/*
    $Id: kcalc_core.cpp 541875 2006-05-17 14:42:51Z zander $

    kCalculator, a scientific calculator for the X window system using the
    TQt widget libraries, available at no cost at http://www.troll.no

    The stack engine conatined in this file was take from
    Martin Bartlett's xfrmcalc

    portions:   Copyright (C) 1996 Bernd Johannes Wuebben
                                   wuebben@math.cornell.edu

    portions:   Copyright (C) 1995 Martin Bartlett

    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.

*/

#include <config.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <limits.h>
#include <math.h>
#include <signal.h>
#include <klocale.h>
#include <kmessagebox.h>
#include <knotifyclient.h>

#include "kcalc.h"

//What's that?!? (Werner)
//#define i18n( x ) x

// Undefine HAVE_LONG_DOUBLE for Beta 4 since RedHat 5.0 comes with a borken
// glibc

#ifdef HAVE_LONG_DOUBLE
#undef HAVE_LONG_DOUBLE
#endif

#ifndef HAVE_FUNC_ISINF
#ifdef HAVE_IEEEFP_H
#include <ieeefp.h>
#else
#include <math.h>
#endif

int isinf(double x) { return !finite(x) && x==x; }
#endif

extern TQPtrList<CALCAMNT> temp_stack;
last_input_type last_input;
char            display_str[DSP_SIZE+1];

stack_ptr       top_of_stack = NULL;
stack_ptr       top_type_stack[2] = { NULL, NULL };
int             stack_next, stack_last;
stack_item      process_stack[STACK_SIZE];

int             inverse = FALSE;
int             precedence_base = 0;
num_base        current_base = NB_DECIMAL;
int             input_limit = 0;
int             input_count = 0;

//item_contents         display_data = { ITEM_AMOUNT, 0 };
item_contents   display_data;

int             display_size = DEC_SIZE;

int             hyp_mode = 0;
int             angle_mode = ANG_DEGREE;
int             refresh_display; // if 1 we start a new number
int             display_error = 0;
int             decimal_point = 0;
int             percent_mode = 0;
bool            eestate = false; // if true then we are in ee input mode

CALCAMNT        pi;
CALCAMNT        memory_num = 0.0;

int precedence[14] = { 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7, 6 };

    int         adjust_op[14][3] = {
                                {FUNC_NULL,     FUNC_NULL,     FUNC_NULL},
                                {FUNC_OR,       FUNC_OR,       FUNC_XOR },
                                {FUNC_XOR,      FUNC_XOR,      FUNC_XOR },
                                {FUNC_AND,      FUNC_AND,      FUNC_AND },
                                {FUNC_LSH,      FUNC_LSH,      FUNC_RSH },
                                {FUNC_RSH,      FUNC_RSH,      FUNC_RSH },
                                {FUNC_ADD,      FUNC_ADD,      FUNC_ADD },
                                {FUNC_SUBTRACT, FUNC_SUBTRACT, FUNC_SUBTRACT},
                                {FUNC_MULTIPLY, FUNC_MULTIPLY, FUNC_MULTIPLY},
                                {FUNC_DIVIDE,   FUNC_DIVIDE,   FUNC_DIVIDE},
                                {FUNC_MOD,      FUNC_MOD,      FUNC_INTDIV },
                                {FUNC_POWER,    FUNC_POWER,    FUNC_PWR_ROOT},
                                {FUNC_PWR_ROOT, FUNC_PWR_ROOT, FUNC_PWR_ROOT},
                                {FUNC_INTDIV,   FUNC_INTDIV,   FUNC_INTDIV},
    };
/*
    char                *function_desc[] = {

      "Null",
      "Or",
      "Exclusive Or",
      "And",
      "Left Shift",
      "Right Shift",
      "Add",
      "Subtract",
      "Multiply",
      "Divide",
      "Modulus"
      "Power"
      "Reciprocal Power"
      "Integer Division"
    };
    */
    Arith       Arith_ops[14] = { NULL,
                                  ExecOr,
                                  ExecXor,
                                  ExecAnd,
                                  ExecLsh,
                                  ExecRsh,
                                  ExecAdd, ExecSubtract,
                                  ExecMultiply,
                                  ExecDivide, ExecMod,
                                  ExecPower, ExecPwrRoot,
                                  ExecIntDiv
    };

