From ea92e17ca0f4187cbf207551a9f1fa175b303238 Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Sat, 18 Dec 2021 22:56:36 +0100
Subject: [PATCH] patterns: Added basic support for in/out variables

---
 .../content/views/view_pattern_editor.hpp     |  33 +-
 .../content/views/view_pattern_editor.cpp     | 382 ++++++++++++------
 .../include/hex/pattern_language/ast_node.hpp |  12 +-
 .../hex/pattern_language/evaluator.hpp        |  25 +-
 .../hex/pattern_language/pattern_language.hpp |  16 +-
 .../include/hex/pattern_language/token.hpp    |   6 +-
 .../source/pattern_language/evaluator.cpp     |  13 +-
 .../source/pattern_language/lexer.cpp         |   4 +
 .../source/pattern_language/parser.cpp        |  14 +-
 .../pattern_language/pattern_language.cpp     |  59 ++-
 10 files changed, 411 insertions(+), 153 deletions(-)

diff --git a/plugins/builtin/include/content/views/view_pattern_editor.hpp b/plugins/builtin/include/content/views/view_pattern_editor.hpp
index 2bb9ffb59..a2a8be879 100644
--- a/plugins/builtin/include/content/views/view_pattern_editor.hpp
+++ b/plugins/builtin/include/content/views/view_pattern_editor.hpp
@@ -25,11 +25,15 @@ namespace hex::plugin::builtin {
         void drawContent() override;
 
     private:
-        pl::PatternLanguage *m_patternLanguageRuntime;
+        pl::PatternLanguage *m_parserRuntime, *m_evaluatorRuntime;
+
         std::vector<std::filesystem::path> m_possiblePatternFiles;
         u32 m_selectedPatternFile = 0;
         bool m_runAutomatically = false;
+
         bool m_evaluatorRunning = false;
+        bool m_parserRunning = false;
+
         bool m_hasUnevaluatedChanges = false;
 
         bool m_acceptPatternWindowOpen = false;
@@ -37,6 +41,17 @@ namespace hex::plugin::builtin {
         TextEditor m_textEditor;
         std::vector<std::pair<pl::LogConsole::Level, std::string>> m_console;
 
+        struct PatternVariable {
+            bool inVariable;
+            bool outVariable;
+
+            pl::Token::ValueType type;
+            pl::Token::Literal value;
+        };
+
+        std::map<std::string, PatternVariable> m_patternVariables;
+        std::vector<std::string> m_patternTypes;
+
         enum class EnvVarType {
             Integer,
             Float,
@@ -45,16 +60,28 @@ namespace hex::plugin::builtin {
         };
 
         struct EnvVar {
+            u64 id;
             std::string name;
             pl::Token::Literal value;
             EnvVarType type;
+
+            bool operator==(const EnvVar &other) const {
+                return this->id == other.id;
+            }
         };
 
-        std::vector<EnvVar> m_envVarEntries;
+        u64 m_envVarIdCounter;
+        std::list<EnvVar> m_envVarEntries;
+
+        void drawConsole(ImVec2 size);
+        void drawEnvVars(ImVec2 size);
+        void drawVariableSettings(ImVec2 size);
 
         void loadPatternFile(const std::string &path);
         void clearPatternData();
-        void parsePattern(char *buffer);
+
+        void parsePattern(const std::string &code);
+        void evaluatePattern(const std::string &code);
     };
 
 }
\ No newline at end of file
diff --git a/plugins/builtin/source/content/views/view_pattern_editor.cpp b/plugins/builtin/source/content/views/view_pattern_editor.cpp
index 098db04eb..74247e148 100644
--- a/plugins/builtin/source/content/views/view_pattern_editor.cpp
+++ b/plugins/builtin/source/content/views/view_pattern_editor.cpp
@@ -3,6 +3,7 @@
 #include <hex/helpers/project_file_handler.hpp>
 #include <hex/pattern_language/preprocessor.hpp>
 #include <hex/pattern_language/pattern_data.hpp>
+#include <hex/pattern_language/ast_node.hpp>
 #include <hex/helpers/paths.hpp>
 #include <hex/helpers/utils.hpp>
 #include <hex/helpers/file.hpp>
@@ -24,7 +25,7 @@ namespace hex::plugin::builtin {
         static TextEditor::LanguageDefinition langDef;
         if (!initialized) {
             static const char* const keywords[] = {
-                "using", "struct", "union", "enum", "bitfield", "be", "le", "if", "else", "false", "true", "this", "parent", "addressof", "sizeof", "$", "while", "for", "fn", "return", "namespace"
+                "using", "struct", "union", "enum", "bitfield", "be", "le", "if", "else", "false", "true", "this", "parent", "addressof", "sizeof", "$", "while", "for", "fn", "return", "namespace", "in", "out"
             };
             for (auto& k : keywords)
                 langDef.mKeywords.insert(k);
@@ -83,12 +84,14 @@ namespace hex::plugin::builtin {
 
 
     ViewPatternEditor::ViewPatternEditor() : View("hex.builtin.view.pattern_editor.name") {
-        this->m_patternLanguageRuntime = new pl::PatternLanguage();
+        this->m_evaluatorRuntime = new pl::PatternLanguage();
+        this->m_parserRuntime = new pl::PatternLanguage();
 
         this->m_textEditor.SetLanguageDefinition(PatternLanguage());
         this->m_textEditor.SetShowWhitespaces(false);
 
