018 — Namespace Rename: Duct → Microsoft.UI.Reactor

Status: Draft
Date: 2026-04-16

Overview

Rename the root namespace from Duct to Microsoft.UI.Reactor and eliminate every occurrence of the word "Duct" from the codebase. In the same pass, merge the DuctD3 charting library into the main assembly.

In documentation, the first mention uses the full name Microsoft.UI.Reactor; subsequent references use Reactor for brevity.

The CLI tool is renamed to mur (Microsoft.UI.Reactor).

1. Namespace Mappings

Old namespace	New namespace
`Duct`	`Microsoft.UI.Reactor`
`Duct.Animation`	`Microsoft.UI.Reactor.Animation`
`Duct.Controls.AutoSuggest`	`Microsoft.UI.Reactor.Controls` (flattened — see Section 9a)
`Duct.Controls.Formatting`	`Microsoft.UI.Reactor.Controls` (flattened)
`Duct.Controls.MaskedTextBox`	`Microsoft.UI.Reactor.Controls` (flattened)
`Duct.Core`	`Microsoft.UI.Reactor.Core`
`Duct.Core.Localization`	`Microsoft.UI.Reactor.Localization` (promoted — WinUI keeps functional areas at top level)
`Duct.Core.Navigation`	`Microsoft.UI.Reactor.Navigation` (promoted — matches `Microsoft.UI.Xaml.Navigation`)
`Duct.D3`	`Microsoft.UI.Reactor.Charting.D3` (D3 port — see Section 9b)
`Duct.D3.Charts`	`Microsoft.UI.Reactor.Charting` (controls & DSL — see Section 9b)
(new)	`Microsoft.UI.Reactor.Hosting` (ReactorHost, ReactorHostControl, PageHelper — matches `Microsoft.UI.Xaml.Hosting`)
`Duct.Data`	`Microsoft.UI.Reactor.Data`
`Duct.Data.Providers`	`Microsoft.UI.Reactor.Data.Providers`
`Duct.DataGrid`	`Microsoft.UI.Reactor.Controls` (flattened — see Section 9a)
`Duct.Elements`	`Microsoft.UI.Reactor.Elements`
`Duct.Flex`	`Microsoft.UI.Reactor.Layout` (merged — see Section 10)
`Duct.Hooks`	`Microsoft.UI.Reactor.Hooks`
`Duct.Layout`	`Microsoft.UI.Reactor.Layout` (Yoga types made internal — see Section 10)
`Duct.Localization.Generator`	`Microsoft.UI.Reactor.Localization.Generator`
`Duct.Markdown`	`Microsoft.UI.Reactor.Markdown`
`Duct.Monaco`	`Microsoft.UI.Reactor.Monaco`
`Duct.PropertyGrid`	`Microsoft.UI.Reactor.Controls` (flattened — see Section 9a)
`Duct.Validation`	`Microsoft.UI.Reactor.Controls.Validation` (under Controls — WPF pattern)
`Duct.Validation.Validators`	`Microsoft.UI.Reactor.Controls.Validation` (flattened into parent)
`Duct.Virtualization`	`Microsoft.UI.Reactor.Controls` (flattened — see Section 9a)
`Duct.Analyzers`	`Microsoft.UI.Reactor.Analyzers`
`Duct.Cli`	`Microsoft.UI.Reactor.Cli`
`Duct.Cli.Docs`	`Microsoft.UI.Reactor.Cli.Docs`
`Duct.Cli.Loc`	`Microsoft.UI.Reactor.Cli.Loc`
`Duct.Accessibility`	`Microsoft.UI.Reactor.Accessibility`
`Duct.Interop.WinForms`	`Microsoft.UI.Reactor.Interop.WinForms`

Test / infrastructure namespaces

Old	New
`Duct.Tests`	`Microsoft.UI.Reactor.Tests`
`Duct.Tests.*`	`Microsoft.UI.Reactor.Tests.*`
`Duct.D3.Tests`	`Microsoft.UI.Reactor.Charting.D3.Tests`
`Duct.AppTests.*`	`Microsoft.UI.Reactor.AppTests.*`
`CmdPerf.Duct`	`CmdPerf.Reactor`
`StressPerf.Duct`	`StressPerf.Reactor`
`StressPerf.DuctGrid`	`StressPerf.ReactorGrid`
`Duct.WinFormsTests.Host`	`Reactor.WinFormsTests.Host`
`PerfBench.*.Duct` (all variants)	`PerfBench.*.Reactor`

Sample app namespaces

Old	New
`DuctFiles` / `DuctFiles.*`	`ReactorFiles` / `ReactorFiles.*`
`DuctOutlook` / `DuctOutlook.*`	`ReactorOutlook` / `ReactorOutlook.*`
`DuctRegedit` / `DuctRegedit.*`	`ReactorRegedit` / `ReactorRegedit.*`
`DuctD3.Gallery`	`ReactorCharting.Gallery`
`DuctHostControlDemo`	`ReactorHostControlDemo`
`WinUIGalleryDuct`	`WinUIGalleryReactor`
`Duct.TestApp`	`Reactor.TestApp`

2. Type Renames

Public API types (prefix dropped — the namespace provides disambiguation)

Old	New	Notes
`DuctCommand`	`Command`	Record in `Microsoft.UI.Reactor.Core`
`DuctCommand<T>`	`Command<T>`	Record in `Microsoft.UI.Reactor.Core`
`DuctContext<T>`	`Context<T>`	Sealed class in `Microsoft.UI.Reactor.Core`
`DuctContextBase`	`ContextBase`	Abstract class in `Microsoft.UI.Reactor.Core`
`DuctElementFactory<T>`	`ElementFactory<T>`	Sealed class in `Microsoft.UI.Reactor.Core`
`DuctPageHelper`	`PageHelper`	Static helper in `Microsoft.UI.Reactor.Hosting`

Logger types removed: IDuctLogger, DuctLogLevel, DebugDuctLogger, and NullDuctLogger are deleted — replaced by Microsoft.Extensions.Logging (see Section 2a).

