Implement `static func Binding<Value>.constant` (#178)

Unrelated formatting changes were added by the SwiftFormat pre-commit hook.

Sources/TokamakCore/Binding.swift

@@ -37,7 +37,9 @@ typealias Updater<T> = (inout T) -> ()
     self.set = set
   }
 
-  public subscript<Subject>(dynamicMember keyPath: WritableKeyPath<Value, Subject>) -> Binding<Subject> {
+  public subscript<Subject>(
+    dynamicMember keyPath: WritableKeyPath<Value, Subject>
+  ) -> Binding<Subject> {
     .init(
       get: {
         self.wrappedValue[keyPath: keyPath]
@@ -46,4 +48,8 @@ typealias Updater<T> = (inout T) -> ()
       }
     )
   }
+
+  static func constant(_ value: Value) -> Self {
+    .init(get: { value }, set: { _ in })
+  }
 }

Sources/TokamakDOM/Views/SecureField.swift

@@ -29,10 +29,10 @@ extension SecureField: ViewDeferredToRenderer where Label == Text {
     ], listeners: [
       "keypress": { event in if event.key == "Enter" { proxy.onCommit() } },
       "input": { event in
-          if let newValue = event.target.object?.value.string {
-            proxy.textBinding.wrappedValue = newValue
-          }
-        },
+        if let newValue = event.target.object?.value.string {
+          proxy.textBinding.wrappedValue = newValue
+        }
+      },
     ]))
   }
 }

Sources/TokamakDOM/Views/TextField.swift

@@ -44,10 +44,10 @@ extension TextField: ViewDeferredToRenderer where Label == Text {
       "blur": { _ in proxy.onEditingChanged(false) },
       "keypress": { event in if event.key == "Enter" { proxy.onCommit() } },
       "input": { event in
-          if let newValue = event.target.object?.value.string {
-            proxy.textBinding.wrappedValue = newValue
-          }
-        },
+        if let newValue = event.target.object?.value.string {
+          proxy.textBinding.wrappedValue = newValue
+        }
+      },
     ]))
   }
 }