From bdf1b724289fec7dd8f257ada89d74286ed5884e Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 14:56:24 +0800
Subject: [PATCH 01/15] MVar

---
 include/hspp.h    |  37 ++++++++++--
 test/hspp/stm.cpp | 150 +++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 169 insertions(+), 18 deletions(-)

diff --git a/include/hspp.h b/include/hspp.h
index a2c8789..9c3853e 100644
--- a/include/hspp.h
+++ b/include/hspp.h
@@ -1262,18 +1262,32 @@ template <typename T>
 constexpr static auto isIOV = IsIO<std::decay_t<T>>::value;
 
 template <typename Func>
-auto io(Func func)
+constexpr auto io(Func func)
 {
     using Data = std::invoke_result_t<Func>;
-    return IO<Data, Func>{func};
+    return IO<Data, Func>{std::move(func)};
 }
 
 template <typename Data>
-auto ioData(Data data)
+constexpr auto ioData(Data data)
 {
     return io([data=std::move(data)] { return data; });
 }
 
+template <typename Data, typename Func>
+constexpr auto toTEIOImpl(IO<Data, Func> const& p)
+{
+    return IO<Data>{[p]{
+        return p.run();
+    }};
+}
+
+constexpr auto toTEIO = toGFunc<1> | [](auto p)
+{
+    return toTEIOImpl(p);
+};
+
+
 constexpr auto putChar = toFunc<> | [](char c)
 {
     return io(
@@ -3577,6 +3591,13 @@ class IsNullary<Nullary<T>> : public std::true_type
 template <typename T>
 constexpr auto isNullary = IsNullary<std::decay_t<T>>::value;
 
+template <typename ClassT, typename T , typename = std::enable_if_t<isNullary<T>, void>>
+constexpr auto evalDeferredImpl(T&& t)
+{
+    static_assert(std::is_same_v<MonadType<ClassT>, MonadType<std::invoke_result_t<T>>>);
+    return t();
+}
+
 template <typename T>
 class IsNullaryOrId : public IsNullary<T>
 {
@@ -3825,7 +3846,15 @@ template <typename Head, typename... Rest>
 constexpr auto do_(Head const& head, Rest const&... rest)
 {
     using MClass = MonadClassType<Head, Rest...>;
-    return doImpl<MClass>(head, rest...);
+    auto result = doImpl<MClass>(head, rest...);
+    static_assert(!isNullaryOrIdV<decltype(result)>);
+    return result;
+}
+
+template <typename... Args>
+constexpr auto doInner(Args&&... args)
+{
+    return nullary([=] { return do_(evaluate_(args)...); });
 }
 
 template <typename Head, typename... Rest>
diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 7e62823..466ffff 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -51,22 +51,22 @@ TEST(forkIO, 1)
     io_.run();
 }
 
-TEST(forkIO, 2)
+constexpr auto setReminder = toFunc<> | [](std::string const& s)
 {
-    auto setReminder = toFunc<> | [](std::string const& s)
-    {
-        Id<size_t> n;
-        return do_(
-            n = (hspp::read<size_t> | s),
-            putStr | "Ok, I'll remind you in ",
-            print | n,
-            putStrLn | " seconds",
-            threadDelay | (1000000U * n),
-            print | n,
-            putStrLn | " seconds is up! BING!BEL"
-        );
-    };
+    Id<size_t> n;
+    return do_(
+        n = (hspp::read<size_t> | s), // let expression.
+        putStr | "Ok, I'll remind you in ",
+        print | n,
+        putStrLn | " seconds",
+        threadDelay | (1000000U * n),
+        print | n,
+        putStrLn | " seconds is up! BING!BEL"
+    );
+};
 
