feat: implement dimensional quantities and generated arithmetic

.editorconfig

@@ -0,0 +1,104 @@
+root = true
+
+[*.cs]
+indent_style = tab
+indent_size = tab
+tab_width = 4
+csharp_new_line_before_open_brace = all
+csharp_style_namespace_declarations = file_scoped
+
+# State accessibility explicitly on types and non-interface members.
+dotnet_style_require_accessibility_modifiers = for_non_interface_members
+dotnet_diagnostic.IDE0040.severity = warning
+
+# Braces are required even around a single statement.
+csharp_prefer_braces = true
+dotnet_diagnostic.IDE0011.severity = warning
+
+# Long lines are acceptable; this is an editor guide, not a compiler limit.
+max_line_length = 240
+
+# Declare the type explicitly, including when the initializer makes it obvious.
+csharp_style_var_for_built_in_types = false
+csharp_style_var_when_type_is_apparent = false
+csharp_style_var_elsewhere = false
+dotnet_diagnostic.IDE0008.severity = warning
+
+# Use target-typed new() when the destination type is apparent.
+csharp_style_implicit_object_creation_when_type_is_apparent = true
+dotnet_diagnostic.IDE0090.severity = warning
+
+# Do not suggest primary constructors for classes or structs. This does not
+# diagnose existing primary constructors; the record-only rule needs review
+# guidance or a separate analyzer.
+csharp_style_prefer_primary_constructors = false
+dotnet_diagnostic.IDE0290.severity = none
+
+# Requires StyleCop.Analyzers in the consuming project. Its default setting
+# only covers some type kinds; strict one-type-per-file also needs stylecop.json.
+dotnet_diagnostic.SA1402.severity = warning
+
+# Standard C# identifier casing.
+dotnet_naming_symbols.interfaces.applicable_kinds = interface
+dotnet_naming_symbols.interfaces.applicable_accessibilities = *
+dotnet_naming_symbols.types.applicable_kinds = class, struct, enum, delegate
+dotnet_naming_symbols.types.applicable_accessibilities = *
+dotnet_naming_symbols.members.applicable_kinds = property, method, event, local_function
+dotnet_naming_symbols.members.applicable_accessibilities = *
+dotnet_naming_symbols.private_fields.applicable_kinds = field
+dotnet_naming_symbols.private_fields.applicable_accessibilities = private
+dotnet_naming_symbols.constants.applicable_kinds = field
+dotnet_naming_symbols.constants.applicable_accessibilities = *
+dotnet_naming_symbols.constants.required_modifiers = const
+dotnet_naming_symbols.locals_and_parameters.applicable_kinds = local, parameter
+dotnet_naming_symbols.locals_and_parameters.applicable_accessibilities = *
+dotnet_naming_symbols.type_parameters.applicable_kinds = type_parameter
+dotnet_naming_symbols.type_parameters.applicable_accessibilities = *
+
+dotnet_naming_style.pascal_case.capitalization = pascal_case
+dotnet_naming_style.interface_pascal_case.capitalization = pascal_case
+dotnet_naming_style.interface_pascal_case.required_prefix = I
+dotnet_naming_style.camel_case.capitalization = camel_case
+dotnet_naming_style.private_field_camel_case.capitalization = camel_case
+dotnet_naming_style.private_field_camel_case.required_prefix = _
+dotnet_naming_style.type_parameter_pascal_case.capitalization = pascal_case
+dotnet_naming_style.type_parameter_pascal_case.required_prefix = T
+
+dotnet_naming_rule.interfaces.symbols = interfaces
+dotnet_naming_rule.interfaces.style = interface_pascal_case
+dotnet_naming_rule.interfaces.severity = warning
+dotnet_naming_rule.types.symbols = types
+dotnet_naming_rule.types.style = pascal_case
+dotnet_naming_rule.types.severity = warning
+dotnet_naming_rule.members.symbols = members
+dotnet_naming_rule.members.style = pascal_case
+dotnet_naming_rule.members.severity = warning
+dotnet_naming_rule.private_fields.symbols = private_fields
+dotnet_naming_rule.private_fields.style = private_field_camel_case
+dotnet_naming_rule.private_fields.severity = warning
+dotnet_naming_rule.constants.symbols = constants
+dotnet_naming_rule.constants.style = pascal_case
+dotnet_naming_rule.constants.severity = warning
+dotnet_naming_rule.locals_and_parameters.symbols = locals_and_parameters
+dotnet_naming_rule.locals_and_parameters.style = camel_case
+dotnet_naming_rule.locals_and_parameters.severity = warning
+dotnet_naming_rule.type_parameters.symbols = type_parameters
+dotnet_naming_rule.type_parameters.style = type_parameter_pascal_case
+dotnet_naming_rule.type_parameters.severity = warning
+dotnet_diagnostic.IDE1006.severity = warning
+
+# Keep analyzer warnings out of generated source.
+[*.g.cs]
+generated_code = true
+
+[*.g.i.cs]
+generated_code = true
+
+[*.generated.cs]
+generated_code = true
+
+[*.designer.cs]
+generated_code = true
+
+[*.Designer.cs]
+generated_code = true