    Prcnt       Prcnt_ops[14] = { NULL,
                                  NULL,
                                  NULL,
                                  NULL,
                                  NULL,
                                  NULL,
                                  ExecAddSubP,  ExecAddSubP,
                                  ExecMultiplyP,
                                  ExecDivideP, ExecDivideP,
                                  ExecPowerP, ExecPwrRootP,
                                  ExecDivideP
    };


void TQtCalculator::InitializeCalculator(void) {

  //
  // Basic initialization involves initializing the calcultion
  // stack, forcing the display to refresh to zero, and setting
  // up the floating point excetion signal handler to trap the
  // errors that the code can/has not been written to trap.
  //
  // We also calculate pi as double the arc sine of 1.
  //

  display_data.s_item_type = ITEM_AMOUNT;
  display_data.s_item_data.item_amount = 0.0;
  display_data.s_item_data.item_func_data.item_function = 0;
  display_data.s_item_data.item_func_data.item_precedence = 0;

  void fpe_handler(int fpe_parm);
  struct sigaction  fpe_trap;

  fpe_trap.sa_handler = &fpe_handler;
#ifdef SA_RESTART
  fpe_trap.sa_flags = SA_RESTART;
#endif

  sigaction(SIGFPE, &fpe_trap, NULL);

  RefreshCalculator();
  pi = ASIN(1.0) * 2L;
}

void fpe_handler(int fpe_parm)
{
  (void) fpe_parm;

  display_error = 1;
  DISPLAY_AMOUNT = 0L;

}

void TQtCalculator::setData( const TQRect& _range, const char *_sheet )
{
  sheet_range = _range;
  sheet_name = _sheet;
}

void TQtCalculator::setValue( double _value )
{
  last_input = DIGIT;
  DISPLAY_AMOUNT = _value;
  decimal_point = 0;
  refresh_display = 1;
  input_count = 0;

  UpdateDisplay();
}

void TQtCalculator::setLabel( const char *_text )
{
  last_input = DIGIT;
  DISPLAY_AMOUNT = 0L;
  decimal_point = 0;
  refresh_display = 0;
  input_count = 0;

  calc_display->setText( _text );
}

void TQtCalculator::RefreshCalculator(void)
{
        InitStack();
        display_error = 0;
        DISPLAY_AMOUNT = 0L;
        inverse = FALSE;
        UpdateDisplay();
        last_input = DIGIT; // must set last to DIGIT after Update Display in order
                            // not to get a display holding e.g. 0.000
        input_count = 0;
        decimal_point = 0;
}

void TQtCalculator::EnterDigit(int data)
{

  if(eestate){

    TQString string;
    string.setNum(data);
    strcat(display_str, string.latin1());
    DISPLAY_AMOUNT = (CALCAMNT) strtod(display_str,0);
    UpdateDisplay();
    return;

  }

  last_input = DIGIT;
  if (refresh_display) {
    DISPLAY_AMOUNT = 0L;
    decimal_point = 0;
    refresh_display = 0;
    input_count = 0;
  }

  if (!(input_limit && input_count >= input_limit))
    if (DISPLAY_AMOUNT < 0)
      DISPLAY_AMOUNT = decimal_point ?
        DISPLAY_AMOUNT - ((CALCAMNT)data /
                          POW((float)current_base, decimal_point++)) :
    (current_base * DISPLAY_AMOUNT) - data;
    else
      DISPLAY_AMOUNT = decimal_point ?
        DISPLAY_AMOUNT + ((CALCAMNT)data /
                          POW((float)current_base, decimal_point++)) :
    (current_base * DISPLAY_AMOUNT) + data;

  if (decimal_point){
    input_count ++;

#ifdef MYDEBUG
    printf("EnterDigit() inc dec.point:%d\n",input_count);
#endif

  }
  UpdateDisplay();
}

void TQtCalculator::button0()
{
  EnterDigit(0);
}

void TQtCalculator::button1()
{
  EnterDigit(1);
 }

void TQtCalculator::button2()
{
  if (current_base == NB_BINARY)
    return;
  EnterDigit(2);
}

void TQtCalculator::button3()
{
  if (current_base == NB_BINARY)
    return;
  EnterDigit(3);
}

void TQtCalculator::button4()
{
  if (current_base == NB_BINARY)
    return;
  EnterDigit(4);
}

void TQtCalculator::button5()
{
  if (current_base == NB_BINARY)
    return;
  EnterDigit(5);
}

void TQtCalculator::button6()
{
  if (current_base == NB_BINARY)
    return;
  EnterDigit(6);
}

void TQtCalculator::button7()
{
  if (current_base == NB_BINARY)
    return;
  EnterDigit(7);
}

void TQtCalculator::button8()
{
  if ((current_base == NB_BINARY) || (current_base == NB_OCTAL))
    return;
  EnterDigit(8);
}

