refactor: refactor compiler

.github/workflows/ci.yml

@@ -28,11 +28,11 @@ jobs:
 
       - name: Verify samples are regenerated cleanly
         run: |
-          if ! git diff --quiet -- js/ 2>&1; then
+          if ! git diff --quiet -- targets/ 2>&1; then
             echo "Generated TS files are out of sync with the C# source."
             echo "Run 'dotnet build' locally and commit the regenerated files."
-            git status -- js/
-            git diff -- js/ | head -100
+            git status -- targets/
+            git diff -- targets/ | head -100
             exit 1
           fi
 
@@ -54,16 +54,16 @@ jobs:
         run: bun install
 
       - name: metano-runtime
-        run: cd js/metano-runtime && bun run build && bun test
+        run: cd targets/js/metano-runtime && bun run build && bun test
 
       - name: sample-todo
-        run: cd js/sample-todo && bun run build && bun test
+        run: cd targets/js/sample-todo && bun run build && bun test
 
       - name: sample-todo-service
-        run: cd js/sample-todo-service && bun run build && bun test
+        run: cd targets/js/sample-todo-service && bun run build && bun test
 
       - name: sample-issue-tracker
-        run: cd js/sample-issue-tracker && bun run build && bun test
+        run: cd targets/js/sample-issue-tracker && bun run build && bun test
 
       - name: Biome check
         run: bunx biome check .

.github/workflows/release.yml

@@ -47,7 +47,7 @@ jobs:
       - name: Build metano-runtime
         run: |
           bun install
-          cd js/metano-runtime && bun run build
+          cd targets/js/metano-runtime && bun run build
 
       # Sync version from the tag and publish to npm via Trusted Publishing.
       # No NPM_TOKEN — the npm CLI uses the OIDC token from id-token: write.

CLAUDE.md

@@ -19,7 +19,10 @@ dotnet run --project tests/Metano.Tests/ -- \
   --results-directory TestResults                     # run tests with code coverage
 dotnet run --project src/Metano.Compiler.TypeScript/ -- \
   -p samples/SampleTodo/SampleTodo.csproj \
-  -o js/sample-todo/src --clean                       # transpile SampleTodo to TypeScript
+  -o targets/js/sample-todo/src --clean               # transpile SampleTodo to TypeScript
+dotnet run --project src/Metano.Compiler.Dart/ -- \
+  -p samples/SampleCounter/SampleCounter.csproj \
+  -o targets/flutter/sample_counter/lib/sample_counter --clean  # transpile SampleCounter to Dart
 dotnet csharpier .                                    # format C# code
 ```
 
@@ -28,12 +31,13 @@ TUnit on .NET 10 requires `dotnet run` instead of `dotnet test`.
 ### JavaScript/TypeScript (Bun)
 