-        this->m_envVarEntries = { { "", s128(0), EnvVarType::Integer } };
+        this->m_envVarEntries.push_back({ 0, "", 0, EnvVarType::Integer });
+        this->m_envVarIdCounter = 1;
 
         EventManager::subscribe<EventProjectFileStore>(this, [this]() {
             ProjectFile::setPattern(this->m_textEditor.GetText());
@@ -96,7 +99,7 @@ namespace hex::plugin::builtin {
 
         EventManager::subscribe<EventProjectFileLoad>(this, [this]() {
             this->m_textEditor.SetText(ProjectFile::getPattern());
-            this->parsePattern(this->m_textEditor.GetText().data());
+            this->evaluatePattern(this->m_textEditor.GetText());
         });
 
         EventManager::subscribe<RequestSetPatternLanguageCode>(this, [this](std::string code) {
@@ -156,7 +159,7 @@ namespace hex::plugin::builtin {
 
         EventManager::subscribe<EventFileUnloaded>(this, [this]{
             this->m_textEditor.SetText("");
-            this->m_patternLanguageRuntime->abort();
+            this->m_evaluatorRuntime->abort();
         });
 
         /* Settings */
@@ -181,7 +184,8 @@ namespace hex::plugin::builtin {
     }
 
     ViewPatternEditor::~ViewPatternEditor() {
-        delete this->m_patternLanguageRuntime;
+        delete this->m_evaluatorRuntime;
+        delete this->m_parserRuntime;
 
         EventManager::unsubscribe<EventProjectFileStore>(this);
         EventManager::unsubscribe<EventProjectFileLoad>(this);
@@ -232,49 +236,38 @@ namespace hex::plugin::builtin {
 
             if (ImHexApi::Provider::isValid() && provider->isAvailable()) {
                 auto textEditorSize = ImGui::GetContentRegionAvail();
-                textEditorSize.y *= 4.0/5.0;
+                textEditorSize.y *= 3.75/5.0;
                 textEditorSize.y -= ImGui::GetTextLineHeightWithSpacing();
                 this->m_textEditor.Render("hex.builtin.view.pattern_editor.name"_lang, textEditorSize, true);
 
-                auto consoleSize = ImGui::GetContentRegionAvail();
-                consoleSize.y -= ImGui::GetTextLineHeightWithSpacing();
+                auto size = ImGui::GetContentRegionAvail();
+                size.y -= ImGui::GetTextLineHeightWithSpacing() * 2.5;
 
-                ImGui::PushStyleColor(ImGuiCol_ChildBg, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Background)]);
-                if (ImGui::BeginChild("##console", consoleSize, true, ImGuiWindowFlags_AlwaysVerticalScrollbar)) {
-                    for (auto &[level, message] : this->m_console) {
-                        switch (level) {
-                            case pl::LogConsole::Level::Debug:
-                                ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Comment)]);
-                                break;
-                            case pl::LogConsole::Level::Info:
-                                ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Default)]);
-                                break;
-                            case pl::LogConsole::Level::Warning:
-                                ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Preprocessor)]);
-                                break;
-                            case pl::LogConsole::Level::Error:
-                                ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::ErrorMarker)]);
-                                break;
-                            default: continue;
-                        }
-
-                        ImGui::TextUnformatted(message.c_str());
-
-                        ImGui::PopStyleColor();
+                if (ImGui::BeginTabBar("settings")) {
+                    if (ImGui::BeginTabItem("Console")) {
+                        this->drawConsole(size);
+                        ImGui::EndTabItem();
+                    }
+                    if (ImGui::BeginTabItem("Environment Variables")) {
+                        this->drawEnvVars(size);
+                        ImGui::EndTabItem();
+                    }
+                    if (ImGui::BeginTabItem("Settings")) {
+                        this->drawVariableSettings(size);
+                        ImGui::EndTabItem();
                     }
 
+                    ImGui::EndTabBar();
                 }
-                ImGui::EndChild();
-                ImGui::PopStyleColor(1);
 
                 ImGui::PushStyleVar(ImGuiStyleVar_FrameBorderSize, 1);
 
                 if (this->m_evaluatorRunning) {
                     if (ImGui::IconButton(ICON_VS_DEBUG_STOP, ImGui::GetCustomColorVec4(ImGuiCustomCol_ToolbarRed)))
-                        this->m_patternLanguageRuntime->abort();
+                        this->m_evaluatorRuntime->abort();
                 } else {
                     if (ImGui::IconButton(ICON_VS_DEBUG_START, ImGui::GetCustomColorVec4(ImGuiCustomCol_ToolbarGreen)))
-                        this->parsePattern(this->m_textEditor.GetText().data());
+                        this->evaluatePattern(this->m_textEditor.GetText());
                 }
 
 
@@ -294,87 +287,25 @@ namespace hex::plugin::builtin {
                     ImGui::SameLine();
 
                     ImGui::TextUnformatted(hex::format("{} / {}",
-                                                       this->m_patternLanguageRuntime->getCreatedPatternCount(),
-                                                       this->m_patternLanguageRuntime->getMaximumPatternCount()
+                                                       this->m_evaluatorRuntime->getCreatedPatternCount(),
+                                                       this->m_evaluatorRuntime->getMaximumPatternCount()
                                                        ).c_str()
                                            );
 
