scummvm/engines/stark/tools/abstractsyntaxtree.h
2021-12-26 21:19:38 +01:00

146 lines
4.6 KiB
C++

/* 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