+TEST(forkIO, 2)
+{
     Id<std::string> s;
     auto io_ = forever || do_(
         s <= getLine,
@@ -74,7 +74,129 @@ TEST(forkIO, 2)
     );
     // io.run();
     (void)io_;
+
+}
+
+TEST(forkIO, 3)
+{
+    IO<_O_> loop0 = []{ return _o_; };
+    auto loop = loop0;
+
+    Id<std::string> s;
+    loop = toTEIO | do_(
+        s <= getLine,
+        ifThenElse(s == "exit")
+            || loop0
+            || toTEIO | (doInner(forkIO || setReminder | s,
+                nullary([&]{ return loop;}))) // capturing by ref is important, so that loop is not fixed to loop0.
+    );
+
+    loop.run();
+}
+
+template <typename A>
+struct MVar
+{
+    std::shared_ptr<std::atomic<std::optional<A>>> data = std::make_shared<std::atomic<std::optional<A>>>();
+};
+
+template <typename A>
+constexpr auto newEmptyMVar = io([]{ return MVar<A>{}; });
+
+template <typename A>
+constexpr auto newMVarImpl(A a)
+{
+    return io([&]{ return MVar<A>{std::move(a)}; });
+}
+
+constexpr auto newMVar = toGFunc<1> | [](auto a)
+{
+    return newMVarImpl(a);
+};
+
+template <typename A>
+constexpr auto takeMVarImpl(MVar<A> const& a)
+{
+    return io([a]
+    {
+        std::optional<A> result{};
+        do {
+            std::this_thread::yield();
+            result = a.data->exchange(std::optional<A>{});
+        } while(!result.has_value());
+        return result.value();
+    });
+}
+
+constexpr auto takeMVar = toGFunc<1> | [](auto a)
+{
+    return takeMVarImpl(a);
+};
+
+template <typename A>
+constexpr auto putMVarImpl(MVar<A>& a, A new_)
+{
+    return io([a, new_=std::make_optional(std::move(new_))]
+    {
+        std::optional<A> old{};
+        while (!a.data->compare_exchange_weak(old, new_))
+        {
+            std::this_thread::yield();
+        }
+        return _o_;
+    });
+}
+
+constexpr auto putMVar = toGFunc<2> | [](auto a, auto new_)
+{
+    return putMVarImpl(a, new_);
+};
+
+TEST(MVar, 1)
+{
+    (void)newMVar;
+
+    Id<MVar<char>> m;
+    Id<char> r;
+    auto const io_ = do_(
+        m <= newEmptyMVar<char>,
+        forkIO || putMVar | m | 'x',
+        r <= (takeMVar | m),
+        print | r
+    );
+    io_.run();
+}
+
+TEST(MVar, 2)
+{
+    Id<MVar<char>> m;
+    Id<char> r;
+    auto io_ = do_(
+        m <= newEmptyMVar<char>,
+        forkIO || doInner(
+            putMVar | m | 'x',
+            putMVar | m | 'y'
+        ),
+        r <= (takeMVar | m),
+        print | r,
+        r <= (takeMVar | m),
+        print | r
+    );
+    io_.run();
+}
+
+// stuck
+#if 0
+TEST(MVar, 3)
+{
+    Id<MVar<char>> m;
+    auto io_ = do_(
+        m <= newEmptyMVar<char>,
+        takeMVar | m
+    );
+    io_.run();
 }
+#endif
 
 template <typename A>
 struct IORef

From b6da8c0429bac965fb8411e8dde064b37d7e1b14 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 15:01:11 +0800
Subject: [PATCH 02/15] Fix tests

---
 test/hspp/stm.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 466ffff..599e755 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -91,7 +91,8 @@ TEST(forkIO, 3)
                 nullary([&]{ return loop;}))) // capturing by ref is important, so that loop is not fixed to loop0.
     );
 
-    loop.run();
+    // loop.run();
+    (void)loop;
 }
 
 template <typename A>

From eb54c93cd614b81a55c771bad99578436b10ecc0 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 15:08:52 +0800
Subject: [PATCH 03/15] Fix tests

---
 test/hspp/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/hspp/CMakeLists.txt b/test/hspp/CMakeLists.txt
index 13c37ff..65f1566 100644
--- a/test/hspp/CMakeLists.txt
+++ b/test/hspp/CMakeLists.txt
@@ -1,6 +1,6 @@
 add_executable(unittests test.cpp stm.cpp)
 target_include_directories(unittests PRIVATE)
 target_compile_options(unittests PRIVATE ${BASE_COMPILE_FLAGS})
-target_link_libraries(unittests PRIVATE hspp gtest_main)
+target_link_libraries(unittests PRIVATE hspp gtest_main atomic)
 set_target_properties(unittests PROPERTIES CXX_EXTENSIONS OFF)
 gtest_discover_tests(unittests)
\ No newline at end of file