-                    ImGui::SameLine();
-
-                    if (ImGui::IconButton(ICON_VS_GLOBE, ImGui::GetStyleColorVec4(ImGuiCol_Text)))
-                        ImGui::OpenPopup("env_vars");
-
-                    if (ImGui::BeginPopup("env_vars")) {
-                        ImGui::TextUnformatted("hex.builtin.view.pattern_editor.env_vars"_lang);
-                        ImGui::SameLine();
-                        if (ImGui::IconButton(ICON_VS_ADD, ImGui::GetStyleColorVec4(ImGuiCol_Text))) this->m_envVarEntries.push_back({ "", s128(0), EnvVarType::Integer });
-                        ImGui::Separator();
-
-                        int index = 0;
-                        for (auto &[name, value, type] : this->m_envVarEntries) {
-                            ImGui::PushID(index++);
-
-                            ImGui::PushItemWidth(ImGui::GetTextLineHeightWithSpacing() * 2);
-                            constexpr const char* Types[] = { "I", "F", "S", "B" };
-                            if (ImGui::BeginCombo("", Types[static_cast<int>(type)])) {
-                                for (auto i = 0; i < IM_ARRAYSIZE(Types); i++) {
-                                    if (ImGui::Selectable(Types[i]))
-                                        type = static_cast<EnvVarType>(i);
-                                }
-
-                                ImGui::EndCombo();
-                            }
-                            ImGui::PopItemWidth();
-
-                            ImGui::SameLine();
-
-                            ImGui::InputText("###name",  name.data(), name.capacity(), ImGuiInputTextFlags_CallbackResize, ImGui::UpdateStringSizeCallback, &name);
-                            ImGui::SameLine();
-
-                            switch (type) {
-                                case EnvVarType::Integer: {
-                                    s64 displayValue = hex::get_or<s128>(value, 0);
-                                    ImGui::InputScalar("###value",  ImGuiDataType_S64, &displayValue);
-                                    value = s128(displayValue);
-                                    break;
-                                }
-                                case EnvVarType::Float: {
-                                    auto displayValue = hex::get_or<double>(value, 0.0);
-                                    ImGui::InputDouble("###value", &displayValue);
-                                    value = displayValue;
-                                    break;
-                                }
-                                case EnvVarType::Bool: {
-                                    auto displayValue = hex::get_or<bool>(value, false);
-                                    ImGui::Checkbox("###value", &displayValue);
-                                    value = displayValue;
-                                    break;
-                                }
-                                case EnvVarType::String: {
-                                    auto displayValue = hex::get_or<std::string>(value, "");
-                                    ImGui::InputText("###value",  displayValue.data(), displayValue.capacity(), ImGuiInputTextFlags_CallbackResize, ImGui::UpdateStringSizeCallback, &displayValue);
-                                    value = displayValue;
-                                    break;
-                                }
-                            }
-
-                            ImGui::PopID();
-                        }
-
-                        ImGui::EndPopup();
-                    }
                 }
 
                 if (this->m_textEditor.IsTextChanged()) {
                     ProjectFile::markDirty();
-
-                    if (this->m_runAutomatically)
-                        this->m_hasUnevaluatedChanges = true;
+                    this->m_hasUnevaluatedChanges = true;
                 }
 
-                if (this->m_hasUnevaluatedChanges && !this->m_evaluatorRunning) {
+                if (this->m_hasUnevaluatedChanges && !this->m_evaluatorRunning && !this->m_parserRunning) {
                     this->m_hasUnevaluatedChanges = false;
-                    this->parsePattern(this->m_textEditor.GetText().data());
+
+                    if (this->m_runAutomatically)
+                        this->evaluatePattern(this->m_textEditor.GetText());
+                    else
+                        this->parsePattern(this->m_textEditor.GetText());
                 }
             }
 
@@ -383,6 +314,179 @@ namespace hex::plugin::builtin {
         ImGui::End();
     }
 