Public API types (keep prefix — protect generic names)

Old	New	Notes
`DuctApp`	`ReactorApp`	Static entry point — stays in root `Microsoft.UI.Reactor`
`DuctApplication`	`ReactorApplication`	WinUI Application subclass — stays in root (like `Microsoft.UI.Xaml.Application`)
`DuctHost`	`ReactorHost`	Core render host — moves to `Microsoft.UI.Reactor.Hosting`
`DuctHostControl`	`ReactorHostControl`	WinUI ContentControl — moves to `Microsoft.UI.Reactor.Hosting`

Internal types

Old	New
`DuctAppOptions`	`ReactorAppOptions`
`DuctFilesApp`	`ReactorFilesApp`
`DuctFilesEvents`	`ReactorFilesEvents`
`DuctComponentTypeConverter`	`ReactorComponentTypeConverter`

Test fixture classes

Old	New
`DuctCommandTests`	`CommandTests`
`DuctHostControlTests`	`HostControlTests`
`DuctHostRenderLoopTests`	`HostRenderLoopTests`
`DuctHostControlMountComponent`	`HostControlMountComponent`
`DuctHostControlMountFunc`	`HostControlMountFunc`
`DuctHostControlFactory`	`HostControlFactory`
`DuctHostControlRenderCallback`	`HostControlRenderCallback`
`DuctHostRenderStats`	`HostRenderStats`
`DuctHostDispose`	`HostDispose`
`DuctPageHelperExercise`	`PageHelperExercise`
`TestDuctComponent`	`TestReactorComponent`
`SampleDuctComponent`	`SampleReactorComponent`

DSL entry point class

Old	New	Notes
`UI` (static class in `Duct.Elements.Dsl.cs`)	`Factories`	`using static Microsoft.UI.Reactor.Factories;`

2a. Replace Custom Logger with Microsoft.Extensions.Logging

The custom logger (IDuctLogger, DuctLogLevel, DebugDuctLogger, NullDuctLogger) is deleted and replaced with Microsoft.Extensions.Logging.ILogger — the standard .NET logging abstraction.

Why

The custom logger is a near-duplicate of ILogger with fewer features.
Only 3 internal consumers: ReactorHost, ReactorHostControl, Reconciler.
Eliminates 4 public types from the API surface.
Consumers can wire Reactor logging into whatever system they already use (Serilog, NLog, ETW, console, etc.) with zero adapter code.

New dependency

Add Microsoft.Extensions.Logging.Abstractions to Reactor.csproj. This is a ~50KB package with no transitive dependencies — it defines ILogger, ILoggerFactory, LogLevel, NullLogger, and the Log*() extension methods.

Migration

Old	New
`IDuctLogger`	`Microsoft.Extensions.Logging.ILogger`
`DuctLogLevel.Error`	`Microsoft.Extensions.Logging.LogLevel.Error`
`DuctLogLevel.Debug`	`Microsoft.Extensions.Logging.LogLevel.Debug`
`DuctLogLevel.Warning`	`Microsoft.Extensions.Logging.LogLevel.Warning`
`DuctLogLevel.Info`	`Microsoft.Extensions.Logging.LogLevel.Information`
`DuctLogLevel.Trace`	`Microsoft.Extensions.Logging.LogLevel.Trace`
`DebugDuctLogger`	(deleted — use `ILoggerFactory` to create a logger)
`NullDuctLogger.Instance`	`Microsoft.Extensions.Logging.Abstractions.NullLogger.Instance`

Call-site changes

// Before:
_logger.Log(DuctLogLevel.Error, "Render FAILED", ex);
_logger.Log(DuctLogLevel.Debug, $"Theme changed to {theme}");

// After:
_logger.LogError(ex, "Render FAILED");
_logger.LogDebug("Theme changed to {Theme}", theme);

Constructor changes

// Before (ReactorHost):
public ReactorHost(Window window, IDuctLogger? logger = null)
{
    _logger = logger ?? new DebugDuctLogger();
}

// After:
public ReactorHost(Window window, ILogger<ReactorHost>? logger = null)
{
    _logger = logger ?? NullLogger<ReactorHost>.Instance;
}

Files changed

File	Change
`Duct/Core/IDuctLogger.cs`	Delete entire file
`Duct/Hosting/DuctHost.cs`	Replace `IDuctLogger` field/ctor with `ILogger<ReactorHost>`
`Duct/Hosting/DuctHostControl.cs`	Replace `IDuctLogger` field/ctor with `ILogger<ReactorHostControl>`
`Duct/Hosting/DuctApp.cs`	Replace `IDuctLogger` field with `ILogger<ReactorApplication>`
`Duct/Core/Reconciler.cs`	Replace `IDuctLogger` field/ctor with `ILogger<Reconciler>`
`Duct/Duct.csproj`	Add `<PackageReference Include="Microsoft.Extensions.Logging.Abstractions" />`
`tests/Duct.Tests/DuctHostRenderLoopTests.cs`	Replace `NullDuctLogger` with `NullLogger`

3. MSBuild Properties

Old	New
`DuctLocDefaultLocale`	`ReactorLocDefaultLocale`
`DuctLocStringsPath`	`ReactorLocStringsPath`
`DuctLocMissingKeySeverity`	`ReactorLocMissingKeySeverity`

These appear in:

Duct/Duct.csproj (property defaults and AdditionalFiles glob)
Duct.Localization.Generator/LocSourceGenerator.cs (reads build_property.*)
tests/Duct.Tests/Localization/LocSourceGeneratorTests.cs (test data)
Any consumer .csproj that sets these properties

4. Analyzer Diagnostic Category

Old	New
`"Duct.Style"`	`"Reactor.Style"`

Used in: UseThemeRefAnalyzer.cs, UseLightweightStylingAnalyzer.cs, RequestedThemeSetAnalyzer.cs

5. Source Generator Attribution

Old	New
`[GeneratedCode("Duct.Localization.Generator", "1.0.0")]`	`[GeneratedCode("Reactor.Localization.Generator", "1.0.0")]`

