yack.h

/* 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 TWP_YACK_H
#define TWP_YACK_H

#include "common/array.h"
#include "common/str.h"
#include "common/stream.h"
#include "common/debug.h"
#include "twp/util.h"

namespace Twp {

enum class YackTokenId {
    None,
    NewLine,
    Identifier,
    WaitWhile,
    Int,
    Float,
    Whitespace,
    Colon,
    Condition,
    String,
    Assign,
    Comment,
    Goto,
    Code,
    Dollar,
    End
};

// enumeration that lists all errors that can occur
enum YackError {
    ERR_NONE,              // no error
    ERR_INVALIDYackToken,  // invalid YackToken
    ERR_STRINGEXPECTED,    // string expected
    ERR_COLONEXPECTED,     // `:` expected
    ERR_COMMAEXPECTED,     // `,` expected
    ERR_BRACKETRIEXPECTED, // `]` expected
    ERR_CURLYRIEXPECTED,   // `}` expected
    ERR_QUOTEEXPECTED,     // `"` or `'` expected
    ERR_EOC_EXPECTED,      // `*/` expected
    ERR_EOFEXPECTED,       // EOF expected
    ERR_EXPREXPECTED       // expr expected
};

class YackVisitor;
class YackNode {
public:
    virtual ~YackNode() {}

    virtual void accept(YackVisitor &v) = 0;
};

// Represents a condition
class YCond : public YackNode {
public:
    virtual ~YCond() {}

public:
    int _line;
};

class YCodeCond : public YCond {
public:
    YCodeCond(int line) { _line = line; }
    virtual ~YCodeCond() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _code;
};

class YOnce : public YCond {
public:
    YOnce(int line) { _line = line; }
    virtual ~YOnce() {}
    virtual void accept(YackVisitor &v) override;
};

class YShowOnce : public YCond {
public:
    YShowOnce(int line) { _line = line; }
    virtual ~YShowOnce() {}
    virtual void accept(YackVisitor &v) override;
};

class YOnceEver : public YCond {
public:
    YOnceEver(int line) { _line = line; }
    virtual ~YOnceEver() {}
    virtual void accept(YackVisitor &v) override;
};

class YTempOnce : public YCond {
public:
    YTempOnce(int line) { _line = line; }
    virtual ~YTempOnce() {}
    virtual void accept(YackVisitor &v) override;
};

// Expression
class YExp : public YackNode {
public:
    YExp() {}
    virtual ~YExp() {}
};

class YGoto : public YExp {
public:
    YGoto(int line) { _line = line; }
    virtual ~YGoto() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _name;
    int _line = 0;
};

class YCodeExp : public YExp {
public:
    virtual ~YCodeExp() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _code;
};

class YChoice : public YExp {
public:
    virtual ~YChoice() {}
    virtual void accept(YackVisitor &v) override;

public:
    int _number = 0;
    Common::String _text;
    Common::SharedPtr<YGoto> _goto;
};

class YSay : public YExp {
public:
    virtual ~YSay() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _actor;
    Common::String _text;
};

class YPause : public YExp {
public:
    virtual ~YPause() {}
    virtual void accept(YackVisitor &v) override;

public:
    int _time = 0;
};

class YParrot : public YExp {
public:
    virtual ~YParrot() {}
    virtual void accept(YackVisitor &v) override;

public:
    bool _active = true;
};

class YDialog : public YExp {
public:
    virtual ~YDialog() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _actor;
};

class YOverride : public YExp {
public:
    virtual ~YOverride() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _node;
};

class YShutup : public YExp {
public:
    virtual ~YShutup() {}
    virtual void accept(YackVisitor &v) override;
};

class YAllowObjects : public YExp {
public:
    virtual ~YAllowObjects() {}
    virtual void accept(YackVisitor &v) override;

public:
    bool _active = true;
};

class YLimit : public YExp {
public:
    virtual ~YLimit() {}
    virtual void accept(YackVisitor &v) override;

public:
    int _max = 8;
};

class YWaitWhile : public YExp {
public:
    virtual ~YWaitWhile() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _cond;
};

class YWaitFor : public YExp {
public:
    virtual ~YWaitFor() {}
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _actor;
};

