@DatabaseState

Package.swift

@@ -16,6 +16,7 @@ let package = Package(
     .library(name: "VergeORM", targets: ["VergeORM"]),
     .library(name: "VergeRx", targets: ["VergeRx"]),
     .library(name: "VergeClassic", targets: ["VergeClassic"]),
+    .library(name: "VergeMacros", targets: ["VergeMacros"])
   ],
   dependencies: [
     .package(url: "https://github.com/ReactiveX/RxSwift.git", from: "6.0.0"),
@@ -26,25 +27,27 @@ let package = Package(
 
     /// for testing
     .package(url: "https://github.com/nalexn/ViewInspector.git", from: "0.9.3"),
-
-      .package(url: "https://github.com/apple/swift-syntax.git", from: "509.0.0-swift-5.9-DEVELOPMENT-SNAPSHOT-2023-04-25-b")
+    .package(url: "https://github.com/apple/swift-syntax.git", from: "509.0.0-swift-5.9-DEVELOPMENT-SNAPSHOT-2023-04-25-b")
   ],
   targets: [
+
+    // compiler plugin
     .macro(
-      name: "VergeMacros",
+      name: "VergeMacrosPlugin",
       dependencies: [
         .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
         .product(name: "SwiftCompilerPlugin", package: "swift-syntax")
       ]
     ),
 
-    .target(name: "VergeMacrosExports", dependencies: ["VergeMacros"]),
+    // macro exports
+    .target(name: "VergeMacros", dependencies: ["VergeMacrosPlugin"]),
 
     .target(name: "VergeTiny", dependencies: []),
     .target(
       name: "Verge",
       dependencies: [
-        "VergeMacrosExports",
+        "VergeMacros",
         .product(name: "Atomics", package: "swift-atomics"),
         .product(name: "DequeModule", package: "swift-collections"),
         .product(name: "ConcurrencyTaskManager", package: "swift-concurrency-task-manager"),
@@ -92,6 +95,10 @@ let package = Package(
       name: "VergeTinyTests",
       dependencies: ["VergeTiny"]
     ),
+    .testTarget(name: "VergeMacrosTests", dependencies: [
+      "VergeMacros",
+      .product(name: "SwiftSyntaxMacrosTestSupport", package: "swift-syntax"),
+    ])
   ],
   swiftLanguageVersions: [.v5]
 )

Sources/VergeMacros/Source.swift

@@ -1,11 +1,22 @@
-import SwiftCompilerPlugin
-import SwiftSyntax
-import SwiftSyntaxBuilder
-import SwiftSyntaxMacros
 
-@main
-struct VergeMacroPlugin: CompilerPlugin {
-  let providingMacros: [Macro.Type] = [
+//@freestanding(expression) public macro
+// #externalMacro(module: "MacroExamplesPlugin", type: "FontLiteralMacro")
 
-  ]
-}
+/**
+     struct Database: DatabaseType {
+
+      struct Schema: EntitySchemaType {
+        let author = Author.EntityTableKey()
+      }
+
+      struct Indexes: IndexesType {
+        let allBooks = HashIndex<Schema, String, Author>.Key()
+      }
+
+      var _backingStorage: BackingStorage = .init()
+    }
+ */
+
+@attached(member, names: named(_backingStorage))
+@attached(conformance)
+public macro DatabaseState() = #externalMacro(module: "VergeMacrosPlugin", type: "DatabaseStateMacro")

Sources/VergeMacrosPlugin/DatabaseStateMacro.swift

@@ -0,0 +1,48 @@
+import SwiftSyntax
+import SwiftSyntaxBuilder
+import SwiftSyntaxMacros
+
+public struct DatabaseStateMacro {
+
+}
+
+extension DatabaseStateMacro: ConformanceMacro {
+  public static func expansion<Declaration, Context>(
+    of node: SwiftSyntax.AttributeSyntax,
+    providingConformancesOf declaration: Declaration,
+    in context: Context
+  ) throws -> [(SwiftSyntax.TypeSyntax, SwiftSyntax.GenericWhereClauseSyntax?)]
+  where Declaration: SwiftSyntax.DeclGroupSyntax, Context: SwiftSyntaxMacros.MacroExpansionContext {
+
+    // Decode the expansion arguments.
+    guard let structDecl = declaration.as(StructDeclSyntax.self) else {
+//      context.diagnose(OptionSetMacroDiagnostic.requiresStruct.diagnose(at: decl))
+      return []
+    }
+
+    // If there is an explicit conformance to OptionSet already, don't add one.
+    if let inheritedTypes = structDecl.inheritanceClause?.inheritedTypeCollection,
+       inheritedTypes.contains(where: { inherited in inherited.typeName.trimmedDescription == "DatabaseType" }) {
+      return []
+    }
+
+    return [("DatabaseType", nil)]
+  }
+
+}
+
+extension DatabaseStateMacro: MemberMacro {
+
+  public static func expansion<Declaration, Context>(
+    of node: SwiftSyntax.AttributeSyntax,
+    providingMembersOf declaration: Declaration,
+    in context: Context
+  ) throws -> [SwiftSyntax.DeclSyntax]
+  where Declaration: SwiftSyntax.DeclGroupSyntax, Context: SwiftSyntaxMacros.MacroExpansionContext {
+
+    return [
+      "var _backingStorage: BackingStorage = .init()"
+    ]
+
+  }
+}

Sources/VergeMacrosPlugin/VergeMacrosPlugin.swift

@@ -0,0 +1,16 @@
+import SwiftCompilerPlugin
+import SwiftSyntax
+import SwiftSyntaxBuilder
+import SwiftSyntaxMacros
+
+struct _Macro: AttachedMacro {
+
+}
+
+
+@main
+struct VergeMacroPlugin: CompilerPlugin {
+  let providingMacros: [Macro.Type] = [
+    DatabaseStateMacro.self,
+  ]
+}

Sources/VergeMacrosExports/Source.swift → Tests/VergeMacrosTests/VergeMacrosTests.swift

@@ -2,7 +2,7 @@
 //  File.swift
 //  
 //
-//  Created by Muukii on 2023/06/12.
+//  Created by Muukii on 2023/06/17.
 //
 
 import Foundation

Tests/VergeORMTests/RootState.swift

@@ -10,6 +10,7 @@ import Foundation
 
 import Verge
 import VergeORM
+import VergeMacros
 
 struct Book: EntityType, Hashable {
 
@@ -39,8 +40,9 @@ struct Author: EntityType {
 }
 
 struct RootState: StateType {
-
-  struct Database: DatabaseType {
+
+  @DatabaseState
+  struct Database {
 
     struct Schema: EntitySchemaType {
       let book = Book.EntityTableKey()
@@ -62,8 +64,6 @@ struct RootState: StateType {
         })
       ]
     }
-
-    var _backingStorage: BackingStorage = .init()
   }
 
   struct Other: Equatable {