 ```sh
-cd js/metano-runtime && bun run build             # TypeScript build (tsgo)
-cd js/metano-runtime && bun test                  # run runtime tests
-cd js/sample-todo && bun run build                    # TS build of generated code
-cd js/sample-todo && bun test                         # end-to-end tests (18 tests)
-cd js/sample-issue-tracker && bun run build && bun test  # 65 tests
-cd js/sample-todo-service && bun run build && bun test   # 19 tests (cross-package + Hono CRUD + JSON serialization)
+cd targets/js/metano-runtime && bun run build             # TypeScript build (tsgo)
+cd targets/js/metano-runtime && bun test                  # run runtime tests
+cd targets/js/sample-todo && bun run build                # TS build of generated code
+cd targets/js/sample-todo && bun test                     # end-to-end tests (18 tests)
+cd targets/js/sample-issue-tracker && bun run build && bun test  # 65 tests
+cd targets/js/sample-todo-service && bun run build && bun test   # 19 tests (cross-package + Hono CRUD + JSON serialization)
+cd targets/js/sample-counter && bun run dev               # Vite + SolidJS counter MVP sample
 ```
 
 Always use **Bun** — never npm, yarn, or pnpm.
@@ -51,24 +55,36 @@ Metano.slnx
 │   │   ├── TranspilerHost.cs            # Orchestrates load → compile → target.Transform → write
 │   │   ├── SymbolHelper.cs              # Target-agnostic Roslyn helpers (attribute readers, type checks)
 │   │   └── Diagnostics/                 # MetanoDiagnostic + DiagnosticCodes (MS0001–MS0008)
-│   └── Metano.Compiler.TypeScript/   # TypeScript target (depends on the core)
-│       ├── TypeScriptTarget.cs          # ITranspilerTarget adapter
-│       ├── Commands.cs                  # CLI (ConsoleAppFramework) — `metano-typescript`
-│       ├── PackageJsonWriter.cs         # Auto-generates package.json (imports/exports/dependencies)
-│       ├── Transformation/              # 39 focused handlers (TypeTransformer, ExpressionTransformer, etc.)
-│       └── TypeScript/AST + Printer.cs  # ~65 TS AST record types and the printer
+│   ├── Metano.Compiler.TypeScript/   # TypeScript target (depends on the core)
+│   │   ├── TypeScriptTarget.cs          # ITranspilerTarget adapter
+│   │   ├── Commands.cs                  # CLI (ConsoleAppFramework) — `metano-typescript`
+│   │   ├── Bridge/                      # IR → TS AST bridges (enums, interfaces, plain objects)
+│   │   ├── PackageJsonWriter.cs         # Auto-generates package.json (imports/exports/dependencies)
+│   │   ├── Transformation/              # 39 focused handlers (TypeTransformer, ExpressionTransformer, etc.)
+│   │   └── TypeScript/AST + Printer.cs  # ~65 TS AST record types and the printer
+│   └── Metano.Compiler.Dart/         # Dart/Flutter target (prototype — shape-only, no bodies yet)
+│       ├── DartTarget.cs                # ITranspilerTarget adapter
+│       ├── Commands.cs                  # CLI — `metano-dart`
+│       ├── Bridge/                      # IR → Dart AST (enum, interface, class)
+│       ├── Transformation/              # Dart transformer orchestrator
+│       └── Dart/AST + Printer.cs        # Minimal Dart AST + printer
 ├── tests/
 │   └── Metano.Tests/                 # 337 TUnit tests with inline C# compilation
 │       └── Expected/                    # Expected .ts output files for golden tests
 ├── samples/
 │   ├── SampleTodo/                      # Sample C# project for end-to-end validation
 │   ├── SampleTodo.Service/              # Hono-based service sample (cross-package + [PlainObject] CRUD)
-│   └── SampleIssueTracker/              # Larger sample exercising LINQ, records, modules, overloads
-├── js/                                  # Bun workspace
-│   ├── metano-runtime/              # metano-runtime (HashCode, HashSet, LINQ, type checks)
-│   ├── sample-todo/                     # Generated TS from SampleTodo + bun tests (18)
-│   ├── sample-todo-service/             # Generated TS from SampleTodo.Service + bun tests (9)
-│   └── sample-issue-tracker/            # Generated TS from SampleIssueTracker + bun tests (51)
+│   ├── SampleIssueTracker/              # Larger sample exercising LINQ, records, modules, overloads
+│   └── SampleCounter/                   # Counter MVP sample (used by Vite + SolidJS consumer)
+└── targets/                             # One subfolder per language target + its samples
+    ├── js/                              # Bun workspace (TypeScript target)
+    │   ├── metano-runtime/              # metano-runtime (HashCode, HashSet, LINQ, type checks)
+    │   ├── sample-todo/                 # Generated TS from SampleTodo + bun tests (18)
+    │   ├── sample-todo-service/         # Generated TS from SampleTodo.Service + bun tests (9)
+    │   ├── sample-issue-tracker/        # Generated TS from SampleIssueTracker + bun tests (51)
+    │   └── sample-counter/              # Vite + SolidJS MVP consumer of generated SampleCounter TS
+    └── flutter/                         # Dart/Flutter target consumers
+        └── sample_counter/              # Flutter app consuming generated Dart from SampleCounter
 ```
 
 ### Pipeline

Metano.slnx

@@ -3,6 +3,7 @@
     <Project Path="src/Metano/Metano.csproj" />
     <Project Path="src/Metano.Compiler/Metano.Compiler.csproj" />
     <Project Path="src/Metano.Compiler.TypeScript/Metano.Compiler.TypeScript.csproj" />
+    <Project Path="src/Metano.Compiler.Dart/Metano.Compiler.Dart.csproj" />
     <Project Path="src/Metano.Build/Metano.Build.csproj" />
   </Folder>
   <Folder Name="/tests/">

