From 412ff6d265adb060295edc892ccc8ac0e8e98fa7 Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 11:28:29 +0100
Subject: [PATCH 1/9] Add support for hat predicate LLVM code

---
 include/scratchcpp/executablecode.h           |  3 +
 .../internal/llvm/llvmexecutablecode.cpp      | 24 ++++--
 src/engine/internal/llvm/llvmexecutablecode.h |  9 +-
 test/llvm/llvmexecutablecode_test.cpp         | 86 ++++++++++++++++---
 test/llvm/testfunctions.cpp                   |  8 ++
 test/llvm/testfunctions.h                     |  1 +
 test/llvm/testmock.h                          |  1 +
 test/mocks/executablecodemock.h               |  1 +
 8 files changed, 115 insertions(+), 18 deletions(-)

diff --git a/include/scratchcpp/executablecode.h b/include/scratchcpp/executablecode.h
index 094d0181..c55a4983 100644
--- a/include/scratchcpp/executablecode.h
+++ b/include/scratchcpp/executablecode.h
@@ -21,6 +21,9 @@ class LIBSCRATCHCPP_EXPORT ExecutableCode
         /*! Runs the script until it finishes or yields. */
         virtual void run(ExecutionContext *context) = 0;
 
+        /*! Runs the hat predicate and returns its return value. */
+        virtual bool runPredicate(ExecutionContext *context) = 0;
+
         /*! Stops the code. isFinished() will return true. */
         virtual void kill(ExecutionContext *context) = 0;
 
diff --git a/src/engine/internal/llvm/llvmexecutablecode.cpp b/src/engine/internal/llvm/llvmexecutablecode.cpp
index 60f69531..f41c660b 100644
--- a/src/engine/internal/llvm/llvmexecutablecode.cpp
+++ b/src/engine/internal/llvm/llvmexecutablecode.cpp
@@ -16,10 +16,11 @@
 
 using namespace libscratchcpp;
 
-LLVMExecutableCode::LLVMExecutableCode(LLVMCompilerContext *ctx, const std::string &mainFunctionName, const std::string &resumeFunctionName) :
+LLVMExecutableCode::LLVMExecutableCode(LLVMCompilerContext *ctx, const std::string &mainFunctionName, const std::string &resumeFunctionName, bool isPredicate) :
     m_ctx(ctx),
     m_mainFunctionName(mainFunctionName),
-    m_resumeFunctionName(resumeFunctionName)
+    m_resumeFunctionName(resumeFunctionName),
+    m_isPredicate(isPredicate)
 {
     assert(m_ctx);
 
@@ -31,7 +32,7 @@ LLVMExecutableCode::LLVMExecutableCode(LLVMCompilerContext *ctx, const std::stri
 
 void LLVMExecutableCode::run(ExecutionContext *context)
 {
-    assert(m_mainFunction);
+    assert(std::holds_alternative<MainFunctionType>(m_mainFunction));
     assert(m_resumeFunction);
     LLVMExecutionContext *ctx = getContext(context);
 
@@ -56,7 +57,8 @@ void LLVMExecutableCode::run(ExecutionContext *context)
         ctx->setFinished(done);
     } else {
         Target *target = ctx->thread()->target();
-        void *handle = m_mainFunction(context, target, target->variableData(), target->listData());
+        MainFunctionType f = std::get<MainFunctionType>(m_mainFunction);
+        void *handle = f(context, target, target->variableData(), target->listData());
 
         if (!handle)
             ctx->setFinished(true);
@@ -65,6 +67,14 @@ void LLVMExecutableCode::run(ExecutionContext *context)
     }
 }
 
+bool LLVMExecutableCode::runPredicate(ExecutionContext *context)
+{
+    assert(std::holds_alternative<PredicateFunctionType>(m_mainFunction));
+    Target *target = context->thread()->target();
+    PredicateFunctionType f = std::get<PredicateFunctionType>(m_mainFunction);
+    return f(context, target, target->variableData(), target->listData());
+}
+
 void LLVMExecutableCode::kill(ExecutionContext *context)
 {
     LLVMExecutionContext *ctx = getContext(context);
@@ -91,7 +101,11 @@ std::shared_ptr<ExecutionContext> LLVMExecutableCode::createExecutionContext(Thr
     if (!m_ctx->jitInitialized())
         m_ctx->initJit();
 
-    m_mainFunction = m_ctx->lookupFunction<MainFunctionType>(m_mainFunctionName);
+    if (m_isPredicate)
+        m_mainFunction = m_ctx->lookupFunction<PredicateFunctionType>(m_mainFunctionName);
+    else
+        m_mainFunction = m_ctx->lookupFunction<MainFunctionType>(m_mainFunctionName);
+
     m_resumeFunction = m_ctx->lookupFunction<ResumeFunctionType>(m_resumeFunctionName);
     return std::make_shared<LLVMExecutionContext>(thread);
 }
diff --git a/src/engine/internal/llvm/llvmexecutablecode.h b/src/engine/internal/llvm/llvmexecutablecode.h
index 3242e315..5526bed5 100644
--- a/src/engine/internal/llvm/llvmexecutablecode.h
+++ b/src/engine/internal/llvm/llvmexecutablecode.h
@@ -16,9 +16,10 @@ class LLVMExecutionContext;
 class LLVMExecutableCode : public ExecutableCode
 {
     public:
-        LLVMExecutableCode(LLVMCompilerContext *ctx, const std::string &mainFunctionName, const std::string &resumeFunctionName);
+        LLVMExecutableCode(LLVMCompilerContext *ctx, const std::string &mainFunctionName, const std::string &resumeFunctionName, bool isPredicate);
 
         void run(ExecutionContext *context) override;
+        bool runPredicate(ExecutionContext *context) override;
         void kill(libscratchcpp::ExecutionContext *context) override;
         void reset(ExecutionContext *context) override;
 
@@ -28,14 +29,18 @@ class LLVMExecutableCode : public ExecutableCode
 
     private:
         using MainFunctionType = void *(*)(ExecutionContext *, Target *, ValueData **, List **);
+        using PredicateFunctionType = bool (*)(ExecutionContext *, Target *, ValueData **, List **);
         using ResumeFunctionType = bool (*)(void *);
 
         static LLVMExecutionContext *getContext(ExecutionContext *context);
 
         LLVMCompilerContext *m_ctx = nullptr;
         std::string m_mainFunctionName;
+        std::string m_predicateFunctionName;
         std::string m_resumeFunctionName;
-        mutable MainFunctionType m_mainFunction = nullptr;
+        bool m_isPredicate = false;
+
+        mutable std::variant<MainFunctionType, PredicateFunctionType> m_mainFunction;
         mutable ResumeFunctionType m_resumeFunction = nullptr;
 };
 
diff --git a/test/llvm/llvmexecutablecode_test.cpp b/test/llvm/llvmexecutablecode_test.cpp
index 17712d8e..f025831e 100644
--- a/test/llvm/llvmexecutablecode_test.cpp
+++ b/test/llvm/llvmexecutablecode_test.cpp
@@ -17,6 +17,8 @@
 
 using namespace libscratchcpp;
 
+using ::testing::Return;
+
 class LLVMExecutableCodeTest : public testing::Test
 {
     public:
@@ -34,11 +36,12 @@ class LLVMExecutableCodeTest : public testing::Test
 
         inline llvm::Constant *nullPointer() { return llvm::ConstantPointerNull::get(llvm::PointerType::get(llvm::Type::getInt8Ty(*m_llvmCtx), 0)); }
 
-        llvm::Function *beginMainFunction()
+        llvm::Function *beginMainFunction(bool predicate = false)
         {
             // void *f(ExecutionContext *, Target *, ValueData **, List **)
+            // bool f(...) (hat predicates)
             llvm::Type *pointerType = llvm::PointerType::get(llvm::Type::getInt8Ty(*m_llvmCtx), 0);
-            llvm::FunctionType *funcType = llvm::FunctionType::get(pointerType, { pointerType, pointerType, pointerType, pointerType }, false);
+            llvm::FunctionType *funcType = llvm::FunctionType::get(predicate ? m_builder->getInt1Ty() : pointerType, { pointerType, pointerType, pointerType, pointerType }, false);
             llvm::Function *func = llvm::Function::Create(funcType, llvm::Function::ExternalLinkage, "f", m_module);
 
             llvm::BasicBlock *entry = llvm::BasicBlock::Create(*m_llvmCtx, "entry", func);
@@ -70,6 +73,17 @@ class LLVMExecutableCodeTest : public testing::Test
             m_builder->CreateCall(func, { mockPtr, mainFunc->getArg(0), mainFunc->getArg(1), mainFunc->getArg(2), mainFunc->getArg(3) });
         }
 