+    void ViewPatternEditor::drawConsole(ImVec2 size) {
+        ImGui::PushStyleColor(ImGuiCol_ChildBg, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Background)]);
+        if (ImGui::BeginChild("##console", size, true, ImGuiWindowFlags_AlwaysVerticalScrollbar)) {
+            for (auto &[level, message] : this->m_console) {
+                switch (level) {
+                    case pl::LogConsole::Level::Debug:
+                        ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Comment)]);
+                        break;
+                    case pl::LogConsole::Level::Info:
+                        ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Default)]);
+                        break;
+                    case pl::LogConsole::Level::Warning:
+                        ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::Preprocessor)]);
+                        break;
+                    case pl::LogConsole::Level::Error:
+                        ImGui::PushStyleColor(ImGuiCol_Text, this->m_textEditor.GetPalette()[u32(TextEditor::PaletteIndex::ErrorMarker)]);
+                        break;
+                    default: continue;
+                }
+
+                ImGui::TextUnformatted(message.c_str());
+
+                ImGui::PopStyleColor();
+            }
+
+        }
+        ImGui::EndChild();
+        ImGui::PopStyleColor(1);
+    }
+
+    void ViewPatternEditor::drawEnvVars(ImVec2 size) {
+        if (ImGui::BeginChild("##env_vars", size, true, ImGuiWindowFlags_AlwaysVerticalScrollbar)) {
+            int index = 0;
+            if (ImGui::BeginTable("##env_vars_table", 4, ImGuiTableFlags_SizingStretchProp | ImGuiTableFlags_BordersInnerH)) {
+                ImGui::TableSetupColumn("Type", ImGuiTableColumnFlags_WidthStretch, 0.1F);
+                ImGui::TableSetupColumn("Name", ImGuiTableColumnFlags_WidthStretch, 0.4F);
+                ImGui::TableSetupColumn("Value", ImGuiTableColumnFlags_WidthStretch, 0.38F);
+                ImGui::TableSetupColumn("Remove", ImGuiTableColumnFlags_WidthStretch, 0.12F);
+
+                for (auto iter = this->m_envVarEntries.begin(); iter != this->m_envVarEntries.end(); iter++) {
+                    ImGui::TableNextRow();
+                    ImGui::TableNextColumn();
+
+                    auto &[id, name, value, type] = *iter;
+
+                    ImGui::PushID(index++);
+                    ON_SCOPE_EXIT { ImGui::PopID(); };
+
+                    ImGui::PushItemWidth(ImGui::GetContentRegionAvailWidth());
+                    constexpr const char* Types[] = { "I", "F", "S", "B" };
+                    if (ImGui::BeginCombo("", Types[static_cast<int>(type)])) {
+                        for (auto i = 0; i < IM_ARRAYSIZE(Types); i++) {
+                            if (ImGui::Selectable(Types[i]))
+                                type = static_cast<EnvVarType>(i);
+                        }
+
+                        ImGui::EndCombo();
+                    }
+                    ImGui::PopItemWidth();
+
+                    ImGui::TableNextColumn();
+
+                    ImGui::PushItemWidth(ImGui::GetContentRegionAvailWidth());
+                    ImGui::InputText("###name",  name.data(), name.capacity(), ImGuiInputTextFlags_CallbackResize, ImGui::UpdateStringSizeCallback, &name);
+                    ImGui::PopItemWidth();
+
+                    ImGui::TableNextColumn();
+
+                    ImGui::PushItemWidth(ImGui::GetContentRegionAvailWidth());
+                    switch (type) {
+                        case EnvVarType::Integer: {
+                            s64 displayValue = hex::get_or<s128>(value, 0);
+                            ImGui::InputScalar("###value",  ImGuiDataType_S64, &displayValue);
+                            value = s128(displayValue);
+                            break;
+                        }
+                        case EnvVarType::Float: {
+                            auto displayValue = hex::get_or<double>(value, 0.0);
+                            ImGui::InputDouble("###value", &displayValue);
+                            value = displayValue;
+                            break;
+                        }
+                        case EnvVarType::Bool: {
+                            auto displayValue = hex::get_or<bool>(value, false);
+                            ImGui::Checkbox("###value", &displayValue);
+                            value = displayValue;
+                            break;
+                        }
+                        case EnvVarType::String: {
+                            auto displayValue = hex::get_or<std::string>(value, "");
+                            ImGui::InputText("###value",  displayValue.data(), displayValue.capacity(), ImGuiInputTextFlags_CallbackResize, ImGui::UpdateStringSizeCallback, &displayValue);
+                            value = displayValue;
+                            break;
+                        }
+                    }
+                    ImGui::PopItemWidth();
+
+                    ImGui::TableNextColumn();
+
+                    if (ImGui::IconButton(ICON_VS_ADD, ImGui::GetStyleColorVec4(ImGuiCol_Text))) {
+                        iter++;
+                        this->m_envVarEntries.insert(iter, { this->m_envVarIdCounter++, "", s128(0), EnvVarType::Integer });
+                        iter--;
+                    }
+
+                    ImGui::SameLine();
+
+                    ImGui::BeginDisabled(this->m_envVarEntries.size() <= 1);
+                    {
+                        if (ImGui::IconButton(ICON_VS_REMOVE, ImGui::GetStyleColorVec4(ImGuiCol_Text))) {
+                            bool isFirst = iter == this->m_envVarEntries.begin();
+                            this->m_envVarEntries.erase(iter);
+
+                            if (isFirst)
+                                iter = this->m_envVarEntries.begin();
+                        }
+                    }
+                    ImGui::EndDisabled();
+                }
+
+                ImGui::EndTable();
+            }
+        }
+        ImGui::EndChild();
+    }
+
+    void ViewPatternEditor::drawVariableSettings(ImVec2 size) {
+        if (ImGui::BeginChild("##settings", size, true, ImGuiWindowFlags_AlwaysVerticalScrollbar)) {
+            if (ImGui::BeginTable("##env_vars_table", 2, ImGuiTableFlags_SizingStretchProp | ImGuiTableFlags_BordersInnerH)) {
+                ImGui::TableSetupColumn("Name", ImGuiTableColumnFlags_WidthStretch, 0.4F);
+                ImGui::TableSetupColumn("Value", ImGuiTableColumnFlags_WidthStretch, 0.6F);
+
+                for (auto &[name, variable] : this->m_patternVariables) {
+                    ImGui::TableNextRow();
+                    ImGui::TableNextColumn();
+
+                    ImGui::TextUnformatted(name.c_str());
+
+                    ImGui::TableNextColumn();
+
+                    if (variable.outVariable) {
+                        ImGui::TextUnformatted(pl::Token::literalToString(variable.value, true).c_str());
+                    } else if (variable.inVariable) {
+                        if (pl::Token::isSigned(variable.type)) {
+                            s64 value = hex::get_or<s128>(variable.value, 0);
+                            ImGui::InputScalar("", ImGuiDataType_S64, &value);
+                            variable.value = s128(value);
+                        } else if (pl::Token::isUnsigned(variable.type)) {
+                            u64 value = hex::get_or<u128>(variable.value, 0);
+                            ImGui::InputScalar("", ImGuiDataType_U64, &value);
+                            variable.value = u128(value);
+                        } else if (pl::Token::isFloatingPoint(variable.type)) {
+                            double value = hex::get_or<double>(variable.value, 0.0);
+                            ImGui::InputScalar("", ImGuiDataType_Double, &value);
+                            variable.value = value;
+                        } else if (variable.type == pl::Token::ValueType::Boolean) {
+                            bool value = hex::get_or<bool>(variable.value, false);
+                            ImGui::Checkbox("", &value);
+                            variable.value = value;
+                        } else if (variable.type == pl::Token::ValueType::Character) {
+                            char buffer[2];
+                            ImGui::InputText("", buffer, 2);
+                            variable.value = buffer[0];
+                        }
+                    }
+                }
+
+                ImGui::EndTable();
+            }
+        }
+        ImGui::EndChild();
+    }
+
     void ViewPatternEditor::drawAlwaysVisible() {
 
