From 646e05a3e9d5182b7afb41cfb5976f5e697a113b Mon Sep 17 00:00:00 2001
From: Vlad Voronenkov <v.v.voronenkov@ya.ru>
Date: Wed, 3 Aug 2022 17:26:31 +0200
Subject: [PATCH] Add Electric Field quantity with corresponding units and
 test.

---
 src/si/electric_field.rs | 89 ++++++++++++++++++++++++++++++++++++++++
 src/si/mod.rs            |  1 +
 2 files changed, 90 insertions(+)
 create mode 100644 src/si/electric_field.rs

diff --git a/src/si/electric_field.rs b/src/si/electric_field.rs
new file mode 100644
index 00000000..7e99d4fd
--- /dev/null
+++ b/src/si/electric_field.rs
@@ -0,0 +1,89 @@
+//! Electric field (base unit volt per meter, m ⋅ kg ⋅ s⁻³ ⋅ A⁻¹).
+
+quantity! {
+    /// Electric field (base unit volt per meter, m ⋅ kg ⋅ s⁻³ ⋅ A⁻¹).
+    quantity: ElectricField; "electric field";
+    /// Dimension of electric field, LMT⁻³I⁻¹ (base unit volt per meter, m ⋅ kg ⋅ s⁻³ ⋅ A⁻¹).
+    dimension: ISQ<
+        P1,     // length
+        P1,     // mass
+        N3,     // time
+        N1,     // electric current
+        Z0,     // thermodynamic temperature
+        Z0,     // amount of substance
+        Z0>;    // luminous intensity
+    units {
+        @volt_per_meter: prefix!(none); "V/m", "volt per meter", "volts per meter";
+        @volt_per_centimeter: prefix!(none) / prefix!(centi); "V/cm", "volt per centimeter",
+            "volts per centimeter";
+        @volt_per_millimeter: prefix!(none) / prefix!(milli); "V/mm", "volt per millimeter",
+            "volts per millimeter";
+        @volt_per_micrometer: prefix!(none) / prefix!(micro); "V/μm", "volt per micrometer",
+            "volts per micrometer";
+        @kilovolt_per_millimeter: prefix!(kilo) / prefix!(milli); "kV/mm",
+            "kilovolt per millimeter", "kilovolts per millimeter";
+        @megavolt_per_meter: prefix!(mega); "MV/m", "megavolt per meter", "megavolts per meter";
+        @megavolt_per_centimeter: prefix!(mega) / prefix!(centi); "MV/cm",
+            "megavolt per centimeter", "megavolts per centimeter";
+        @volt_per_mil: prefix!(none) / 2.54_E-5; "V/mil", "volt per mil", "volts per mil";
+
+        /// Hartree atomic unit of electric field Eₕ / (e ⋅ a₀), where Eₕ is Hartree energy, e is
+        /// elementary charge, and a₀ is Bohr radius.
+        @atomic_unit_of_electric_field: 5.142_206_747_632_595_E11; "a.u. of electric field",
+            "atomic unit of electric field", "atomic units of electric field";
+    }
+}
+
+#[cfg(test)]
+mod test {
+    storage_types! {
+        use crate::num::One;
+        use crate::si::electric_field as ef;
+        use crate::si::quantities::*;
+        use crate::si::electric_potential as ep;
+        use crate::si::energy as en;
+        use crate::si::electric_charge as ec;
+        use crate::si::length as l;
+        use crate::tests::Test;
+
+        #[test]
+        fn check_dimension() {
+            let _: ElectricField<V> = ElectricPotential::new::<ep::volt>(V::one())
+                / Length::new::<l::meter>(V::one());
+        }
+
+        #[test]
+        fn check_units() {
+            test::<ep::volt, l::meter, ef::volt_per_meter>();
+            test::<ep::volt, l::centimeter, ef::volt_per_centimeter>();
+            test::<ep::volt, l::millimeter, ef::volt_per_millimeter>();
+            test::<ep::volt, l::micrometer, ef::volt_per_micrometer>();
+            test::<ep::kilovolt, l::millimeter, ef::kilovolt_per_millimeter>();
+            test::<ep::megavolt, l::centimeter, ef::megavolt_per_centimeter>();
+            test::<ep::megavolt, l::meter, ef::megavolt_per_meter>();
+            test::<ep::volt, l::mil, ef::volt_per_mil>();
+
+            fn test<EP: ep::Conversion<V>, L: l::Conversion<V>, EF: ef::Conversion<V>>() {
+                Test::assert_approx_eq(&ElectricField::new::<EF>(V::one()),
+                    &(ElectricPotential::new::<EP>(V::one())
+                        / Length::new::<L>(V::one())));
+            }
+        }
+
+        #[test]
+        fn check_units_eql() {
+            test::<en::joule, ec::coulomb, l::meter, ef::volt_per_meter>();
+            test::<en::hartree, ec::elementary_charge, l::bohr_radius,
+                ef::atomic_unit_of_electric_field>();
+
+            fn test<EN: en::Conversion<V>, Q: ec::Conversion<V>, L: l::Conversion<V>,
+                EF: ef::Conversion<V>>()
+            {
+                Test::assert_approx_eq(&ElectricField::new::<EF>(V::one()),
+                    &(Energy::new::<EN>(V::one())
+                        / ElectricCharge::new::<Q>(V::one())
+                        / Length::new::<L>(V::one())));
+            }
+        }
+    }
+}
diff --git a/src/si/mod.rs b/src/si/mod.rs
index d7783a5c..1ae0f6bc 100644
--- a/src/si/mod.rs
+++ b/src/si/mod.rs
@@ -70,6 +70,7 @@ system! {
         electric_charge_volumetric_density::ElectricChargeVolumetricDensity,
         electric_current::ElectricCurrent,
         electric_displacement_field::ElectricDisplacementField,
+        electric_field::ElectricField,
         electric_flux::ElectricFlux,
         electric_permittivity::ElectricPermittivity,
         electric_potential::ElectricPotential,