Add _modify to @perceptible

pointfreeco · Jun 25, 2024 · de05abb · de05abb
1 parent 0fb2e78
commit de05abb
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Showing 3 changed files with 20 additions and 2 deletions.
diff --git a/Sources/Perception/Macros.swift b/Sources/Perception/Macros.swift
@@ -16,7 +16,7 @@
 public macro Perceptible() =
   #externalMacro(module: "PerceptionMacros", type: "PerceptibleMacro")
 
-@attached(accessor, names: named(init), named(get), named(set))
+@attached(accessor, names: named(init), named(get), named(set), named(_modify))
 @attached(peer, names: prefixed(_))
 public macro PerceptionTracked() =
   #externalMacro(module: "PerceptionMacros", type: "PerceptionTrackedMacro")

diff --git a/Sources/PerceptionMacros/PerceptibleMacro.swift b/Sources/PerceptionMacros/PerceptibleMacro.swift
@@ -367,7 +367,17 @@ public struct PerceptionTrackedMacro: AccessorMacro {
       }
       """
 
-    return [initAccessor, getAccessor, setAccessor]
+    let modifyAccessor: AccessorDeclSyntax =
+      """
+      _modify {
+      access(keyPath: \\.\(identifier))
+      \(raw: PerceptibleMacro.registrarVariableName).willSet(self, keyPath: \\.\(identifier))
+      defer { \(raw: PerceptibleMacro.registrarVariableName).didSet(self, keyPath: \\.\(identifier)) }
+      yield &_\(identifier)
+      }
+      """
+
+    return [initAccessor, getAccessor, setAccessor, modifyAccessor]
   }
 }
 

diff --git a/Tests/PerceptionMacrosTests/PerceptionMacrosTests.swift b/Tests/PerceptionMacrosTests/PerceptionMacrosTests.swift
@@ -42,6 +42,14 @@
                 _count = newValue
               }
             }
+            _modify {
+              access(keyPath: \.count)
+              _$perceptionRegistrar.willSet(self, keyPath: \.count)
+              defer {
+                _$perceptionRegistrar.didSet(self, keyPath: \.count)
+              }
+              yield &_count
+            }
           }
 
           private let _$perceptionRegistrar = Perception.PerceptionRegistrar()