[wpiunits] Java units API rewrite (#6958)

Java generics are too limited to do what we need. This refactors generic code previously in Unit and Measure into unit-specific classes that can have unit-safe math operations (notably, times and divide) that can return values in known units instead of a wildcarded Measure<?>.

Unit-specific measure implementations are automatically generated by ./wpiunits/generate_units.py, which generates generic interfaces and mutable and immutable implementations of those interfaces. These make up the bulk of the diff of this PR (approximately 9300 LOC).

This also adds units for angular and linear velocities, accelerations, and momenta; moment of inertia; and torque.

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

@@ -0,0 +1,111 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.units;
+
+import edu.wpi.first.units.measure.ImmutableLinearMomentum;
+import edu.wpi.first.units.measure.LinearMomentum;
+import edu.wpi.first.units.measure.MutLinearMomentum;
+
+/** A unit of linear momentum like {@link edu.wpi.first.units.Units#KilogramMetersPerSecond}. */
+public final class LinearMomentumUnit extends MultUnit<MassUnit, LinearVelocityUnit> {
+  private static final CombinatoryUnitCache<MassUnit, LinearVelocityUnit, LinearMomentumUnit>
+      cache = new CombinatoryUnitCache<>(LinearMomentumUnit::new);
+
+  LinearMomentumUnit(MassUnit unit, LinearVelocityUnit linearVelocityUnit) {
+    super(
+        unit.isBaseUnit() && linearVelocityUnit.isBaseUnit()
+            ? null
+            : combine(unit.getBaseUnit(), linearVelocityUnit.getBaseUnit()),
+        unit,
+        linearVelocityUnit);
+  }
+
+  LinearMomentumUnit(
+      MultUnit<MassUnit, LinearVelocityUnit> baseUnit,
+      UnaryFunction toBaseConverter,
+      UnaryFunction fromBaseConverter,
+      String name,
+      String symbol) {
+    super(baseUnit, toBaseConverter, fromBaseConverter, name, symbol);
+  }
+
+  /**
+   * Combines a mass and linear velocity unit to form a combined linear momentum unit.
+   *
+   * @param mass the unit of mass
+   * @param velocity the unit of velocity
+   * @return the combined unit of momentum
+   */
+  public static LinearMomentumUnit combine(MassUnit mass, LinearVelocityUnit velocity) {
+    return cache.combine(mass, velocity);
+  }
+
+  @Override
+  public LinearMomentumUnit getBaseUnit() {
+    return (LinearMomentumUnit) super.getBaseUnit();
+  }
+
+  @Override
+  public LinearMomentum of(double magnitude) {
+    return new ImmutableLinearMomentum(magnitude, toBaseUnits(magnitude), this);
+  }
+
+  @Override
+  public LinearMomentum ofBaseUnits(double baseUnitMagnitude) {
+    return new ImmutableLinearMomentum(fromBaseUnits(baseUnitMagnitude), baseUnitMagnitude, this);
+  }
+
+  @Override
+  public LinearMomentum zero() {
+    return (LinearMomentum) super.zero();
+  }
+
+  @Override
+  public LinearMomentum one() {
+    return (LinearMomentum) super.one();
+  }
+
+  @Override
+  public MutLinearMomentum mutable(double initialMagnitude) {
+    return new MutLinearMomentum(initialMagnitude, toBaseUnits(initialMagnitude), this);
+  }
+
+  @Override
+  public VelocityUnit<LinearMomentumUnit> per(TimeUnit time) {
+    return VelocityUnit.combine(this, time);
+  }
+
+  /**
+   * Creates a ratio unit between this unit and an arbitrary other unit.
+   *
+   * @param other the other unit
+   * @param <U> the type of the other unit
+   * @return the ratio unit
+   */
+  public <U extends Unit> PerUnit<LinearMomentumUnit, U> per(U other) {
+    return PerUnit.combine(this, other);
+  }
+
+  /**
+   * Converts a measurement value in terms of another unit to this unit.
+   *
+   * @param magnitude the magnitude of the measurement in terms of the other unit
+   * @param otherUnit the other unit
+   * @return the value of the measurement in terms of this unit
+   */
+  public double convertFrom(double magnitude, LinearMomentumUnit otherUnit) {
+    return fromBaseUnits(otherUnit.toBaseUnits(magnitude));
+  }
+
+  /**
+   * Multiplies this unit by distance to form a unit of angular momentum.
+   *
+   * @param distance the unit of distance
+   * @return the combined unit of angular momentum
+   */
+  public AngularMomentumUnit mult(DistanceUnit distance) {
+    return AngularMomentumUnit.combine(this, distance);
+  }
+}