         ImGui::SetNextWindowPos(ImGui::GetMainViewport()->GetCenter(), ImGuiCond_Appearing, ImVec2(0.5F, 0.5F));
@@ -476,7 +580,7 @@ namespace hex::plugin::builtin {
 
             fclose(file);
 
-            this->parsePattern(buffer);
+            this->evaluatePattern(buffer);
             this->m_textEditor.SetText(buffer);
 
             delete[] buffer;
@@ -491,7 +595,43 @@ namespace hex::plugin::builtin {
         pl::PatternData::resetPalette();
     }
 
-    void ViewPatternEditor::parsePattern(char *buffer) {
+
+    void ViewPatternEditor::parsePattern(const std::string &code) {
+        this->m_parserRunning = true;
+        std::thread([this, code] {
+            auto ast = this->m_parserRuntime->parseString(code);
+
+            this->m_patternVariables.clear();
+            this->m_patternTypes.clear();
+
+            if (ast) {
+                for (auto node : *ast) {
+                    if (auto variableDecl = dynamic_cast<pl::ASTNodeVariableDecl*>(node)) {
+                        auto type = dynamic_cast<pl::ASTNodeTypeDecl*>(variableDecl->getType());
+                        if (type == nullptr) continue;
+
+                        auto builtinType = dynamic_cast<pl::ASTNodeBuiltinType*>(type->getType());
+                        if (builtinType == nullptr) continue;
+
+                        PatternVariable variable = {
+                                .inVariable = variableDecl->isInVariable(),
+                                .outVariable = variableDecl->isOutVariable(),
+                                .type = builtinType->getType()
+                        };
+
+                        if (variable.inVariable || variable.outVariable) {
+                            if (!this->m_patternVariables.contains(variableDecl->getName()))
+                                this->m_patternVariables[variableDecl->getName()] = variable;
+                        }
+                    }
+                }
+            }
+
+            this->m_parserRunning = false;
+        }).detach();
+    }
+
+    void ViewPatternEditor::evaluatePattern(const std::string &code) {
         this->m_evaluatorRunning = true;
 
         this->m_textEditor.SetErrorMarkers({ });
@@ -499,25 +639,35 @@ namespace hex::plugin::builtin {
         this->clearPatternData();
         EventManager::post<EventPatternChanged>();
 
-        std::thread([this, buffer = std::string(buffer)] {
+        std::thread([this, code] {
             std::map<std::string, pl::Token::Literal> envVars;
-            for (const auto &[name, value, type] : this->m_envVarEntries)
+            for (const auto &[id, name, value, type] : this->m_envVarEntries)
                 envVars.insert({ name, value });
 
-            auto result = this->m_patternLanguageRuntime->executeString(ImHexApi::Provider::get(), buffer, envVars);
+            std::map<std::string, pl::Token::Literal> inVariables;
+            for (auto &[name, variable] : this->m_patternVariables) {
+                if (variable.inVariable)
+                    inVariables[name] = variable.value;
+            }
 
-            auto error = this->m_patternLanguageRuntime->getError();
+            auto result = this->m_evaluatorRuntime->executeString(ImHexApi::Provider::get(), code, envVars, inVariables);
+
+            auto error = this->m_evaluatorRuntime->getError();
             if (error.has_value()) {
                 this->m_textEditor.SetErrorMarkers({ error.value() });
             }
 
-            this->m_console = this->m_patternLanguageRuntime->getConsoleLog();
+            this->m_console = this->m_evaluatorRuntime->getConsoleLog();
+
+            auto outVariables = this->m_evaluatorRuntime->getOutVariables();
+            for (auto &[name, variable] : this->m_patternVariables) {
+                if (variable.outVariable && outVariables.contains(name))
+                    variable.value = outVariables.at(name);
+            }
 
             if (result.has_value()) {
                 SharedData::patternData = std::move(result.value());
-                //View::doLater([]{
-                    EventManager::post<EventPatternChanged>();
-                //});
+                EventManager::post<EventPatternChanged>();
             }
 
             this->m_evaluatorRunning = false;
diff --git a/plugins/libimhex/include/hex/pattern_language/ast_node.hpp b/plugins/libimhex/include/hex/pattern_language/ast_node.hpp
index 1b3de4c84..03f71a2ac 100644
--- a/plugins/libimhex/include/hex/pattern_language/ast_node.hpp
+++ b/plugins/libimhex/include/hex/pattern_language/ast_node.hpp
@@ -714,8 +714,8 @@ namespace hex::pl {
 
     class ASTNodeVariableDecl : public ASTNode, public Attributable {
     public:
-        ASTNodeVariableDecl(std::string name, ASTNode *type, ASTNode *placementOffset = nullptr)
-                : ASTNode(), m_name(std::move(name)), m_type(type), m_placementOffset(placementOffset) { }
+        ASTNodeVariableDecl(std::string name, ASTNode *type, ASTNode *placementOffset = nullptr, bool inVariable = false, bool outVariable = false)
+                : ASTNode(), m_name(std::move(name)), m_type(type), m_placementOffset(placementOffset), m_inVariable(inVariable), m_outVariable(outVariable) { }
 
