From ba6c4cc905360e31d9a110bc0c9e561ac663d99e Mon Sep 17 00:00:00 2001
From: Denis Blank <denis.blank@outlook.com>
Date: Mon, 26 Feb 2018 18:55:06 +0100
Subject: [PATCH] More work on the sequential compositioning

---
 include/continuable/detail/composition.hpp    |  9 ++-
 .../continuable/detail/composition_all.hpp    | 58 +++++++++++++++++--
 .../continuable/detail/composition_any.hpp    |  4 ++
 .../detail/composition_remapping.hpp          |  5 +-
 .../continuable/detail/composition_seq.hpp    | 25 ++++----
 test/playground/test-playground.cpp           | 12 +++-
 6 files changed, 93 insertions(+), 20 deletions(-)

diff --git a/include/continuable/detail/composition.hpp b/include/continuable/detail/composition.hpp
index 5050b1c..91e3f4e 100644
--- a/include/continuable/detail/composition.hpp
+++ b/include/continuable/detail/composition.hpp
@@ -49,6 +49,7 @@ namespace detail {
 namespace composition {
 struct composition_strategy_all_tag {};
 struct composition_strategy_any_tag {};
+struct composition_strategy_any_fail_fast_tag {};
 struct composition_strategy_seq_tag {};
 
 template <typename T>
@@ -60,6 +61,12 @@ struct is_composition_strategy<composition_strategy_all_tag> // ...
 template <>
 struct is_composition_strategy<composition_strategy_any_tag> // ...
     : std::true_type {};
+template <>
+struct is_composition_strategy<composition_strategy_any_fail_fast_tag> // ...
+    : std::true_type {};
+template <>
+struct is_composition_strategy<composition_strategy_seq_tag> // ...
+    : std::true_type {};
 
 /// Adds the given continuation tuple to the left composition
 template <typename... LeftArgs, typename... RightArgs>
@@ -158,7 +165,7 @@ struct consume_ownership {
   template <typename Continuable,
             std::enable_if_t<base::is_continuable<
                 std::decay_t<Continuable>>::value>* = nullptr>
-  void operator()(Continuable& continuable) noexcept {
+  void operator()(Continuable&& continuable) noexcept {
     util::ownership other = base::attorney::ownership_of(continuable);
 
     assert(other.is_acquired() && "Only valid continuables should be passed!");
diff --git a/include/continuable/detail/composition_all.hpp b/include/continuable/detail/composition_all.hpp
index fce2291..cc63beb 100644
--- a/include/continuable/detail/composition_all.hpp
+++ b/include/continuable/detail/composition_all.hpp
@@ -163,10 +163,61 @@ auto make_all_result_submitter(Callback&& callback,
 /// A callable object to merge multiple signature hints together
 struct entry_merger {
   template <typename... T>
-  constexpr auto operator()(T&... entries) const noexcept {
-    return traits::merge(hints::hint_of(traits::identity_of(entries))...);
+  constexpr auto operator()(T&&...) const noexcept {
+    return traits::merge(hints::hint_of(traits::identify<T>())...);
   }
 };
+
+struct all_hint_deducer {
+  static constexpr auto deduce(hints::signature_hint_tag<>) noexcept {
+    return spread_this();
+  }
+  template <typename First>
+  static constexpr auto deduce(hints::signature_hint_tag<First>) {
+    return First{};
+  }
+  template <typename First, typename Second, typename... Args>
+  static constexpr auto
+  deduce(hints::signature_hint_tag<First, Second, Args...>) {
+    return std::make_tuple(First{}, Second{}, Args{}...);
+  }
+
+  template <
+      typename T,
+      std::enable_if_t<base::is_continuable<std::decay_t<T>>::value>* = nullptr>
+  auto operator()(T&& /*continuable*/) const {
+    return deduce(hints::hint_of(traits::identify<T>{}));
+  }
+};
+
+/// Converts the given argument to a tuple if it isn't a tuple already
+template <typename T>
+constexpr auto tupelize(T&& arg) {
+  return std::make_tuple(std::forward<T>(arg));
+}
+/// Converts the given argument to a tuple if it isn't a tuple already
+template <typename... T>
+constexpr auto tupelize(std::tuple<T...> arg) {
+  return std::move(arg);
+}
+
+/// Lift the first tuple hierarchy inside the given tuple
+template <typename T>
+constexpr auto flatten(T&& tuple) {
+  return traits::unpack(std::forward<T>(tuple), [](auto&&... args) {
+    return std::tuple_cat(tupelize(std::forward<decltype(args)>(args))...);
+  });
+}
+
+template <typename Composition>
+constexpr auto deduce_hint(Composition&& composition) {
+  auto deduced = flatten(
+      map_pack(all_hint_deducer{}, std::forward<Composition>(composition)));
+
+  return traits::unpack(std::move(deduced), [](auto... args) {
+    return hints::signature_hint_tag<decltype(args)...>{};
+  });
+}
 } // namespace all
 
 /// Finalizes the all logic of a given composition
@@ -174,8 +225,7 @@ template <>
 struct composition_finalizer<composition_strategy_all_tag> {
   template <typename Composition>
   static constexpr auto hint() {
-    return decltype(
-        traits::unpack(std::declval<Composition>(), all::entry_merger{})){};
+    return decltype(all::deduce_hint(std::declval<Composition>())){};
   }
 