//

class YStatement : public YackNode {
public:
    virtual ~YStatement() override {}

    virtual void accept(YackVisitor &v) override;

public:
    Common::SharedPtr<YExp> _exp;
    Common::Array<Common::SharedPtr<YCond> > _conds;
};

class YLabel : public YackNode {
public:
    YLabel(int line);
    virtual ~YLabel() override;
    virtual void accept(YackVisitor &v) override;

public:
    Common::String _name;
    Common::Array<Common::SharedPtr<YStatement> > _stmts;
    int _line = 0;
};

class YCompilationUnit : public YackNode {
public:
    virtual ~YCompilationUnit() override;
    virtual void accept(YackVisitor &v) override;

public:
    Common::Array<Common::SharedPtr<YLabel> > _labels;
};

class YackVisitor {
public:
    virtual ~YackVisitor() {}

    virtual void visit(const YCompilationUnit &node) { defaultVisit(node); }
    virtual void visit(const YStatement &node) { defaultVisit(node); }
    virtual void visit(const YWaitFor &node) { defaultVisit(node); }
    virtual void visit(const YWaitWhile &node) { defaultVisit(node); }
    virtual void visit(const YLimit &node) { defaultVisit(node); }
    virtual void visit(const YAllowObjects &node) { defaultVisit(node); }
    virtual void visit(const YShutup &node) { defaultVisit(node); }
    virtual void visit(const YOverride &node) { defaultVisit(node); }
    virtual void visit(const YDialog &node) { defaultVisit(node); }
    virtual void visit(const YParrot &node) { defaultVisit(node); }
    virtual void visit(const YPause &node) { defaultVisit(node); }
    virtual void visit(const YSay &node) { defaultVisit(node); }
    virtual void visit(const YChoice &node) { defaultVisit(node); }
    virtual void visit(const YCodeExp &node) { defaultVisit(node); }
    virtual void visit(const YGoto &node) { defaultVisit(node); }
    virtual void visit(const YTempOnce &node) { defaultVisit(node); }
    virtual void visit(const YOnceEver &node) { defaultVisit(node); }
    virtual void visit(const YShowOnce &node) { defaultVisit(node); }
    virtual void visit(const YOnce &node) { defaultVisit(node); }
    virtual void visit(const YCodeCond &node) { defaultVisit(node); }
    virtual void visit(const YLabel &node) { defaultVisit(node); }

    virtual void defaultVisit(const YackNode &node) {}
};

struct YackToken {
    YackTokenId id = YackTokenId::None;
    int64 start = 0;
    int64 end = 0;
    int line = 0;

    Common::String toString() const;
};

class YackTokenReader {
public:
    class Iterator {
    public:
        using value_type = YackToken;
        using difference_type = ptrdiff_t;
        using pointer = YackToken *;
        using reference = YackToken &;

    private:
        YackTokenReader *_reader = nullptr;
        int64 _pos = 0;
        YackToken _token;

    public:
        Iterator() {}
        Iterator(YackTokenReader &reader, int64 pos);
        Iterator(const Iterator &it);
        Iterator &operator++();
        Iterator operator++(int);

        Iterator &operator=(const Iterator &rhs) {
            _pos = rhs._pos;
            _token = rhs._token;
            _reader = rhs._reader;
            return *this;
        }
        bool operator==(const Iterator &rhs) const { return _pos == rhs._pos; }
        bool operator!=(const Iterator &rhs) const { return _pos != rhs._pos; }
        YackToken &operator*();
        const YackToken &operator*() const;
        YackToken *operator->();
    };

    using iterator = Iterator;

public:
    void open(Common::SeekableReadStream *stream);

    iterator begin();
    iterator end();
    Common::String readText(const YackToken &YackToken);