+        llvm::Value *addPredicateFunction(llvm::Function *mainFunc)
+        {
+            auto ptrType = llvm::PointerType::get(llvm::Type::getInt8Ty(*m_llvmCtx), 0);
+            auto func = m_module->getOrInsertFunction("test_predicate", llvm::FunctionType::get(m_builder->getInt1Ty(), { ptrType, ptrType, ptrType, ptrType, ptrType }, false));
+
+            llvm::Constant *mockInt = llvm::ConstantInt::get(llvm::Type::getInt64Ty(*m_llvmCtx), (uintptr_t)&m_mock, false);
+            llvm::Constant *mockPtr = llvm::ConstantExpr::getIntToPtr(mockInt, ptrType);
+
+            return m_builder->CreateCall(func, { mockPtr, mainFunc->getArg(0), mainFunc->getArg(1), mainFunc->getArg(2), mainFunc->getArg(3) });
+        }
+
         void addTestPrintFunction(llvm::Value *arg1, llvm::Value *arg2)
         {
             auto ptrType = llvm::PointerType::get(llvm::Type::getInt8Ty(*m_llvmCtx), 0);
@@ -95,13 +109,34 @@ TEST_F(LLVMExecutableCodeTest, CreateExecutionContext)
     llvm::Function *resumeFunc = beginResumeFunction();
     endFunction(m_builder->getInt1(true));
 
-    auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str());
-    m_script->setCode(code);
-    Thread thread(&m_target, &m_engine, m_script.get());
-    auto ctx = code->createExecutionContext(&thread);
-    ASSERT_TRUE(ctx);
-    ASSERT_EQ(ctx->thread(), &thread);
-    ASSERT_TRUE(dynamic_cast<LLVMExecutionContext *>(ctx.get()));
+    {
+        auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str(), false);
+        m_script->setCode(code);
+        Thread thread(&m_target, &m_engine, m_script.get());
+        auto ctx = code->createExecutionContext(&thread);
+        ASSERT_TRUE(ctx);
+        ASSERT_EQ(ctx->thread(), &thread);
+        ASSERT_TRUE(dynamic_cast<LLVMExecutionContext *>(ctx.get()));
+    }
+}
+
+TEST_F(LLVMExecutableCodeTest, CreatePredicateExecutionContext)
+{
+    llvm::Function *mainFunc = beginMainFunction(true);
+    endFunction(m_builder->getInt1(false));
+
+    llvm::Function *resumeFunc = beginResumeFunction();
+    endFunction(m_builder->getInt1(true));
+
+    {
+        auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str(), true);
+        m_script->setCode(code);
+        Thread thread(&m_target, &m_engine, m_script.get());
+        auto ctx = code->createExecutionContext(&thread);
+        ASSERT_TRUE(ctx);
+        ASSERT_EQ(ctx->thread(), &thread);
+        ASSERT_TRUE(dynamic_cast<LLVMExecutionContext *>(ctx.get()));
+    }
 }
 
 TEST_F(LLVMExecutableCodeTest, MainFunction)
@@ -116,7 +151,7 @@ TEST_F(LLVMExecutableCodeTest, MainFunction)
     llvm::Function *resumeFunc = beginResumeFunction();
     endFunction(m_builder->getInt1(true));
 
-    auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str());
+    auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str(), false);
     m_script->setCode(code);
     Thread thread(&m_target, &m_engine, m_script.get());
     auto ctx = code->createExecutionContext(&thread);
@@ -160,6 +195,35 @@ TEST_F(LLVMExecutableCodeTest, MainFunction)
     ASSERT_FALSE(code->isFinished(ctx.get()));
 }
 
+TEST_F(LLVMExecutableCodeTest, PredicateFunction)
+{
+    m_target.addVariable(std::make_shared<Variable>("", ""));
+    m_target.addList(std::make_shared<List>("", ""));
+
+    llvm::Function *mainFunc = beginMainFunction(true);
+    endFunction(addPredicateFunction(mainFunc));
+
+    llvm::Function *resumeFunc = beginResumeFunction();
+    endFunction(m_builder->getInt1(true));
+
+    auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str(), true);
+    m_script->setCode(code);
+    Thread thread(&m_target, &m_engine, m_script.get());
+    auto ctx = code->createExecutionContext(&thread);
+
+    EXPECT_CALL(m_mock, predicate(ctx.get(), &m_target, m_target.variableData(), m_target.listData())).WillOnce(Return(true));
+    ASSERT_TRUE(code->runPredicate(ctx.get()));
+
+    EXPECT_CALL(m_mock, predicate(ctx.get(), &m_target, m_target.variableData(), m_target.listData())).WillOnce(Return(true));
+    ASSERT_TRUE(code->runPredicate(ctx.get()));
+
+    EXPECT_CALL(m_mock, predicate(ctx.get(), &m_target, m_target.variableData(), m_target.listData())).WillOnce(Return(false));
+    ASSERT_FALSE(code->runPredicate(ctx.get()));
+
+    EXPECT_CALL(m_mock, predicate(ctx.get(), &m_target, m_target.variableData(), m_target.listData())).WillOnce(Return(false));
+    ASSERT_FALSE(code->runPredicate(ctx.get()));
+}
+
 TEST_F(LLVMExecutableCodeTest, Promise)
 {
     llvm::Function *mainFunc = beginMainFunction();
@@ -169,7 +233,7 @@ TEST_F(LLVMExecutableCodeTest, Promise)
     llvm::Function *resumeFunc = beginResumeFunction();
     endFunction(m_builder->getInt1(true));
 
-    auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str());
+    auto code = std::make_shared<LLVMExecutableCode>(m_ctx.get(), mainFunc->getName().str(), resumeFunc->getName().str(), false);
     m_script->setCode(code);
     Thread thread(&m_target, &m_engine, m_script.get());
     auto ctx = code->createExecutionContext(&thread);
diff --git a/test/llvm/testfunctions.cpp b/test/llvm/testfunctions.cpp
index cf88194a..3aaccb10 100644
--- a/test/llvm/testfunctions.cpp
+++ b/test/llvm/testfunctions.cpp
@@ -21,6 +21,14 @@ extern "C"
             mock->f(ctx, target, varData, listData);
     }
 
+    bool test_predicate(TestMock *mock, ExecutionContext *ctx, Target *target, ValueData **varData, List **listData)
+    {
+        if (mock)
+            return mock->predicate(ctx, target, varData, listData);
+
+        return false;
+    }
+
     void test_print_function(ValueData *arg1, ValueData *arg2)
     {
         std::string s1, s2;
diff --git a/test/llvm/testfunctions.h b/test/llvm/testfunctions.h
index 490ffdf1..0a8ded8c 100644
--- a/test/llvm/testfunctions.h
+++ b/test/llvm/testfunctions.h
@@ -13,6 +13,7 @@ struct StringPtr;
 extern "C"
 {
     void test_function(TestMock *mock, ExecutionContext *ctx, Target *target, ValueData **varData, List **listData);
+    bool test_predicate(TestMock *mock, ExecutionContext *ctx, Target *target, ValueData **varData, List **listData);
     void test_print_function(ValueData *arg1, ValueData *arg2);
 
     void test_empty_function();
diff --git a/test/llvm/testmock.h b/test/llvm/testmock.h
index 5573f247..14ef3453 100644
--- a/test/llvm/testmock.h
+++ b/test/llvm/testmock.h
@@ -13,6 +13,7 @@ class TestMock
 {
     public:
         MOCK_METHOD(void, f, (ExecutionContext * ctx, Target *, ValueData **, List **));
+        MOCK_METHOD(bool, predicate, (ExecutionContext * ctx, Target *, ValueData **, List **));
 };
 
 } // namespace libscratchcpp
diff --git a/test/mocks/executablecodemock.h b/test/mocks/executablecodemock.h
index b2997460..4d113c26 100644
--- a/test/mocks/executablecodemock.h
+++ b/test/mocks/executablecodemock.h
@@ -9,6 +9,7 @@ class ExecutableCodeMock : public ExecutableCode
 {
     public:
         MOCK_METHOD(void, run, (ExecutionContext *), (override));
+        MOCK_METHOD(bool, runPredicate, (ExecutionContext *), (override));
         MOCK_METHOD(void, kill, (ExecutionContext *), (override));
         MOCK_METHOD(void, reset, (ExecutionContext *), (override));
 

From 66978e03bae04a45e0b252add6e5bbb6a1dead36 Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 11:46:57 +0100
Subject: [PATCH 2/9] LLVMCodeBuilder: Implement hat predicates

---
 src/engine/internal/llvm/llvmcodebuilder.cpp | 32 ++++++++++-----
 src/engine/internal/llvm/llvmcodebuilder.h   |  3 +-
 test/llvm/llvmcodebuilder_test.cpp           | 41 +++++++++++++++++++-
 3 files changed, 63 insertions(+), 13 deletions(-)

diff --git a/src/engine/internal/llvm/llvmcodebuilder.cpp b/src/engine/internal/llvm/llvmcodebuilder.cpp
index dd452c7f..e212b3cf 100644
--- a/src/engine/internal/llvm/llvmcodebuilder.cpp
+++ b/src/engine/internal/llvm/llvmcodebuilder.cpp
@@ -26,7 +26,7 @@ static std::unordered_map<ValueType, Compiler::StaticType>
 static const std::unordered_set<LLVMInstruction::Type>
     VAR_LIST_READ_INSTRUCTIONS = { LLVMInstruction::Type::ReadVariable, LLVMInstruction::Type::GetListItem, LLVMInstruction::Type::GetListItemIndex, LLVMInstruction::Type::ListContainsItem };
 