6. String Literals

Location	Old	New
`DuctApp.cs` default title	`"Duct App"`	`"Reactor App"`
`DuctApp.cs` Run method default	`"Duct App"`	`"Reactor App"`
`DuctApp.cs` type filter	`!t.FullName!.StartsWith("Duct.")`	`!t.FullName!.StartsWith("Microsoft.UI.Reactor.")`
Test host window title	`"Duct Test Host"`	`"Reactor Test Host"`
Self-test window title	`"Duct Self-Test"`	`"Reactor Self-Test"`
TestSession.cs process name	`"Duct.AppTests.Host"`	`"Reactor.AppTests.Host"`
TestSession.cs / SelfTestBatch.cs	`"Duct.sln"` file probe	`"Reactor.sln"`
TestSession.cs exe path	`"Duct.AppTests.Host.exe"`	`"Reactor.AppTests.Host.exe"`
TestSession.cs window name	`"Duct Test Host"`	`"Reactor Test Host"`
CompileCommand.cs sln probe	`"Duct.sln"`	`"Reactor.sln"`
CLI scaffolding (Program.cs)	`"Duct"` / `"Duct.csproj"` in template	`"Reactor"` / `"Reactor.csproj"`
readme sample	`"Duct Showcase"`	`"Reactor Showcase"`
readme sample	`"Duct Framework"`	`"Reactor Framework"`
Duct.TestApp	`"Duct Demo"`	`"Reactor Demo"`
CommandingDemo display text	`"DuctCommand"` references in UI text	`"Command"`
TreeChartDsl.cs TypeKey	`"DuctD3Force"`	`"ChartingD3Force"`
EventSource name	`[EventSource(Name = "DuctFiles")]`	`[EventSource(Name = "ReactorFiles")]`
DuctHostControlDemo XAML	`Title="DuctHostControl Demo"`	`Title="ReactorHostControl Demo"`
flex-layout sample tags	`"Duct"` in tag list	`"Reactor"`
UseAnnounce.cs TypeKey	`"DuctAnnounce"`	`"ReactorAnnounce"`
RenderContext.cs debug prefix	`"[Duct] "` in Debug.WriteLine calls	`"[Reactor] "`
XamlIslandControl.cs category	`[Category("Duct")]`	`[Category("Reactor")]`
XamlIslandControl.cs description	`"The Duct Component type to host. Creates a DuctHostControl…"`	`"The Reactor Component type to host. Creates a ReactorHostControl…"`
TestDuctComponent.cs title	`"Duct Island Content"`	`"Reactor Island Content"`
TestDuctComponent.cs AutomationIds	`"Duct_Title"`, `"Duct_TextField1"`, `"Duct_Button1"`, `"Duct_TextDisplay"`, `"Duct_CountDisplay"`, `"Duct_TextField2"`, `"Duct_LiveRegion"`, `"Duct_RenderProof"`	`"Reactor_Title"`, `"Reactor_TextField1"`, etc.
WinFormsInteropTests.cs	Same AutomationId strings in test assertions	Match test host renames
WinFormsOutsideForm.Designer.cs title	`"WinForms hosts Duct"`	`"WinForms hosts Reactor"`
WinFormsOutsideForm.Designer.cs text	`"hosting a Duct component tree"`	`"hosting a Reactor component tree"`
SampleDuctComponent.cs heading	`"Duct Component (via XAML Island)"`	`"Reactor Component (via XAML Island)"`
SampleDuctComponent.cs body	`"This Duct/WinUI component…"`	`"This Reactor/WinUI component…"`
GalleryShell.cs title	`"Duct WinUI Gallery"`	`"Reactor WinUI Gallery"`
HomePage.cs heading	`"Duct WinUI Gallery"`	`"Reactor WinUI Gallery"`
SettingsPage.cs label	`"Duct (declarative C# DSL)"`	`"Reactor (declarative C# DSL)"`
TypographyPage.cs body	`"Duct provides shorthand helpers…"`	`"Reactor provides shorthand helpers…"`
GAPS.md (Gallery)	~20 occurrences of `"Duct"` in prose and table	`"Reactor"` throughout
a11y-showcase App.cs comment	`"Duct's accessibility tooling"`	`"Reactor's accessibility tooling"`

7. Directory & File Renames

Core framework

Old path	New path
`Duct/`	`Reactor/`
`Duct/Duct.csproj`	`Reactor/Reactor.csproj`
`Duct/DataGrid/`	`Reactor/Controls/DataGrid/` (see Section 9a)
`Duct/PropertyGrid/`	`Reactor/Controls/PropertyGrid/` (see Section 9a)
`Duct/Validation/`	`Reactor/Controls/Validation/` (see Section 9a)
`Duct/Virtualization/`	`Reactor/Controls/Virtualization/` (see Section 9a)
`Duct/Flex/`	(merged into `Reactor/Layout/`)
`Duct/Accessibility/`	`Reactor/Accessibility/`
`Duct/Yoga/`	`Reactor/Layout/`
`Duct.Analyzers/`	`Reactor.Analyzers/`
`Duct.Interop.WinForms/`	`Reactor.Interop.WinForms/`
`Duct.Cli/`	`Reactor.Cli/`
`Duct.Localization.Generator/`	`Reactor.Localization.Generator/`
`DuctD3/`	(merged into `Reactor/Charting/` — see Section 9b)
`Duct.sln`	`Reactor.sln`

Test projects

Old path	New path
`tests/Duct.Tests/`	`tests/Reactor.Tests/`
`tests/Duct.AppTests/`	`tests/Reactor.AppTests/`
`tests/Duct.AppTests.Host/`	`tests/Reactor.AppTests.Host/`
`tests/DuctD3.Tests/`	`tests/ReactorCharting.Tests/`
`tests/cmd_perf/CmdPerf.Duct/`	`tests/cmd_perf/CmdPerf.Reactor/`
`tests/stress_perf/StressPerf.Duct/`	`tests/stress_perf/StressPerf.Reactor/`
`tests/stress_perf/StressPerf.DuctGrid/`	`tests/stress_perf/StressPerf.ReactorGrid/`
`tests/Duct.WinFormsTests.Host/`	`tests/Reactor.WinFormsTests.Host/`

Perf bench projects (`tests/perf_bench/`)

Every *.Duct/ directory becomes *.Reactor/:

Allocation.Duct/ → Allocation.Reactor/
DeferredMount.Duct/ → DeferredMount.Reactor/
DirtyTracking.Duct/ → DirtyTracking.Reactor/
InteractivePool.Duct/ → InteractivePool.Reactor/
Journal.Duct/ → Journal.Reactor/
OffThread.Duct/ → OffThread.Reactor/
Priorities.Duct/ → Priorities.Reactor/
PropertyDiff.Duct/ → PropertyDiff.Reactor/
StructuralSharing.Duct/ → StructuralSharing.Reactor/
TimeSlice.Duct/ → TimeSlice.Reactor/

Sample projects

Old path	New path
`samples/apps/ductfiles/`	`samples/apps/reactorfiles/`
`samples/apps/outlook/DuctOutlook.csproj`	`samples/apps/outlook/ReactorOutlook.csproj`
`samples/apps/regedit/DuctRegedit.csproj`	`samples/apps/regedit/ReactorRegedit.csproj`
`samples/Duct.TestApp/`	`samples/Reactor.TestApp/`
`samples/DuctHostControlDemo/`	`samples/ReactorHostControlDemo/`
`samples/DuctD3.Gallery/`	`samples/ReactorCharting.Gallery/`
`samples/DuctD3.Sample/`	`samples/ReactorCharting.Sample/`
`samples/WinUI-Gallery-Duct/`	`samples/ReactorGallery/`

.csproj file renames (within directories)

Each project's .csproj filename changes to match, e.g.:

Duct.Tests.csproj → Reactor.Tests.csproj
DuctFiles.csproj → ReactorFiles.csproj
DuctD3.Tests.csproj → ReactorD3.Tests.csproj
Duct.Interop.WinForms.csproj → Reactor.Interop.WinForms.csproj
Duct.WinFormsTests.Host.csproj → Reactor.WinFormsTests.Host.csproj
WinUI-Gallery-Duct.csproj → ReactorGallery.csproj
etc.