private:
    bool readYackToken(YackToken &YackToken);
    Common::String readText(int64 pos, int64 size);
    YackTokenId readYackTokenId();
    YackTokenId readCode();
    YackTokenId readCondition();
    YackTokenId readDollar();
    YackTokenId readNumber();
    YackTokenId readComment();
    YackTokenId readString();
    YackTokenId readIdentifier(char c);
    byte peek();
    void ignore(int64 n = 1, int delim = EOF);

private:
    Common::SeekableReadStream *_stream = nullptr;
    int _line = 0;

    friend class YackParser;
};

class YackParser {
public:
    YackParser() {}
    YCompilationUnit *parse(Common::SeekableReadStream *stream);

private:
    bool match(const std::initializer_list<YackTokenId> &ids);
    Common::SharedPtr<YLabel> parseLabel();
    Common::SharedPtr<YStatement> parseStatement();
    Common::SharedPtr<YCond> parseCondition();
    Common::SharedPtr<YExp> parseExpression();
    Common::SharedPtr<YSay> parseSayExpression();
    Common::SharedPtr<YExp> parseWaitWhileExpression();
    Common::SharedPtr<YExp> parseInstructionExpression();
    Common::SharedPtr<YGoto> parseGotoExpression();
    Common::SharedPtr<YCodeExp> parseCodeExpression();
    Common::SharedPtr<YChoice> parseChoiceExpression();

private:
    YackTokenReader _reader;
    YackTokenReader::iterator _it;
};

class YackDump : public YackVisitor {
public:
    virtual ~YackDump() {}

    virtual void visit(const YCompilationUnit &node) {
        debug("CompilationUnit:");
        for (const auto &cond : node._labels) {
            cond->accept(*this);
        }
    }
    virtual void visit(const YLabel &node) {
        debug("Label: %s [%d]", node._name.c_str(), node._line);
        for (const auto &stmt : node._stmts) {
            stmt->accept(*this);
        }
    }
    virtual void visit(const YStatement &node) {
        debug("Statement:");
        for (const auto &cond : node._conds) {
            cond->accept(*this);
        }
        node._exp->accept(*this);
    }
    virtual void visit(const YWaitFor &node) { debug("WaifFor %s", node._actor.c_str()); }
    virtual void visit(const YWaitWhile &node) { debug("WaitWhile %s", node._cond.c_str()); }
    virtual void visit(const YLimit &node) { debug("Limit: %d", node._max); }
    virtual void visit(const YAllowObjects &node) { debug("AllowObjects"); }
    virtual void visit(const YShutup &node) { debug("Shutup"); }
    virtual void visit(const YOverride &node) { defaultVisit(node); }
    virtual void visit(const YDialog &node) { debug("Dialog: %s", node._actor.c_str()); }
    virtual void visit(const YParrot &node) { debug("Parrot: %s", node._active ? "YES" : "NO"); }
    virtual void visit(const YPause &node) { debug("Pause: %d", node._time); }
    virtual void visit(const YSay &node) { debug("Say: actor: %s, text = %s", node._actor.c_str(), node._text.c_str()); }
    virtual void visit(const YChoice &node) { debug("Choice %d: %s -> %s", node._number, node._text.c_str(), node._goto->_name.c_str()); }
    virtual void visit(const YCodeExp &node) { debug("Code: %s", node._code.c_str()); }
    virtual void visit(const YGoto &node) { debug("Goto: %s", node._name.c_str()); }
    virtual void visit(const YTempOnce &node) { debug("TempOnce"); }
    virtual void visit(const YOnceEver &node) { debug("OnceEver"); }
    virtual void visit(const YShowOnce &node) { debug("ShowOnce"); }
    virtual void visit(const YOnce &node) { debug("Once"); }
    virtual void visit(const YCodeCond &node) { debug("Cond: %s", node._code.c_str()); }

    virtual void defaultVisit(const YackNode &node) {}
};

} // namespace Twp

#endif