-LLVMCodeBuilder::LLVMCodeBuilder(LLVMCompilerContext *ctx, BlockPrototype *procedurePrototype) :
+LLVMCodeBuilder::LLVMCodeBuilder(LLVMCompilerContext *ctx, BlockPrototype *procedurePrototype, bool isPredicate) :
     m_ctx(ctx),
     m_target(ctx->target()),
     m_llvmCtx(*ctx->llvmCtx()),
@@ -34,7 +34,8 @@ LLVMCodeBuilder::LLVMCodeBuilder(LLVMCompilerContext *ctx, BlockPrototype *proce
     m_builder(m_llvmCtx),
     m_procedurePrototype(procedurePrototype),
     m_defaultWarp(procedurePrototype ? procedurePrototype->warp() : false),
-    m_warp(m_defaultWarp)
+    m_warp(m_defaultWarp),
+    m_isPredicate(isPredicate)
 {
     initTypes();
     createVariableMap();
@@ -54,6 +55,10 @@ std::shared_ptr<ExecutableCode> LLVMCodeBuilder::finalize()
 
         if (it == m_instructions.end())
             m_warp = true;
+
+        // Do not create coroutine in hat predicates
+        if (m_isPredicate)
+            m_warp = true;
     }
 
     // Set fast math flags
@@ -1314,10 +1319,16 @@ std::shared_ptr<ExecutableCode> LLVMCodeBuilder::finalize()
     // End and verify the function
     llvm::PointerType *pointerType = llvm::PointerType::get(llvm::Type::getInt8Ty(m_llvmCtx), 0);
 
-    if (m_warp)
-        m_builder.CreateRet(llvm::ConstantPointerNull::get(pointerType));
-    else
-        coro->end();
+    if (m_isPredicate) {
+        // Use last instruction return value
+        assert(!m_instructions.empty());
+        m_builder.CreateRet(m_instructions.back()->functionReturnReg->value);
+    } else {
+        if (m_warp)
+            m_builder.CreateRet(llvm::ConstantPointerNull::get(pointerType));
+        else
+            coro->end();
+    }
 
     verifyFunction(m_function);
 
@@ -1338,7 +1349,7 @@ std::shared_ptr<ExecutableCode> LLVMCodeBuilder::finalize()
 
     verifyFunction(resumeFunc);
 
-    return std::make_shared<LLVMExecutableCode>(m_ctx, m_function->getName().str(), resumeFunc->getName().str());
+    return std::make_shared<LLVMExecutableCode>(m_ctx, m_function->getName().str(), resumeFunc->getName().str(), m_isPredicate);
 }
 
 CompilerValue *LLVMCodeBuilder::addFunctionCall(const std::string &functionName, Compiler::StaticType returnType, const Compiler::ArgTypes &argTypes, const Compiler::Args &args)
@@ -2008,7 +2019,7 @@ void LLVMCodeBuilder::popLoopScope()
 
 std::string LLVMCodeBuilder::getMainFunctionName(BlockPrototype *procedurePrototype)
 {
-    return procedurePrototype ? "proc." + procedurePrototype->procCode() : "script";
+    return procedurePrototype ? "proc." + procedurePrototype->procCode() : (m_isPredicate ? "predicate" : "script");
 }
 
 std::string LLVMCodeBuilder::getResumeFunctionName(BlockPrototype *procedurePrototype)
@@ -2019,7 +2030,8 @@ std::string LLVMCodeBuilder::getResumeFunctionName(BlockPrototype *procedureProt
 llvm::FunctionType *LLVMCodeBuilder::getMainFunctionType(BlockPrototype *procedurePrototype)
 {
     // void *f(ExecutionContext *, Target *, ValueData **, List **, (warp arg), (procedure args...))
-    llvm::PointerType *pointerType = llvm::PointerType::get(llvm::Type::getInt8Ty(m_llvmCtx), 0);
+    // bool f(...) (hat predicates)
+    llvm::Type *pointerType = llvm::PointerType::get(llvm::Type::getInt8Ty(m_llvmCtx), 0);
     std::vector<llvm::Type *> argTypes = { pointerType, pointerType, pointerType, pointerType };
 
     if (procedurePrototype) {
@@ -2034,7 +2046,7 @@ llvm::FunctionType *LLVMCodeBuilder::getMainFunctionType(BlockPrototype *procedu
         }
     }
 
-    return llvm::FunctionType::get(pointerType, argTypes, false);
+    return llvm::FunctionType::get(m_isPredicate ? m_builder.getInt1Ty() : pointerType, argTypes, false);
 }
 
 llvm::Function *LLVMCodeBuilder::getOrCreateFunction(const std::string &name, llvm::FunctionType *type)
diff --git a/src/engine/internal/llvm/llvmcodebuilder.h b/src/engine/internal/llvm/llvmcodebuilder.h
index f0bee6a7..5a765270 100644
--- a/src/engine/internal/llvm/llvmcodebuilder.h
+++ b/src/engine/internal/llvm/llvmcodebuilder.h
@@ -25,7 +25,7 @@ class LLVMLoopScope;
 class LLVMCodeBuilder : public ICodeBuilder
 {
     public:
-        LLVMCodeBuilder(LLVMCompilerContext *ctx, BlockPrototype *procedurePrototype = nullptr);
+        LLVMCodeBuilder(LLVMCompilerContext *ctx, BlockPrototype *procedurePrototype = nullptr, bool isPredicate = false);
 
         std::shared_ptr<ExecutableCode> finalize() override;
 
@@ -239,6 +239,7 @@ class LLVMCodeBuilder : public ICodeBuilder
         bool m_defaultWarp = false;
         bool m_warp = false;
         int m_defaultArgCount = 0;
+        bool m_isPredicate = false; // for hat predicates
 
         long m_loopScope = -1; // index
         std::vector<std::shared_ptr<LLVMLoopScope>> m_loopScopes;
diff --git a/test/llvm/llvmcodebuilder_test.cpp b/test/llvm/llvmcodebuilder_test.cpp
index 7f3b9f51..86cbfe0b 100644
--- a/test/llvm/llvmcodebuilder_test.cpp
+++ b/test/llvm/llvmcodebuilder_test.cpp
@@ -67,12 +67,12 @@ class LLVMCodeBuilderTest : public testing::Test
             test_function(nullptr, nullptr, nullptr, nullptr, nullptr); // force dependency
         }
 
-        void createBuilder(Target *target, BlockPrototype *procedurePrototype)
+        void createBuilder(Target *target, BlockPrototype *procedurePrototype, bool isPredicate = false)
         {
             if (m_contexts.find(target) == m_contexts.cend() || !target)
                 m_contexts[target] = std::make_unique<LLVMCompilerContext>(&m_engine, target);
 
-            m_builder = std::make_unique<LLVMCodeBuilder>(m_contexts[target].get(), procedurePrototype);
+            m_builder = std::make_unique<LLVMCodeBuilder>(m_contexts[target].get(), procedurePrototype, isPredicate);
         }
 
         void createBuilder(Target *target, bool warp)
@@ -82,6 +82,8 @@ class LLVMCodeBuilderTest : public testing::Test
             createBuilder(target, m_procedurePrototype.get());
         }
 
+        void createPredicateBuilder(Target *target) { createBuilder(target, nullptr, true); }
+
         void createBuilder(bool warp) { createBuilder(nullptr, warp); }
 
         CompilerValue *callConstFuncForType(ValueType type, CompilerValue *arg)
@@ -5995,3 +5997,38 @@ TEST_F(LLVMCodeBuilderTest, Procedures)
     ASSERT_EQ(testing::internal::GetCapturedStdout(), expected2 + expected3);
     ASSERT_TRUE(code->isFinished(ctx.get()));
 }
+
+TEST_F(LLVMCodeBuilderTest, HatPredicates)
+{
+    Sprite sprite;
+
+    // Predicate 1
+    createPredicateBuilder(&sprite);
+
+    CompilerValue *v = m_builder->addConstValue(true);
+    m_builder->addFunctionCall("test_const_bool", Compiler::StaticType::Bool, { Compiler::StaticType::Bool }, { v });
+
+    auto code1 = m_builder->finalize();
+
+    // Predicate 2
+    createPredicateBuilder(&sprite);
+
+    v = m_builder->addConstValue(false);
+    m_builder->addFunctionCall("test_const_bool", Compiler::StaticType::Bool, { Compiler::StaticType::Bool }, { v });
+
+    auto code2 = m_builder->finalize();
+
+    Script script1(&sprite, nullptr, nullptr);
+    script1.setCode(code1);
+    Thread thread1(&sprite, nullptr, &script1);
+    auto ctx = code1->createExecutionContext(&thread1);
+
+    ASSERT_TRUE(code1->runPredicate(ctx.get()));
+
+    Script script2(&sprite, nullptr, nullptr);
+    script2.setCode(code2);
+    Thread thread2(&sprite, nullptr, &script2);
+    ctx = code2->createExecutionContext(&thread2);
+
+    ASSERT_FALSE(code2->runPredicate(ctx.get()));
+}