         ASTNodeVariableDecl(const ASTNodeVariableDecl &other) : ASTNode(other), Attributable(other) {
             this->m_name = other.m_name;
@@ -740,6 +740,9 @@ namespace hex::pl {
         [[nodiscard]] constexpr ASTNode* getType() const { return this->m_type; }
         [[nodiscard]] constexpr auto getPlacementOffset() const { return this->m_placementOffset; }
 
+        [[nodiscard]] constexpr bool isInVariable() const { return this->m_inVariable; }
+        [[nodiscard]] constexpr bool isOutVariable() const { return this->m_outVariable; }
+
         [[nodiscard]] std::vector<PatternData*> createPatterns(Evaluator *evaluator) const override {
             if (this->m_placementOffset != nullptr) {
                 auto offset = dynamic_cast<ASTNodeLiteral *>(this->m_placementOffset->evaluate(evaluator));
@@ -770,6 +773,8 @@ namespace hex::pl {
         std::string m_name;
         ASTNode *m_type;
         ASTNode *m_placementOffset;
+
+        bool m_inVariable, m_outVariable;
     };
 
     class ASTNodeArrayVariableDecl : public ASTNode, public Attributable {
@@ -1459,7 +1464,8 @@ namespace hex::pl {
 
                     std::visit(overloaded {
                             [&](std::string &assignmentValue) { },
-                            [&](auto &&assignmentValue) { std::memcpy(&value, &assignmentValue, pattern->getSize()); }
+                            [&](PatternData *assignmentValue) { },
+                            [&](auto &&assignmentValue) { value = assignmentValue; }
                     }, literal);
                 }
                 else
diff --git a/plugins/libimhex/include/hex/pattern_language/evaluator.hpp b/plugins/libimhex/include/hex/pattern_language/evaluator.hpp
index 3039200bc..17a617a4f 100644
--- a/plugins/libimhex/include/hex/pattern_language/evaluator.hpp
+++ b/plugins/libimhex/include/hex/pattern_language/evaluator.hpp
@@ -64,6 +64,21 @@ namespace hex::pl {
             this->m_provider = provider;
         }
 
+        void setInVariables(const std::map<std::string, Token::Literal> &inVariables) {
+            this->m_inVariables = inVariables;
+        }
+
+        [[nodiscard]]
+        std::map<std::string, Token::Literal> getOutVariables() const {
+            std::map<std::string, Token::Literal> result;
+
+            for (const auto &[name, offset] : this->m_outVariables) {
+                result.insert({ name, this->getStack()[offset] });
+            }
+
+            return result;
+        }
+
         [[nodiscard]]
         prv::Provider *getProvider() const {
             return this->m_provider;
@@ -137,7 +152,12 @@ namespace hex::pl {
             return this->m_stack;
         }
 
-        void createVariable(const std::string &name, ASTNode *type, const std::optional<Token::Literal> &value = std::nullopt);
+        [[nodiscard]]
+        const std::vector<Token::Literal>& getStack() const {
+            return this->m_stack;
+        }
+
+        void createVariable(const std::string &name, ASTNode *type, const std::optional<Token::Literal> &value = std::nullopt, bool outVariable = false);
         void setVariable(const std::string &name, const Token::Literal& value);
 
         void abort() {
@@ -185,7 +205,10 @@ namespace hex::pl {
         std::map<std::string, ContentRegistry::PatternLanguageFunctions::Function> m_customFunctions;
         std::vector<ASTNode*> m_customFunctionDefinitions;
         std::vector<Token::Literal> m_stack;
+
         std::map<std::string, Token::Literal> m_envVariables;
+        std::map<std::string, Token::Literal> m_inVariables;
+        std::map<std::string, size_t> m_outVariables;
 
         friend class PatternCreationLimiter;
     };
diff --git a/plugins/libimhex/include/hex/pattern_language/pattern_language.hpp b/plugins/libimhex/include/hex/pattern_language/pattern_language.hpp
index 1795fc3e7..8c1b29efc 100644
--- a/plugins/libimhex/include/hex/pattern_language/pattern_language.hpp
+++ b/plugins/libimhex/include/hex/pattern_language/pattern_language.hpp
@@ -30,15 +30,27 @@ namespace hex::pl {
         PatternLanguage();
         ~PatternLanguage();
 