8. Assembly Names

Old	New
`duct-cli`	`mur`
`Duct.Analyzers` (PackageId)	`Reactor.Analyzers`

9a. Controls Namespace Consolidation

Six separate namespaces flatten into one Microsoft.UI.Reactor.Controls, matching WinUI's pattern where Microsoft.UI.Xaml.Controls is a single flat namespace containing all controls (Button, TextBox, NavigationView, TreeView, ItemsRepeater, etc.).

Type counts per source namespace

Old namespace	Public types	Internal	What moves
`Duct.Controls.AutoSuggest`	4	0	`SearchState`, `AutoSuggestElement<T>`, `AutoSuggestDsl`, `SearchManager<T>`
`Duct.Controls.Formatting`	3	10	`FormatResult`, `InputFormatter`, `FormatterPipeline` (+ 10 internal formatters)
`Duct.Controls.MaskedTextBox`	4	2	`MaskedTextFieldElement`, `MaskedTextFieldDsl`, `MaskEngine`, `MaskPreset`
`Duct.DataGrid`	11	3	`DataGridComponent<T>`, `DataGridElement<T>`, `DataGridState<T>`, `Factories`, `Factories`, `ColumnBuilder<T>`, `SelectionMode`, `EditMode`, `CellContext<T>`, `RowContext<T>`, `HeaderContext`
`Duct.PropertyGrid`	18	3	`PropertyGridComponent`, `PropertyGridElement`, `Factories`, `PropertyGridDefaults`, 7 attributes, 4 delegates, `TypeMetadata`, `ArrayTypeMetadata`, `TypeRegistry`, `EditorTier`, `ReflectionTypeMetadataProvider`
`Duct.Virtualization`	4	0	`VirtualListComponent`, `Factories`, `VirtualListElement`, `VirtualListRef`
Total in Controls	44	18

44 public types in Controls is well within WinUI norms (Microsoft.UI.Xaml.Controls has 200+).

Validation goes under Controls.Validation (WPF-style sub-namespace):

Old namespace	Public types	Internal	What moves
`Duct.Validation`	23	0	`ValidationContext`, `ValidationReconciler`, `ValidationMessage`, `Severity`, `ValidationRuleElement`, `ValidationRuleDsl`, `ValidationAttached`, `ValidateExtensions`, `ValidationContexts`, `ValidationContextHookExtensions`, `ValidationContextComponentExtensions`, `FormFieldElement`, `FormFieldDsl`, `FormFieldHelpers`, `ErrorStyling`, `ErrorStylingExtensions`, `ErrorStylingAttached`, `ShowWhen`, `ValidationVisualizerElement`, `ValidationVisualizerDsl`, `VisualizerStyle`, `ShowErrorsExtension`, `ErrorBubbling`
`Duct.Validation.Validators`	3	10	`IValidator`, `IAsyncValidator`, `Validate` (factory — flattened into `Controls.Validation`)
Total in Controls.Validation	26	10

Directory layout after merge

Reactor/Controls/
  AutoSuggest/           ← files stay grouped by feature subdirectory
  Formatting/
  MaskedTextBox/
  DataGrid/              ← moved from Duct/DataGrid/
  PropertyGrid/          ← moved from Duct/PropertyGrid/
  Validation/            ← moved from Duct/Validation/ (namespace: Controls.Validation)
  Virtualization/        ← moved from Duct/Virtualization/

Files keep their subdirectories for organization — only the namespace changes. All files in Controls/ declare namespace Microsoft.UI.Reactor.Controls; except Validation/ which declares namespace Microsoft.UI.Reactor.Controls.Validation;.

Not moved into Controls

Namespace	Reason
`Duct.Markdown` → `Microsoft.UI.Reactor.Markdown`	Parser/renderer library (~24 public Md4c types), not a single control
`Duct.Monaco` → `Microsoft.UI.Reactor.Monaco`	WebView2-based editor integration, separate concern

9b. DuctD3 → Merge into Main Assembly (Charting namespace)

The DuctD3/ project (separate assembly, ~108 types) merges into the main Reactor/ assembly. The two old namespaces are replaced by a new hierarchy:

Microsoft.UI.Reactor.Charting — high-level chart controls and DSL that most developers use directly.
Microsoft.UI.Reactor.Charting.D3 — the D3 algorithm port (scales, shapes, layouts, color, interpolation, etc.) for custom/advanced charting.

Directory layout after merge

Reactor/Charting/
  Charts.cs               ← Charts/Charts.cs
  TreeChartDsl.cs            ← Charts/TreeChartDsl.cs
  D3Charts.cs                  ← Charts/D3Charts.cs
  PathDataParser.cs          ← Charts/PathDataParser.cs
  D3/
    Array/                   ← from DuctD3/Array/
    Scale/                   ← from DuctD3/Scale/
    Shape/                   ← from DuctD3/Shape/
    Layout/                  ← from DuctD3/Layout/
    Color/                   ← from DuctD3/Color/
    Interpolate/             ← from DuctD3/Interpolate/
    Path/                    ← from DuctD3/Path/
    Ease/                    ← from DuctD3/Ease/
    Random/                  ← from DuctD3/Random/
    Format/                  ← from DuctD3/Format/
    Polygon/                 ← from DuctD3/Polygon/
    Contour/                 ← from DuctD3/Contour/
    Voronoi/                 ← from DuctD3/Voronoi/
    Chord/                   ← from DuctD3/Chord/

Class-by-class mapping: `Microsoft.UI.Reactor.Charting`

These are the controls and DSL factories that most developers import.