From f25be29988c7909996161fca2a97011a9bd55b71 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 15:22:56 +0800
Subject: [PATCH 04/15] Fix atomic

---
 CMakeLists.txt           | 5 +++++
 test/hspp/CMakeLists.txt | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ac1b764..67a0635 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,6 +20,11 @@ list(APPEND
     "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>,$<CXX_COMPILER_ID:GNU>>:-Wall;-Wextra;-pedantic;-Werror;-Wno-parentheses;-Wno-shadow;-Wconversion;-Wsign-conversion>"
         "$<$<CXX_COMPILER_ID:MSVC>:/W4>") # /WX for -Werror
 
+# Fix atomic lib linking for gcc.
+list(APPEND
+    BASE_COMPILE_FLAGS
+    "$<$<OR:$<CXX_COMPILER_ID:GNU>>:-latomic>")
+
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)
diff --git a/test/hspp/CMakeLists.txt b/test/hspp/CMakeLists.txt
index 65f1566..13c37ff 100644
--- a/test/hspp/CMakeLists.txt
+++ b/test/hspp/CMakeLists.txt
@@ -1,6 +1,6 @@
 add_executable(unittests test.cpp stm.cpp)
 target_include_directories(unittests PRIVATE)
 target_compile_options(unittests PRIVATE ${BASE_COMPILE_FLAGS})
-target_link_libraries(unittests PRIVATE hspp gtest_main atomic)
+target_link_libraries(unittests PRIVATE hspp gtest_main)
 set_target_properties(unittests PROPERTIES CXX_EXTENSIONS OFF)
 gtest_discover_tests(unittests)
\ No newline at end of file

From cac9d1f2bb144e72a17601bcd6b4ff7f1faf4054 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 15:25:50 +0800
Subject: [PATCH 05/15] Fix atomic

---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 67a0635..be77529 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@ list(APPEND
 # Fix atomic lib linking for gcc.
 list(APPEND
     BASE_COMPILE_FLAGS
-    "$<$<OR:$<CXX_COMPILER_ID:GNU>>:-latomic>")
+    "$<$<OR:$<CXX_COMPILER_ID:Clang>:$<CXX_COMPILER_ID:GNU>>:-latomic>")
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)

From 2c053b5db3102427393650380a5bd42c1a11d1c2 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 15:26:48 +0800
Subject: [PATCH 06/15] Fix atomic

---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index be77529..7de28a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@ list(APPEND
 # Fix atomic lib linking for gcc.
 list(APPEND
     BASE_COMPILE_FLAGS
-    "$<$<OR:$<CXX_COMPILER_ID:Clang>:$<CXX_COMPILER_ID:GNU>>:-latomic>")
+    "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-latomic>")
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)

From 893eb4085e1ae6444b1a7dab9914e23dc24569e9 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 15:28:22 +0800
Subject: [PATCH 07/15] Fix atomic

---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7de28a8..67a0635 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@ list(APPEND
 # Fix atomic lib linking for gcc.
 list(APPEND
     BASE_COMPILE_FLAGS
-    "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-latomic>")
+    "$<$<OR:$<CXX_COMPILER_ID:GNU>>:-latomic>")
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)

From 566818b5517b0053720c789f423d23bc0cb2dfc5 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 15:47:51 +0800
Subject: [PATCH 08/15] Fix atomic

---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 67a0635..7de28a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@ list(APPEND
 # Fix atomic lib linking for gcc.
 list(APPEND
     BASE_COMPILE_FLAGS
-    "$<$<OR:$<CXX_COMPILER_ID:GNU>>:-latomic>")
+    "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-latomic>")
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)

From f972782d4b96227cb1a538b3c52c904ee973dbdb Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 16:13:08 +0800
Subject: [PATCH 09/15] Fix atomic

---
 CMakeLists.txt           |  2 +-
 test/hspp/CMakeLists.txt |  1 +
 test/hspp/stm.cpp        | 39 +++++++++++++++++++++++++++++++++++----
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7de28a8..1b35047 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,7 +22,7 @@ list(APPEND
 