-        std::optional<std::vector<PatternData*>> executeString(prv::Provider *provider, const std::string &string, const std::map<std::string, Token::Literal> &envVars = { });
-        std::optional<std::vector<PatternData*>> executeFile(prv::Provider *provider, const std::string &path, const std::map<std::string, Token::Literal> &envVars = { });
+        [[nodiscard]]
+        std::optional<std::vector<ASTNode*>> parseString(const std::string &code);
+        [[nodiscard]]
+        std::optional<std::vector<PatternData*>> executeString(prv::Provider *provider, const std::string &string, const std::map<std::string, Token::Literal> &envVars = { }, const std::map<std::string, Token::Literal> &inVariables = { });
+        [[nodiscard]]
+        std::optional<std::vector<PatternData*>> executeFile(prv::Provider *provider, const std::string &path, const std::map<std::string, Token::Literal> &envVars = { }, const std::map<std::string, Token::Literal> &inVariables = { });
+        [[nodiscard]]
+        const std::vector<ASTNode*>& getCurrentAST() const;
 
         void abort();
 
+        [[nodiscard]]
         const std::vector<std::pair<LogConsole::Level, std::string>>& getConsoleLog();
+        [[nodiscard]]
         const std::optional<std::pair<u32, std::string>>& getError();
+        [[nodiscard]]
+        std::map<std::string, Token::Literal> getOutVariables() const;
 
+        [[nodiscard]]
         u32 getCreatedPatternCount();
+        [[nodiscard]]
         u32 getMaximumPatternCount();
 
     private:
diff --git a/plugins/libimhex/include/hex/pattern_language/token.hpp b/plugins/libimhex/include/hex/pattern_language/token.hpp
index c74d54688..dcfde4125 100644
--- a/plugins/libimhex/include/hex/pattern_language/token.hpp
+++ b/plugins/libimhex/include/hex/pattern_language/token.hpp
@@ -40,7 +40,9 @@ namespace hex::pl {
             For,
             Function,
             Return,
-            Namespace
+            Namespace,
+            In,
+            Out
         };
 
         enum class Operator {
@@ -285,6 +287,8 @@ namespace hex::pl {
 #define KEYWORD_FUNCTION                    COMPONENT(Keyword, Function)
 #define KEYWORD_RETURN                      COMPONENT(Keyword, Return)
 #define KEYWORD_NAMESPACE                   COMPONENT(Keyword, Namespace)
+#define KEYWORD_IN                          COMPONENT(Keyword, In)
+#define KEYWORD_OUT                         COMPONENT(Keyword, Out)
 
 #define INTEGER                             hex::pl::Token::Type::Integer, hex::pl::Token::Literal(u128(0))
 #define IDENTIFIER                          hex::pl::Token::Type::Identifier, ""
diff --git a/plugins/libimhex/source/pattern_language/evaluator.cpp b/plugins/libimhex/source/pattern_language/evaluator.cpp
index 716678f01..5f994931c 100644
--- a/plugins/libimhex/source/pattern_language/evaluator.cpp
+++ b/plugins/libimhex/source/pattern_language/evaluator.cpp
@@ -3,7 +3,7 @@
 
 namespace hex::pl {
 
-    void Evaluator::createVariable(const std::string &name, ASTNode *type, const std::optional<Token::Literal> &value) {
+    void Evaluator::createVariable(const std::string &name, ASTNode *type, const std::optional<Token::Literal> &value, bool outVariable) {
         auto &variables = *this->getScope(0).scope;
         for (auto &variable : variables) {
             if (variable->getVariableName() == name) {
@@ -44,6 +44,9 @@ namespace hex::pl {
 
         this->getStack().emplace_back();
         variables.push_back(pattern);
+
+        if (outVariable)
+            this->m_outVariables[name] = pattern->getOffset();
     }
 
     void Evaluator::setVariable(const std::string &name, const Token::Literal& value) {
@@ -115,6 +118,7 @@ namespace hex::pl {
             }, value);
 
         this->getStack()[pattern->getOffset()] = castedLiteral;
+
     }
 
     std::optional<std::vector<PatternData*>> Evaluator::evaluate(const std::vector<ASTNode*> &ast) {
@@ -153,7 +157,12 @@ namespace hex::pl {
                         auto type = varDeclNode->getType()->evaluate(this);
                         ON_SCOPE_EXIT { delete type; };
 
-                        this->createVariable(pattern->getVariableName(), type);
+                        auto &name = pattern->getVariableName();
+                        this->createVariable(name, type, std::nullopt, varDeclNode->isOutVariable());
+
+                        if (varDeclNode->isInVariable() && this->m_inVariables.contains(name))
+                            this->setVariable(name, this->m_inVariables[name]);
+
                         delete pattern;
                   } else {
                     patterns.push_back(pattern);
diff --git a/plugins/libimhex/source/pattern_language/lexer.cpp b/plugins/libimhex/source/pattern_language/lexer.cpp
index fabdaeccc..d153837b5 100644
--- a/plugins/libimhex/source/pattern_language/lexer.cpp
+++ b/plugins/libimhex/source/pattern_language/lexer.cpp
@@ -416,6 +416,10 @@ namespace hex::pl {
                         tokens.emplace_back(TOKEN(Keyword, Return));
                     else if (identifier == "namespace")
                         tokens.emplace_back(TOKEN(Keyword, Namespace));
+                    else if (identifier == "in")
+                        tokens.emplace_back(TOKEN(Keyword, In));
+                    else if (identifier == "out")
+                        tokens.emplace_back(TOKEN(Keyword, Out));
 
                         // Check for built-in types
                     else if (identifier == "u8")
diff --git a/plugins/libimhex/source/pattern_language/parser.cpp b/plugins/libimhex/source/pattern_language/parser.cpp
index 5ca9df90d..495c049a3 100644
--- a/plugins/libimhex/source/pattern_language/parser.cpp
+++ b/plugins/libimhex/source/pattern_language/parser.cpp
@@ -1024,16 +1024,22 @@ namespace hex::pl {
 