Type	Kind	Description
`Charts`	`public static partial class`	Factory methods: `LineChart()`, `BarChart()`, `AreaChart()`, `PieChart()`, `TreeChart()`, `ForceGraph()`
`ChartType`	`public enum`	Line, Bar, Area
`ChartElement<T>`	`public sealed class`	Line/bar/area chart builder (data, axes, grid, colors, margins)
`ChartHandle<T>`	`public sealed class`	Handle from OnReady; exposes underlying Canvas
`PieChartElement<T>`	`public sealed class`	Pie/donut chart builder
`PieChartHandle<T>`	`public sealed class`	Pie chart handle
`TreeChartElement<T>`	`public sealed class`	Tree diagram builder
`TreeChartHandle`	`public sealed class`	Tree chart handle
`ForceGraphElement`	`public sealed class`	Force-directed graph renderer
`ForceGraphHandle`	`public sealed class`	Force graph handle (drag/animation)
`D3`	`public static class`	Declarative drawing primitives: rect, circle, line, path, text, axes, grid, legend
`PathDataParser`	`public static class`	SVG path data → WinUI PathGeometry

Class-by-class mapping: `Microsoft.UI.Reactor.Charting.D3`

Everything below is the D3 algorithm port. Grouped by subdirectory.

Array utilities

Type	Kind	Description
`BinGenerator<T>`	`public sealed class`	Histogram binning (d3.bin)
`Bin<T>`	`public sealed class`	Individual histogram bin
`BinGenerator`	`public static class`	Factory methods
`D3Bisect`	`public static class`	Binary search on sorted arrays
`D3Extent`	`public static class`	Min/max from collections
`D3Group`	`public static class`	Group and rollup by key
`D3Range`	`public static class`	Evenly-spaced numeric ranges
`D3Statistics`	`public static class`	Mean, median, quantile, variance, deviation
`D3Ticks`	`public static class`	Human-readable tick generation

Scales

Type	Kind	Description
`LinearScale`	`public sealed class`	Continuous linear mapping
`LogScale`	`public sealed class`	Logarithmic mapping
`PowScale`	`public sealed class`	Power/exponent mapping
`BandScale<T>`	`public sealed class`	Categorical band mapping
`BandScale`	`public static class`	Factory
`PointScale<T>`	`public sealed class`	Categorical point mapping
`PointScale`	`public static class`	Factory
`OrdinalScale<T>`	`public sealed class`	Discrete-to-discrete mapping
`OrdinalScale`	`public static class`	Factory
`QuantizeScale`	`public sealed class`	Continuous → discrete bins
`QuantileScale`	`public sealed class`	Equal-probability bins
`ThresholdScale`	`public sealed class`	Threshold-based binning

Shape generators

Type	Kind	Description
`ArcGenerator`	`public sealed class`	Arc/pie-slice paths
`LineGenerator<T>`	`public sealed class`	Line path from data points
`LineGenerator`	`public static class`	Factory
`AreaGenerator<T>`	`public sealed class`	Filled area between baselines
`AreaGenerator`	`public static class`	Factory
`PieGenerator<T>`	`public sealed class`	Compute arc data from values
`PieGenerator`	`public static class`	Factory
`StackGenerator<T>`	`public sealed class`	Stacked series offsets
`StackPoint`	`public record struct`	Stacked data point (Y0/Y1)
`StackSeries`	`public sealed class`	Stacked series container
`StackGenerator`	`public static class`	Factory
`RadialLineGenerator<T>`	`public sealed class`	Polar line paths
`RadialLineGenerator`	`public static class`	Factory
`RadialAreaGenerator<T>`	`public sealed class`	Polar area paths
`RadialAreaGenerator`	`public static class`	Factory
`RadialLinkGenerator<T>`	`public sealed class`	Polar tree link paths
`RadialLinkGenerator`	`public static class`	Factory
`ISymbolType`	`public interface`	Symbol shape contract
`SymbolGenerator<T>`	`public sealed class`	Data point markers
`SymbolGenerator`	`public static class`	Factory
`D3Symbol`	`public static class`	Predefined symbols (circle, cross, diamond, square, star, triangle, wye)
`ICurve`	`public interface`	Curve interpolation contract
`CurveFactory`	`public delegate`	Curve factory delegate
`D3Curve`	`public static class`	Curve factories (linear, step, basis, cardinal, catmull-rom, monotone-x)

Layout algorithms

Type	Kind	Description
`TreeNode<T>`	`public sealed class`	Tree hierarchy node
`TreeLayout<T>`	`public sealed class`	Reingold-Tilford tree positioning
`TreeLayout`	`public static class`	Factory
`ClusterLayout<T>`	`public sealed class`	Dendrogram layout
`ClusterLayout`	`public static class`	Factory
`TreemapLayout<T>`	`public sealed class`	Rectangular partitioning
`TreemapNode<T>`	`public sealed class`	Treemap node with bounds
`TreemapTiling`	`public enum`	Squarified, Binary, Slice, Dice, SliceDice
`TreemapLayout`	`public static class`	Factory
`PackLayout<T>`	`public sealed class`	Circle packing
`PackNode<T>`	`public sealed class`	Pack node with radius
`PackLayout`	`public static class`	Factory
`PartitionLayout<T>`	`public sealed class`	Sunburst/icicle layout
`PartitionNode<T>`	`public sealed class`	Partition node with bounds
`PartitionLayout`	`public static class`	Factory
`Stratify<T>`	`public sealed class`	Flat data → hierarchy
`Stratify`	`public static class`	Factory
`SankeyLayout`	`public sealed class`	Sankey flow diagram
`SankeyGraph`	`public sealed class`	Sankey result container
`SankeyNode`	`public sealed class`	Flow node with bounds
`SankeyLink`	`public sealed class`	Flow connection
`SankeyNodeAlign`	`public enum`	Top, Middle, Bottom, Justify
`ForceNode`	`public sealed class`	Simulation particle
`ForceLink`	`public record struct`	Link constraint
`ForceSimulation`	`public sealed class`	N-body force simulation

Color, interpolation, path

Type	Kind	Description
`D3Color`	`public readonly struct`	Color parsing, manipulation, palettes
`D3Interpolate`	`public static class`	Value interpolation
`D3InterpolateColor`	`public static class`	Color-space interpolation (RGB, HSL, Lab, LCh)
`PathBuilder`	`public sealed class`	SVG path command builder