void TQtCalculator::button9()
{
  if ((current_base == NB_BINARY) || (current_base == NB_OCTAL))
    return;
  EnterDigit(9);
}


void TQtCalculator::buttonA()
{
  if ((current_base == NB_BINARY) || (current_base == NB_OCTAL)
      || (current_base == NB_DECIMAL))
    return;
  EnterDigit(10);
}


void TQtCalculator::buttonB()
{
  if ((current_base == NB_BINARY) || (current_base == NB_OCTAL)
      || (current_base == NB_DECIMAL))
    return;
  EnterDigit(11);
}


void TQtCalculator::buttonC()
{
   if ((current_base == NB_BINARY) || (current_base == NB_OCTAL)
      || (current_base == NB_DECIMAL))
    return;
  EnterDigit(12);
}


void TQtCalculator::buttonD()
{
   if ((current_base == NB_BINARY) || (current_base == NB_OCTAL)
      || (current_base == NB_DECIMAL))
    return;
  EnterDigit(13);
}


void TQtCalculator::buttonE()
{
   if ((current_base == NB_BINARY) || (current_base == NB_OCTAL)
      || (current_base == NB_DECIMAL))
    return;
  EnterDigit(14);
}

void TQtCalculator::buttonF()
{
   if ((current_base == NB_BINARY) || (current_base == NB_OCTAL)
      || (current_base == NB_DECIMAL))
    return;
  EnterDigit(15);
}



void TQtCalculator::EnterDecimal()
{

  if(eestate){
    KNotifyClient::beep();
    return;
  }

  decimal_point = 1;
  if (refresh_display) {
    DISPLAY_AMOUNT = 0L;
    refresh_display = 0;
    input_count = 0;
  }

  if (last_input == DIGIT && !strpbrk( display_str,".")){

    // if the last input was a DIGIT and we don't have already a period in our
    // display string then display a period

    calc_display->setText(strcat(display_str, "."));
  }
  else {

    // the last input wasn't a DIGIT so we are about to
    // input a new number in particular we neet do display a "0.".

    DISPLAY_AMOUNT = 0L;
    refresh_display = 0;
    //    decimal_point = 1;
    //    input_count = 1;
    strcpy(display_str, "0.");
    calc_display->setText(display_str);
  }
}


void TQtCalculator::Or()
{
  eestate = false;
  if (inverse){
    EnterStackFunction(2);   // XOR
    inverse = FALSE;
  }
  else {
    EnterStackFunction(1);   // OR
  }
  last_input = OPERATION;
}

void TQtCalculator::And()
{
  eestate = false;
  last_input = OPERATION;
  EnterStackFunction(3);
}


void TQtCalculator::Shift()
{
  eestate = false;
  last_input = OPERATION;
  if (inverse){
    EnterStackFunction(5);   // Rsh
    inverse = FALSE;
  }
  else {
    EnterStackFunction(4);   // Lsh
  }

}

void TQtCalculator::Plus()
{
  eestate = false;
  last_input = OPERATION;
  EnterStackFunction(6);
}

void TQtCalculator::Minus()
{
  eestate = false;
  last_input = OPERATION;
  EnterStackFunction(7);

}

void TQtCalculator::Multiply()
{
  eestate = false;
  last_input = OPERATION;
  EnterStackFunction(8);
}

void TQtCalculator::Divide()
{
  eestate = false;
  last_input = OPERATION;
  EnterStackFunction(9);
}

void TQtCalculator::Mod()
{
  eestate = false;
  last_input = OPERATION;
  if (inverse){
    EnterStackFunction(13);   // InvMod
    inverse = FALSE;
  }
  else {
    EnterStackFunction(10);   // Mod
  }
}

void TQtCalculator::Power()
{
  eestate = false;
  last_input = OPERATION;
  if (inverse){
    EnterStackFunction(12);   // InvPower
    inverse = FALSE;
  }
  else {
    EnterStackFunction(11);   // Power
  }

}



void TQtCalculator::EnterStackFunction(int data)
{
        item_contents   new_item;
        int             new_precedence;
        int             dummy;

        dummy = 0;

        /*
        if (inverse ) {
          dummy = 3;
          inverse = FALSE;
        }
        else {
          dummy = 1;
        }
        */

        //      printf("data %d dummy %d\n",data,dummy);
        data = adjust_op[data][dummy];
        //      printf("data %d \n",data );

