()) {

+			map.put(key, this.getExponent(key) * exp);

+		}

+		return new UnitDimension(map);

+	}

+

+	@Override

+	public String toString() {

+		final List<String> positiveStringComponents = new ArrayList<>();

+		final List<String> negativeStringComponents = new ArrayList<>();

+

+		// for each base dimension that makes up this dimension, add it and its exponent

+		for (final BaseDimension dimension : this.getBaseSet()) {

+			final int exponent = this.exponents.get(dimension);

+			if (exponent > 0) {

+				positiveStringComponents.add(String.format("%s^%d", dimension.getSymbol(), exponent));

+			} else if (exponent < 0) {

+				negativeStringComponents.add(String.format("%s^%d", dimension.getSymbol(), -exponent));

+			}

+		}

+

+		final String positiveString = positiveStringComponents.isEmpty() ? "1"

+				: String.join(" ", positiveStringComponents);

+		final String negativeString = negativeStringComponents.isEmpty() ? ""

+				: " / " + String.join(" ", negativeStringComponents);

+

+		return positiveString + negativeString;

+	}

+}

diff --git a/src/unitConverter/dimension/UnitDimensionTest.java b/src/unitConverter/dimension/UnitDimensionTest.java
new file mode 100755
index 0000000..603320b
--- /dev/null
+++ b/src/unitConverter/dimension/UnitDimensionTest.java
@@ -0,0 +1,56 @@
+/**
+ * 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 unitConverter.dimension;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static unitConverter.dimension.StandardDimensions.AREA;
+import static unitConverter.dimension.StandardDimensions.ENERGY;
+import static unitConverter.dimension.StandardDimensions.LENGTH;
+import static unitConverter.dimension.StandardDimensions.MASS;
+import static unitConverter.dimension.StandardDimensions.MASS_DENSITY;
+import static unitConverter.dimension.StandardDimensions.QUANTITY;
+import static unitConverter.dimension.StandardDimensions.TIME;
+import static unitConverter.dimension.StandardDimensions.VOLUME;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author Adrien Hopkins
+ * @since 2018-12-12
+ */
+class UnitDimensionTest {
+	@Test
+	void testEquals() {
+		assertEquals(LENGTH, LENGTH);
+		assertFalse(LENGTH.equals(QUANTITY));
+	}
+
+	@Test
+	void testExponents() {
+		assertEquals(1, LENGTH.getExponent(SIBaseDimension.LENGTH));
+		assertEquals(3, VOLUME.getExponent(SIBaseDimension.LENGTH));
+	}
+
+	@Test
+	void testMultiplicationAndDivision() {
+		assertEquals(AREA, LENGTH.times(LENGTH));
+		assertEquals(MASS_DENSITY, MASS.dividedBy(VOLUME));
+		assertEquals(ENERGY, AREA.times(MASS).dividedBy(TIME).dividedBy(TIME));
+		assertEquals(LENGTH, LENGTH.times(TIME).dividedBy(TIME));
+	}
+}
diff --git a/src/unitConverter/dimension/package-info.java b/src/unitConverter/dimension/package-info.java
new file mode 100755
index 0000000..74895ce
--- /dev/null
+++ b/src/unitConverter/dimension/package-info.java
@@ -0,0 +1,23 @@
+/**
+ * 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/>.
+ */
+/**
+ * Everything to do with what a unit measures, or its dimension.
+ * 
+ * @author Adrien Hopkins
+ * @since 2018-12-22
+ */
+package unitConverter.dimension;
\ No newline at end of file
diff --git a/src/unitConverter/package-info.java b/src/unitConverter/package-info.java
new file mode 100644
index 0000000..e2f7ff7
--- /dev/null
+++ b/src/unitConverter/package-info.java
@@ -0,0 +1,23 @@
+/**
+ * Copyright (C) 2019 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/>.
+ */
+/**
+ * A program that converts units.
+ * 
+ * @author Adrien Hopkins
+ * @since 2019-01-25
+ */
+package unitConverter;
\ No newline at end of file
diff --git a/src/unitConverter/unit/Unit.java b/src/unitConverter/unit/Unit.java
