Pressure units

shared/src/main/scala/squants/motion/Pressure.scala

@@ -30,10 +30,12 @@ final class Pressure private (val value: Double, val unit: PressureUnit)
   def *(that: Area): Force = Newtons(toPascals * that.toSquareMeters)
   def *(that: Time) = ??? // returns DynamicViscosity
 
-  def toPascals = to(Pascals)
-  def toBars = to(Bars)
-  def toPoundsPerSquareInch = to(PoundsPerSquareInch)
-  def toStandardAtmospheres = to(StandardAtmospheres)
+  def toPascals: Double              = to(Pascals)
+  def toBars: Double                 = to(Bars)
+  def toPoundsPerSquareInch: Double  = to(PoundsPerSquareInch)
+  def toStandardAtmospheres: Double  = to(StandardAtmospheres)
+  def toMillimetersOfMercury: Double = to(MillimetersOfMercury)
+  def toTorr: Double                 = to(Torrs)
 }
 
 object Pressure extends Dimension[Pressure] {
@@ -42,7 +44,7 @@ object Pressure extends Dimension[Pressure] {
   def name = "Pressure"
   def primaryUnit = Pascals
   def siUnit = Pascals
-  def units = Set(Pascals, Bars, PoundsPerSquareInch, StandardAtmospheres)
+  def units = Set(Pascals, Bars, PoundsPerSquareInch, StandardAtmospheres, MillimetersOfMercury, Torrs)
 }
 
 trait PressureUnit extends UnitOfMeasure[Pressure] with UnitConverter {
@@ -68,18 +70,32 @@ object StandardAtmospheres extends PressureUnit {
   val conversionFactor = Newtons.conversionFactor * 1.01325e5
 }
 
+object MillimetersOfMercury extends PressureUnit {
+  val symbol = "mmHg"
+  val conversionFactor = Newtons.conversionFactor * 133.322387415
+}
+
+object Torrs extends PressureUnit {
+  val symbol = "Torr"
+  val conversionFactor = StandardAtmospheres.conversionFactor / 760d
+}
+
 object PressureConversions {
   lazy val pascal = Pascals(1)
-  lazy val bar = Bars(1)
-  lazy val psi = PoundsPerSquareInch(1)
-  lazy val atm = StandardAtmospheres(1)
+  lazy val bar    = Bars(1)
+  lazy val psi    = PoundsPerSquareInch(1)
+  lazy val atm    = StandardAtmospheres(1)
+  lazy val mmHg   = MillimetersOfMercury(1)
+  lazy val torr   = Torrs(1)
 
   implicit class PressureConversions[A](n: A)(implicit num: Numeric[A]) {
     def pascals = Pascals(n)
-    def bars = Bars(n)
-    def psi = PoundsPerSquareInch(n)
-    def atm = StandardAtmospheres(n)
+    def bars    = Bars(n)
+    def psi     = PoundsPerSquareInch(n)
+    def atm     = StandardAtmospheres(n)
+    def mmHg    = MillimetersOfMercury(n)
+    def torr    = Torrs(n)
   }
 
   implicit object PressureNumeric extends AbstractQuantityNumeric[Pressure](Pressure.primaryUnit)
-}
+}

shared/src/test/scala/squants/motion/PressureSpec.scala

@@ -26,12 +26,16 @@ class PressureSpec extends FlatSpec with Matchers {
     Bars(10).toBars should be(10)
     PoundsPerSquareInch(1).toPoundsPerSquareInch should be(1)
     StandardAtmospheres(1).toStandardAtmospheres should be(1)
+    MillimetersOfMercury(1).toMillimetersOfMercury should be(1)
+    Torrs(1).toTorr should be(1)
   }
 
   it should "create values from properly formatted Strings" in {
     Pressure("10.22 Pa").get should be(Pascals(10.22))
     Pressure("10.22 bar").get should be(Bars(10.22))
     Pressure("10.22 psi").get should be(PoundsPerSquareInch(10.22))
+    Pressure("10.22 mmHg").get should be(MillimetersOfMercury(10.22))
+    Pressure("10.22 Torr").get should be(Torrs(10.22))
     Pressure("10.22 zz").failed.get should be(QuantityParseException("Unable to parse Pressure", "10.22 zz"))
     Pressure("zz Pa").failed.get should be(QuantityParseException("Unable to parse Pressure", "zz Pa"))
   }
@@ -43,13 +47,17 @@ class PressureSpec extends FlatSpec with Matchers {
     x.toBars should be(1e-5)
     x.toPoundsPerSquareInch should be(Newtons(1).toPoundForce / SquareMeters(1).toSquareInches +- tolerance)
     x.toStandardAtmospheres should be(1d / 101325d)
+    x.toMillimetersOfMercury should be(1d / 133.322387415d)
+    x.toTorr should be(760d / 101325d)
   }
 
   it should "return properly formatted strings for all supported Units of Measure" in {
     Pascals(1).toString(Pascals) should be("1.0 Pa")
     Bars(1).toString(Bars) should be("1.0 bar")
     PoundsPerSquareInch(1).toString(PoundsPerSquareInch) should be("1.0 psi")
     StandardAtmospheres(1).toString(StandardAtmospheres) should be("1.0 atm")
+    MillimetersOfMercury(1).toString(MillimetersOfMercury) should be("1.0 mmHg")
+    Torrs(1).toString(Torrs) should be("1.0 Torr")
   }
 
   it should "return Force when multiplied by Area" in {
@@ -65,6 +73,8 @@ class PressureSpec extends FlatSpec with Matchers {
     bar should be(Bars(1))
     psi should be(PoundsPerSquareInch(1))
     atm should be(StandardAtmospheres(1))
+    mmHg should be(MillimetersOfMercury(1))
+    torr should be(Torrs(1))
   }
   it should "provide implicit conversion from Double" in {
     import PressureConversions._
@@ -74,6 +84,8 @@ class PressureSpec extends FlatSpec with Matchers {
     d.bars should be(Bars(d))
     d.psi should be(PoundsPerSquareInch(d))
     d.atm should be(StandardAtmospheres(d))
+    d.mmHg should be(MillimetersOfMercury(d))
+    d.torr should be(Torrs(d))
   }
 
   it should "provide Numeric support" in {