        PushStack(&display_data);

        new_item.s_item_type = ITEM_FUNCTION;
        new_item.s_item_data.item_func_data.item_function = data;
        new_item.s_item_data.item_func_data.item_precedence =
                new_precedence = precedence[data] + precedence_base;

        refresh_display = 1;
        if (UpdateStack(new_precedence))
                UpdateDisplay();
        PushStack(&new_item);
}

void TQtCalculator::EnterNegate()
{

  if(eestate){
    TQString string;
    string = display_str;
    int pos;
    pos = string.findRev('e',-1,false);
    if(pos == -1)
      return;

    if(display_str[pos+1] == '+')
      display_str[pos+1] = '-';
    else{
      if(display_str[pos+1] == '-')
        display_str[pos+1] = '+';
      else{
        string.insert(pos +1,'-');
        strncpy(display_str,string.latin1(),DSP_SIZE);
      }
    }
    DISPLAY_AMOUNT = (CALCAMNT)strtod(display_str,0);
    UpdateDisplay();
  }
  else{
    //    last_input = OPERATION;
    if (DISPLAY_AMOUNT != 0) {
      DISPLAY_AMOUNT *= -1;
      UpdateDisplay();
    }
  }
  last_input = DIGIT;
}

void TQtCalculator::EnterOpenParen()
{
  eestate = false;
        last_input = OPERATION;
        precedence_base += PRECEDENCE_INCR;
        refresh_display = 1;

}

void TQtCalculator::EnterCloseParen()
{
  eestate = false;
        last_input = OPERATION;
        PushStack(&display_data);
        refresh_display = 1;
        if (UpdateStack(precedence_base))
                UpdateDisplay();
        if ((precedence_base -= PRECEDENCE_INCR) < 0)
                precedence_base = 0;

}

void TQtCalculator::EnterRecip()
{
  eestate = false;
  last_input = OPERATION;
  DISPLAY_AMOUNT = 1 / DISPLAY_AMOUNT;
  refresh_display = 1;
  UpdateDisplay();
}

void TQtCalculator::EnterInt()
{
  eestate = false;
  CALCAMNT work_amount1 = 0.0, work_amount2 = 0.0;

        last_input = OPERATION;
        if (!inverse){
          work_amount2 = MODF(DISPLAY_AMOUNT, &work_amount1);
          DISPLAY_AMOUNT = work_amount2 ;
            }
        else {
          DISPLAY_AMOUNT = work_amount1;
          inverse = FALSE;
        }

        refresh_display = 1;
        UpdateDisplay();

}

void TQtCalculator::EnterFactorial()
{
  eestate = false;
        CALCAMNT work_amount1, work_amount2;
        int      incr;

        MODF(DISPLAY_AMOUNT, &work_amount1);

        incr = work_amount1 < 0 ? -1 : 1;
        work_amount2 = work_amount1 - incr;
        while (work_amount1 != 0 && work_amount2 != 0 && !display_error) {
                work_amount1 *= work_amount2;
                work_amount2 -= incr;
                if(isinf(work_amount1)) {
                  display_error=1;
                   break;
                }
        }

        if( work_amount1 == 0.0)
          work_amount1 = 1.0;

        DISPLAY_AMOUNT = work_amount1;
        refresh_display = 1;
        last_input = OPERATION;
        UpdateDisplay();

}

void TQtCalculator::EnterSquare()
{
  eestate = false;
        if (!inverse){
                DISPLAY_AMOUNT *= DISPLAY_AMOUNT;
        }
        else if (DISPLAY_AMOUNT < 0)
        display_error = 1;
        else
                DISPLAY_AMOUNT = SQRT(DISPLAY_AMOUNT);
        refresh_display = 1;
        inverse = FALSE;
        last_input = OPERATION;
        UpdateDisplay();

}

void TQtCalculator::EnterNotCmp()
{
  eestate = false;
        CALCAMNT        boh_work_d;
        long            boh_work;

        MODF(DISPLAY_AMOUNT, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX)
                display_error = 1;
                else {
                boh_work = (long int) boh_work_d;
                DISPLAY_AMOUNT = ~boh_work;
                        }
        refresh_display = 1;
        last_input = OPERATION;
        UpdateDisplay();

}

void TQtCalculator::EnterHyp()
{

  switch(kcalcdefaults.style){
  case 2:
  case 1:{
    if ( !sheet_name.isEmpty() )
      useData();

    if(!inverse){
    eestate = false; // terminate ee input mode
    DISPLAY_AMOUNT =  stats.count();
    last_input = OPERATION;
    refresh_display = 1;
    UpdateDisplay();
    }
    else{
    inverse = false;
    eestate = false; // terminate ee input mode
    DISPLAY_AMOUNT =  stats.sum();
    last_input = OPERATION;
    refresh_display = 1;
    UpdateDisplay();
    }

    break;
  }

  case 0: {
    // toggle between hyperbolic and standart trig functions
    hyp_mode = !hyp_mode;

    if (hyp_mode){
      statusHYPLabel->setText("HYP");
    }
    else{
      statusHYPLabel->setText("");
    }
    break;
  }
  }
}


void TQtCalculator::ExecSin(){

  switch(kcalcdefaults.style){

  case 0:{ // trig mode

    ComputeSin();
    break;
  }

  case 1:{ // stats mode
    if ( !sheet_name.isEmpty() )
      useData();