 # Fix atomic lib linking for gcc.
 list(APPEND
-    BASE_COMPILE_FLAGS
+    BASE_LINK_FLAGS
     "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-latomic>")
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
diff --git a/test/hspp/CMakeLists.txt b/test/hspp/CMakeLists.txt
index 13c37ff..a906bd7 100644
--- a/test/hspp/CMakeLists.txt
+++ b/test/hspp/CMakeLists.txt
@@ -2,5 +2,6 @@ add_executable(unittests test.cpp stm.cpp)
 target_include_directories(unittests PRIVATE)
 target_compile_options(unittests PRIVATE ${BASE_COMPILE_FLAGS})
 target_link_libraries(unittests PRIVATE hspp gtest_main)
+add_link_options($BASE_LINK_FLAGS)
 set_target_properties(unittests PROPERTIES CXX_EXTENSIONS OFF)
 gtest_discover_tests(unittests)
\ No newline at end of file
diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 599e755..487b8c7 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -186,8 +186,6 @@ TEST(MVar, 2)
     io_.run();
 }
 
-// stuck
-#if 0
 TEST(MVar, 3)
 {
     Id<MVar<char>> m;
@@ -195,9 +193,42 @@ TEST(MVar, 3)
         m <= newEmptyMVar<char>,
         takeMVar | m
     );
-    io_.run();
+    // stuck
+    (void)io_;
+    // io_.run();
+}
+
+#if 0
+class Message : public std::string{};
+class Stop : public MVar<_O_>{};
+
+using LogCommand = std::variant<Message, Stop>;
+class Logger : public MVar<LogCommand>{};
+
+constexpr auto logger(Logger& l)
+{
+    auto loop = 
+    where
+    loop = do_(
+        cmd <= (takeMVar | m),
+        case cmd of
+            Message msg -> doInner(putStrLn | msg, loop),
+            Stop s -> doInner(putStrLn | "logger: stop", putMVar | s | _o_)
+    );
+}
+
+constexpr auto initLoggerImpl()
+{
+    Id<LogCommand> m;
+    Id<Logger> l;
+    return do_(
+        m <= newEmptyMVar,
+        l = (Logger | m),
+        forkIO | (logger | l),
+        return_ | l
+    );
 }
-#endif
+#endif // 0
 
 template <typename A>
 struct IORef

From 7ca733cf7567259b734be18f3e9da9a2146cb622 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 16:43:45 +0800
Subject: [PATCH 10/15] Fix linker

---
 CMakeLists.txt    |  2 +-
 include/hspp.h    | 11 +++++++++++
 test/hspp/stm.cpp | 29 +++++++++++++++++++++--------
 3 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1b35047..7256a34 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@ list(APPEND
 # Fix atomic lib linking for gcc.
 list(APPEND
     BASE_LINK_FLAGS
-    "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-latomic>")
+    "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-latomic;-v>")
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)
diff --git a/include/hspp.h b/include/hspp.h
index 9c3853e..26120f8 100644
--- a/include/hspp.h
+++ b/include/hspp.h
@@ -3578,6 +3578,17 @@ constexpr auto nullary(T const &t)
     return Nullary<T>{t};
 }
 
+template <typename T>
+constexpr auto toTENullaryImpl(Nullary<T> const &t)
+{
+    return nullary(std::function<std::invoke_result_t<T>>{t});
+}
+
+constexpr auto toTENullary = toGFunc<1> | [](auto const& t)
+{
+    return toTENullaryImpl(t);
+};
+
 template <typename T>
 class IsNullary : public std::false_type
 {
diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 487b8c7..8c5050c 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -205,15 +205,28 @@ class Stop : public MVar<_O_>{};
 using LogCommand = std::variant<Message, Stop>;
 class Logger : public MVar<LogCommand>{};
 
-constexpr auto logger(Logger& l)
+
+auto logger(Logger& m)
 {
-    auto loop = 
-    where
-    loop = do_(
+    IO<_O_> loop0 = []{ return _o_; };
+    auto loop = loop0;
+
+    auto const dispatchCmd = toFunc<> | [&loop](LogCommand const& lc)
+    {
+        return std::visit(overload(
+            [&](Message const& msg){
+                return toTEIO | do_(print | msg, loop);
+            },
+            [](Stop s){
+                return toTEIO | do_(putStrLn | "logger: stop", putMVar | s | _o_);
+            }
+        ), lc);
+    };
+
+    Id<LogCommand> cmd;
+    loop = toTEIO | do_(
         cmd <= (takeMVar | m),
-        case cmd of
-            Message msg -> doInner(putStrLn | msg, loop),
-            Stop s -> doInner(putStrLn | "logger: stop", putMVar | s | _o_)
+        dispatchCmd | cmd
     );
 }
 