From 22661492f67f4ff7bd35643204e430f72345e26b Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 19:52:42 +0100
Subject: [PATCH 3/9] Implement hat predicates in Compiler

---
 include/scratchcpp/compiler.h              |  2 +-
 src/engine/compiler.cpp                    | 23 ++++++++++--
 src/engine/internal/codebuilderfactory.cpp |  4 +--
 src/engine/internal/codebuilderfactory.h   |  2 +-
 src/engine/internal/icodebuilderfactory.h  |  2 +-
 test/compiler/compiler_test.cpp            | 42 +++++++++++++++++++---
 test/mocks/codebuilderfactorymock.h        |  2 +-
 7 files changed, 65 insertions(+), 12 deletions(-)

diff --git a/include/scratchcpp/compiler.h b/include/scratchcpp/compiler.h
index 9a604702..cc7db35a 100644
--- a/include/scratchcpp/compiler.h
+++ b/include/scratchcpp/compiler.h
@@ -49,7 +49,7 @@ class LIBSCRATCHCPP_EXPORT Compiler
         Target *target() const;
         std::shared_ptr<Block> block() const;
 
-        std::shared_ptr<ExecutableCode> compile(std::shared_ptr<Block> startBlock);
+        std::shared_ptr<ExecutableCode> compile(std::shared_ptr<Block> startBlock, bool isHatPredicate = false);
         void preoptimize();
 
         CompilerValue *addFunctionCall(const std::string &functionName, StaticType returnType = StaticType::Void, const ArgTypes &argTypes = {}, const Args &args = {});
diff --git a/src/engine/compiler.cpp b/src/engine/compiler.cpp
index dda27e2f..17ea93ce 100644
--- a/src/engine/compiler.cpp
+++ b/src/engine/compiler.cpp
@@ -44,7 +44,7 @@ std::shared_ptr<libscratchcpp::Block> Compiler::block() const
 }
 
 /*! Compiles the script starting with the given block. */
-std::shared_ptr<ExecutableCode> Compiler::compile(std::shared_ptr<Block> startBlock)
+std::shared_ptr<ExecutableCode> Compiler::compile(std::shared_ptr<Block> startBlock, bool isHatPredicate)
 {
     BlockPrototype *procedurePrototype = nullptr;
 
@@ -60,13 +60,32 @@ std::shared_ptr<ExecutableCode> Compiler::compile(std::shared_ptr<Block> startBl
         }
     }
 
-    impl->builder = impl->builderFactory->create(impl->ctx, procedurePrototype);
+    impl->builder = impl->builderFactory->create(impl->ctx, procedurePrototype, isHatPredicate);
     impl->substackTree.clear();
     impl->substackHit = false;
     impl->emptySubstack = false;
     impl->warp = false;
     impl->block = startBlock;
 
+    if (impl->block && isHatPredicate) {
+        auto f = impl->block->hatPredicateCompileFunction();
+
+        if (f) {
+            CompilerValue *ret = f(this);
+            assert(ret);
+
+            if (!ret)
+                std::cout << "warning: '" << impl->block->opcode() << "' hat predicate compile function doesn't return a valid value" << std::endl;
+        } else {
+            std::cout << "warning: unsupported hat predicate: " << impl->block->opcode() << std::endl;
+            impl->unsupportedBlocks.insert(impl->block->opcode());
+            addConstValue(false); // return false if unsupported
+        }
+
+        impl->block = nullptr;
+        return impl->builder->finalize();
+    }
+
     while (impl->block) {
         if (impl->block->compileFunction()) {
             assert(impl->customIfStatementCount == 0);
diff --git a/src/engine/internal/codebuilderfactory.cpp b/src/engine/internal/codebuilderfactory.cpp
index bb3cb1e9..42ea1122 100644
--- a/src/engine/internal/codebuilderfactory.cpp
+++ b/src/engine/internal/codebuilderfactory.cpp
@@ -13,10 +13,10 @@ std::shared_ptr<CodeBuilderFactory> CodeBuilderFactory::instance()
     return m_instance;
 }
 
-std::shared_ptr<ICodeBuilder> CodeBuilderFactory::create(CompilerContext *ctx, BlockPrototype *procedurePrototype) const
+std::shared_ptr<ICodeBuilder> CodeBuilderFactory::create(CompilerContext *ctx, BlockPrototype *procedurePrototype, bool isPredicate) const
 {
     assert(dynamic_cast<LLVMCompilerContext *>(ctx));
-    return std::make_shared<LLVMCodeBuilder>(static_cast<LLVMCompilerContext *>(ctx), procedurePrototype);
+    return std::make_shared<LLVMCodeBuilder>(static_cast<LLVMCompilerContext *>(ctx), procedurePrototype, isPredicate);
 }
 
 std::shared_ptr<CompilerContext> CodeBuilderFactory::createCtx(IEngine *engine, Target *target) const
diff --git a/src/engine/internal/codebuilderfactory.h b/src/engine/internal/codebuilderfactory.h
index 942a9a1e..c0c29568 100644
--- a/src/engine/internal/codebuilderfactory.h
+++ b/src/engine/internal/codebuilderfactory.h
@@ -11,7 +11,7 @@ class CodeBuilderFactory : public ICodeBuilderFactory
 {
     public:
         static std::shared_ptr<CodeBuilderFactory> instance();
-        std::shared_ptr<ICodeBuilder> create(CompilerContext *ctx, BlockPrototype *procedurePrototype) const override;
+        std::shared_ptr<ICodeBuilder> create(CompilerContext *ctx, BlockPrototype *procedurePrototype, bool isPredicate) const override;
         std::shared_ptr<CompilerContext> createCtx(IEngine *engine, Target *target) const override;
 
     private:
diff --git a/src/engine/internal/icodebuilderfactory.h b/src/engine/internal/icodebuilderfactory.h
index 6e031b2d..eecc3c0a 100644
--- a/src/engine/internal/icodebuilderfactory.h
+++ b/src/engine/internal/icodebuilderfactory.h
@@ -18,7 +18,7 @@ class ICodeBuilderFactory
     public:
         virtual ~ICodeBuilderFactory() { }
 
-        virtual std::shared_ptr<ICodeBuilder> create(CompilerContext *ctx, BlockPrototype *procedurePrototype = nullptr) const = 0;
+        virtual std::shared_ptr<ICodeBuilder> create(CompilerContext *ctx, BlockPrototype *procedurePrototype = nullptr, bool isPredicate = false) const = 0;
         virtual std::shared_ptr<CompilerContext> createCtx(IEngine *engine, Target *target) const = 0;
 };
 
diff --git a/test/compiler/compiler_test.cpp b/test/compiler/compiler_test.cpp
index 3b098284..3b823b7b 100644
--- a/test/compiler/compiler_test.cpp
+++ b/test/compiler/compiler_test.cpp
@@ -46,12 +46,12 @@ class CompilerTest : public testing::Test
             m_testVar.reset();
         }
 
-        void compile(Compiler *compiler, std::shared_ptr<Block> block, BlockPrototype *procedurePrototype = nullptr)
+        void compile(Compiler *compiler, std::shared_ptr<Block> block, BlockPrototype *procedurePrototype = nullptr, bool isHatPredicate = false)
         {
             ASSERT_EQ(compiler->block(), nullptr);
-            EXPECT_CALL(m_builderFactory, create(m_ctx.get(), procedurePrototype)).WillOnce(Return(m_builder));
+            EXPECT_CALL(m_builderFactory, create(m_ctx.get(), procedurePrototype, isHatPredicate)).WillOnce(Return(m_builder));
             EXPECT_CALL(*m_builder, finalize()).WillOnce(Return(m_code));
-            ASSERT_EQ(compiler->compile(block), m_code);
+            ASSERT_EQ(compiler->compile(block, isHatPredicate), m_code);
             ASSERT_EQ(compiler->block(), nullptr);
         }
 
@@ -1778,7 +1778,23 @@ TEST_F(CompilerTest, UnsupportedBlocks)
     EXPECT_CALL(*m_builder, addConstValue).WillRepeatedly(Return(nullptr));
     compile(m_compiler.get(), block1);
 