   /// Finalizes the all logic of a given composition
diff --git a/include/continuable/detail/composition_any.hpp b/include/continuable/detail/composition_any.hpp
index cb9f6d8..5e28fa3 100644
--- a/include/continuable/detail/composition_any.hpp
+++ b/include/continuable/detail/composition_any.hpp
@@ -179,6 +179,10 @@ struct composition_finalizer<composition_strategy_any_tag> {
     };
   }
 };
+
+template <>
+struct composition_finalizer<composition_strategy_any_fail_fast_tag>
+    : composition_finalizer<composition_strategy_any_tag> {};
 } // namespace composition
 } // namespace detail
 } // namespace cti
diff --git a/include/continuable/detail/composition_remapping.hpp b/include/continuable/detail/composition_remapping.hpp
index 274c99f..31be52d 100644
--- a/include/continuable/detail/composition_remapping.hpp
+++ b/include/continuable/detail/composition_remapping.hpp
@@ -79,7 +79,8 @@ struct result_extractor_mapper {
   }
   /// Initialize a multiple values as tuple
   template <typename First, typename Second, typename... Args>
-  static constexpr auto initialize(hints::signature_hint_tag<>) {
+  static constexpr auto
+  initialize(hints::signature_hint_tag<First, Second, Args...>) {
     // TODO Fix non default constructible values
     return std::make_tuple(First{}, Second{}, Args{}...);
   }
@@ -116,7 +117,6 @@ struct result_relocator_mapper {
   void traverse(traversal::container_category_tag<false, false>, Index* index,
                 Result* result) {
 
-    evaluator(index, result);
     traverse_one(traits::is_invocable<Evaluator, Index, Result>{}, index,
                  result);
   }
@@ -186,7 +186,6 @@ constexpr void relocate_index_pack(Relocator&& relocator, Index* index,
 
   mapper.traverse(tag, index, target);
 }
-
 } // namespace remapping
 } // namespace composition
 } // namespace detail
diff --git a/include/continuable/detail/composition_seq.hpp b/include/continuable/detail/composition_seq.hpp
index 4269e7c..43d07d1 100644
--- a/include/continuable/detail/composition_seq.hpp
+++ b/include/continuable/detail/composition_seq.hpp
@@ -90,7 +90,8 @@ struct result_indexer_mapper {
   auto operator()(T& continuable) {
     auto constexpr const hint = hints::hint_of(traits::identify<T>{});
 
-    using target = decltype(result_extractor_mapper::initialize(hint));
+    using target =
+        decltype(remapping::detail::result_extractor_mapper::initialize(hint));
 
     using type = indexed_continuable<std::decay_t<T>, target>;
     return type{std::move(continuable), nullptr};
@@ -138,7 +139,7 @@ struct sequential_dispatch_data {
 
 template <typename Data>
 class sequential_dispatch_visitor
-    : std::enable_shared_from_this<sequential_dispatch_visitor<Data>> {
+    : public std::enable_shared_from_this<sequential_dispatch_visitor<Data>> {
 
   Data data_;
 
@@ -146,16 +147,19 @@ public:
   explicit sequential_dispatch_visitor(Data&& data) : data_(std::move(data)) {
     // Assign the address of each result target to the corresponding
     // indexed continuable.
-    relocate_index_pack(index_relocator{}, &data.index, &data.result);
+    remapping::relocate_index_pack(index_relocator{}, &data.index,
+                                   &data.result);
   }
 
+  virtual ~sequential_dispatch_visitor() = default;
+
   /// Returns the pack that should be traversed
   auto& head() {
     return data_.index;
   }
 
-  template <typename Index,
-            std::enable_if_t<is_indexed_continuable<Index>::value>* = nullptr>
+  template <typename Index, std::enable_if_t<is_indexed_continuable<
+                                std::decay_t<Index>>::value>* = nullptr>
   bool operator()(async_traverse_visit_tag, Index&& /*index*/) {
     return false;
   }
@@ -165,7 +169,7 @@ public:
 
     std::move(index.continuable)
         .then([ target = index.target,
-                next = std::forward<N>(next) ](auto&&... args) {
+                next = std::forward<N>(next) ](auto&&... args) mutable {
 
           // Assign the result to the target
           *target = wrap(std::forward<decltype(args)>(args)...);
@@ -177,10 +181,10 @@ public:
   }
 
   template <typename T>
-  void operator()(async_traverse_complete_tag, T&& pack) {
+  void operator()(async_traverse_complete_tag, T&& /*pack*/) {
     // Remove void result guard tags
-    auto cleaned =
-        map_pack(remapping::clean_void_results{}, std::forward<T>(pack));
+    auto cleaned = all::flatten(
+        map_pack(remapping::clean_void_results{}, std::move(data_.result)));
 
     // Call the final callback with the cleaned result
     traits::unpack(std::move(cleaned), std::move(data_.callback));
@@ -193,8 +197,7 @@ template <>
 struct composition_finalizer<composition_strategy_seq_tag> {
   template <typename Composition>
   static constexpr auto hint() {
-    return decltype(
-        traits::unpack(std::declval<Composition>(), all::entry_merger{})){};
+    return decltype(all::deduce_hint(std::declval<Composition>())){};
   }
 
   /// Finalizes the all logic of a given composition
diff --git a/test/playground/test-playground.cpp b/test/playground/test-playground.cpp
index 766c862..17ead1f 100644
--- a/test/playground/test-playground.cpp
+++ b/test/playground/test-playground.cpp
@@ -68,7 +68,7 @@ struct my_callable {
   }
 };
 
-int main(int, char**) {
+void old() {
   http_request("github.com").next(my_callable{});
 
   http_request("github.com") | [](std::string) {
@@ -118,3 +118,13 @@ int main(int, char**) {
         // ...
       });
 }
+
+int main(int, char**) {
+  using namespace cti::detail;
+
+  apply_composition(composition::composition_strategy_seq_tag{},
+                    cti::make_ready_continuable(0, 1), 2)
+      .then([](int a0, int a1, int a2) {
+        // ...
+      });
+}