Use optional package

dub.sdl

@@ -4,8 +4,9 @@ authors "Johannes Loher"
 copyright "Copyright © 2018, Johannes Loher"
 license "MIT"
 dependency "aedi" version="~>1.0.0"
-dependency "fluent-asserts" version="~>0.12.3"
-dependency "vibe-d" version="~>0.8.4"
+dependency "fluent-asserts" version="~>0.12.4"
+dependency "vibe-d" version="~>0.8.5"
+dependency "optional" version="~>0.15.0"
 
 configuration "executable" {
     targetType "executable"

dub.selections.json

@@ -2,21 +2,24 @@
 	"fileVersion": 1,
 	"versions": {
 		"aedi": "1.0.0",
+		"bolts": "0.11.1",
 		"botan": "1.12.10",
 		"botan-math": "1.0.3",
 		"ddmp": "0.0.1-0.dev.3",
 		"diet-ng": "1.5.0",
-		"eventcore": "0.8.40",
-		"fluent-asserts": "0.12.3",
-		"libasync": "0.8.3",
+		"eventcore": "0.8.43",
+		"fluent-asserts": "0.12.4",
+		"libasync": "0.8.4",
 		"libdparse": "0.8.8",
 		"libevent": "2.0.2+2.0.16",
 		"memutils": "0.4.13",
 		"mir-linux-kernel": "1.0.1",
 		"openssl": "1.1.6+1.0.1g",
+		"optional": "0.15.0",
+		"silly": "0.8.2",
 		"stdx-allocator": "2.77.5",
-		"taggedalgebraic": "0.10.12",
-		"vibe-core": "1.4.6",
-		"vibe-d": "0.8.4"
+		"taggedalgebraic": "0.11.4",
+		"vibe-core": "1.6.2",
+		"vibe-d": "0.8.5"
 	}
 }

source/d_webservice_example/business/todo_service.d

@@ -36,10 +36,13 @@ public:
     {
         import std.exception : enforce;
         import vibe.http.common : HTTPStatus, HTTPStatusException;
+        import optional.optional : orElse;
 
-        immutable maybeTodo = todoRepository.findByUuid(uuid);
-        enforce(!maybeTodo.isNull, new HTTPStatusException(HTTPStatus.NotFound));
-        return maybeTodo.get;
+        immutable todo = todoRepository.findByUuid(uuid).orElse!(function Todo() {
+            throw new HTTPStatusException(HTTPStatus.NotFound);
+        });
+
+        return todo;
     }
 
     Todo updateTodo(UUID uuid, const TodoUpdateDO todoUpdate) @safe
@@ -66,10 +69,10 @@ public:
 
 interface TodoRepository
 {
-    import std.typecons : Nullable;
+    import optional.optional : Optional;
 
     Todo save(Todo todo) @safe;
     bool remove(Todo todo) @safe;
-    Nullable!Todo findByUuid(UUID uuid) @safe;
+    Optional!Todo findByUuid(UUID uuid) @safe;
     Todo[] findAll() @safe;
 }

source/d_webservice_example/controller/todo_controller.d

@@ -5,22 +5,22 @@ import std.typecons : Nullable;
 import std.uuid : UUID;
 import vibe.web.rest : path;
 
-@path("/api/v1/todos")
+@path("/api/v1/")
 interface TodoApi
 {
-    @path("/")
+    @path("todos")
     TodoTO addTodo(string title, string content) @safe;
 
-    @path("/")
+    @path("todos")
     TodoTO[] getTodos() @safe;
 
-    @path("/:uuid")
+    @path("todos/:uuid")
     TodoTO getTodo(UUID _uuid) @safe;
 
-    @path("/:uuid")
+    @path("todos/:uuid")
     TodoTO updateTodo(UUID _uuid, Nullable!string title, Nullable!string content) @safe;
 
-    @path("/:uuid")
+    @path("todos/:uuid")
     void deleteTodo(UUID _uuid) @safe;
 }
 

source/d_webservice_example/dataaccess/in_memory_todo_repository.d

@@ -10,7 +10,7 @@ version (unittest)
 class InMemoryTodoRepository : TodoRepository
 {
     import d_webservice_example.model.todo : Todo;
-    import std.typecons : Nullable, nullable;
+    import optional.optional : Optional;
     import std.uuid : randomUUID, UUID;
 
 private:
@@ -71,15 +71,11 @@ public:
         return todos.byValue.array;
     }
 
-    override Nullable!Todo findByUuid(UUID uuid)
+    override Optional!Todo findByUuid(UUID uuid)
     {
-        import std.algorithm.searching : find;
+        import d_webservice_example.util.algorithm : findFirst;
 
-        auto foundTodos = todos.byValue.find!(todo => todo.uuid == uuid);
-        if (foundTodos.empty)
-            return Nullable!Todo.init;
-        else
-            return nullable(foundTodos.front);
+        return todos.byValue.findFirst!(todo => todo.uuid == uuid);
     }
 
     override bool remove(Todo todo)

source/d_webservice_example/transport/todo_to.d

@@ -2,7 +2,6 @@ module d_webservice_example.transport.todo_to;
 
 struct TodoTO
 {
-    import std.typecons : Nullable;
     import std.uuid : UUID;
 
     UUID uuid;

source/d_webservice_example/util/algorithm.d

+module d_webservice_example.util.algorithm;
+
+import d_webservice_example.util.meta : from;
+
+auto findFirst(alias pred, InputRange)(InputRange haystack)
+        if (from!"std.range".isInputRange!InputRange)
+{
+    import optional.optional : toOptional;
+    import std.algorithm.searching : find;
+    import std.range : take;
+
+    return haystack.find!(pred).take(1).toOptional();
+}

source/d_webservice_example/util/meta.d

+module d_webservice_example.util.meta;
+
+template from(string moduleName)
+{
+    mixin("import from = " ~ moduleName ~ ";");
+}