.gitattributes

@@ -0,0 +1 @@
+* text=auto eol=lf

.github/scripts/publish.sh

@@ -6,6 +6,10 @@ if [[ -n "${ACT:-}" ]]; then
 fi
 : "${GITHUB_TOKEN:?GITHUB_TOKEN is required}"
 : "${GITHUB_REPOSITORY_OWNER:?GITHUB_REPOSITORY_OWNER is required}"
+: "${NUGET_API_KEY:?NUGET_API_KEY is required}"
+dotnet nuget push 'artifacts/packages/*.nupkg' \
+  --source 'https://api.nuget.org/v3/index.json' \
+  --api-key "$NUGET_API_KEY" --skip-duplicate
 dotnet nuget push 'artifacts/packages/*.nupkg' \
   --source "https://nuget.pkg.github.com/${GITHUB_REPOSITORY_OWNER}/index.json" \
   --api-key "$GITHUB_TOKEN" --skip-duplicate

.github/testing/run-act.py

@@ -53,4 +53,4 @@ def git(*arguments):
 if args.workflow in ("ci", "both"):
     subprocess.run([*base, "pull_request", "-W", ".github/workflows/ci.yml"], cwd=fixture, check=True)
 if args.workflow in ("release", "both"):
-    subprocess.run([*base, "push", "-W", ".github/workflows/release.yml"], cwd=fixture, check=True)
+    subprocess.run([*base, "push", "-W", ".github/workflows/cd.yml"], cwd=fixture, check=True)

.github/workflows/release.yml → .github/workflows/cd.yml

@@ -19,22 +19,29 @@ jobs:
     permissions:
       contents: write
       packages: write
+      id-token: write
     steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@v7.0.1
         with:
           fetch-depth: 0
-      - uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6.0.0
+      - uses: actions/setup-dotnet@v6.0.0
         with:
           global-json-file: global.json
-      - uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
+      - uses: actions/setup-node@v7.1.0
         with:
           node-version: '24.10.0'
       - name: Prepare isolated act release destination
         if: env.ACT
         run: bash .github/testing/prepare-local-remote.sh
+      - name: NuGet trusted publishing login
+        if: ${{ !env.ACT }}
+        uses: NuGet/login@v1
+        id: nuget-login
+        with:
+          user: ${{ vars.NUGET_USER }}
       - name: Version, package and release
         id: release
-        uses: cycjimmy/semantic-release-action@d9bf53a078bd2f86aaffaec796dbb3d28f1b6f34 # v8.1.3
+        uses: cycjimmy/semantic-release-action@v8.1.3
         with:
           semantic_version: 25.0.9
           repository_url: ${{ env.ACT && 'file:///tmp/dimensional-quantities-remote.git' || '' }}
@@ -46,6 +53,7 @@ jobs:
             conventional-changelog-conventionalcommits@9.1.0
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          NUGET_API_KEY: ${{ steps.nuget-login.outputs.NUGET_API_KEY }}
       - name: Verify local release
         if: env.ACT
         env:

.github/workflows/ci.yml

@@ -10,24 +10,24 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@v7.0.1
       - name: Check conventional PR title
         if: github.event_name == 'pull_request'
         env:
           PR_TITLE: ${{ github.event.pull_request.title }}
         run: python3 .github/scripts/check-pr-title.py
-      - uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6.0.0
+      - uses: actions/setup-dotnet@v6.0.0
         with:
           global-json-file: global.json
       - name: Restore
         run: dotnet restore src/DimensionalQuantities.slnx
       - name: Build
         run: dotnet build src/DimensionalQuantities.slnx -c Release --no-restore -p:ContinuousIntegrationBuild=true
       - name: Test
-        run: dotnet test --solution src/DimensionalQuantities.slnx -c Release --no-build --no-restore --report-trx --ignore-exit-code 8 --results-directory artifacts/test-results
+        run: dotnet test --solution src/DimensionalQuantities.slnx -c Release --no-build --no-restore --report-trx --results-directory artifacts/test-results
       - name: Check NuGet package
         run: bash .github/scripts/pack.sh 0.0.0-ci
-      - uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
+      - uses: actions/upload-artifact@v7.0.2
         if: ${{ always() && !env.ACT }}
         with:
           name: ci-results

