[wpiunits] Add Measure.divide(Measure<U2>) (#6611)

wpiunits/src/main/java/edu/wpi/first/units/Measure.java

@@ -137,16 +137,29 @@ public interface Measure<U extends Unit<U>> extends Comparable<Measure<U>> {
   }
 
   /**
-   * Divides this measurement by some constant divisor and returns the result. This is equivalent to
-   * {@code divide(divisor.baseUnitMagnitude())}
+   * Divides this measurement by another measure and performs some dimensional analysis to reduce
+   * the units.
    *
-   * @param divisor the dimensionless measure to divide by
+   * @param <U2> the type of the other measure to multiply by
+   * @param other the unit to multiply by
    * @return the resulting measure
-   * @see #divide(double)
-   * @see #times(double)
    */
-  default Measure<U> divide(Measure<Dimensionless> divisor) {
-    return divide(divisor.baseUnitMagnitude());
+  default <U2 extends Unit<U2>> Measure<?> divide(Measure<U2> other) {
+    if (unit().getBaseUnit().equals(other.unit().getBaseUnit())) {
+      return Units.Value.ofBaseUnits(baseUnitMagnitude() / other.baseUnitMagnitude());
+    }
+    if (other.unit() instanceof Dimensionless) {
+      return divide(other.baseUnitMagnitude());
+    }
+    if (other.unit() instanceof Velocity<?> velocity
+        && velocity.getUnit().getBaseUnit().equals(unit().getBaseUnit())) {
+      return times(velocity.reciprocal().ofBaseUnits(1 / other.baseUnitMagnitude()));
+    }
+    if (other.unit() instanceof Per<?, ?> per
+        && per.numerator().getBaseUnit().equals(unit().getBaseUnit())) {
+      return times(per.reciprocal().ofBaseUnits(1 / other.baseUnitMagnitude()));
+    }
+    return unit().per(other.unit()).ofBaseUnits(baseUnitMagnitude() / other.baseUnitMagnitude());
   }
 
   /**

wpiunits/src/main/java/edu/wpi/first/units/Per.java

@@ -109,6 +109,15 @@ public class Per<N extends Unit<N>, D extends Unit<D>> extends Unit<Per<N, D>> {
     return m_denominator;
   }
 
+  /**
+   * Returns the reciprocal of this Per.
+   *
+   * @return the reciprocal
+   */
+  public Per<D, N> reciprocal() {
+    return m_denominator.per(m_numerator);
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) {

wpiunits/src/main/java/edu/wpi/first/units/Velocity.java

@@ -157,6 +157,15 @@ public class Velocity<D extends Unit<D>> extends Unit<Velocity<D>> {
     return m_period;
   }
 
+  /**
+   * Returns the reciprocal of this velocity.
+   *
+   * @return the reciprocal
+   */
+  public Per<Time, D> reciprocal() {
+    return m_period.per(m_unit);
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) {