1 files changed, 47 insertions, 72 deletions

diff --git a/src/org/unitConverter/UnitsDatabase.java b/src/org/unitConverter/UnitsDatabase.java
index c3d3131..a7e6047 100755
--- a/src/org/unitConverter/UnitsDatabase.java
+++ b/src/org/unitConverter/UnitsDatabase.java
@@ -33,7 +33,6 @@ import java.util.Set;
 import org.unitConverter.dimension.UnitDimension;
 import org.unitConverter.math.DecimalComparison;
 import org.unitConverter.math.ExpressionParser;
-import org.unitConverter.unit.BaseUnit;
 import org.unitConverter.unit.DefaultUnitPrefix;
 import org.unitConverter.unit.LinearUnit;
 import org.unitConverter.unit.SI;
@@ -109,6 +108,21 @@ public final class UnitsDatabase {
 					.addBinaryOperator("/", (o1, o2) -> o1.dividedBy(o2), 1)
 					.addBinaryOperator("^", UnitsDatabase::exponent, 2).build();
 
+	/**
+	 * A parser that can parse unit prefix expressions
+	 * 
+	 * @since 2019-04-13
+	 */
+	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
+	 */
 	private final ExpressionParser<UnitDimension> unitDimensionParser = new ExpressionParser.Builder<>(
 			this::getDimension).addBinaryOperator("*", (o1, o2) -> o1.times(o2), 0).addSpaceFunction("*")
 					.addBinaryOperator("/", (o1, o2) -> o1.dividedBy(o2), 0).build();
@@ -462,7 +476,11 @@ public final class UnitsDatabase {
 	 * @since v0.1.0
 	 */
 	public UnitPrefix getPrefix(final String name) {
-		return this.prefixes.get(name);
+		try {
+			return new DefaultUnitPrefix(Double.parseDouble(name));
+		} catch (final NumberFormatException e) {
+			return this.prefixes.get(name);
+		}
 	}
 
 	/**
@@ -485,33 +503,20 @@ public final class UnitsDatabase {
 	public UnitPrefix getPrefixFromExpression(final String expression) {
 		Objects.requireNonNull(expression, "expression must not be null.");
 
-		try {
-			return new DefaultUnitPrefix(Double.parseDouble(expression));
-		} catch (final NumberFormatException e) {
-			if (expression.contains("^")) {
-				final String[] baseAndExponent = expression.split("\\^");
+		// attempt to get a unit as an alias first
+		if (this.containsUnitName(expression))
+			return this.getPrefix(expression);
 
-				final double base;
-				try {
-					base = Double.parseDouble(baseAndExponent[0]);
-				} catch (final NumberFormatException e2) {
-					throw new IllegalArgumentException("Base of exponientation must be a number.");
-				}
+		// force operators to have spaces
+		String modifiedExpression = expression;
+		modifiedExpression = modifiedExpression.replaceAll("\\*", " \\* ");
+		modifiedExpression = modifiedExpression.replaceAll("/", " / ");
+		modifiedExpression = modifiedExpression.replaceAll("\\^", " \\^ ");
 
-				final int exponent;
-				try {
-					exponent = Integer.parseInt(baseAndExponent[baseAndExponent.length - 1]);
-				} catch (final NumberFormatException e2) {
-					throw new IllegalArgumentException("Exponent must be an integer.");
-				}
+		// fix broken spaces
+		modifiedExpression = modifiedExpression.replaceAll(" +", " ");
 
-				return new DefaultUnitPrefix(Math.pow(base, exponent));
-			} else {
-				if (!this.containsPrefixName(expression))
-					throw new IllegalArgumentException("Unrecognized prefix name \"" + expression + "\".");
-				return this.getPrefix(expression);
-			}
-		}
+		return this.prefixExpressionParser.parseExpression(modifiedExpression);
 	}
 
 	/**
@@ -541,57 +546,27 @@ public final class UnitsDatabase {
 			final double value = Double.parseDouble(name);
 			return SI.SI.getBaseUnit(UnitDimension.EMPTY).times(value);
 		} catch (final NumberFormatException e) {
-			if (name.contains("^")) {
-				final String[] baseAndExponent = name.split("\\^");
-
-				LinearUnit base;
-				try {
-					base = SI.SI.getBaseUnit(UnitDimension.EMPTY).times(Double.parseDouble(baseAndExponent[0]));
-				} catch (final NumberFormatException e2) {
-					final Unit unit = this.getUnit(baseAndExponent[0]);
-					if (unit instanceof LinearUnit) {
-						base = (LinearUnit) unit;
-					} else
-						throw new IllegalArgumentException("Base of exponientation must be a linear or base unit.");
-				}
-
-				final int exponent;
-				try {
-					exponent = Integer.parseInt(baseAndExponent[baseAndExponent.length - 1]);
-				} catch (final NumberFormatException e2) {
-					throw new IllegalArgumentException("Exponent must be an integer.");
-				}
-
-				final LinearUnit exponentiated = base.toExponent(exponent);
-				if (exponentiated.getConversionFactor() == 1)
-					return exponentiated.getSystem().getBaseUnit(exponentiated.getDimension());
-				else
-					return exponentiated;
-			} else {
-				for (final String prefixName : this.prefixNameSet()) {
-					// check for a prefix
-					if (name.startsWith(prefixName)) {
-						// prefix found! Make sure what comes after it is actually a unit!
-						final String prefixless = name.substring(prefixName.length());
-						if (this.containsUnitName(prefixless)) {
-							// yep, it's a proper prefix! Get the unit!
-							final Unit unit = this.getUnit(prefixless);
-							final UnitPrefix prefix = this.getPrefix(prefixName);
-
-							// Prefixes only work with linear and base units, so make sure it's one of those
-							if (unit instanceof LinearUnit) {
-								final LinearUnit linearUnit = (LinearUnit) unit;
-								return linearUnit.times(prefix.getMultiplier());
-							} else if (unit instanceof BaseUnit) {
-								final BaseUnit baseUnit = (BaseUnit) unit;
-								return baseUnit.times(prefix.getMultiplier());
-							}
+			for (final String prefixName : this.prefixNameSet()) {
+				// check for a prefix
+				if (name.startsWith(prefixName)) {
+					// prefix found! Make sure what comes after it is actually a unit!
+					final String prefixless = name.substring(prefixName.length());
+					if (this.containsUnitName(prefixless)) {
+						// yep, it's a proper prefix! Get the unit!
+						final Unit unit = this.getUnit(prefixless);
+						final UnitPrefix prefix = this.getPrefix(prefixName);
+
+						// Prefixes only work with linear and base units, so make sure it's one of those
+						if (unit instanceof LinearUnit) {
+							final LinearUnit linearUnit = (LinearUnit) unit;
+							return linearUnit.withPrefix(prefix);
 						}
 					}
 				}
-				return this.units.get(name);
 			}
+			return this.units.get(name);
 		}
+
 	}
 
 	/**