feat: add nautical unit conversions

README.md

@@ -35,6 +35,17 @@ double metres = depth.AsSiBaseUnit(); // 1.8288
 
 `BritishThermalUnitIT` is the International Table definition (exactly 1055.05585262 J); other BTU definitions differ. US and Imperial liquid measures are named separately. Imperial helpers do not generate SI-prefixed variants.
 
+Add `DimensionalQuantities.Extensions.Nautical` for international nautical miles, fathoms, square nautical miles and knots. Import its namespace to use the helpers:
+
+```csharp
+using DimensionalQuantities.Extensions.Nautical;
+
+Length passage = Length.FromNauticalMiles(12);
+Speed vesselSpeed = Speed.FromKnots(8);
+```
+
+A nautical mile is exactly 1852 m, and a knot is one nautical mile per hour. Nautical helpers do not generate SI-prefixed variants.
+
 ```csharp
 Voltage voltage = Voltage.FromVolts(12);
 Current current = Current.FromAmps(3);

src/DimensionalQuantities.Extensions.Nautical.Tests/DimensionalQuantities.Extensions.Nautical.Tests.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net11.0</TargetFramework>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+    <OutputType>Exe</OutputType>
+    <UseMicrosoftTestingPlatformRunner>true</UseMicrosoftTestingPlatformRunner>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="xunit.v3" Version="4.0.2" />
+    <PackageReference Include="Microsoft.Testing.Extensions.TrxReport" Version="2.5.1" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="../DimensionalQuantities.Extensions.Nautical/DimensionalQuantities.Extensions.Nautical.csproj" />
+    <ProjectReference Include="../DimensionalQuantities.Roslyn/DimensionalQuantities.Roslyn.csproj"
+                      OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+    <Analyzer Include="../DimensionalQuantities/bin/$(Configuration)/netstandard2.0/DimensionalQuantities.dll" />
+  </ItemGroup>
+</Project>

src/DimensionalQuantities.Extensions.Nautical.Tests/NauticalConversionsTests.cs

@@ -0,0 +1,51 @@
+using System.Reflection;
+using DimensionalQuantities.Extensions.Nautical;
+using Xunit;
+
+namespace DimensionalQuantities.Extensions.Nautical.Tests;
+
+public sealed class NauticalConversionsTests
+{
+	[Fact]
+	public void NauticalUnitsConvertToExpectedSiValues()
+	{
+		double[] result =
+		[
+			Length.FromNauticalMiles(1).AsSiBaseUnit(),
+			Length.FromFathoms(1).AsSiBaseUnit(),
+			Area.FromSquareNauticalMiles(1).AsSiBaseUnit(),
+			Speed.FromKnots(1).AsSiBaseUnit(),
+		];
+
+		double[] expected = [1852d, 1.8288d, 3_429_904d, 1852d / 3600d];
+		Assert.Equal(expected, result);
+	}
+
+	[Fact]
+	public void NauticalUnitsConvertBackFromSiValues()
+	{
+		double[] result =
+		[
+			Length.FromSiBaseUnit(1852).AsNauticalMiles(),
+			Length.FromSiBaseUnit(1.8288).AsFathoms(),
+			Area.FromSiBaseUnit(3_429_904).AsSquareNauticalMiles(),
+			Speed.FromSiBaseUnit(1852d / 3600d).AsKnots(),
+		];
+
+		Assert.Equal([1d, 1d, 1d, 1d], result);
+	}
+
+	[Fact]
+	public void NauticalUnitsDoNotGenerateSiPrefixedConversions()
+	{
+		string[] names = Assembly.Load("DimensionalQuantities.Extensions.Nautical").GetExportedTypes()
+			.Where(type => type.Namespace == "DimensionalQuantities.Extensions.Nautical")
+			.SelectMany(type => type.GetMethods()).Select(method => method.Name).ToArray();
+
+		Assert.Multiple(
+			() => Assert.DoesNotContain("FromKiloNauticalMiles", names),
+			() => Assert.DoesNotContain("FromMilliKnots", names),
+			() => Assert.DoesNotContain("FromPrefixedUnits", names),
+			() => Assert.DoesNotContain("AsPrefixedUnits", names));
+	}
+}

src/DimensionalQuantities.Extensions.Nautical/DimensionalQuantities.Extensions.Nautical.csproj

@@ -0,0 +1,35 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <Authors>GoSim</Authors>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+    <PackageProjectUrl>https://github.com/GoSimulate/DimensionalQuantities</PackageProjectUrl>
+    <Description>Named nautical conversions for dimensional quantities.</Description>
+    <RepositoryType>git</RepositoryType>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+    <CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)$(Configuration)/$(TargetFramework)/generated</CompilerGeneratedFilesOutputPath>
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <EmbedUntrackedSources>true</EmbedUntrackedSources>
+    <Deterministic>true</Deterministic>
+    <DebugType>portable</DebugType>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../DimensionalQuantities/DimensionalQuantities.csproj" PrivateAssets="none" />
+    <ProjectReference Include="../DimensionalQuantities.Roslyn/DimensionalQuantities.Roslyn.csproj"
+                      OutputItemType="Analyzer" ReferenceOutputAssembly="false" PrivateAssets="all" />