.gitignore

@@ -8,3 +8,4 @@ TestResults/
 *.snupkg
 artifacts/
 node_modules/
+HANDOFF*.md

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 GoSim
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,75 @@
+# DimensionalQuantities
+
+A C# library for dimensional quantities, with generated type aliases, SI unit conversions, and compile-time dimensional arithmetic.
+
+> [!WARNING]
+> We developed this library for our own internal use and are sharing it because we believe it may be useful to the wider developer community. Issues and pull requests are welcome, but we make no support commitments or warranties, and we cannot guarantee that we will respond to issues or review or merge pull requests.
+
+## Usage
+
+Requires .NET 10 and C# 14. The `DimensionalQuantities` NuGet package includes both the runtime library and its source generator.
+
+```csharp
+Voltage voltage = Voltage.FromVolts(12);
+Current current = Current.FromAmps(3);
+
+Resistance resistance = voltage / current;
+Power power = voltage * current;
+
+double ohms = resistance.AsOhms(); // 4
+double watts = power.AsWatts();    // 36
+```
+
+### SI prefixes and compound units
+
+Named helpers handle conversion into and out of SI prefixes, including powers of prefixed units:
+
+```csharp
+Length length = Length.FromMilliMetres(2500);
+double metres = length.AsMetres(); // 2.5
+
+Density density = Density.FromGramsPerCubicCentiMetre(1);
+double kilogramsPerCubicMetre = density.AsSiBaseUnit(); // 1000
+```
+
+For more control, `FromPrefixedUnits` and `AsPrefixedUnits` accept decimal prefix exponents for each unit factor. Powers are taken into account automatically:
+
+```csharp
+// 1 A/mm² = 1,000,000 A/m²
+CurrentDensity density = CurrentDensity.FromPrefixedUnits(
+    1, ampPrefixExponent: 0, metrePrefixExponent: -3);
+
+double ampsPerSquareMillimetre = density.AsPrefixedUnits(
+    ampPrefixExponent: 0, metrePrefixExponent: -3); // 1
+```
+
+Named compound units remain a single factor where appropriate: `Voltage.FromPrefixedUnits(2, -3)` means 2 millivolts, without requiring you to know the SI dimensions of a volt.
+
+### Arithmetic and generated intermediate quantities
+
+The generator follows multiplication and division through nested expressions, derives their dimensions, and generates the required operators and intermediate aliases:
+
+```csharp
+Current current = Current.FromAmps(3);
+Resistance resistance = Resistance.FromOhms(4);
+
+CurrentSquared squared = current * current;
+Power heating = current * current * resistance; // 36 W
+Current doubled = 2 * current;
+Current halved = current / 2;
+Frequency frequency = 1 / Time.FromSeconds(0.02); // 50 Hz
+```
+
+Known dimensions use names from the engineering catalogue, such as `Power`, `Voltage`, `Permeability` and `MagneticFluxDensity`. Other dimensions receive mechanical names such as `CurrentSquared` or `TimePerCurrent`. Discovered quantities have SI base-unit and generic prefix conversion helpers.
+
+Aliases with the same dimensions share a type. For example, `Energy` and `Torque` are interchangeable: the library checks dimensions, not the physical meaning of a calculation. Magnitudes are stored as `double` in coherent SI base units.
+
+### Current scope
+
+Arithmetic discovery currently supports multiplication and division with known quantity operands, scalar factors, and nested expressions. Roots, powers, dimensionless results and inference through unresolved intermediate local variables are not yet supported by discovery.
+
+The library is under active development; the API and supported expression patterns are still evolving.
+
+## Licence
+
+[MIT](LICENSE), copyright GoSim.

src/DimensionalQuantities.IntegrationTests/DimensionalQuantities.IntegrationTests.csproj

@@ -12,9 +12,12 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="../DimensionalQuantities/DimensionalQuantities.csproj" />
-    <ProjectReference Include="../DimensionalQuantities.Roslyn/DimensionalQuantities.Roslyn.csproj" />
+    <ProjectReference Include="../DimensionalQuantities.Roslyn/DimensionalQuantities.Roslyn.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+    <Analyzer Include="../DimensionalQuantities/bin/$(Configuration)/net10.0/DimensionalQuantities.dll" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="5.0.0" />
+    <PackageReference Include="Microsoft.Build" Version="18.6.3" ExcludeAssets="runtime" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.Build.Locator" Version="1.11.2" />
+    <PackageReference Include="MSBuild.ProjectCreation" Version="19.1.4" />
   </ItemGroup>
 </Project>

src/DimensionalQuantities.IntegrationTests/GeneratedQuantityTests/MsbuildCollection.cs

@@ -0,0 +1,6 @@
+using Xunit;
+
+namespace DimensionalQuantities.IntegrationTests.GeneratedQuantityTests;
+
+[CollectionDefinition("MSBuild", DisableParallelization = true)]
+public sealed class MsbuildCollection;