| // MODULE: distance |
| // FILE: entities.kt |
| value class Length(val meters: Double) |
| value class SurfaceArea(val squareMeters: Double) |
| value class Volume(val cubicMeters: Double) |
| |
| // FILE: extensions.kt |
| val Number.Meters: Length get() = Length(toDouble()) |
| val Number.SquareMeters: SurfaceArea get() = SurfaceArea(toDouble()) |
| val Number.CubicMeters: Volume get() = Volume(toDouble()) |
| |
| // FILE: operators.kt |
| operator fun Number.times(length: Length): Length = Length(toDouble() * length.meters) |
| operator fun Number.times(surfaceArea: SurfaceArea): SurfaceArea = SurfaceArea(toDouble() * surfaceArea.squareMeters) |
| operator fun Number.times(volume: Volume): Volume = Volume(toDouble() * volume.cubicMeters) |
| |
| operator fun Length.times(factor: Number): Length = Length(meters * factor.toDouble()) |
| operator fun Length.times(length: Length): SurfaceArea = SurfaceArea(meters * length.meters) |
| operator fun Length.times(surfaceArea: SurfaceArea): Volume = Volume(meters * surfaceArea.squareMeters) |
| |
| operator fun SurfaceArea.times(factor: Number): SurfaceArea = SurfaceArea(squareMeters * factor.toDouble()) |
| operator fun SurfaceArea.times(length: Length): Volume = Volume(squareMeters * length.meters) |
| |
| operator fun Volume.times(factor: Number): Volume = Volume(cubicMeters * factor.toDouble()) |
| |
| // MODULE: density |
| // FILE: entities.kt |
| value class Density(val kilogramsPerCubicMeter: Double) { |
| companion object { |
| val AIR: Density = 1.2.KilogramsPerCubicMeter |
| val WATER: Density = 1000.KilogramsPerCubicMeter |
| } |
| } |
| |
| // FILE: extensions.kt |
| val Number.KilogramsPerCubicMeter: Density get() = Density(toDouble()) |
| |
| // MODULE: mass(distance,density) |
| // FILE: entities.kt |
| value class Mass(val kilograms: Double) |
| |
| // FILE: extensions.kt |
| val Number.Kilograms: Mass get() = Mass(toDouble()) |
| |
| // FILE: operators.kt |
| operator fun Volume.times(density: Density): Mass = Mass(cubicMeters * density.kilogramsPerCubicMeter) |
| operator fun Density.times(volume: Volume): Mass = Mass(kilogramsPerCubicMeter * volume.cubicMeters) |
| |
| // MODULE: constants |
| // FILE: main.kt |
| const val TRIVIAL_PI = 3.14 |
| |
| // MODULE: shapes(mass,constants) |
| // FILE: default.kt |
| class Ball(private val radius: Length) { |
| val surfaceArea1: SurfaceArea get() = TRIVIAL_PI * radius * radius |
| val surfaceArea2: SurfaceArea get() = radius * TRIVIAL_PI * radius |
| val surfaceArea3: SurfaceArea get() = radius * radius * TRIVIAL_PI |
| |
| val volume1: Volume get() = 0.75 * surfaceArea1 * radius |
| val volume2: Volume get() = 0.75 * (radius * surfaceArea1) |
| val volume3: Volume get() = surfaceArea1 * radius * 0.75 |
| } |
| |
| // MODULE: assertions(shapes) |
| // FILE: checks.kt |
| import kotlin.test.* |
| |
| @Test |
| fun surfaceArea() { |
| with(Ball(10.Meters)) { |
| assertEquals(314.SquareMeters, surfaceArea1) |
| assertEquals(314.SquareMeters, surfaceArea2) |
| assertEquals(314.SquareMeters, surfaceArea3) |
| } |
| } |
| |
| @Test |
| fun volume() { |
| with(Ball(20.Meters)) { |
| assertEquals(18840.CubicMeters, volume1) |
| assertEquals(18840.CubicMeters, volume2) |
| assertEquals(18840.CubicMeters, volume3) |
| } |
| } |
| |
| @Test |
| fun mass() { |
| assertEquals(6.Kilograms, 5.CubicMeters * Density.AIR) |
| assertEquals(3500.Kilograms, 3.5.CubicMeters * Density.WATER) |
| } |
| |