    ComputeMean();
    break;
  }

  case 2:{ // sheet mode
    if ( !sheet_name.isEmpty() )
      useData();

    ComputeMin();
    break;
  }

  }

}

void TQtCalculator::ComputeSum()
{
  inverse = false;
  eestate = false;
  DISPLAY_AMOUNT = stats.sum();
  if (stats.error())
      display_error = 1;

  refresh_display = 1;
  last_input = OPERATION;
  UpdateDisplay();
}

void TQtCalculator::ComputeMul()
{
  inverse = false;
  eestate = false;
  DISPLAY_AMOUNT = stats.mul();
  if (stats.error())
      display_error = 1;

  refresh_display = 1;
  last_input = OPERATION;
  UpdateDisplay();
}

void TQtCalculator::ComputeMin()
{
  inverse = false;
  eestate = false;
  DISPLAY_AMOUNT = stats.min();
  if (stats.error())
      display_error = 1;

  refresh_display = 1;
  last_input = OPERATION;
  UpdateDisplay();
}

void TQtCalculator::ComputeMax()
{
  inverse = false;
  eestate = false;
  DISPLAY_AMOUNT = stats.max();
  if (stats.error())
      display_error = 1;

  refresh_display = 1;
  last_input = OPERATION;
  UpdateDisplay();
}

void TQtCalculator::ComputeMean(){

  if(!inverse){
    eestate = false;
    DISPLAY_AMOUNT = stats.mean();
    if (stats.error())
      display_error = 1;

    refresh_display = 1;
    last_input = OPERATION;
    UpdateDisplay();
  }
  else{
    inverse = false;
    eestate = false;
    DISPLAY_AMOUNT = stats.sum_of_squares();
    if (stats.error())
      display_error = 1;
    refresh_display = 1;
    last_input = OPERATION;
    UpdateDisplay();

  }

}

void TQtCalculator::ComputeSin()
{
  CALCAMNT      work_amount;
  eestate = false;
  work_amount = DISPLAY_AMOUNT;

  if (hyp_mode){
    // sinh or arcsinh
    if (!inverse){
      DISPLAY_AMOUNT = SINH( work_amount);
    }
    else {
      DISPLAY_AMOUNT = ASINH( work_amount);
      if (errno == EDOM || errno == ERANGE)
        display_error = 1;
      inverse = FALSE;       // reset the inverse flag
    }
  }
  else {
    // sine or arcsine
    if (!inverse){
      // sine
      switch (angle_mode) {
      case ANG_DEGREE:
        work_amount = DEG2RAD(DISPLAY_AMOUNT);
        break;
      case ANG_GRADIENT:
        work_amount = GRA2RAD(DISPLAY_AMOUNT);
        break;
      case ANG_RADIAN:
        work_amount = DISPLAY_AMOUNT;
        break;
      }
      DISPLAY_AMOUNT = SIN( work_amount);
    }
    else {
      // arcsine
      DISPLAY_AMOUNT = ASIN(work_amount);
            switch (angle_mode) {
      case ANG_DEGREE:
        work_amount = RAD2DEG(DISPLAY_AMOUNT);
        break;
      case ANG_GRADIENT:
        work_amount = RAD2GRA(DISPLAY_AMOUNT);
        break;
      case ANG_RADIAN:
        work_amount = DISPLAY_AMOUNT;
        break;
      }
      DISPLAY_AMOUNT = work_amount;
      if (errno == EDOM || errno == ERANGE)
        display_error = 1;
      inverse = FALSE;          // reset the inverse flag
    }
  }

// Now a cheat to help the weird case of COS 90 degrees not being 0!!!

  if (DISPLAY_AMOUNT < POS_ZERO && DISPLAY_AMOUNT > NEG_ZERO)
    DISPLAY_AMOUNT=0;
  refresh_display = 1;
  last_input = OPERATION;
  UpdateDisplay();

}

void TQtCalculator::ExecCos(){

  switch(kcalcdefaults.style){

  case 0:{ // trig mode

    ComputeCos();
    break;
  }

  case 1:{ // stats mode
      if ( !sheet_name.isEmpty() )
      useData();