README.md

@@ -211,7 +211,7 @@ public record TodoItem(string Title, bool Completed = false, Priority Priority =
 }
 ```
 
-**Output** — `js/sample-todo/src/todo-item.ts`:
+**Output** — `targets/js/sample-todo/src/todo-item.ts`:
 
 ```typescript
 import { HashCode } from "metano-runtime";
@@ -263,7 +263,7 @@ export class TodoItem {
 }
 ```
 
-And `js/sample-todo/src/priority.ts`:
+And `targets/js/sample-todo/src/priority.ts`:
 
 ```typescript
 export const Priority = {
@@ -326,15 +326,19 @@ Real C# projects transpiled into TypeScript and exercised with Bun tests —
 each one validates a different slice of the compiler:
 
 - [`samples/SampleTodo`](samples/SampleTodo/) — minimal records + string
-  enums. Good starting point. Generates [`js/sample-todo`](js/sample-todo/).
+  enums. Good starting point. Generates
+  [`targets/js/sample-todo`](targets/js/sample-todo/).
 - [`samples/SampleTodo.Service`](samples/SampleTodo.Service/) — Hono CRUD
   service showing cross-package imports, `[PlainObject]` DTOs, and
   `[ModuleEntryPoint]`. Generates
-  [`js/sample-todo-service`](js/sample-todo-service/).
+  [`targets/js/sample-todo-service`](targets/js/sample-todo-service/).
 - [`samples/SampleIssueTracker`](samples/SampleIssueTracker/) — larger
   domain model with branded IDs, rich aggregates, LINQ queries,
   inheritance, and a repository. Generates
-  [`js/sample-issue-tracker`](js/sample-issue-tracker/).
+  [`targets/js/sample-issue-tracker`](targets/js/sample-issue-tracker/).
+- [`samples/SampleCounter`](samples/SampleCounter/) — Counter MVP
+  (model + view interface + presenter) consumed by a Vite + SolidJS
+  frontend in [`targets/js/sample-counter`](targets/js/sample-counter/).
 
 ---
 

biome.json

@@ -36,6 +36,6 @@
     }
   },
   "files": {
-    "includes": ["js/metano-runtime/src/**", "js/metano-runtime/test/**"]
+    "includes": ["targets/js/metano-runtime/src/**", "targets/js/metano-runtime/test/**"]
   }
 }

docs/adr/0005-inline-wrapper-branded-types.md

@@ -121,7 +121,7 @@ also protects BCL identifiers that cross the TS boundary.
 - `src/Metano.Compiler.TypeScript/Transformation/InlineWrapperTransformer.cs`
 - `src/Metano.Compiler.TypeScript/Transformation/TypeMapper.cs` — `Guid`
   → `UUID` mapping
-- `js/metano-runtime/src/system/uuid.ts` — runtime-provided branded type
+- `targets/js/metano-runtime/src/system/uuid.ts` — runtime-provided branded type
 - `samples/SampleIssueTracker` — `UserId`, `IssueId` as inline wrappers
 - `tests/Metano.Tests/InlineWrapperTranspileTests.cs`
 - Related: [ADR-0003](0003-declarative-bcl-mappings.md) — how the

docs/adr/0009-type-guards.md

@@ -128,8 +128,8 @@ namespace barrel. The `TsTypePredicateType` AST node carries the
 - `src/Metano.Compiler.TypeScript/Transformation/TypeGuardBuilder.cs`
 - `src/Metano.Compiler.TypeScript/TypeScript/AST/TsTypePredicateType.cs`
 - `src/Metano/Annotations/GenerateGuardAttribute.cs`
-- `js/metano-runtime/src/system/primitives/` — `isInt32`, `isString`,
-  etc.
+- `targets/js/metano-runtime/src/type-checking/primitive-type-checks.ts` —
+  `isInt32`, `isString`, etc.
 - `tests/Metano.Tests/TypeGuardTranspileTests.cs`
 - [Issue #24](https://github.com/danfma/metano/issues/24) — `assertX`
   throwing variant + discriminated unions (tracked follow-ups).

docs/adr/0012-linq-eager-wrapper.md

@@ -140,7 +140,7 @@ single C# file.
 
 ## References
 
-- `js/metano-runtime/src/system/linq/` — `EnumerableBase` +
+- `targets/js/metano-runtime/src/system/linq/` — `EnumerableBase` +
   operator subclasses + terminals
 - `src/Metano/Runtime/Linq.cs` — declarative LINQ mappings via
   `[MapMethod]`