     // (parseType) Identifier @ Integer
     ASTNode* Parser::parseVariablePlacement(ASTNodeTypeDecl *type) {
+        bool inVariable = false;
+        bool outVariable = false;
+
         auto name = getValue<Token::Identifier>(-1).get();
 
-        ASTNode *placementOffset;
+        ASTNode *placementOffset = nullptr;
         if (MATCHES(sequence(OPERATOR_AT))) {
             placementOffset = parseMathematicalExpression();
-        } else {
-            placementOffset = nullptr;
+        } else if (MATCHES(sequence(KEYWORD_IN))) {
+            inVariable = true;
+        }
+        else if (MATCHES(sequence(KEYWORD_OUT))) {
+            outVariable = true;
         }
 
-        return create(new ASTNodeVariableDecl(name, type, placementOffset));
+        return create(new ASTNodeVariableDecl(name, type, placementOffset, inVariable, outVariable));
     }
 
     // (parseType) Identifier[[(parseMathematicalExpression)]] @ Integer
diff --git a/plugins/libimhex/source/pattern_language/pattern_language.cpp b/plugins/libimhex/source/pattern_language/pattern_language.cpp
index 7b367d052..e5f11dadd 100644
--- a/plugins/libimhex/source/pattern_language/pattern_language.cpp
+++ b/plugins/libimhex/source/pattern_language/pattern_language.cpp
@@ -94,25 +94,8 @@ namespace hex::pl {
         delete this->m_validator;
     }
 
-
-    std::optional<std::vector<PatternData*>> PatternLanguage::executeString(prv::Provider *provider, const std::string &string, const std::map<std::string, Token::Literal> &envVars) {
-        this->m_currError.reset();
-        this->m_evaluator->getConsole().clear();
-        this->m_evaluator->setProvider(provider);
-        this->m_evaluator->setDefaultEndian(std::endian::native);
-        this->m_evaluator->setEvaluationDepth(32);
-        this->m_evaluator->setArrayLimit(0x1000);
-        this->m_evaluator->setPatternLimit(0x2000);
-        this->m_evaluator->setLoopLimit(0x1000);
-
-        for (const auto &[name, value] : envVars)
-            this->m_evaluator->setEnvVariable(name, value);
-
-        for (auto &node : this->m_currAST)
-            delete node;
-        this->m_currAST.clear();
-
-        auto preprocessedCode = this->m_preprocessor->preprocess(string);
+    std::optional<std::vector<ASTNode*>> PatternLanguage::parseString(const std::string &code) {
+        auto preprocessedCode = this->m_preprocessor->preprocess(code);
         if (!preprocessedCode.has_value()) {
             this->m_currError = this->m_preprocessor->getError();
             return { };
@@ -130,6 +113,31 @@ namespace hex::pl {
             return { };
         }
 
+        return ast;
+    }
+
+    std::optional<std::vector<PatternData*>> PatternLanguage::executeString(prv::Provider *provider, const std::string &code, const std::map<std::string, Token::Literal> &envVars, const std::map<std::string, Token::Literal> &inVariables) {
+        this->m_currError.reset();
+        this->m_evaluator->getConsole().clear();
+        this->m_evaluator->setProvider(provider);
+        this->m_evaluator->setDefaultEndian(std::endian::native);
+        this->m_evaluator->setEvaluationDepth(32);
+        this->m_evaluator->setArrayLimit(0x1000);
+        this->m_evaluator->setPatternLimit(0x2000);
+        this->m_evaluator->setLoopLimit(0x1000);
+        this->m_evaluator->setInVariables(inVariables);
+
+        for (const auto &[name, value] : envVars)
+            this->m_evaluator->setEnvVariable(name, value);
+
+        for (auto &node : this->m_currAST)
+            delete node;
+        this->m_currAST.clear();
+
+        auto ast = this->parseString(code);
+        if (!ast)
+            return { };
+
         this->m_currAST = ast.value();
 
         auto patterns = this->m_evaluator->evaluate(ast.value());
@@ -141,16 +149,25 @@ namespace hex::pl {
         return patterns;
     }
 
-    std::optional<std::vector<PatternData*>> PatternLanguage::executeFile(prv::Provider *provider, const std::string &path, const std::map<std::string, Token::Literal> &envVars) {
+    std::optional<std::vector<PatternData*>> PatternLanguage::executeFile(prv::Provider *provider, const std::string &path, const std::map<std::string, Token::Literal> &envVars, const std::map<std::string, Token::Literal> &inVariables) {
         File file(path, File::Mode::Read);
 
-        return this->executeString(provider, file.readString(), envVars);
+        return this->executeString(provider, file.readString(), envVars, inVariables);
     }
 
     void PatternLanguage::abort() {
         this->m_evaluator->abort();
     }
 
+    const std::vector<ASTNode*> &PatternLanguage::getCurrentAST() const {
+        return this->m_currAST;
+    }
+
+    [[nodiscard]]
+    std::map<std::string, Token::Literal> PatternLanguage::getOutVariables() const {
+        return this->m_evaluator->getOutVariables();
+    }
+
 
     const std::vector<std::pair<LogConsole::Level, std::string>>& PatternLanguage::getConsoleLog() {
         return this->m_evaluator->getConsole().getLog();