    ComputeStd();
    break;
  }

  case 2:{ // sheet mode
      if ( !sheet_name.isEmpty() )
      useData();

    ComputeMax();
    break;
  }

  }

}

void TQtCalculator::ComputeStd(){

  if(!inverse){ // std (n-1)
    inverse = false;
    eestate = false;
    DISPLAY_AMOUNT = stats.std();

    if (stats.error()){
      display_error = 1;
    }

    refresh_display = 1;
    last_input = OPERATION;
    UpdateDisplay();
  }
  else{ // std (n)

    inverse = false;
    eestate = false;
    DISPLAY_AMOUNT = stats.sample_std();

    if (stats.error())
      display_error = 1;

    refresh_display = 1;
    last_input = OPERATION;
    UpdateDisplay();



  }

}

void TQtCalculator::ComputeCos()
{
  CALCAMNT      work_amount;
  eestate = false;
  work_amount = DISPLAY_AMOUNT;

  if (hyp_mode){
    // cosh or arccosh
    if (!inverse){
      DISPLAY_AMOUNT = COSH( work_amount);
    }
    else {
      DISPLAY_AMOUNT = ACOSH( work_amount);
      if (errno == EDOM || errno == ERANGE)
        display_error = 1;
      inverse = FALSE;       // reset the inverse flag
    }
  }
  else {
    // cosine or arccosine
    if (!inverse){
      // sine
      switch (angle_mode) {
      case ANG_DEGREE:
        work_amount = DEG2RAD(DISPLAY_AMOUNT);
        break;
      case ANG_GRADIENT:
        work_amount = GRA2RAD(DISPLAY_AMOUNT);
        break;
      case ANG_RADIAN:
        work_amount = DISPLAY_AMOUNT;
        break;
      }
      DISPLAY_AMOUNT = COS( work_amount);
    }
    else {
      // arccosine
      DISPLAY_AMOUNT = ACOS(work_amount);
      switch (angle_mode) {
      case ANG_DEGREE:
        work_amount = RAD2DEG(DISPLAY_AMOUNT);
        break;
      case ANG_GRADIENT:
        work_amount = RAD2GRA(DISPLAY_AMOUNT);
        break;
      case ANG_RADIAN:
        work_amount = DISPLAY_AMOUNT;
        break;
      }

      DISPLAY_AMOUNT = work_amount;

      if (errno == EDOM || errno == ERANGE)
        display_error = 1;
      inverse = FALSE;          // reset the inverse flag
    }
  }

// Now a cheat to help the weird case of COS 90 degrees not being 0!!!


  if (DISPLAY_AMOUNT < POS_ZERO && DISPLAY_AMOUNT > NEG_ZERO)
    DISPLAY_AMOUNT=0;
  refresh_display = 1;
  last_input = OPERATION;
  UpdateDisplay();

}

void TQtCalculator::ExecTan(){

  switch(kcalcdefaults.style){

  case 0:{ // trig mode

    ComputeTan();
    break;
  }

  case 2:
  case 1:{ // stats mode

    if ( !sheet_name.isEmpty() )
      useData();

    ComputeMedean();
    break;
  }

  }

}

void TQtCalculator::ComputeMedean(){

  if(!inverse){ // std (n-1)
    inverse = false;
    eestate = false;
    DISPLAY_AMOUNT = stats.median();

    if (stats.error()){
      display_error = 1;
    }

    refresh_display = 1;
    last_input = OPERATION;
    UpdateDisplay();
  }
  else{ // std (n)

    inverse = false;
    eestate = false;
    DISPLAY_AMOUNT = stats.median();

    if (stats.error())
      display_error = 1;

    refresh_display = 1;
    last_input = OPERATION;
    UpdateDisplay();

  }
}


void TQtCalculator::ComputeTan()
{
  CALCAMNT      work_amount;
  eestate = false;
  work_amount = DISPLAY_AMOUNT;