Utilities

Type	Kind	Description
`D3Ease`	`public static class`	Easing functions (Quad, Cubic, Sine, Expo, Elastic, Bounce, etc.)
`D3Random`	`public static class`	Seedable PRNG
`D3Format`	`public static class`	D3 number formatting
`D3Polygon`	`public static class`	Polygon hull, centroid, area, contains
`ContourGenerator`	`public sealed class`	Marching-squares contours
`DensityContourGenerator`	`public sealed class`	KDE contours from point clouds
`ContourMultiPolygon`	`public sealed class`	Contour result
`Delaunay`	`public sealed class`	Delaunay triangulation
`Voronoi`	`public sealed class`	Voronoi diagram
`ChordLayout`	`public sealed class`	Chord diagram layout
`RibbonGenerator`	`public sealed class`	Chord ribbon paths
`ChordData`	`public record struct`	Chord result
`ChordGroup`	`public record struct`	Chord group arc
`ChordArc`	`public record struct`	Arc segment
`ChordEnd`	`public record struct`	Chord endpoint

Merge steps

Move DuctD3/Charts/*.cs into Reactor/Charting/.
Move all other DuctD3/ subdirectories into Reactor/Charting/D3/.
Update namespaces: Duct.D3.Charts → Microsoft.UI.Reactor.Charting, Duct.D3 → Microsoft.UI.Reactor.Charting.D3.
Remove DuctD3/DuctD3.csproj.
Remove <ProjectReference> to DuctD3 from all consumers — now part of the main library.
Update Reactor.sln to remove the DuctD3 project entry.
Update tests/ReactorD3.Tests/ to reference Reactor instead of DuctD3.
Update using static Duct.D3.Charts.Charts → using static Microsoft.UI.Reactor.Charting.Charts everywhere.

10. Flex / Layout Namespace Merge & Yoga Internalization

The current codebase has two namespaces for layout:

Duct.Flex (directory Duct/Flex/, 2 files) — public API: FlexPanel, FlexEnums (enums: FlexAlign, FlexDirection, FlexJustify, FlexLayoutDirection, FlexPositionType, FlexWrap).
Duct.Layout (directory Duct/Yoga/, 9 files) — Yoga layout engine. Has types currently marked public (YogaNode, YogaConfig, YogaValue, 13 enums, 3 delegates) but no external consumer actually references them. The only code-level consumers are FlexPanel.cs (same assembly) and the generated Yoga test suite (covered by InternalsVisibleTo).

Yoga types → all made internal

Since no code outside the main assembly or test project uses the Yoga types, every Yoga* public type becomes internal. This eliminates the "Yoga" name from the public API entirely.

Type	Current visibility	New visibility
`YogaNode`	`public sealed`	`internal sealed`
`YogaConfig`	`public sealed`	`internal sealed`
`YogaValue`	`public readonly record struct`	`internal readonly record struct`
`YogaSize`	`public struct`	`internal struct`
`YogaMeasureFunc`	`public delegate`	`internal delegate`
`YogaBaselineFunc`	`public delegate`	`internal delegate`
`YogaDirtiedFunc`	`public delegate`	`internal delegate`
`YogaBoxSizing`	`public enum`	`internal enum`
`YogaDimension`	`public enum`	`internal enum`
`YogaDisplay`	`public enum`	`internal enum`
`YogaEdge`	`public enum`	`internal enum`
`YogaPhysicalEdge`	`public enum`	`internal enum`
`YogaErrata`	`public enum`	`internal enum`
`YogaExperimentalFeature`	`public enum`	`internal enum`
`YogaGutter`	`public enum`	`internal enum`
`YogaLogLevel`	`public enum`	`internal enum`
`YogaMeasureMode`	`public enum`	`internal enum`
`YogaNodeType`	`public enum`	`internal enum`
`YogaOverflow`	`public enum`	`internal enum`
`YogaUnit`	`public enum`	`internal enum`

The test project Reactor.Tests already has InternalsVisibleTo access, so the ~20 generated Yoga test files (tests/Reactor.Tests/YogaGenerated/) continue to compile. The one sample string reference in FlexPanelDemo.cs ("powered by the Yoga engine") will be updated to remove the Yoga mention.

Directory layout after merge

All files move into Reactor/Layout/. No sub-namespace needed — the types are either public (FlexPanel, FlexEnums) or internal (everything from Yoga).

Reactor/Layout/
  FlexPanel.cs              ← from Flex/  (public, namespace: M.UI.Reactor.Layout)
  FlexEnums.cs              ← from Flex/  (public, namespace: M.UI.Reactor.Layout)
  YogaNode.cs               ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  YogaConfig.cs             ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  YogaValue.cs              ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  YogaEnums.cs              ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  YogaStyle.cs              ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  YogaAlgorithm.cs          ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  AlgorithmUtils.cs         ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  LayoutResults.cs          ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)
  FlexDirectionHelper.cs    ← from Yoga/  (internal, namespace: M.UI.Reactor.Layout)

Impact on consumers

using Duct.Flex; → using Microsoft.UI.Reactor.Layout;
using Duct.Layout; → no longer needed (was only for Yoga types, now internal)
XAML: xmlns:flex="using:Duct.Flex" → xmlns:layout="using:Microsoft.UI.Reactor.Layout"

Old directories removed

Duct/Flex/ (files move to Reactor/Layout/)
Duct/Yoga/ (files move to Reactor/Layout/)

11. XAML Namespace References

Old	New
`xmlns:flex="using:Duct.Flex"`	`xmlns:layout="using:Microsoft.UI.Reactor.Layout"`

Affected files (all in samples/FlexPanelGallery/Pages/):

AbsolutePositionPage.xaml
AlignItemsPage.xaml
DirectionPage.xaml
GapPage.xaml
GrowShrinkPage.xaml
JustifyContentPage.xaml
NestedFlexPage.xaml
OverviewPage.xaml
WrapPage.xaml

Note: The XAML alias changes from flex: to layout: to match the new namespace. All <flex:FlexPanel> usages become <layout:FlexPanel>.

Also: ReactorHostControlDemo/*.xaml — x:Class and Title attributes.

