ParseNode.h

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/* ParseNode.h
 
   Copyright (C)  David C. J. Matthews 2004  dm at prolingua.co.uk
 
   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 2
   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, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
   Or, point your browser to http://www.gnu.org/copyleft/gpl.html
 
*/
 
 
#if !defined(PARSE_NODE_H)
#define PARSE_NODE_H
 
#include "BaseClasses.h"
 
class MHGroup;
 
// Abstract base class for the text and binary parsers.
class MHParseBase {
  public:
    virtual ~MHParseBase() = default;
    virtual MHParseNode *Parse() = 0;
};
 
// Element of the parse tree, basically a piece of the program.
class MHParseNode  
{
  public:
    enum NodeType : std::uint8_t { PNTagged, PNBool, PNInt, PNEnum, PNString, PNNull, PNSeq };
  protected:
    explicit MHParseNode(enum NodeType nt): m_nNodeType(nt) {}
  public:
    virtual ~MHParseNode() = default;
    enum NodeType m_nNodeType;
 
    [[noreturn]] static void Failure(const char *p); // Report a parse failure.
 
    // Destructors - extract data and raise an exception if the Node Type is wrong.
 
    // Tagged
    int GetTagNo();
    int GetArgCount();
    MHParseNode *GetArgN(int n);
    MHParseNode *GetNamedArg(int nTag); // Also for sequence.
 
    // Sequence.
    int GetSeqCount();
    MHParseNode *GetSeqN(int n);
 
    // Int
    int GetIntValue();
    // Enum
    int GetEnumValue();
    // Bool
    bool GetBoolValue();
    // String
    void GetStringValue(MHOctetString &str);
 
    void PrintMe(FILE *f);
};
 
// Sequence of parse nodes.
class MHParseSequence: public MHParseNode, public MHOwnPtrSequence<MHParseNode>
{
  public:
    MHParseSequence(): MHParseNode(PNSeq) {}
    void PrintUnbracketed(int nTabs);
};
 
// At the moment all tagged items, i.e. everything except a primitive constant, belong
// to this class.  We will make derived classes in due course.
class MHPTagged: public MHParseNode
{
  public:
    explicit MHPTagged(int nTag)
        : MHParseNode(PNTagged), m_TagNo(nTag) {}
    void AddArg(MHParseNode *pArg);
 
    int m_TagNo;
    MHParseSequence m_Args;
};
 
// Primitive integer value.
class MHPInt: public MHParseNode
{
  public:
    explicit MHPInt(int v): MHParseNode(PNInt), m_Value(v) {}
 
  public:
    int m_Value;
};
 
// Enumerated type - treat much as integer
class MHPEnum: public MHParseNode
{
  public:
    explicit MHPEnum(int v): MHParseNode(PNEnum), m_Value(v) {}
  public:
    int m_Value;
};
 
// Primitive boolean value
class MHPBool: public MHParseNode
{
  public:
    explicit MHPBool(bool v): MHParseNode(PNBool),  m_Value(v) {}
 
  public:
    bool m_Value;
};
 
// Primitive string value
class MHPString: public MHParseNode
{
  public:
    explicit MHPString(const MHOctetString &pSrc): MHParseNode(PNString) { m_Value.Copy(pSrc); }
 
  public:
    MHOctetString m_Value;
};
 
// ASN1 NULL value.
class MHPNull: public MHParseNode
{
  public:
    MHPNull(): MHParseNode(PNNull) {}
};
 
void PrintTabs(FILE *fd, int nTabs); // Support function for printing.
 
#endif