From c053d54d1027223a473182e1480a17d93965fd58 Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Wed, 25 Aug 2021 17:54:47 +0200
Subject: [PATCH] patterns: Add multi-variable declarations

---
 .../libimhex/include/hex/lang/ast_node.hpp    | 26 +++++++++++++++++++
 plugins/libimhex/source/lang/evaluator.cpp    | 16 ++++++++++++
 plugins/libimhex/source/lang/parser.cpp       | 17 +++++++++++-
 3 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/plugins/libimhex/include/hex/lang/ast_node.hpp b/plugins/libimhex/include/hex/lang/ast_node.hpp
index 49f3da09f..5b36bd184 100644
--- a/plugins/libimhex/include/hex/lang/ast_node.hpp
+++ b/plugins/libimhex/include/hex/lang/ast_node.hpp
@@ -285,6 +285,32 @@ namespace hex::lang {
         ASTNode *m_placementOffset;
     };
 
+    class ASTNodeMultiVariableDecl : public ASTNode {
+    public:
+        explicit ASTNodeMultiVariableDecl(std::vector<ASTNode*> variables) : m_variables(std::move(variables)) { }
+
+        ASTNodeMultiVariableDecl(const ASTNodeMultiVariableDecl &other) : ASTNode(other) {
+            for (auto &variable : other.m_variables)
+                this->m_variables.push_back(variable->clone());
+        }
+
+        ~ASTNodeMultiVariableDecl() override {
+            for (auto &variable : this->m_variables)
+                delete variable;
+        }
+
+        [[nodiscard]] ASTNode* clone() const override {
+            return new ASTNodeMultiVariableDecl(*this);
+        }
+
+        [[nodiscard]] std::vector<ASTNode*> getVariables() {
+            return this->m_variables;
+        }
+
+    private:
+        std::vector<ASTNode*> m_variables;
+    };
+
     class ASTNodeStruct : public ASTNode, public Attributable {
     public:
         ASTNodeStruct() : ASTNode() { }
diff --git a/plugins/libimhex/source/lang/evaluator.cpp b/plugins/libimhex/source/lang/evaluator.cpp
index fe3a45519..5b9b3cf0f 100644
--- a/plugins/libimhex/source/lang/evaluator.cpp
+++ b/plugins/libimhex/source/lang/evaluator.cpp
@@ -521,6 +521,14 @@ namespace hex::lang {
             } else if (auto varDeclNode = dynamic_cast<ASTNodeVariableDecl*>(statement); varDeclNode != nullptr) {
                 auto pattern = this->evaluateVariable(varDeclNode);
                 this->createLocalVariable(varDeclNode->getName(), pattern);
+            } else if (auto multiVarDeclNode = dynamic_cast<ASTNodeMultiVariableDecl*>(statement); multiVarDeclNode != nullptr) {
+                for (auto &delc : multiVarDeclNode->getVariables()) {
+                    if (auto varDecl = dynamic_cast<ASTNodeVariableDecl*>(delc); varDecl != nullptr) {
+                        auto pattern = this->evaluateVariable(varDecl);
+                        this->createLocalVariable(varDecl->getName(), pattern);
+                    } else
+                        this->getConsole().abortEvaluation("invalid multi-variable declaration");
+                }
             } else if (auto assignmentNode = dynamic_cast<ASTNodeAssignment*>(statement); assignmentNode != nullptr) {
                 if (auto numericExpressionNode = dynamic_cast<ASTNodeNumericExpression*>(assignmentNode->getRValue()); numericExpressionNode != nullptr) {
                     auto value = this->evaluateMathematicalExpression(numericExpressionNode);
@@ -677,6 +685,14 @@ namespace hex::lang {
 
         if (auto memberVariableNode = dynamic_cast<ASTNodeVariableDecl*>(node); memberVariableNode != nullptr)
             currMembers.push_back(this->evaluateVariable(memberVariableNode));
+        else if (auto memberMultiVariableNode = dynamic_cast<ASTNodeMultiVariableDecl*>(node); memberMultiVariableNode != nullptr) {
+            for (auto decl : memberMultiVariableNode->getVariables()) {
+                if (auto variableDecl = dynamic_cast<ASTNodeVariableDecl*>(decl); variableDecl != nullptr)
+                    currMembers.push_back(this->evaluateVariable(variableDecl));
+                else
+                    this->getConsole().abortEvaluation("invalid multi-variable declaration");
+            }
+        }
         else if (auto memberArrayNode = dynamic_cast<ASTNodeArrayVariableDecl*>(node); memberArrayNode != nullptr)
             currMembers.push_back(this->evaluateArray(memberArrayNode));
         else if (auto memberPointerNode = dynamic_cast<ASTNodePointerVariableDecl*>(node); memberPointerNode != nullptr)
diff --git a/plugins/libimhex/source/lang/parser.cpp b/plugins/libimhex/source/lang/parser.cpp
index 112fdafbf..95fa1abb4 100644
--- a/plugins/libimhex/source/lang/parser.cpp
+++ b/plugins/libimhex/source/lang/parser.cpp
@@ -634,7 +634,22 @@ namespace hex::lang {
     ASTNode* Parser::parseMemberVariable(ASTNodeTypeDecl *type) {
         if (type == nullptr) throwParseError("invalid type used in variable declaration", -1);
 
-        return new ASTNodeVariableDecl(getValue<std::string>(-1), type);
+        if (peek(SEPARATOR_COMMA)) {
+
+            std::vector<ASTNode*> variables;
+            auto variableCleanup = SCOPE_GUARD { for (auto var : variables) delete var; };
+
+            do {
+                variables.push_back(new ASTNodeVariableDecl(getValue<std::string>(-1), type->clone()));
+            } while (MATCHES(sequence(SEPARATOR_COMMA, IDENTIFIER)));
+
+            delete type;
+
+            variableCleanup.release();
+
+            return new ASTNodeMultiVariableDecl(variables);
+        } else
+            return new ASTNodeVariableDecl(getValue<std::string>(-1), type);
     }
 
     // (parseType) Identifier[(parseMathematicalExpression)]