/* 
*
*  ProLinga-Calc
*
*  Copyright (C) 2002-2008 Xobas Software
*  All rights reserved.
*  
*  This file is part of ProLinga-Calc.
*
*  ProLinga-Calc 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.
*
*  ProLinga-Calc 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 ProLinga-Calc.  If not, see <http://www.gnu.org/licenses/>.
*
*  More information is available at the following addresses:
*
*  Website     : http://www.prolinga.org
*
*  Email       : prolinga-list@prolinga.org
*
*
*/

#ifndef __CALC_LIB_HPP
#define __CALC_LIB_HPP 1

class symbol;

enum t_value
{ 
	INT, 
	FLOAT
};

class value
{ 
	public:
		t_value tag;
		symbol* var;
		int pos;
		union
		{ 
			int    ival;
			double fval;
		};
    
		double get() 
		{ 
			return tag == INT ? (double)ival : fval;
		}

		int get_int()
		{ 
			return tag == INT ? ival : (int)fval;
    		}
};

enum t_operator
{ 
	BEGIN, OPERAND, ERROR, END, 
	LPAR, RPAR, FUNC, POSTINC, POSTDEC,
	PREINC, PREDEC, PLUS, MINUS, NOT, COM,
	POW,
	MUL, DIV, MOD,
	ADD, SUB, 
	ASL, ASR, LSR, 
	GT, GE, LT, LE,     
	EQ, NE, 
	AND,
	XOR,
	OR,
	SET, SETADD, SETSUB, SETMUL, SETDIV, SETMOD, SETASL, SETASR, SETLSR, 
	SETAND, SETXOR, SETOR, SETPOW,
	COMMA,
	TERMINALS
};

#define BINARY(opd) (opd >= POW)

enum t_symbol 
{ 
	VARIABLE, 
	IFUNC1, 
	FFUNC1, 
	FFUNC2 
};


#define CALC_MAX_STACK_SIZE	256
#define CALC_MAX_EXP_LEN	1024
#define CALC_HASH_TABLE_SIZE	1013

class symbol
{ 
	public:
		t_symbol tag;
		void* func;
		value val;
		char* name;
		symbol* next;

		static symbol* hash_table[CALC_HASH_TABLE_SIZE];

		static symbol* add(t_symbol tag, const char* name, void* func = NULL);
};
	       
class calculator
{ 
	public:
		value v_stack[CALC_MAX_STACK_SIZE];
		int v_sp;
		int o_stack[CALC_MAX_STACK_SIZE];
		int o_sp;
		char* buf;
		int pos;
		int tmp_var_count;
    
		void evaluate(char* expr);
		t_operator scan(bool operand);
		void calcerror(int pos, const char* msg);
		void calcerror(const char* msg) { calcerror(pos-1, msg); }
		bool assign();

		calculator() { tmp_var_count = 0; }
};

#endif /* __CALC_LIB_HPP */