new file mode 100755
index 0000000..3e7f9da
--- /dev/null
+++ b/src/unitConverter/unit/Unit.java
@@ -0,0 +1,103 @@
+/**
+ * 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 unitConverter.unit;
+
+import java.util.Objects;
+
+import unitConverter.dimension.UnitDimension;
+
+/**
+ * A unit that has an associated base unit, and can convert a value expressed in it to and from that base.
+ * 
+ * @author Adrien Hopkins
+ * @since 2018-12-22
+ */
+public interface Unit {
+	/**
+	 * Checks if a value expressed in this unit can be converted to a value expressed in {@code other}
+	 * 
+	 * @param other
+	 *            unit to test with
+	 * @return true if the units are compatible
+	 * @since 2019-01-13
+	 */
+	default boolean canConvertTo(final Unit other) {
+		return Objects.equals(this.getBase(), other.getBase());
+	}
+
+	/**
+	 * Converts from a value expressed in this unit's base unit to a value expressed in this unit.
+	 * <p>
+	 * This must be the inverse of {@code convertToBase}, so {@code convertFromBase(convertToBase(value))} must be equal
+	 * to {@code value} for any value, ignoring precision loss by roundoff error.
+	 * </p>
+	 * <p>
+	 * If this unit <i>is</i> a base unit, this method should return {@code value}.
+	 * </p>
+	 * 
+	 * @param value
+	 *            value expressed in <b>base</b> unit
+	 * @return value expressed in <b>this</b> unit
+	 * @since 2018-12-22
+	 */
+	double convertFromBase(double value);
+
+	/**
+	 * Converts from a value expressed in this unit to a value expressed in this unit's base unit.
+	 * <p>
+	 * This must be the inverse of {@code convertFromBase}, so {@code convertToBase(convertFromBase(value))} must be
+	 * equal to {@code value} for any value, ignoring precision loss by roundoff error.
+	 * </p>
+	 * <p>
+	 * If this unit <i>is</i> a base unit, this method should return {@code value}.
+	 * </p>
+	 * 
+	 * @param value
+	 *            value expressed in <b>this</b> unit
+	 * @return value expressed in <b>base</b> unit
+	 * @since 2018-12-22
+	 */
+	double convertToBase(double value);
+
+	/**
+	 * <p>
+	 * Returns the base unit associated with this unit.
+	 * </p>
+	 * <p>
+	 * The dimension of this unit must be equal to the dimension of the returned unit.
+	 * </p>
+	 * <p>
+	 * If this unit <i>is</i> a base unit, this method should return this unit.\
+	 * </p>
+	 * 
+	 * @return base unit associated with this unit
+	 * @since 2018-12-22
+	 */
+	Unit getBase();
+
+	/**
+	 * @return dimension measured by this unit
+	 * @since 2018-12-22
+	 */
+	UnitDimension getDimension();
+
+	/**
+	 * @return system that this unit is a part of
+	 * @since 2018-12-23
+	 */
+	UnitSystem getSystem();
+}
diff --git a/src/unitConverter/unit/UnitSystem.java b/src/unitConverter/unit/UnitSystem.java
new file mode 100755
index 0000000..2e3a5d8
--- /dev/null
+++ b/src/unitConverter/unit/UnitSystem.java
@@ -0,0 +1,31 @@
+/**
+ * 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 unitConverter.unit;
+
+/**
+ * A system of units. Each unit should be aware of its system.
+ * 
+ * @author Adrien Hopkins
+ * @since 2018-12-23
+ */
+public interface UnitSystem {
+	/**
+	 * @return name of system
+	 * @since 2019-01-25
+	 */
+	String getName();
+}
diff --git a/src/unitConverter/unit/package-info.java b/src/unitConverter/unit/package-info.java
new file mode 100644
index 0000000..b5deb0c
--- /dev/null
+++ b/src/unitConverter/unit/package-info.java
@@ -0,0 +1,23 @@
+/**
+ * Copyright (C) 2019 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/>.
+ */
+/**
+ * All of the classes that correspond to the units being converted.
+ * 
+ * @author Adrien Hopkins
+ * @since 2019-01-25
+ */
+package unitConverter.unit;
\ No newline at end of file