+    <Analyzer Include="../DimensionalQuantities/bin/$(Configuration)/netstandard2.0/DimensionalQuantities.dll" />
+    <None Include="../../LICENSE" Pack="true" PackagePath="" />
+    <None Include="../../README.md" Pack="true" PackagePath="" />
+  </ItemGroup>
+  <Target Name="PinCorePackageDependency" AfterTargets="_GetProjectReferenceVersions" BeforeTargets="GenerateNuspec">
+    <ItemGroup>
+      <_ProjectReferencesWithVersions Update="@(_ProjectReferencesWithVersions)"
+                                      Condition="'%(_ProjectReferencesWithVersions.Filename)' == 'DimensionalQuantities'">
+        <ProjectVersion>[$(PackageVersion)]</ProjectVersion>
+      </_ProjectReferencesWithVersions>
+    </ItemGroup>
+  </Target>
+</Project>

src/DimensionalQuantities.Extensions.Nautical/NauticalSymbols.cs

@@ -0,0 +1,15 @@
+using DimensionalQuantities.Units.Declarations;
+
+namespace DimensionalQuantities.Extensions.Nautical;
+
+internal static class NauticalSymbols
+{
+	[UnitSymbol("NauticalMile", "NauticalMiles", "nmi", Scale = 1852)]
+	internal sealed class NauticalMile { }
+
+	[UnitSymbol("Fathom", "Fathoms", "ftm", Scale = 1.8288)]
+	internal sealed class Fathom { }
+
+	[UnitSymbol("Knot", "Knots", "kn", Scale = 1852d / 3600d)]
+	internal sealed class Knot { }
+}

src/DimensionalQuantities.Extensions.Nautical/NauticalUnits.cs

@@ -0,0 +1,23 @@
+using DimensionalQuantities.Units.Declarations;
+
+namespace DimensionalQuantities.Extensions.Nautical;
+
+[UnitProvider]
+internal static class NauticalUnits
+{
+	[QuantityUnit(typeof(Length))]
+	[UnitFactor(typeof(NauticalSymbols.NauticalMile))]
+	private sealed class NauticalMileUnit { }
+
+	[QuantityUnit(typeof(Length))]
+	[UnitFactor(typeof(NauticalSymbols.Fathom))]
+	private sealed class FathomUnit { }
+
+	[QuantityUnit(typeof(Area))]
+	[UnitFactor(typeof(NauticalSymbols.NauticalMile), Power = 2)]
+	private sealed class SquareNauticalMileUnit { }
+
+	[QuantityUnit(typeof(Speed))]
+	[UnitFactor(typeof(NauticalSymbols.Knot))]
+	private sealed class KnotUnit { }
+}

src/DimensionalQuantities.IntegrationTests/Packaging/PackagedGeneratorTests.cs

@@ -99,6 +99,31 @@ public static class Consumer
 			() => Assert.Equal(273.15, InvokeDouble(type, "ConvertTemperature"), 12));
 	}
 
+	[Fact]
+	public void NauticalPackageProvidesConversionsThroughCoreDependency()
+	{
+		using PackageRepository repository = PackageRepository.Create(_scratch, new Uri("https://api.nuget.org/v3/index.json"));
+		PackCore(repository);
+		Package nautical = PackSourceProject(repository, "DimensionalQuantities.Extensions.Nautical");
+		ProjectCreator consumer = CreateProject("NauticalConsumer", """
+			using DimensionalQuantities.Extensions.Nautical;
+
+			public static class Consumer
+			{
+				public static double ConvertLength() => Length.FromNauticalMiles(1).AsSiBaseUnit();
+				public static double ConvertSpeed() => Speed.FromKnots(1).AsSiBaseUnit();
+			}
+			""", nautical);
+		Build(consumer);
+
+		using PackageAssemblyContext context = new(OutputDirectory("NauticalConsumer"));
+		Type type = context.LoadFromAssemblyPath(Path.Combine(OutputDirectory("NauticalConsumer"), "NauticalConsumer.dll"))
+			.GetType("Consumer", throwOnError: true)!;
+		Assert.Multiple(
+			() => Assert.Equal(1852, InvokeDouble(type, "ConvertLength")),
+			() => Assert.Equal(1852d / 3600d, InvokeDouble(type, "ConvertSpeed")));
+	}
+
 	[Fact]
 	public void MetricNamedConversionsRequireNamespaceImport()
 	{

src/DimensionalQuantities.IntegrationTests/Packaging/SymbolPackageTests.cs

@@ -52,6 +52,7 @@ public void CoreSymbolPackageMatchesRuntimeAndAnalyzerAssemblies()
 	[Theory]
 	[InlineData("Metric")]
 	[InlineData("Imperial")]
+	[InlineData("Nautical")]
 	public void ExtensionSymbolPackageMatchesAssemblyAndEmbedsGeneratedSource(string extension)
 	{
 		string projectName = "DimensionalQuantities.Extensions." + extension;

src/DimensionalQuantities.slnx

@@ -11,6 +11,10 @@
     <Project Path="DimensionalQuantities.Extensions.Imperial/DimensionalQuantities.Extensions.Imperial.csproj" />
     <Project Path="DimensionalQuantities.Extensions.Imperial.Tests/DimensionalQuantities.Extensions.Imperial.Tests.csproj" />
   </Folder>
+  <Folder Name="/Nautical/">
+    <Project Path="DimensionalQuantities.Extensions.Nautical/DimensionalQuantities.Extensions.Nautical.csproj" />
+    <Project Path="DimensionalQuantities.Extensions.Nautical.Tests/DimensionalQuantities.Extensions.Nautical.Tests.csproj" />
+  </Folder>
   <Folder Name="/Roslyn/">
     <Project Path="DimensionalQuantities.Roslyn.CodeFixes/DimensionalQuantities.Roslyn.CodeFixes.csproj" />
     <Project Path="DimensionalQuantities.Roslyn.Tests/DimensionalQuantities.Roslyn.Tests.csproj" />