Add power quantity and associated units.

Closes #69.

src/si/mod.rs

@@ -33,6 +33,7 @@ system! {
         length::Length,
         luminous_intensity::LuminousIntensity,
         mass::Mass,
+        power::Power,
         thermodynamic_temperature::ThermodynamicTemperature,
         time::Time,
         velocity::Velocity,

src/si/power.rs

@@ -0,0 +1,106 @@
+//! Power (base unit watt, m<sup>2</sup> · kg · s<sup>-3</sup>).
+
+quantity! {
+    /// Available energy (base unit watt, m<sup>2</sup> · kg · s<sup>-3</sup>).
+    quantity: Power; "power";
+    /// Power dimension, m<sup>2</sup> · kg · s<sup>-3</sup>.
+    dimension: ISQ<
+        P2,     // length
+        P1,     // mass
+        N3,     // time
+        Z0,     // electric current
+        Z0,     // thermodynamic temperature
+        Z0,     // amount of substance
+        Z0>;    // luminous intensity
+    units {
+        @yottawatt: prefix!(yotta); "YW", "yottawatt", "yottawatts";
+        @zettawatt: prefix!(zetta); "ZW", "zettawatt", "zettawatts";
+        @exawatt: prefix!(exa); "EW", "exawatt", "exawatts";
+        @petawatt: prefix!(peta); "PW", "petawatt", "petawatts";
+        @terawatt: prefix!(tera); "TW", "terawatt", "terawatts";
+        @gigawatt: prefix!(giga); "GW", "gigawatt", "gigawatts";
+        @megawatt: prefix!(mega); "MW", "megawatt", "megawatts";
+        @kilowatt: prefix!(kilo); "kW", "kilowatt", "kilowatts";
+        @hectowatt: prefix!(hecto); "hW", "hectowatt", "hectowatts";
+        @decawatt: prefix!(deca); "daW", "decawatt", "decawatts";
+        /// Derived unit of power.
+        @watt: prefix!(none); "W", "watt", "watts";
+        @deciwatt: prefix!(deci); "dW", "deciwatt", "deciwatts";
+        @centiwatt: prefix!(centi); "cW", "centiwatt", "centiwatts";
+        @milliwatt: prefix!(milli); "mW", "milliwatt", "milliwatts";
+        @microwatt: prefix!(micro); "µW", "microwatt", "microwatts";
+        @nanowatt: prefix!(nano); "nW", "nanowatt", "nanowatts";
+        @picowatt: prefix!(pico); "pW", "picowatt", "picowatts";
+        @femtowatt: prefix!(femto); "fW", "femtowatt", "femtowatts";
+        @attowatt: prefix!(atto); "aW", "attowatt", "attowatts";
+        @zeptowatt: prefix!(zepto); "zW", "zeptowatt", "zeptowatts";
+        @yoctowatt: prefix!(yocto); "yW", "yoctowatt", "yoctowatts";
+
+        @erg_per_second: 1.0_E-7; "erg/s", "erg per second", "ergs per second";
+        @foot_pound_per_hour: 3.766_161_111_111_111_E-4; "ft · lbf/h", "foot pound-force per hour",
+            "foot pounds-force per hour";
+        @foot_pound_per_minute: 2.259_696_666_666_666_6_E-2; "ft · lbf/min",
+            "foot pound-force per minute", "foot pounds-force per minute";
+        @foot_pound_per_second: 1.355_818; "ft · lbf/s", "foot pound-force per second",
+            "foot pounds-force per second";
+        @horsepower: 7.456_999_E2; "hp", "horsepower", "horsepower";
+        @horsepower_boiler: 9.809_50_E3; "hp (S)", "horsepower (boiler)",
+            "horsepower (boiler)";
+        @horsepower_electric: 7.46_E2; "hp (E)", "horsepower (electric)",
+            "horsepower (electric)";
+        @horsepower_metric: 7.354_988_E2; "hp (M)", "metric horsepower", "metric horsepower";
+        @horsepower_imperial: 7.457_0_E2; "hp (I)", "horsepower (Imperial)",
+            "horsepower (Imperial)";
+        @hydraulic_horsepower: 7.460_43_E2; "hp (hydraulic)", "hydraulic horsepower",
+            "hydraulic horsepower";
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    storage_types! {
+        use num::One;
+        use si::quantities::*;
+        use si::energy as e;
+        use si::time as t;
+        use si::power as p;
+        use tests::Test;
+
+        #[test]
+        fn check_dimension() {
+            let _: Power<V> =  Energy::new::<e::joule>(V::one())
+                / Time::new::<t::second>(V::one());
+        }
+
+        #[test]
+        fn check_units() {
+            test::<e::zettajoule, t::second, p::zettawatt>();
+            test::<e::exajoule, t::second, p::exawatt>();
+            test::<e::petajoule, t::second, p::petawatt>();
+            test::<e::terajoule, t::second, p::terawatt>();
+            test::<e::gigajoule, t::second, p::gigawatt>();
+            test::<e::megajoule, t::second, p::megawatt>();
+            test::<e::kilojoule, t::second, p::kilowatt>();
+            test::<e::joule, t::second, p::watt>();
+            test::<e::centijoule, t::second, p::centiwatt>();
+            test::<e::millijoule, t::second, p::milliwatt>();
+            test::<e::microjoule, t::second, p::microwatt>();
+            test::<e::nanojoule, t::second, p::nanowatt>();
+            test::<e::picojoule, t::second, p::picowatt>();
+            test::<e::femtojoule, t::second, p::femtowatt>();
+            test::<e::attojoule, t::second, p::attowatt>();
+            test::<e::zeptojoule, t::second, p::zeptowatt>();
+            test::<e::yoctojoule, t::second, p::yoctowatt>();
+
+            test::<e::erg, t::second, p::erg_per_second>();
+            test::<e::foot_pound, t::hour, p::foot_pound_per_hour>();
+            test::<e::foot_pound, t::minute, p::foot_pound_per_minute>();
+            test::<e::foot_pound, t::second, p::foot_pound_per_second>();
+
+            fn test<E: e::Conversion<V>, T: t::Conversion<V>, P: p::Conversion<V>>() {
+                Test::assert_approx_eq(&Power::new::<P>(V::one()),
+                    &(Energy::new::<E>(V::one()) / Time::new::<T>(V::one())));
+            }
+        }
+    }
+}