  if (hyp_mode){
    // tanh or arctanh
    if (!inverse){
      DISPLAY_AMOUNT = TANH( work_amount);
    }
    else {
      DISPLAY_AMOUNT = ATANH( work_amount);
      if (errno == EDOM || errno == ERANGE)
        display_error = 1;
      inverse = FALSE;       // reset the inverse flag
    }
  }
  else {
    // tan or arctan
    if (!inverse){
      // tan
      switch (angle_mode) {
      case ANG_DEGREE:
        work_amount = DEG2RAD(DISPLAY_AMOUNT);
        break;
      case ANG_GRADIENT:
        work_amount = GRA2RAD(DISPLAY_AMOUNT);
        break;
      case ANG_RADIAN:
        work_amount = DISPLAY_AMOUNT;
        break;
      }
      DISPLAY_AMOUNT = TAN( work_amount);
      if (errno == EDOM || errno == ERANGE)
        display_error = 1;
    }
    else {
      // arctan
      DISPLAY_AMOUNT = ATAN(work_amount);
      switch (angle_mode) {
      case ANG_DEGREE:
        work_amount = RAD2DEG(DISPLAY_AMOUNT);
        break;
      case ANG_GRADIENT:
        work_amount = RAD2GRA(DISPLAY_AMOUNT);
        break;
      case ANG_RADIAN:
        work_amount = DISPLAY_AMOUNT;
        break;
      }

      DISPLAY_AMOUNT = work_amount;

      if (errno == EDOM || errno == ERANGE)
        display_error = 1;
      inverse = FALSE;          // reset the inverse flag
    }
  }

// Now a cheat to help the weird case of COS 90 degrees not being 0!!!

  if (DISPLAY_AMOUNT < POS_ZERO && DISPLAY_AMOUNT > NEG_ZERO)
    DISPLAY_AMOUNT=0;
  refresh_display = 1;
  last_input = OPERATION;
  UpdateDisplay();

}


void TQtCalculator::EnterPercent()
{
  eestate = false;
  last_input = OPERATION;
  percent_mode = 1;
  EnterEqual();
  percent_mode = 0;

}

void TQtCalculator::EnterLogr()
{

  switch(kcalcdefaults.style){
  case 2:
    {
      if ( !sheet_name.isEmpty() )
        useData();

      ComputeSum();
      break;
    }
  case 1:{

    if ( !sheet_name.isEmpty() )
      useData();

    if(!inverse){
      eestate = false; // terminate ee input mode
      stats.enterData(DISPLAY_AMOUNT);
      last_input = OPERATION;
      refresh_display = 1;
      DISPLAY_AMOUNT = stats.count();
      UpdateDisplay();
    }
    else{
      inverse = false;
      last_input = OPERATION;
      refresh_display = 1;
      stats.clearLast();
      setStatusLabel("Last stat item erased");
      DISPLAY_AMOUNT = stats.count();
      UpdateDisplay();

    }

    break;
  }
  case 0:{

    eestate = false;
    last_input = OPERATION;

    if (!inverse) {
      if (DISPLAY_AMOUNT <= 0)
        display_error = 1;
      else
        DISPLAY_AMOUNT = LOG_TEN(DISPLAY_AMOUNT);
      refresh_display = 1;
      UpdateDisplay();
    } else if (inverse) {
      DISPLAY_AMOUNT = POW(10, DISPLAY_AMOUNT);
      refresh_display = 1;
      inverse = FALSE;
      UpdateDisplay();
    }
    break;
  }
  }
}

void TQtCalculator::EnterLogn()
{

  switch(kcalcdefaults.style){
  case 2:{

    if ( !sheet_name.isEmpty() )
      useData();

    ComputeMul();

    break;
  }
  case 1:{

    if ( !sheet_name.isEmpty() )
      useData();

    if(!inverse){

      stats.clearAll();
      setStatusLabel(i18n("Stat mem cleared"));

    }
    else{
      inverse = false;
      UpdateDisplay();
    }

    break;
  }
  case 0:{
    eestate = false;
    last_input = OPERATION;
    if (!inverse) {
      if (DISPLAY_AMOUNT <= 0)
        display_error = 1;
      else
        DISPLAY_AMOUNT = LOG(DISPLAY_AMOUNT);
      refresh_display = 1;
      UpdateDisplay();
    } else if (inverse) {
      DISPLAY_AMOUNT = EXP(DISPLAY_AMOUNT);
      refresh_display = 1;
      inverse =FALSE;
      UpdateDisplay();
    }
    break;
  }
  }

}


void TQtCalculator::base_selected(int number){

  switch(number){
  case 0:
    SetHex();
    break;
  case 1:
    SetDec();
    break;
  case 2:
    SetOct();
    break;
  case 3:
    SetBin();
    break;
  default: // we shouldn't ever end up here
    SetDec();
    }
}


void TQtCalculator::angle_selected(int number){

  switch(number){
  case 0:
    SetDeg();
    break;
  case 1:
    SetRad();
    break;
  case 2:
    SetGra();
    break;
  default: // we shouldn't ever end up here
    SetRad();
    }
}

void TQtCalculator::SetInverse(){

  inverse = ! inverse;
  if (inverse){
    statusINVLabel->setText("INV");
  }
  else{
    statusINVLabel->setText("NORM");
  }
}


void TQtCalculator::SetDeg() {
        angle_mode = ANG_DEGREE;
}

void TQtCalculator::SetGra() {
        angle_mode = ANG_GRADIENT;
}

void TQtCalculator::SetRad() {
        angle_mode = ANG_RADIAN;

