Add ability to convert expression to sum of units

1 files changed, 71 insertions, 32 deletions

diff --git a/src/main/java/sevenUnits/unit/LinearUnitValue.java b/src/main/java/sevenUnits/unit/LinearUnitValue.java
index 3a9428b..fad3eb0 100644
--- a/src/main/java/sevenUnits/unit/LinearUnitValue.java
+++ b/src/main/java/sevenUnits/unit/LinearUnitValue.java
@@ -17,10 +17,13 @@
 package sevenUnits.unit;
 
 import java.math.RoundingMode;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 
 import sevenUnits.utils.DecimalComparison;
+import sevenUnits.utils.ObjectProduct;
 import sevenUnits.utils.UncertainDouble;
 
 /**
@@ -34,7 +37,7 @@ import sevenUnits.utils.UncertainDouble;
  */
 public final class LinearUnitValue {
 	public static final LinearUnitValue ONE = getExact(Metric.ONE, 1);
-
+	
 	/**
 	 * Gets an exact {@code LinearUnitValue}
 	 * 
@@ -49,7 +52,7 @@ public final class LinearUnitValue {
 				Objects.requireNonNull(unit, "unit must not be null"),
 				UncertainDouble.of(value, 0));
 	}
-
+	
 	/**
 	 * Gets an uncertain {@code LinearUnitValue}
 	 * 
@@ -65,11 +68,11 @@ public final class LinearUnitValue {
 				Objects.requireNonNull(unit, "unit must not be null"),
 				Objects.requireNonNull(value, "value may not be null"));
 	}
-
+	
 	private final LinearUnit unit;
-
+	
 	private final UncertainDouble value;
-
+	
 	/**
 	 * @param unit  unit to express as
 	 * @param value value to express
@@ -79,7 +82,7 @@ public final class LinearUnitValue {
 		this.unit = unit;
 		this.value = value;
 	}
-
+	
 	/**
 	 * @return this value as a {@code UnitValue}. All uncertainty information is
 	 *         removed from the returned value.
@@ -88,7 +91,7 @@ public final class LinearUnitValue {
 	public final UnitValue asUnitValue() {
 		return UnitValue.of(this.unit, this.value.value());
 	}
-
+	
 	/**
 	 * @param other a {@code LinearUnit}
 	 * @return true iff this value can be represented with {@code other}.
@@ -97,7 +100,7 @@ public final class LinearUnitValue {
 	public final boolean canConvertTo(final LinearUnit other) {
 		return this.unit.canConvertTo(other);
 	}
-
+	
 	/**
 	 * Returns a LinearUnitValue that represents the same value expressed in a
 	 * different unit
@@ -109,7 +112,43 @@ public final class LinearUnitValue {
 	public final LinearUnitValue convertTo(final LinearUnit other) {
 		return LinearUnitValue.of(other, this.unit.convertTo(other, this.value));
 	}
-
+	
+	/**
+	 * Convert a LinearUnitValue to a sum of multiple units, where all but the
+	 * last have exact integer values.
+	 *
+	 * @param others units to convert to
+	 * @throws IllegalArgumentException if no units are provided or units
+	 *                                  provided have incompatible bases
+	 * @since 2024-08-15
+	 */
+	public final List<LinearUnitValue> convertToMultiple(
+			final List<LinearUnit> others) {
+		if (others.size() < 1)
+			throw new IllegalArgumentException("Must have at least one unit");
+		final ObjectProduct<BaseUnit> unitBase = others.get(0).getBase();
+		for (final LinearUnit unit : others) {
+			if (!unitBase.equals(unit.getBase()))
+				throw new IllegalArgumentException(
+						"All units must have the same base.");
+		}
+		
+		LinearUnitValue remaining = this;
+		final List<LinearUnitValue> values = new ArrayList<>(others.size());
+		for (final LinearUnit unit : others.subList(0, others.size() - 1)) {
+			final LinearUnitValue remainingInUnit = remaining.convertTo(unit);
+			final LinearUnitValue value = getExact(unit,
+					Math.floor(remainingInUnit.getValueExact()));
+			values.add(value);
+			remaining = remaining.minus(value);
+		}
+		
+		final LinearUnitValue lastValue = remaining
+				.convertTo(others.get(others.size() - 1));
+		values.add(lastValue);
+		return values;
+	}
+	
 	/**
 	 * Divides this value by a scalar
 	 * 
@@ -120,7 +159,7 @@ public final class LinearUnitValue {
 	public LinearUnitValue dividedBy(final double divisor) {
 		return LinearUnitValue.of(this.unit, this.value.dividedByExact(divisor));
 	}
-
+	
 	/**
 	 * Divides this value by another value
 	 * 
@@ -132,7 +171,7 @@ public final class LinearUnitValue {
 		return LinearUnitValue.of(this.unit.dividedBy(divisor.unit),
 				this.value.dividedBy(divisor.value));
 	}
-
+	
 	/**
 	 * Returns true if this and obj represent the same value, regardless of
 	 * whether or not they are expressed in the same unit. So (1000 m).equals(1
@@ -150,7 +189,7 @@ public final class LinearUnitValue {
 				&& this.unit.convertToBase(this.value)
 						.equals(other.unit.convertToBase(other.value));
 	}
-
+	
 	/**