-    ASSERT_EQ(m_compiler->unsupportedBlocks(), std::unordered_set<std::string>({ "block1", "block2", "value_block1", "value_block3", "value_block5", "block4" }));
+    // Hat predicates
+    auto block5 = std::make_shared<Block>("b5", "block5");
+    compile(m_compiler.get(), block5, nullptr, true);
+
+    auto block6 = std::make_shared<Block>("b6", "block6");
+    block6->setCompileFunction([](Compiler *) -> CompilerValue * { return nullptr; });
+    compile(m_compiler.get(), block6, nullptr, true);
+
+    auto block7 = std::make_shared<Block>("b7", "block7");
+    CompilerConstant ret(Compiler::StaticType::Bool, Value(true));
+    block7->setCompileFunction([](Compiler *) -> CompilerValue * { return nullptr; });
+    block7->setHatPredicateCompileFunction([](Compiler *compiler) -> CompilerValue * { return compiler->addConstValue(true); });
+    EXPECT_CALL(*m_builder, addConstValue(Value(true))).WillOnce(Return(&ret));
+    compile(m_compiler.get(), block7, nullptr, true);
+
+    // Check
+    ASSERT_EQ(m_compiler->unsupportedBlocks(), std::unordered_set<std::string>({ "block1", "block2", "value_block1", "value_block3", "value_block5", "block4", "block5", "block6" }));
 }
 
 TEST_F(CompilerTest, Procedure)
@@ -1818,3 +1834,21 @@ TEST_F(CompilerTest, Preoptimize)
     EXPECT_CALL(*ctx, preoptimize());
     compiler.preoptimize();
 }
+
+TEST_F(CompilerTest, HatPredicate)
+{
+    auto block = std::make_shared<Block>("", "");
+    block->setCompileFunction([](Compiler *compiler) -> CompilerValue * { return compiler->addConstValue(true); });
+    block->setHatPredicateCompileFunction([](Compiler *compiler) -> CompilerValue * { return compiler->addConstValue(false); });
+
+    CompilerConstant ret1(Compiler::StaticType::Bool, Value(true));
+    CompilerConstant ret2(Compiler::StaticType::Bool, Value(false));
+
+    // Script
+    EXPECT_CALL(*m_builder, addConstValue(Value(true))).WillOnce(Return(&ret1));
+    compile(m_compiler.get(), block, nullptr, false);
+
+    // Hat predicate
+    EXPECT_CALL(*m_builder, addConstValue(Value(false))).WillOnce(Return(&ret2));
+    compile(m_compiler.get(), block, nullptr, true);
+}
diff --git a/test/mocks/codebuilderfactorymock.h b/test/mocks/codebuilderfactorymock.h
index b585bf48..3489995d 100644
--- a/test/mocks/codebuilderfactorymock.h
+++ b/test/mocks/codebuilderfactorymock.h
@@ -8,6 +8,6 @@ using namespace libscratchcpp;
 class CodeBuilderFactoryMock : public ICodeBuilderFactory
 {
     public:
-        MOCK_METHOD(std::shared_ptr<ICodeBuilder>, create, (CompilerContext *, BlockPrototype *), (const, override));
+        MOCK_METHOD(std::shared_ptr<ICodeBuilder>, create, (CompilerContext *, BlockPrototype *, bool), (const, override));
         MOCK_METHOD(std::shared_ptr<CompilerContext>, createCtx, (IEngine *, Target *), (const, override));
 };

From a30bce3215189cbc097f9285b714f026503ce90c Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 19:56:38 +0100
Subject: [PATCH 4/9] Script: Add hat predicate code

---
 include/scratchcpp/script.h |  3 +++
 src/engine/script.cpp       | 12 ++++++++++++
 src/engine/script_p.h       |  1 +
 test/script/script_test.cpp | 10 ++++++++++
 4 files changed, 26 insertions(+)

diff --git a/include/scratchcpp/script.h b/include/scratchcpp/script.h
index 3032cd4c..13d3b825 100644
--- a/include/scratchcpp/script.h
+++ b/include/scratchcpp/script.h
@@ -31,6 +31,9 @@ class LIBSCRATCHCPP_EXPORT Script
         ExecutableCode *code() const;
         void setCode(std::shared_ptr<ExecutableCode> code);
 
+        ExecutableCode *hatPredicateCode() const;
+        void setHatPredicateCode(std::shared_ptr<ExecutableCode> code);
+
         bool runHatPredicate(Target *target);
 
         std::shared_ptr<Thread> start();
diff --git a/src/engine/script.cpp b/src/engine/script.cpp
index 868ad18e..a56d33bb 100644
--- a/src/engine/script.cpp
+++ b/src/engine/script.cpp
@@ -42,6 +42,18 @@ void Script::setCode(std::shared_ptr<ExecutableCode> code)
     impl->code = code;
 }
 
+/*! Returns the executable code of the hat predicate. */
+ExecutableCode *Script::hatPredicateCode() const
+{
+    return impl->hatPredicateCode.get();
+}
+
+/*! Sets the executable code of the hat predicate. */
+void Script::setHatPredicateCode(std::shared_ptr<ExecutableCode> code)
+{
+    impl->hatPredicateCode = code;
+}
+
 /*!
  * Runs the edge-activated hat predicate as the given target and returns the reported value.
  * \note If there isn't any predicate, nothing will happen and the returned value will be false.
diff --git a/src/engine/script_p.h b/src/engine/script_p.h
index b067b17a..207123d2 100644
--- a/src/engine/script_p.h
+++ b/src/engine/script_p.h
@@ -22,6 +22,7 @@ struct ScriptPrivate
         ScriptPrivate(const ScriptPrivate &) = delete;
 
         std::shared_ptr<ExecutableCode> code;
+        std::shared_ptr<ExecutableCode> hatPredicateCode;
 
         Target *target = nullptr;
         std::shared_ptr<Block> topBlock;
diff --git a/test/script/script_test.cpp b/test/script/script_test.cpp
index 48744545..102e52b3 100644
--- a/test/script/script_test.cpp
+++ b/test/script/script_test.cpp
@@ -41,6 +41,16 @@ TEST_F(ScriptTest, Code)
     ASSERT_EQ(script.code(), code.get());
 }
 
+TEST_F(ScriptTest, HatPredicateCode)
+{
+    Script script(nullptr, nullptr, nullptr);
+    ASSERT_EQ(script.hatPredicateCode(), nullptr);
+
+    auto code = std::make_shared<ExecutableCodeMock>();
+    script.setHatPredicateCode(code);
+    ASSERT_EQ(script.hatPredicateCode(), code.get());
+}
+
 TEST_F(ScriptTest, Start)
 {
     Script script1(nullptr, nullptr, nullptr);

From 8a1cc326e84228fce5e45c16abfb3e8e2d84d395 Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 20:12:42 +0100
Subject: [PATCH 5/9] Thread: Add hat predicate support

---
 include/scratchcpp/thread.h |  1 +
 src/engine/thread.cpp       | 16 ++++++++++++++++
 src/engine/thread_p.h       |  2 ++
 test/thread/thread_test.cpp | 25 +++++++++++++++++++++++++
 4 files changed, 44 insertions(+)

diff --git a/include/scratchcpp/thread.h b/include/scratchcpp/thread.h
index bc0578d7..994de694 100644
--- a/include/scratchcpp/thread.h
+++ b/include/scratchcpp/thread.h
@@ -27,6 +27,7 @@ class LIBSCRATCHCPP_EXPORT Thread
         Script *script() const;
 
         void run();
+        bool runPredicate();
         void kill();
         void reset();
 
diff --git a/src/engine/thread.cpp b/src/engine/thread.cpp
index 0cb6b2ed..ddd96647 100644
--- a/src/engine/thread.cpp
+++ b/src/engine/thread.cpp
@@ -18,9 +18,13 @@ Thread::Thread(Target *target, IEngine *engine, Script *script) :
 
     if (impl->script) {
         impl->code = impl->script->code();
+        impl->hatPredicateCode = impl->script->hatPredicateCode();
 
         if (impl->code)
             impl->executionContext = impl->code->createExecutionContext(this);
+
+        if (impl->hatPredicateCode)
+            impl->hatPredicateExecutionContext = impl->hatPredicateCode->createExecutionContext(this);
     }
 }
 
@@ -56,6 +60,18 @@ void Thread::run()
     string_pool_set_thread(nullptr);
 }
 
+/*! Runs the hat predicate and returns its return value. */
+bool Thread::runPredicate()
+{
+    if (!impl->hatPredicateCode)
+        return false;
+
+    string_pool_set_thread(this);
+    const bool ret = impl->hatPredicateCode->runPredicate(impl->hatPredicateExecutionContext.get());
+    string_pool_set_thread(nullptr);
+    return ret;
+}
+
 /*! Stops the script. */
 void Thread::kill()
 {
diff --git a/src/engine/thread_p.h b/src/engine/thread_p.h
index cf340e2f..fd3e009e 100644
--- a/src/engine/thread_p.h
+++ b/src/engine/thread_p.h
@@ -21,7 +21,9 @@ struct ThreadPrivate
         IEngine *engine = nullptr;
         Script *script = nullptr;
         ExecutableCode *code = nullptr;
+        ExecutableCode *hatPredicateCode = nullptr;
         std::shared_ptr<ExecutionContext> executionContext;
+        std::shared_ptr<ExecutionContext> hatPredicateExecutionContext;
 };
 