12. InternalsVisibleTo

Old	New
`InternalsVisibleTo: Duct.Tests` (in Duct.csproj)	`InternalsVisibleTo: Reactor.Tests`
`InternalsVisibleTo: Duct.Tests` (in Duct.Cli.csproj)	`InternalsVisibleTo: Reactor.Tests`
`InternalsVisibleTo: Duct.Tests` (in Duct.Localization.Generator.csproj)	`InternalsVisibleTo: Reactor.Tests`

13. VS Code Extension (`vscode-duct/`)

Item	Old	New
Directory	`vscode-duct/`	`vscode-reactor/`
`package.json` name	`duct-preview`	`reactor-preview`
`package.json` displayName	`Duct Preview`	`Reactor Preview`
`package.json` publisher	`duct`	`reactor`
Command IDs	`duct.preview`, `duct.previewConnect`, `duct.previewStop`, `duct.previewFocus`	`reactor.preview`, `reactor.previewConnect`, `reactor.previewStop`, `reactor.previewFocus`

14. Config / Metadata Files

File	Changes
`es-metadata.yml`	`"Duct/"` → `"Reactor/"` in scope includes
`reviewer/manifest.json`	All `"Duct"` paths → `"Reactor"` paths
`selfhost/duct-cli.deps.json`	Rename to `selfhost/mur.deps.json`, update internal refs

15. Documentation

All .md files in the repo will be updated:

First occurrence in each document: Microsoft.UI.Reactor (full name)
Subsequent references: Reactor
"Duct" as a standalone word → "Reactor"
"DuctD3" → "Reactor D3" or "Reactor.D3"
Code samples updated with new namespaces and type names

Spec file renames (docs/spec/)

Drop -duct / duct from filenames rather than replacing with -reactor:

Old	New
`001-duct-theming-design.md`	`001-theming-design.md`
`002-duct-winui3-gap-analysis.md`	`002-winui3-gap-analysis.md`
`004-duct-property-grid.md`	`004-property-grid.md`
`005-duct-localization-design.md`	`005-localization-design.md`
`006-duct-accessibility-design.md`	`006-accessibility-design.md`
`007-duct-perf-experiments.md`	`007-perf-experiments.md`
`009-duct-state-and-components-design.md`	`009-state-and-components-design.md`
`010-duct-source-mapping-design.md`	`010-source-mapping-design.md`
`011-duct-navigation-design.md`	`011-navigation-design.md`
`012-duct-commanding-design.md`	`012-commanding-design.md`
`013-duct-doc-system-design.md`	`013-doc-system-design.md`
`014-duct-animation-design.md`	`014-animation-design.md`
`015-duct-styling-design.md`	`015-styling-design.md`
`016-ductd3-native-chart-migration.md`	`016-native-chart-migration.md`
`017-duct-data-system-design.md`	`017-data-system-design.md`
`archived/ductcpp-*.md`	`archived/cpp-*.md`

Other docs

File	Action
`README.md`	Full rewrite of framework name references
`CONTRIBUTING.md`	Update paths, project names, build instructions
`SKILL.md`	Update all code references
`docs/duct-critical-review.md`	Rename file → `docs/critical-review.md`, update content
`docs/flux-ui-analysis.md`	Update Duct references
`docs/winui3-integration-proposals.md`	Update references
`docs/compare/*.md`	Update references
`docs/output/*.md`	Update references
`docs/tasks/*.md`	Update references
`docs/investigation/winforms-interop.md`	Update references (~27 occurrences)
`design-skill/SKILL.md` and `design-skill/docs/*.md`	Update references (~39 occurrences across 7 files)
`samples/WinFormsInterop/README.md`	Update references (~24 occurrences)
`docs/worksummary/work-summary.md`	Update references (~13 occurrences)
`docs/worksummary/*.svg`	Update embedded "Duct" text labels (~7 occurrences across 2 SVGs)
`reviewer/reports/fix-list.md`	Update references
`docs/reactor-pitch.md`	Already uses "Reactor" naming — verify no stale "Duct" refs
`docs/apps/data-system/App.cs`	Update `using Duct` / `using static Duct.UI` / ProjectReference paths
`docs/apps/winforms-interop/App.cs`	Update `using Duct` / `using static Duct.UI` / ProjectReference paths
`samples/WinUI-Gallery-Duct/GAPS.md`	Update ~20 occurrences of "Duct" in prose and table
`Duct/Docs/Architecture.md`	Move to `Reactor/Docs/`, update content
`Duct/Docs/GettingStarted.md`	Move to `Reactor/Docs/`, update content

16. Execution Order

The rename should be executed in this order to keep the build green at each step:

Phase 1: Source code renames (no file/directory moves)

Namespaces — Find-replace all namespace Duct → namespace Microsoft.UI.Reactor and all using Duct → using Microsoft.UI.Reactor across all .cs files.
using static Duct.UI → using static Microsoft.UI.Reactor.Factories and rename the UI class to Factories in Dsl.cs.
Type renames — Apply all type renames from Section 2.
MSBuild properties — Rename DuctLoc* → ReactorLoc* in .csproj and generator.
String literals — Update all string literals from Section 6.
Analyzer category — "Duct.Style" → "Reactor.Style".
Generator attribution — Update GeneratedCode attribute string.
XAML namespaces — Update xmlns references.
InternalsVisibleTo — Update assembly friend names.
RootNamespace / AssemblyName — Update all .csproj files (including WinUI-Gallery-Duct.csproj RootNamespace WinUIGalleryDuct → WinUIGalleryReactor, and docs/apps/ project ProjectReference paths).
Verify build — dotnet build Duct.sln (still old .sln name).

Phase 2: Assembly merges + namespace consolidation

After Phase 1, namespaces are already renamed but files are in old directories.

DuctD3 → Charting merge:

Move DuctD3/Charts/*.cs into Duct/Charting/.
Move all other DuctD3/ subdirectories into Duct/Charting/D3/.
Update namespaces: Microsoft.UI.Reactor.D3.Charts → Microsoft.UI.Reactor.Charting, Microsoft.UI.Reactor.D3 → Microsoft.UI.Reactor.Charting.D3.
Remove DuctD3/DuctD3.csproj.
Remove ProjectReference to DuctD3 from all consumers.

Controls consolidation: 6. Move Duct/DataGrid/, Duct/PropertyGrid/, Duct/Virtualization/ into Duct/Controls/. 7. Move Duct/Validation/ into Duct/Controls/Validation/. 8. Flatten Controls sub-namespaces to namespace Microsoft.UI.Reactor.Controls. Validation gets namespace Microsoft.UI.Reactor.Controls.Validation.

Hosting namespace split: 9. Update ReactorHost, ReactorHostControl, PageHelper, RenderStats, HotReloadService, PreviewCaptureServer, XamlInterop to namespace Microsoft.UI.Reactor.Hosting. ReactorApp and ReactorApplication stay in root Microsoft.UI.Reactor.