 	 * Returns true if this and obj represent the same value, regardless of
 	 * whether or not they are expressed in the same unit. So (1000 m).equals(1
@@ -171,7 +210,7 @@ public final class LinearUnitValue {
 				&& DecimalComparison.equals(this.unit.convertToBase(this.value),
 						other.unit.convertToBase(other.value));
 	}
-
+	
 	/**
 	 * @param other another {@code LinearUnitValue}
 	 * @return true iff this and other are within each other's uncertainty range
@@ -185,10 +224,10 @@ public final class LinearUnitValue {
 		final LinearUnit base = LinearUnit.valueOf(this.unit.getBase(), 1);
 		final LinearUnitValue thisBase = this.convertTo(base);
 		final LinearUnitValue otherBase = other.convertTo(base);
-
+		
 		return thisBase.value.equivalent(otherBase.value);
 	}
-
+	
 	/**
 	 * @return the unit
 	 * @since 2020-09-29
@@ -196,7 +235,7 @@ public final class LinearUnitValue {
 	public final LinearUnit getUnit() {
 		return this.unit;
 	}
-
+	
 	/**
 	 * @return the value
 	 * @since 2020-09-29
@@ -204,7 +243,7 @@ public final class LinearUnitValue {
 	public final UncertainDouble getValue() {
 		return this.value;
 	}
-
+	
 	/**
 	 * @return the exact value
 	 * @since 2020-09-07
@@ -212,13 +251,13 @@ public final class LinearUnitValue {
 	public final double getValueExact() {
 		return this.value.value();
 	}
-
+	
 	@Override
 	public int hashCode() {
 		return Objects.hash(this.unit.getBase(),
 				this.unit.convertToBase(this.getValue()));
 	}
-
+	
 	/**
 	 * Returns the difference of this value and another, expressed in this
 	 * value's unit
@@ -231,17 +270,17 @@ public final class LinearUnitValue {
 	 */
 	public LinearUnitValue minus(final LinearUnitValue subtrahend) {
 		Objects.requireNonNull(subtrahend, "subtrahend may not be null");
-
+		
 		if (!this.canConvertTo(subtrahend.unit))
 			throw new IllegalArgumentException(String.format(
 					"Incompatible units for subtraction \"%s\" and \"%s\".",
 					this.unit, subtrahend.unit));
-
+		
 		final LinearUnitValue otherConverted = subtrahend.convertTo(this.unit);
 		return LinearUnitValue.of(this.unit,
 				this.value.minus(otherConverted.value));
 	}
-
+	
 	/**
 	 * Returns the sum of this value and another, expressed in this value's unit
 	 * 
@@ -253,17 +292,17 @@ public final class LinearUnitValue {
 	 */
 	public LinearUnitValue plus(final LinearUnitValue addend) {
 		Objects.requireNonNull(addend, "addend may not be null");
-
+		
 		if (!this.canConvertTo(addend.unit))
 			throw new IllegalArgumentException(String.format(
 					"Incompatible units for addition \"%s\" and \"%s\".", this.unit,
 					addend.unit));
-
+		
 		final LinearUnitValue otherConverted = addend.convertTo(this.unit);
 		return LinearUnitValue.of(this.unit,
 				this.value.plus(otherConverted.value));
 	}
-
+	
 	/**
 	 * Multiplies this value by a scalar
 	 * 
@@ -274,7 +313,7 @@ public final class LinearUnitValue {
 	public LinearUnitValue times(final double multiplier) {
 		return LinearUnitValue.of(this.unit, this.value.timesExact(multiplier));
 	}
-
+	
 	/**
 	 * Multiplies this value by another value
 	 * 
@@ -286,7 +325,7 @@ public final class LinearUnitValue {
 		return LinearUnitValue.of(this.unit.times(multiplier.unit),
 				this.value.times(multiplier.value));
 	}
-
+	
 	/**
 	 * Raises a value to an exponent
 	 * 
@@ -298,12 +337,12 @@ public final class LinearUnitValue {
 		return LinearUnitValue.of(this.unit.toExponent(exponent),
 				this.value.toExponentExact(exponent));
 	}
-
+	
 	@Override
 	public String toString() {
 		return this.toString(!this.value.isExact(), RoundingMode.HALF_EVEN);
 	}
-
+	
 	/**
 	 * Returns a string representing the object. <br>
 	 * If the attached unit has a name or symbol, the string looks like "12 km".
@@ -321,9 +360,9 @@ public final class LinearUnitValue {
 		final Optional<String> primaryName = this.unit.getPrimaryName();
 		final Optional<String> symbol = this.unit.getSymbol();
 		final String chosenName = symbol.orElse(primaryName.orElse(null));
-
+		
 		final UncertainDouble baseValue = this.unit.convertToBase(this.value);
-
+		
 		// get rounded strings
 		// if showUncertainty is true, add brackets around the string
 		final String valueString = (showUncertainty ? "(" : "")
@@ -332,7 +371,7 @@ public final class LinearUnitValue {
 		final String baseValueString = (showUncertainty ? "(" : "")
 				+ baseValue.toString(showUncertainty, roundingMode)
 				+ (showUncertainty ? ")" : "");
-
+		
 		// create string
 		if (chosenName == null)
 			return String.format("%s unnamed unit (= %s %s)", valueString,