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engines/stark/tools/abstractsyntaxtree.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef STARK_TOOLS_ABSTRACT_SYNTAX_TREE_H
+#define STARK_TOOLS_ABSTRACT_SYNTAX_TREE_H
+
+#include "common/array.h"
+
+#include "engines/stark/tools/command.h"
+
+namespace Stark {
+namespace Tools {
+
+struct ASTCommand;
+
+/**
+ * Base Abstract Syntax Tree node
+ *
+ * The abstract syntax tree directly maps the script source code.
+ */
+struct ASTNode {
+	ASTNode(ASTNode *parent);
+	virtual ~ASTNode();
+
+	/** Print the script source code for this node and its children */
+	virtual void print(uint depth, DefinitionRegistry *definitions) = 0;
+
+	/** Recursively list all the commands in the tree with the requested index */
+	virtual Common::Array<const ASTCommand *> listCommands(uint16 index) const = 0;
+
+	/** Find the successors of a node, either the direct follower or the condition branches */
+	void findSuccessors(ASTNode **follower, ASTNode **trueBranch, ASTNode **falseBranch) const;
+	virtual void findSuccessorsIntern(const ASTNode *node, ASTNode **follower, ASTNode **trueBranch, ASTNode **falseBranch) const = 0;
+
+	/** Find the first command to be executed when running this job */
+	virtual const ASTCommand *getFirstCommand() const = 0;
+
+protected:
+	void printWithDepth(uint depth, const Common::String &string) const;
+
+	ASTNode *_parent;
+};
+
+/**
+ * Command AST Node
+ *
+ * Commands are leaf AST nodes. They represent an engine command call.
+ */
+struct ASTCommand : public ASTNode, public Command {
+	ASTCommand(ASTNode *parent, Command *command, DefinitionRegistry *definitions);
+
+	// ASTNode API
+	void print(uint depth, DefinitionRegistry *definitions) override;
+	Common::Array<const ASTCommand *> listCommands(uint16 index) const override;
+	void findSuccessorsIntern(const ASTNode *node, ASTNode **follower, ASTNode **trueBranch, ASTNode **falseBranch) const override;
+	const ASTCommand *getFirstCommand() const override;
+
+	/** Build a script source code call for this command */
+	Common::String callString(DefinitionRegistry *definitions);
+};
+
+/**
+ * Block AST Node
+ *
+ * A list of consecutive script expressions.
+ */
+struct ASTBlock : public ASTNode {
+	ASTBlock(ASTNode *parent);
+	~ASTBlock() override;
+
+	// ASTNode API
+	void print(uint depth, DefinitionRegistry *definitions) override;
+	Common::Array<const ASTCommand *> listCommands(uint16 index) const override;
+	void findSuccessorsIntern(const ASTNode *node, ASTNode **follower, ASTNode **trueBranch, ASTNode **falseBranch) const override;
+	const ASTCommand *getFirstCommand() const override;
+
+	/** Append a child expression to this block */
+	void addNode(ASTNode *node);
+
+private:
+	Common::Array<ASTNode *> _children;
+};
+
+/**
+ * Condition AST Node
+ *
+ * An if / then / else branching condition.
+ */
+struct ASTCondition : public ASTNode {
+	ASTCondition(ASTNode *parent);
+	~ASTCondition() override;
+
+	// ASTNode API
+	void print(uint depth, DefinitionRegistry *definitions) override;
+	Common::Array<const ASTCommand *> listCommands(uint16 index) const override;
+	void findSuccessorsIntern(const ASTNode *node, ASTNode **follower, ASTNode **trueBranch, ASTNode **falseBranch) const override;
+	const ASTCommand *getFirstCommand() const override;
+
+	ASTCommand *condition;
+	bool invertedCondition;
+	ASTBlock *thenBlock;
+	ASTBlock *elseBlock;
+};
+
+/**
+ * Loop AST Node
+ *
+ * A while loop.
+ */
+struct ASTLoop : public ASTNode {
+	ASTLoop(ASTNode *parent);
+	~ASTLoop() override;
+
+	// ASTNode API
+	void print(uint depth, DefinitionRegistry *definitions) override;
+	Common::Array<const ASTCommand *> listCommands(uint16 index) const override;
+	void findSuccessorsIntern(const ASTNode *node, ASTNode **follower, ASTNode **trueBranch, ASTNode **falseBranch) const override;
+	const ASTCommand *getFirstCommand() const override;
+
+	ASTCommand *condition;
+	bool invertedCondition;
+	ASTBlock *loopBlock;
+};
+
+} // End of namespace Tools
+} // End of namespace Stark
+
+#endif // STARK_TOOLS_ABSTRACT_SYNTAX_TREE_H