Flex/Layout merge: 10. Move Duct/Flex/*.cs into Duct/Yoga/. 11. Remove Duct/Flex/ directory. 12. Change all Yoga* public types to internal. 13. Update namespace Microsoft.UI.Reactor.Flex → namespace Microsoft.UI.Reactor.Layout. 14. Update XAML xmlns:flex=… → xmlns:layout="using:Microsoft.UI.Reactor.Layout" and all flex: element prefixes → layout:.

Navigation / Localization promotion: 15. Update namespace Microsoft.UI.Reactor.Core.Navigation → namespace Microsoft.UI.Reactor.Navigation. 16. Update namespace Microsoft.UI.Reactor.Core.Localization → namespace Microsoft.UI.Reactor.Localization.

Finalize: 17. Update solution file. 18. Verify build.

Phase 3: File and directory renames

Rename directories bottom-up (deepest first to avoid path conflicts).
Rename .csproj files within directories.
Rename .sln file.
Update all <ProjectReference> paths in .csproj files.
Update solution file project paths.
Verify build.

Phase 4: Documentation & metadata

Rename spec files.
Find-replace "Duct" → "Reactor" (with case sensitivity) across all .md files, including samples/ReactorGallery/GAPS.md (~20 occurrences).
Manual review pass: ensure first occurrence in each doc is "Microsoft.UI.Reactor".
Update docs/apps/ project files (ProjectReference paths, using statements).
Update reviewer/manifest.json, es-metadata.yml.
Update VS Code extension (vscode-duct/).
Update selfhost/ artifacts.

Phase 5: Verification

dotnet build Reactor.sln
dotnet test — all unit tests pass.
Global text search for any surviving "Duct" references (case-insensitive).
Verify sample apps launch.

WinUI Namespace Alignment

The final namespace tree compared to WinUI's pattern:

Microsoft.UI.Xaml                          Microsoft.UI.Reactor
Microsoft.UI.Xaml.Controls                 Microsoft.UI.Reactor.Controls
Microsoft.UI.Xaml.Controls.Primitives      Microsoft.UI.Reactor.Controls.Validation
Microsoft.UI.Xaml.Data                     Microsoft.UI.Reactor.Data
                                           Microsoft.UI.Reactor.Data.Providers
Microsoft.UI.Xaml.Hosting                  Microsoft.UI.Reactor.Hosting
Microsoft.UI.Xaml.Media.Animation          Microsoft.UI.Reactor.Animation
Microsoft.UI.Xaml.Navigation               Microsoft.UI.Reactor.Navigation
                                           Microsoft.UI.Reactor.Core (component model — Reactor-specific)
                                           Microsoft.UI.Reactor.Localization
                                           Microsoft.UI.Reactor.Elements (DSL factories)
                                           Microsoft.UI.Reactor.Hooks (React-style — Reactor-specific)
                                           Microsoft.UI.Reactor.Layout (FlexPanel + Yoga)
                                           Microsoft.UI.Reactor.Charting
                                           Microsoft.UI.Reactor.Charting.D3
                                           Microsoft.UI.Reactor.Markdown
                                           Microsoft.UI.Reactor.Monaco

Open Questions

~~Duct.Hosting namespace~~ — Resolved. Split: ReactorApp and ReactorApplication stay in root (like Application in Microsoft.UI.Xaml). ReactorHost, ReactorHostControl, PageHelper, RenderStats, HotReloadService, PreviewCaptureServer, XamlInterop move to Microsoft.UI.Reactor.Hosting (matches Microsoft.UI.Xaml.Hosting).
ElementFactory<T> name conflict — Microsoft.UI.Xaml.Controls.ElementFactory exists in WinUI. Our DuctElementFactory<T> is generic while theirs is not, so overload resolution handles it, but the name similarity may confuse IntelliSense. Consider keeping as ReactorElementFactory<T> instead.
Doc samples referencing DuctD3 as separate package — After the merge, samples that previously had <ProjectReference> to DuctD3 will just reference the main library. Doc prose describing it as a "separate charting package" needs rewriting.
vscode-duct publisher name — Changing the VS Code marketplace publisher from duct to reactor may require a new marketplace registration. Flag for separate handling.
Generated Yoga test files — The tests/Reactor.Tests/YogaGenerated/ directory contains ~20 auto-generated test files that heavily reference Yoga types. After internalization these still compile via InternalsVisibleTo, but the directory name still says "Yoga". Rename to LayoutGenerated/?

FilesExpand file tree

018-namespace-rename.md

Latest commit

History

018-namespace-rename.md

File metadata and controls

018 — Namespace Rename: Duct → Microsoft.UI.Reactor

Overview

1. Namespace Mappings

Test / infrastructure namespaces

Sample app namespaces

2. Type Renames

Public API types (prefix dropped — the namespace provides disambiguation)

Public API types (keep prefix — protect generic names)

Internal types

Test fixture classes

DSL entry point class

2a. Replace Custom Logger with Microsoft.Extensions.Logging

Why

New dependency

Migration

Call-site changes

Constructor changes

Files changed

3. MSBuild Properties

4. Analyzer Diagnostic Category

5. Source Generator Attribution

6. String Literals

7. Directory & File Renames

Core framework

Test projects

Perf bench projects (tests/perf_bench/)

Sample projects

.csproj file renames (within directories)

8. Assembly Names

9a. Controls Namespace Consolidation

Type counts per source namespace

Directory layout after merge

Not moved into Controls

9b. DuctD3 → Merge into Main Assembly (Charting namespace)

Directory layout after merge

Class-by-class mapping: Microsoft.UI.Reactor.Charting

Class-by-class mapping: Microsoft.UI.Reactor.Charting.D3

Array utilities

Scales

Shape generators

Layout algorithms

Color, interpolation, path

Utilities

Merge steps

10. Flex / Layout Namespace Merge & Yoga Internalization

Yoga types → all made internal

Directory layout after merge

Impact on consumers

Old directories removed

11. XAML Namespace References

12. InternalsVisibleTo

13. VS Code Extension (vscode-duct/)

14. Config / Metadata Files

15. Documentation

Spec file renames (docs/spec/)

Other docs

16. Execution Order

Phase 1: Source code renames (no file/directory moves)

Phase 2: Assembly merges + namespace consolidation

Phase 3: File and directory renames

Phase 4: Documentation & metadata

Phase 5: Verification

WinUI Namespace Alignment

Open Questions

Perf bench projects (`tests/perf_bench/`)

Class-by-class mapping: `Microsoft.UI.Reactor.Charting`

Class-by-class mapping: `Microsoft.UI.Reactor.Charting.D3`

13. VS Code Extension (`vscode-duct/`)