@@ -222,7 +235,7 @@ constexpr auto initLoggerImpl()
     Id<LogCommand> m;
     Id<Logger> l;
     return do_(
-        m <= newEmptyMVar,
+        m <= newEmptyMVar<LogCommand>,
         l = (Logger | m),
         forkIO | (logger | l),
         return_ | l

From 8663d73927c881129f9f2c152a11687ea3b5a05e Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 17:12:05 +0800
Subject: [PATCH 11/15] Fix linker

---
 CMakeLists.txt           | 4 ++--
 include/hspp.h           | 6 +++---
 test/hspp/CMakeLists.txt | 4 +---
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7256a34..051fc22 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,8 +22,8 @@ list(APPEND
 
 # Fix atomic lib linking for gcc.
 list(APPEND
-    BASE_LINK_FLAGS
-    "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-latomic;-v>")
+    BASE_ADDITIONAL_LIBS
+    "$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:atomic>")
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/lib)
diff --git a/include/hspp.h b/include/hspp.h
index 26120f8..07b9fb6 100644
--- a/include/hspp.h
+++ b/include/hspp.h
@@ -2677,7 +2677,7 @@ class Functor<data::Reader, FirstArg>
     template <typename Func, typename Repr, typename Ret, typename... Args>
     constexpr static auto fmap(Func&& func, data::Reader<FirstArg, Ret, Repr> const& in)
     {
-        return data::toReader | func <o> (data::runReader | in);
+        return data::toReader || func <o> (data::runReader | in);
     }
 };
 
@@ -2846,12 +2846,12 @@ class Applicative<data::Reader, FirstArg> : public Functor<data::Reader, FirstAr
 public:
     constexpr static auto pure = toGFunc<1> | [](auto ret)
     {
-        return data::toReader | data::toFunc<>([ret=std::move(ret)](FirstArg){ return ret; });
+        return data::toReader || data::toFunc<>([ret=std::move(ret)](FirstArg){ return ret; });
     };
     template <typename Reader1, typename Reader2>
     constexpr static auto ap(Reader1 func, Reader1 in)
     {
-        return data::toReader | data::toFunc<>(
+        return data::toReader || data::toFunc<>(
             [func=std::move(func), in=std::move(in)](FirstArg arg)
             {
                 return data::runReader | func | arg || data::runReader | in | arg;
diff --git a/test/hspp/CMakeLists.txt b/test/hspp/CMakeLists.txt
index a906bd7..145486e 100644
--- a/test/hspp/CMakeLists.txt
+++ b/test/hspp/CMakeLists.txt
@@ -1,7 +1,5 @@
 add_executable(unittests test.cpp stm.cpp)
 target_include_directories(unittests PRIVATE)
-target_compile_options(unittests PRIVATE ${BASE_COMPILE_FLAGS})
-target_link_libraries(unittests PRIVATE hspp gtest_main)
-add_link_options($BASE_LINK_FLAGS)
+target_link_libraries(unittests PRIVATE hspp gtest_main ${BASE_ADDITIONAL_LIBS})
 set_target_properties(unittests PROPERTIES CXX_EXTENSIONS OFF)
 gtest_discover_tests(unittests)
\ No newline at end of file

From 0e9b7789011d77bca8b9ab6016bc05c387e954ae Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 17:58:34 +0800
Subject: [PATCH 12/15] Fix mvar

---
 test/hspp/stm.cpp | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 8c5050c..2ada786 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -98,9 +98,16 @@ TEST(forkIO, 3)
 template <typename A>
 struct MVar
 {
-    std::shared_ptr<std::atomic<std::optional<A>>> data = std::make_shared<std::atomic<std::optional<A>>>();
+    using T = std::pair<std::optional<A>, std::mutex>;
+    std::shared_ptr<T> data = std::make_shared<T>();
+    MVar() = default;
+    MVar(A a)
+    : data{std::make_shared<T>(a, {})}
+    {}
 };
 