 } // namespace libscratchcpp
diff --git a/test/thread/thread_test.cpp b/test/thread/thread_test.cpp
index f44e5402..687bd76b 100644
--- a/test/thread/thread_test.cpp
+++ b/test/thread/thread_test.cpp
@@ -50,6 +50,31 @@ TEST_F(ThreadTest, Run)
     m_thread->run();
 }
 
+TEST_F(ThreadTest, RunPredicate)
+{
+    ASSERT_FALSE(m_thread->runPredicate());
+
+    auto predicateCode = std::make_shared<ExecutableCodeMock>();
+    std::shared_ptr<ExecutionContext> predicateCtx;
+    m_script->setHatPredicateCode(predicateCode);
+    EXPECT_CALL(*m_code, createExecutionContext(_)).WillOnce(Invoke([this](Thread *thread) {
+        m_ctx = std::make_shared<ExecutionContext>(thread);
+        return m_ctx;
+    }));
+    EXPECT_CALL(*predicateCode, createExecutionContext(_)).WillOnce(Invoke([&predicateCtx](Thread *thread) {
+        predicateCtx = std::make_shared<ExecutionContext>(thread);
+        return predicateCtx;
+    }));
+
+    Thread thread(&m_target, &m_engine, m_script.get());
+
+    EXPECT_CALL(*predicateCode, runPredicate(predicateCtx.get())).WillOnce(Return(false));
+    ASSERT_FALSE(thread.runPredicate());
+
+    EXPECT_CALL(*predicateCode, runPredicate(predicateCtx.get())).WillOnce(Return(true));
+    ASSERT_TRUE(thread.runPredicate());
+}
+
 TEST_F(ThreadTest, Kill)
 {
     EXPECT_CALL(*m_code, kill(m_ctx.get()));

From c25145610e61c5cc3af2cf82a42323edc1a93151 Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 20:46:33 +0100
Subject: [PATCH 6/9] Script: Implement runHatPredicate()

---
 src/engine/script.cpp       |  6 ++----
 test/script/script_test.cpp | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/src/engine/script.cpp b/src/engine/script.cpp
index a56d33bb..44fa4177 100644
--- a/src/engine/script.cpp
+++ b/src/engine/script.cpp
@@ -63,10 +63,8 @@ bool Script::runHatPredicate(Target *target)
     if (!target || !impl->engine)
         return false;
 
-    // TODO: Implement this
-    // auto thread = std::make_shared<Thread>(target, impl->engine, this);
-
-    return false;
+    auto thread = std::make_shared<Thread>(target, impl->engine, this);
+    return thread->runPredicate();
 }
 
 /*! Starts the script (creates a thread). */
diff --git a/test/script/script_test.cpp b/test/script/script_test.cpp
index 102e52b3..7fb6f380 100644
--- a/test/script/script_test.cpp
+++ b/test/script/script_test.cpp
@@ -5,6 +5,7 @@
 #include <scratchcpp/stage.h>
 #include <scratchcpp/variable.h>
 #include <scratchcpp/list.h>
+#include <scratchcpp/executioncontext.h>
 #include <enginemock.h>
 #include <executablecodemock.h>
 
@@ -14,6 +15,7 @@ using namespace libscratchcpp;
 
 using ::testing::Return;
 using ::testing::ReturnRef;
+using ::testing::Invoke;
 using ::testing::_;
 
 class ScriptTest : public testing::Test
@@ -51,6 +53,28 @@ TEST_F(ScriptTest, HatPredicateCode)
     ASSERT_EQ(script.hatPredicateCode(), code.get());
 }
 
+TEST_F(ScriptTest, RunHatPredicate)
+{
+    Script script(nullptr, nullptr, &m_engine);
+    auto code = std::make_shared<ExecutableCodeMock>();
+    std::shared_ptr<ExecutionContext> ctx;
+    script.setHatPredicateCode(code);
+
+    EXPECT_CALL(*code, createExecutionContext(_)).WillRepeatedly(Invoke([&ctx](Thread *thread) {
+        ctx = std::make_shared<ExecutionContext>(thread);
+        return ctx;
+    }));
+
+    EXPECT_CALL(*code, runPredicate(_)).WillOnce(Return(true));
+    ASSERT_TRUE(script.runHatPredicate(&m_target));
+
+    EXPECT_CALL(*code, runPredicate(_)).WillOnce(Return(true));
+    ASSERT_TRUE(script.runHatPredicate(&m_target));
+
+    EXPECT_CALL(*code, runPredicate(_)).WillOnce(Return(false));
+    ASSERT_FALSE(script.runHatPredicate(&m_target));
+}
+
 TEST_F(ScriptTest, Start)
 {
     Script script1(nullptr, nullptr, nullptr);

From ce7cd5d747cc93107601594fbb8d74215635a3b1 Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 20:47:12 +0100
Subject: [PATCH 7/9] Engine: Compile hat predicates

---
 src/engine/internal/engine.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/engine/internal/engine.cpp b/src/engine/internal/engine.cpp
index 24a1a36c..cf0e831e 100644
--- a/src/engine/internal/engine.cpp
+++ b/src/engine/internal/engine.cpp
@@ -274,6 +274,9 @@ void Engine::compile()
                     auto script = std::make_shared<Script>(target.get(), block, this);
                     m_scripts[block] = script;
                     script->setCode(compiler.compile(block));
+
+                    if (block->hatPredicateCompileFunction())
+                        script->setHatPredicateCode(compiler.compile(block, true));
                 } else {
                     std::cout << "warning: unsupported top level block: " << block->opcode() << std::endl;
                     m_unsupportedBlocks.insert(block->opcode());

From 2ea668699f8fcdac00a79e5a2d05fb3dd850532b Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Tue, 18 Feb 2025 22:40:22 +0100
Subject: [PATCH 8/9] Implement event_whentouchingobject predicate

---
 src/blocks/eventblocks.cpp        |  44 +++++++++++++
 src/blocks/eventblocks.h          |   1 +
 test/blocks/event_blocks_test.cpp | 102 +++++++++++++++++++++++++++++-
 3 files changed, 144 insertions(+), 3 deletions(-)

diff --git a/src/blocks/eventblocks.cpp b/src/blocks/eventblocks.cpp
index f9777dac..464ab66f 100644
--- a/src/blocks/eventblocks.cpp
+++ b/src/blocks/eventblocks.cpp
@@ -3,6 +3,7 @@
 #include <scratchcpp/iengine.h>
 #include <scratchcpp/compiler.h>
 #include <scratchcpp/block.h>
+#include <scratchcpp/input.h>
 #include <scratchcpp/field.h>
 #include <scratchcpp/broadcast.h>
 #include <scratchcpp/executioncontext.h>
@@ -10,6 +11,7 @@
 #include <scratchcpp/compilerconstant.h>
 #include <scratchcpp/promise.h>
 #include <scratchcpp/stringptr.h>
+#include <scratchcpp/sprite.h>
 #include <utf8.h>
 
 #include "eventblocks.h"
@@ -33,6 +35,7 @@ Rgb EventBlocks::color() const
 
 void EventBlocks::registerBlocks(IEngine *engine)
 {
+    // Blocks
     engine->addCompileFunction(this, "event_whentouchingobject", &compileWhenTouchingObject);
     engine->addCompileFunction(this, "event_whenflagclicked", &compileWhenFlagClicked);
     engine->addCompileFunction(this, "event_whenthisspriteclicked", &compileWhenThisSpriteClicked);
@@ -43,6 +46,9 @@ void EventBlocks::registerBlocks(IEngine *engine)
     engine->addCompileFunction(this, "event_broadcast", &compileBroadcast);
     engine->addCompileFunction(this, "event_broadcastandwait", &compileBroadcastAndWait);
     engine->addCompileFunction(this, "event_whenkeypressed", &compileWhenKeyPressed);
+
+    // Hat predicates
+    engine->addHatPredicateCompileFunction(this, "event_whentouchingobject", &compileWhenTouchingObjectPredicate);
 }
 
 CompilerValue *EventBlocks::compileWhenTouchingObject(Compiler *compiler)
@@ -51,6 +57,21 @@ CompilerValue *EventBlocks::compileWhenTouchingObject(Compiler *compiler)
     return nullptr;
 }
 
+CompilerValue *EventBlocks::compileWhenTouchingObjectPredicate(Compiler *compiler)
+{
+    Input *input = compiler->input("TOUCHINGOBJECTMENU");
+    CompilerValue *name = nullptr;
+
+    if (input->pointsToDropdownMenu()) {
+        std::string value = input->selectedMenuItem();
+
+        name = compiler->addConstValue(value);
+    } else
+        name = compiler->addInput(input);
+
+    return compiler->addTargetFunctionCall("event_whentouchingobject_predicate", Compiler::StaticType::Bool, { Compiler::StaticType::String }, { name });
+}
+
 CompilerValue *EventBlocks::compileWhenFlagClicked(Compiler *compiler)
 {
     compiler->engine()->addGreenFlagScript(compiler->block());
@@ -127,6 +148,29 @@ CompilerValue *EventBlocks::compileWhenKeyPressed(Compiler *compiler)
     return nullptr;
 }
 
