syntax.h

this is a lp0 compilator new

//
// ********************************************************************
// *                            syntax.h
// *   ------------------------------------------------------------    
// *   Author        : Gerald Carter
// *                   [e-mail]
// *   Filename      : syntax.h
// *   Date Created  : 960110
// *
// *   Description : This is the header file for a C++ class
// *       implementation of a syntax tree.
// *
// *   -------------------------
// *   Modifications 
// *   -------------------------
// *   970219  [e-mail]	Gerald Carter
// *		Added the method expression2string in order to convert
// *		a syntax tree to a character string ( stringcl ).
// *
// *********************************************************************
//

// Test for previous inclusion
#ifndef _SYNTAX_H
#define _SYNTAX_H

// ###################################################################
// ## Class Declaration Tag
// ##
class symbolNode;		// defined in symbol.h
class syntaxNode;

// HEADER FILES
#include <iostream.h>
#include "labels.h"
#include "stringcl.h"

typedef struct {
   int		label_id;
   char*	name;
} labelEntry;


// ####################################################################
// ## class syntaxNode
// ##
class syntaxNode {
   private :
      union family_part {
         syntaxNode		**children;
         symbolNode		*lexeme;
      };
 
      int               label;
      int               child_label;
      int               num_children;
      family_part	family;		

      static labelEntry	labels[];

      // Private member function for class use only (utilities)
      void PrintChildren (ostream&, char*, int&);
      void ExpressChildren ( string& );
      void OutputGML ( ostream&, int& );

   public :
      // Constructors & Destructor
      syntaxNode ( void ) { 
         label = child_label = num_children = 0;
	 family.lexeme = 0; 
      }
      syntaxNode (int new_label)
	 { label = new_label;
	   child_label = num_children = 0;
	   family.lexeme = 0; }
      ~syntaxNode (void)
	 { delete [](family.children); }

      // General Access methods
      int SetLabel (int new_label) 
         { label = new_label; return label; }
      int GetLabel (void) { return label; }
      int GetChildLabel (void) { return child_label; }
      syntaxNode** AdoptChildren (int, int, syntaxNode*[]);
      syntaxNode** GetChildren (void) {
	 if ( num_children==0 ) 
            return ( 0 );
         else
            return ( family.children ); 
      }
      int SizeOfFamily (void) { return num_children; }
      symbolNode *SetLexeme (symbolNode* new_lexeme) { 
         num_children = 0; 
         family.lexeme = new_lexeme; 
         return family.lexeme; 
      }
      symbolNode *GetLexeme (void) { return (family.lexeme); }

      // Output method
      virtual void PrintTree (ostream&, char*, int&);
      virtual void PrintTreeLabels (ostream&);
      virtual char* label2string ( int, char[] );
      virtual void PrintGML ( ostream& );
      virtual string& expression2string ( string& );
      
      // Overloaded  Operators
      syntaxNode& operator= (syntaxNode&);
};      // end of class syntaxNode

// MORE HEADER FILES
#include "symbol.h"

#endif

//******** end of syntax.h ********************************************
//*********************************************************************