+static_assert(std::atomic<std::optional<int64_t>>::is_always_lock_free);
+
 template <typename A>
 constexpr auto newEmptyMVar = io([]{ return MVar<A>{}; });
 
@@ -120,12 +127,20 @@ constexpr auto takeMVarImpl(MVar<A> const& a)
 {
     return io([a]
     {
-        std::optional<A> result{};
-        do {
+        while (true)
+        {
+            if (a.data->first.has_value())
+            {
+                std::unique_lock lock{a.data->second};
+                if (a.data->first.has_value())
+                {
+                    auto result = std::move(a.data->first.value());
+                    a.data->first.reset();
+                    return result;
+                }
+            }
             std::this_thread::yield();
-            result = a.data->exchange(std::optional<A>{});
-        } while(!result.has_value());
-        return result.value();
+        }
     });
 }
 
@@ -137,14 +152,21 @@ constexpr auto takeMVar = toGFunc<1> | [](auto a)
 template <typename A>
 constexpr auto putMVarImpl(MVar<A>& a, A new_)
 {
-    return io([a, new_=std::make_optional(std::move(new_))]
+    return io([a, new_]
     {
-        std::optional<A> old{};
-        while (!a.data->compare_exchange_weak(old, new_))
+        while (true)
         {
+            if (!a.data->first.has_value())
+            {
+                std::unique_lock lock{a.data->second};
+                if (!a.data->first.has_value())
+                {
+                    a.data->first = new_;
+                    return _o_;
+                }
+            }
             std::this_thread::yield();
         }
-        return _o_;
     });
 }
 

From ce24063bfd52a97782a9663d8df00cc50a1056c6 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 18:03:08 +0800
Subject: [PATCH 13/15] Fix mvar

---
 test/hspp/stm.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 2ada786..3d00e81 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -6,6 +6,7 @@
 #include <cctype>
 #include <thread>
 #include <atomic>
+#include <shared_mutex>
 
 using namespace hspp;
 using namespace hspp::data;
@@ -98,7 +99,7 @@ TEST(forkIO, 3)
 template <typename A>
 struct MVar
 {
-    using T = std::pair<std::optional<A>, std::mutex>;
+    using T = std::pair<std::optional<A>, std::shared_mutex>;
     std::shared_ptr<T> data = std::make_shared<T>();
     MVar() = default;
     MVar(A a)

From c2e6147fd0a7c210388b1fe2392639bf616fa117 Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 18:13:30 +0800
Subject: [PATCH 14/15] Fix mvar

---
 test/hspp/stm.cpp | 2 --
 1 file changed, 2 deletions(-)

diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 3d00e81..5fea3c6 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -107,8 +107,6 @@ struct MVar
     {}
 };
 
-static_assert(std::atomic<std::optional<int64_t>>::is_always_lock_free);
-
 template <typename A>
 constexpr auto newEmptyMVar = io([]{ return MVar<A>{}; });
 

From 88dc38102c14e814b292352ff1ea53ea25e7576a Mon Sep 17 00:00:00 2001
From: Bowen Fu <missing>
Date: Sun, 10 Jul 2022 18:18:07 +0800
Subject: [PATCH 15/15] Fix mvar

---
 test/hspp/stm.cpp | 2 --
 1 file changed, 2 deletions(-)

diff --git a/test/hspp/stm.cpp b/test/hspp/stm.cpp
index 5fea3c6..f4d134b 100644
--- a/test/hspp/stm.cpp
+++ b/test/hspp/stm.cpp
@@ -128,7 +128,6 @@ constexpr auto takeMVarImpl(MVar<A> const& a)
     {
         while (true)
         {
-            if (a.data->first.has_value())
             {
                 std::unique_lock lock{a.data->second};
                 if (a.data->first.has_value())
@@ -155,7 +154,6 @@ constexpr auto putMVarImpl(MVar<A>& a, A new_)
     {
         while (true)
         {
-            if (!a.data->first.has_value())
             {
                 std::unique_lock lock{a.data->second};
                 if (!a.data->first.has_value())