+extern "C" bool event_whentouchingobject_predicate(Target *target, const StringPtr *name)
+{
+    static const StringPtr MOUSE_STR = StringPtr("_mouse_");
+    static const StringPtr EDGE_STR = StringPtr("_edge_");
+
+    IEngine *engine = target->engine();
+
+    if (string_compare_case_sensitive(name, &MOUSE_STR) == 0)
+        return target->touchingPoint(engine->mouseX(), engine->mouseY());
+    else if (string_compare_case_sensitive(name, &EDGE_STR) == 0)
+        return target->touchingEdge();
+    else {
+        // TODO: Use UTF-16 in engine
+        const std::string u8name = utf8::utf16to8(std::u16string(name->data));
+        Target *anotherTarget = engine->targetAt(engine->findTarget(u8name));
+
+        if (anotherTarget && !anotherTarget->isStage())
+            return target->touchingSprite(static_cast<Sprite *>(anotherTarget));
+        else
+            return false;
+    }
+}
+
 extern "C" void event_broadcast(ExecutionContext *ctx, const StringPtr *name, bool wait)
 {
     Thread *thread = ctx->thread();
diff --git a/src/blocks/eventblocks.h b/src/blocks/eventblocks.h
index 512bae0c..9b01dc46 100644
--- a/src/blocks/eventblocks.h
+++ b/src/blocks/eventblocks.h
@@ -18,6 +18,7 @@ class EventBlocks : public IExtension
 
     private:
         static CompilerValue *compileWhenTouchingObject(Compiler *compiler);
+        static CompilerValue *compileWhenTouchingObjectPredicate(Compiler *compiler);
         static CompilerValue *compileWhenFlagClicked(Compiler *compiler);
         static CompilerValue *compileWhenThisSpriteClicked(Compiler *compiler);
         static CompilerValue *compileWhenStageClicked(Compiler *compiler);
diff --git a/test/blocks/event_blocks_test.cpp b/test/blocks/event_blocks_test.cpp
index 24f18fd2..b66d2c8f 100644
--- a/test/blocks/event_blocks_test.cpp
+++ b/test/blocks/event_blocks_test.cpp
@@ -8,6 +8,7 @@
 #include <scratchcpp/thread.h>
 #include <scratchcpp/executablecode.h>
 #include <enginemock.h>
+#include <targetmock.h>
 
 #include "../common.h"
 #include "blocks/eventblocks.h"
@@ -33,12 +34,10 @@ class EventBlocksTest : public testing::Test
         EngineMock m_engineMock;
 };
 
-// TODO: Add test for when touching object hat predicate
-
 TEST_F(EventBlocksTest, WhenTouchingObject)
 {
     auto target = std::make_shared<Sprite>();
-    ScriptBuilder builder(m_extension.get(), m_engine, target);
+    ScriptBuilder builder(m_extension.get(), m_engine, target, false);
 
     builder.addBlock("event_whentouchingobject");
     builder.addDropdownInput("TOUCHINGOBJECTMENU", "Sprite1");
@@ -49,6 +48,103 @@ TEST_F(EventBlocksTest, WhenTouchingObject)
     compiler.compile(block);
 }
 
+TEST_F(EventBlocksTest, WhenTouchingObjectPredicate)
+{
+    auto target = std::make_shared<TargetMock>();
+    target->setEngine(&m_engineMock);
+    Sprite sprite;
+
+    // "Sprite1"
+    {
+        ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+        builder.addBlock("event_whentouchingobject");
+        builder.addDropdownInput("TOUCHINGOBJECTMENU", "Sprite1");
+        auto block = builder.currentBlock();
+
+        Compiler compiler(&m_engineMock, target.get());
+        auto code = compiler.compile(block, true);
+        Script script(target.get(), block, &m_engineMock);
+        script.setHatPredicateCode(code);
+        Thread thread(target.get(), &m_engineMock, &script);
+
+        EXPECT_CALL(m_engineMock, findTarget("Sprite1")).WillOnce(Return(3));
+        EXPECT_CALL(m_engineMock, targetAt(3)).WillOnce(Return(&sprite));
+        EXPECT_CALL(*target, touchingClones).WillOnce(Return(false));
+        ASSERT_FALSE(thread.runPredicate());
+
+        EXPECT_CALL(m_engineMock, findTarget("Sprite1")).WillOnce(Return(3));
+        EXPECT_CALL(m_engineMock, targetAt(3)).WillOnce(Return(&sprite));
+        EXPECT_CALL(*target, touchingClones).WillOnce(Return(true));
+        ASSERT_TRUE(thread.runPredicate());
+    }
+
+    // "_mouse_"
+    {
+        ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+        builder.addBlock("event_whentouchingobject");
+        builder.addDropdownInput("TOUCHINGOBJECTMENU", "_mouse_");
+        auto block = builder.currentBlock();
+
+        Compiler compiler(&m_engineMock, target.get());
+        auto code = compiler.compile(block, true);
+        Script script(target.get(), block, &m_engineMock);
+        script.setHatPredicateCode(code);
+        Thread thread(target.get(), &m_engineMock, &script);
+
+        EXPECT_CALL(m_engineMock, mouseX()).WillOnce(Return(24.5));
+        EXPECT_CALL(m_engineMock, mouseY()).WillOnce(Return(-16.04));
+        EXPECT_CALL(*target, touchingPoint(24.5, -16.04)).WillOnce(Return(false));
+        ASSERT_FALSE(thread.runPredicate());
+
+        EXPECT_CALL(m_engineMock, mouseX()).WillOnce(Return(24.5));
+        EXPECT_CALL(m_engineMock, mouseY()).WillOnce(Return(-16.04));
+        EXPECT_CALL(*target, touchingPoint(24.5, -16.04)).WillOnce(Return(true));
+        ASSERT_TRUE(thread.runPredicate());
+    }
+
+    // "_edge_"
+    {
+        ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+        builder.addBlock("event_whentouchingobject");
+        builder.addDropdownInput("TOUCHINGOBJECTMENU", "_edge_");
+        auto block = builder.currentBlock();
+
+        Compiler compiler(&m_engineMock, target.get());
+        auto code = compiler.compile(block, true);
+        Script script(target.get(), block, &m_engineMock);
+        script.setHatPredicateCode(code);
+        Thread thread(target.get(), &m_engineMock, &script);
+
+        EXPECT_CALL(m_engineMock, stageWidth()).WillOnce(Return(10));
+        EXPECT_CALL(m_engineMock, stageHeight()).WillOnce(Return(10));
+        EXPECT_CALL(*target, boundingRect()).WillOnce(Return(Rect(-5, 5, 5, -5)));
+        ASSERT_FALSE(thread.runPredicate());
+
+        EXPECT_CALL(m_engineMock, stageWidth()).WillOnce(Return(0));
+        EXPECT_CALL(m_engineMock, stageHeight()).WillOnce(Return(0));
+        EXPECT_CALL(*target, boundingRect()).WillOnce(Return(Rect(-5, 5, 5, -5)));
+        ASSERT_TRUE(thread.runPredicate());
+    }
+
+    // ""
+    {
+        ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+        builder.addBlock("event_whentouchingobject");
+        builder.addDropdownInput("TOUCHINGOBJECTMENU", "");
+        auto block = builder.currentBlock();
+
+        Compiler compiler(&m_engineMock, target.get());
+        auto code = compiler.compile(block, true);
+        Script script(target.get(), block, &m_engineMock);
+        script.setHatPredicateCode(code);
+        Thread thread(target.get(), &m_engineMock, &script);
+
+        EXPECT_CALL(m_engineMock, findTarget("")).WillOnce(Return(-1));
+        EXPECT_CALL(m_engineMock, targetAt(-1)).WillOnce(Return(nullptr));
+        ASSERT_FALSE(thread.runPredicate());
+    }
+}
+
 TEST_F(EventBlocksTest, WhenFlagClicked)
 {
     auto target = std::make_shared<Sprite>();

From f3924cc570444376991822fe988d75ca42a6305d Mon Sep 17 00:00:00 2001
From: adazem009 <68537469+adazem009@users.noreply.github.com>
Date: Wed, 19 Feb 2025 19:26:26 +0100
Subject: [PATCH 9/9] Implement event_whengreaterthan predicate

---
 src/blocks/eventblocks.cpp        | 39 +++++++++++++++
 src/blocks/eventblocks.h          |  5 ++
 test/blocks/event_blocks_test.cpp | 80 +++++++++++++++++++++++++++++--
 3 files changed, 121 insertions(+), 3 deletions(-)

diff --git a/src/blocks/eventblocks.cpp b/src/blocks/eventblocks.cpp
index 464ab66f..7179d59b 100644
--- a/src/blocks/eventblocks.cpp
+++ b/src/blocks/eventblocks.cpp
@@ -12,9 +12,12 @@
 #include <scratchcpp/promise.h>
 #include <scratchcpp/stringptr.h>
 #include <scratchcpp/sprite.h>
+#include <scratchcpp/itimer.h>
 #include <utf8.h>
 
