[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/MassUnit.java

@@ -0,0 +1,112 @@
+// 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.ImmutableMass;
+import edu.wpi.first.units.measure.Mass;
+import edu.wpi.first.units.measure.MutMass;
+
+/**
+ * Unit of mass dimension.
+ *
+ * <p>This is the base type for units of mass dimension. It is also used to specify the dimension
+ * for the mass-specific {@link Mass} measurement type.
+ *
+ * <p>Actual units (such as {@link Units#Grams} and {@link Units#Pounds}) can be found in the {@link
+ * Units} class.
+ */
+public final class MassUnit extends Unit {
+  /** Creates a new unit with the given name and multiplier to the base unit. */
+  MassUnit(MassUnit baseUnit, double baseUnitEquivalent, String name, String symbol) {
+    super(baseUnit, baseUnitEquivalent, name, symbol);
+  }
+
+  MassUnit(
+      MassUnit baseUnit,
+      UnaryFunction toBaseConverter,
+      UnaryFunction fromBaseConverter,
+      String name,
+      String symbol) {
+    super(baseUnit, toBaseConverter, fromBaseConverter, name, symbol);
+  }
+
+  @Override
+  public MassUnit getBaseUnit() {
+    return (MassUnit) super.getBaseUnit();
+  }
+
+  @Override
+  public Mass of(double magnitude) {
+    return new ImmutableMass(magnitude, toBaseUnits(magnitude), this);
+  }
+
+  @Override
+  public Mass ofBaseUnits(double baseUnitMagnitude) {
+    return new ImmutableMass(fromBaseUnits(baseUnitMagnitude), baseUnitMagnitude, this);
+  }
+
+  @Override
+  public Mass zero() {
+    return (Mass) super.zero();
+  }
+
+  @Override
+  public Mass one() {
+    return (Mass) super.one();
+  }
+
+  @Override
+  public MutMass mutable(double initialMagnitude) {
+    return new MutMass(initialMagnitude, toBaseUnits(initialMagnitude), this);
+  }
+
+  @Override
+  public VelocityUnit<MassUnit> per(TimeUnit period) {
+    return VelocityUnit.combine(this, period);
+  }
+
+  /**
+   * 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<MassUnit, U> per(U other) {
+    return PerUnit.combine(this, other);
+  }
+
+  /**
+   * Converts a measurement value in terms of another mass unit to this unit.
+   *
+   * @param magnitude the magnitude of the measurement in terms of the other mass unit
+   * @param otherUnit the other mass unit
+   * @return the value of the measurement in terms of this unit
+   */
+  public double convertFrom(double magnitude, MassUnit otherUnit) {
+    return fromBaseUnits(otherUnit.toBaseUnits(magnitude));
+  }
+
+  /**
+   * Multiplies this mass unit by a unit of linear velocity to form a combined unit of linear
+   * momentum.
+   *
+   * @param velocity the unit of velocity
+   * @return the combined unit of momentum
+   */
+  public LinearMomentumUnit mult(LinearVelocityUnit velocity) {
+    return LinearMomentumUnit.combine(this, velocity);
+  }
+
+  /**
+   * Multiplies this mass unit by a unit of linear acceleration to form a combined unit of force.
+   *
+   * @param acceleration the unit of acceleration
+   * @return the combined unit of force
+   */
+  public ForceUnit mult(LinearAccelerationUnit acceleration) {
+    return ForceUnit.combine(this, acceleration);
+  }
+}