 #include "eventblocks.h"
+#include "audio/audioinput.h"
+#include "audio/iaudioloudness.h"
 
 using namespace libscratchcpp;
 
@@ -49,6 +52,7 @@ void EventBlocks::registerBlocks(IEngine *engine)
 
     // Hat predicates
     engine->addHatPredicateCompileFunction(this, "event_whentouchingobject", &compileWhenTouchingObjectPredicate);
+    engine->addHatPredicateCompileFunction(this, "event_whengreaterthan", &compileWhenGreaterThanPredicate);
 }
 
 CompilerValue *EventBlocks::compileWhenTouchingObject(Compiler *compiler)
@@ -120,6 +124,27 @@ CompilerValue *EventBlocks::compileWhenGreaterThan(Compiler *compiler)
     return nullptr;
 }
 
+CompilerValue *EventBlocks::compileWhenGreaterThanPredicate(Compiler *compiler)
+{
+    Field *field = compiler->field("WHENGREATERTHANMENU");
+    std::string predicate;
+
+    if (field) {
+        const std::string option = field->value().toString();
+
+        if (option == "LOUDNESS")
+            predicate = "event_whengreaterthan_loudness_predicate";
+        else if (option == "TIMER")
+            predicate = "event_whengreaterthan_timer_predicate";
+        else
+            return compiler->addConstValue(false);
+    } else
+        return compiler->addConstValue(false);
+
+    CompilerValue *value = compiler->addInput("VALUE");
+    return compiler->addFunctionCallWithCtx(predicate, Compiler::StaticType::Bool, { Compiler::StaticType::Number }, { value });
+}
+
 CompilerValue *EventBlocks::compileBroadcast(Compiler *compiler)
 {
     auto input = compiler->addInput("BROADCAST_INPUT");
@@ -171,6 +196,20 @@ extern "C" bool event_whentouchingobject_predicate(Target *target, const StringP
     }
 }
 
+extern "C" bool event_whengreaterthan_loudness_predicate(ExecutionContext *ctx, double value)
+{
+    if (!EventBlocks::audioInput)
+        EventBlocks::audioInput = AudioInput::instance().get();
+
+    auto audioLoudness = EventBlocks::audioInput->audioLoudness();
+    return (audioLoudness->getLoudness() > value);
+}
+
+extern "C" bool event_whengreaterthan_timer_predicate(ExecutionContext *ctx, double value)
+{
+    return ctx->engine()->timer()->value() > value;
+}
+
 extern "C" void event_broadcast(ExecutionContext *ctx, const StringPtr *name, bool wait)
 {
     Thread *thread = ctx->thread();
diff --git a/src/blocks/eventblocks.h b/src/blocks/eventblocks.h
index 9b01dc46..360eff7d 100644
--- a/src/blocks/eventblocks.h
+++ b/src/blocks/eventblocks.h
@@ -7,6 +7,8 @@
 namespace libscratchcpp
 {
 
+class IAudioInput;
+
 class EventBlocks : public IExtension
 {
     public:
@@ -16,6 +18,8 @@ class EventBlocks : public IExtension
 
         void registerBlocks(IEngine *engine) override;
 
+        static inline IAudioInput *audioInput = nullptr;
+
     private:
         static CompilerValue *compileWhenTouchingObject(Compiler *compiler);
         static CompilerValue *compileWhenTouchingObjectPredicate(Compiler *compiler);
@@ -25,6 +29,7 @@ class EventBlocks : public IExtension
         static CompilerValue *compileWhenBroadcastReceived(Compiler *compiler);
         static CompilerValue *compileWhenBackdropSwitchesTo(Compiler *compiler);
         static CompilerValue *compileWhenGreaterThan(Compiler *compiler);
+        static CompilerValue *compileWhenGreaterThanPredicate(Compiler *compiler);
         static CompilerValue *compileBroadcast(Compiler *compiler);
         static CompilerValue *compileBroadcastAndWait(Compiler *compiler);
         static CompilerValue *compileWhenKeyPressed(Compiler *compiler);
diff --git a/test/blocks/event_blocks_test.cpp b/test/blocks/event_blocks_test.cpp
index b66d2c8f..a01da37e 100644
--- a/test/blocks/event_blocks_test.cpp
+++ b/test/blocks/event_blocks_test.cpp
@@ -9,6 +9,9 @@
 #include <scratchcpp/executablecode.h>
 #include <enginemock.h>
 #include <targetmock.h>
+#include <audioinputmock.h>
+#include <audioloudnessmock.h>
+#include <timermock.h>
 
 #include "../common.h"
 #include "blocks/eventblocks.h"
@@ -126,6 +129,24 @@ TEST_F(EventBlocksTest, WhenTouchingObjectPredicate)
         ASSERT_TRUE(thread.runPredicate());
     }
 
+    // "_stage_"
+    {
+        ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+        builder.addBlock("event_whentouchingobject");
+        builder.addDropdownInput("TOUCHINGOBJECTMENU", "");
+        auto block = builder.currentBlock();
+
+        Compiler compiler(&m_engineMock, target.get());
+        auto code = compiler.compile(block, true);
+        Script script(target.get(), block, &m_engineMock);
+        script.setHatPredicateCode(code);
+        Thread thread(target.get(), &m_engineMock, &script);
+
+        EXPECT_CALL(m_engineMock, findTarget("")).WillOnce(Return(-1));
+        EXPECT_CALL(m_engineMock, targetAt(-1)).WillOnce(Return(nullptr));
+        ASSERT_FALSE(thread.runPredicate());
+    }
+
     // ""
     {
         ScriptBuilder builder(m_extension.get(), m_engine, target, false);
@@ -215,12 +236,10 @@ TEST_F(EventBlocksTest, WhenBackdropSwitchesTo)
     compiler.compile(block);
 }
 
-// TODO: Add test for when greater than hat predicate
-
 TEST_F(EventBlocksTest, WhenGreaterThan)
 {
     auto target = std::make_shared<Sprite>();
-    ScriptBuilder builder(m_extension.get(), m_engine, target);
+    ScriptBuilder builder(m_extension.get(), m_engine, target, false);
 
     builder.addBlock("event_whengreaterthan");
     builder.addDropdownField("WHENGREATERTHANMENU", "LOUDNESS");
@@ -232,6 +251,61 @@ TEST_F(EventBlocksTest, WhenGreaterThan)
     compiler.compile(block);
 }
 
+TEST_F(EventBlocksTest, WhenGreaterThanPredicate)
+{
+    auto target = std::make_shared<Sprite>();
+    ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+
+    const std::vector<Value> values = { 22.7, 23, 23.5 };
+    const std::vector<bool> retValues = { true, false, false };
+
+    AudioInputMock audioInput;
+    auto audioLoudness = std::make_shared<AudioLoudnessMock>();
+    EventBlocks::audioInput = &audioInput;
+    EXPECT_CALL(audioInput, audioLoudness()).Times(3).WillRepeatedly(Return(audioLoudness));
+    EXPECT_CALL(*audioLoudness, getLoudness()).Times(3).WillRepeatedly(Return(23));
+
+    // when [loudness] > x
+    for (int i = 0; i < values.size(); i++) {
+        ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+        builder.addBlock("event_whengreaterthan");
+        builder.addDropdownField("WHENGREATERTHANMENU", "LOUDNESS");
+        builder.addValueInput("VALUE", values[i]);
+        auto block = builder.currentBlock();
+
+        Compiler compiler(&m_engineMock, target.get());
+        auto code = compiler.compile(block, true);
+        Script script(target.get(), block, &m_engineMock);
+        script.setHatPredicateCode(code);
+        Thread thread(target.get(), &m_engineMock, &script);
+
+        ASSERT_EQ(thread.runPredicate(), retValues[i]);
+    }
+
+    EventBlocks::audioInput = nullptr;
+
+    TimerMock timer;
+    EXPECT_CALL(m_engineMock, timer()).Times(3).WillRepeatedly(Return(&timer));
+    EXPECT_CALL(timer, value()).Times(3).WillRepeatedly(Return(23));
+
+    // when [timer] > x
+    for (int i = 0; i < values.size(); i++) {
+        ScriptBuilder builder(m_extension.get(), m_engine, target, false);
+        builder.addBlock("event_whengreaterthan");
+        builder.addDropdownField("WHENGREATERTHANMENU", "TIMER");
+        builder.addValueInput("VALUE", values[i]);
+        auto block = builder.currentBlock();
+
+        Compiler compiler(&m_engineMock, target.get());
+        auto code = compiler.compile(block, true);
+        Script script(target.get(), block, &m_engineMock);
+        script.setHatPredicateCode(code);
+        Thread thread(target.get(), &m_engineMock, &script);
+
+        ASSERT_EQ(thread.runPredicate(), retValues[i]);
+    }
+}
+
 TEST_F(EventBlocksTest, Broadcast)
 {
     auto broadcast = std::make_shared<Broadcast>("", "test");