}

void TQtCalculator::SetHex() {
        /*
         * Set Hex Mode
         */

        current_base = NB_HEX;
        display_size = BOH_SIZE;
        decimal_point = 0;
        input_limit = 8;

        UpdateDisplay();
}

void TQtCalculator::SetOct() {
        /*
         * Set Oct Mode
         */

        current_base = NB_OCTAL;
        display_size = BOH_SIZE;
        decimal_point = 0;
        input_limit = 11;

        UpdateDisplay();
}

void TQtCalculator::SetBin() {
        /*
         * Set Bin Mode
         */

        current_base = NB_BINARY;
        display_size = BOH_SIZE;
        decimal_point = 0;
        input_limit = 16;

        UpdateDisplay();
}

void TQtCalculator::SetDec()
{
        /*
         * Set Dec Mode
         */

        current_base = NB_DECIMAL;
        display_size = DEC_SIZE;
        input_limit = 0;


        UpdateDisplay();
}


void TQtCalculator::EE()
{
  if(inverse){
    DISPLAY_AMOUNT = pi;
    inverse = FALSE;
    UpdateDisplay();
  }
  else{
    if(eestate == true)
      eestate = false;
    else{
      eestate = true;
      strcat(display_str,"e");
    }

    UpdateDisplay();
  }

}

void TQtCalculator::MR()
{
  eestate = false;
  last_input = OPERATION;
  DISPLAY_AMOUNT = memory_num;
  refresh_display = 1;
  UpdateDisplay();

}

void TQtCalculator::Mplusminus()
{

  eestate = false;
  EnterEqual();
  if (!inverse)
    memory_num += DISPLAY_AMOUNT;
  else {
    memory_num -= DISPLAY_AMOUNT;
    inverse = FALSE;
  }
}

void TQtCalculator::MC()
{

        memory_num = 0;
        refresh_display = 1;
}

void TQtCalculator::EnterEqual()
{
  eestate = false;
        last_input = OPERATION;
        PushStack(&display_data);
        refresh_display = 1;

        /*      if (UpdateStack(0))*/
                    UpdateStack(0);

        UpdateDisplay();
        precedence_base = 0;

        CALCAMNT* number ;

        if(temp_stack.count() > TEMP_STACK_SIZE){

          number = temp_stack.getFirst();
          temp_stack.removeFirst();

          if(number)
            free(number);
        }

        number = (CALCAMNT*) malloc(sizeof(CALCAMNT));
        *number = DISPLAY_AMOUNT;

        //printf("appending %Lg\n",*number);

        temp_stack.append(number);


}

void TQtCalculator::Clear(){

  eestate = false;

  input_count = 0;
  decimal_point = 0;

  if(last_input == OPERATION){
    //    printf("LAST_INPUT = OPERATION\n");
    last_input = DIGIT;
    PopStack();
  }
  else{
    //    printf("LAST_INPUT = DIGIT\n");
    last_input = DIGIT;
  }


  if( display_error){
    display_error = 0;
    refresh_display = 0;
  }

  if (!refresh_display) {
    DISPLAY_AMOUNT = 0L;
    UpdateDisplay();
  }

}

void TQtCalculator::ClearAll()
{

  eestate = false;
  // last_input = OPERATION;
  last_input = DIGIT;
  RefreshCalculator();
  refresh_display = 1;

}



void TQtCalculator::UpdateDisplay()
{

  // this needs to be rewritten based on whether we are currently
  // inputting a number so that the period and the 0 after a period
  // are correctly displayed.

        CALCAMNT        boh_work_d;
        long            boh_work = 0;
        int             str_size = 0;

        if(eestate && (current_base == NB_DECIMAL)){

                calc_display->setText(display_str);
                return;
        }

        if (current_base != NB_DECIMAL) {
                MODF(DISPLAY_AMOUNT, &boh_work_d);
                if (boh_work_d < LONG_MIN || boh_work_d > ULONG_MAX)
                display_error = 1;

        /*
         * We may be in that never-never land where boh numbers
         * turn from positive to negative - if so then we do
         * just that, allowing boh negative numbers to be entered
         * as read (from dumps and the like!)
         */
                else if (boh_work_d > LONG_MAX) {
                        DISPLAY_AMOUNT =
                                LONG_MIN+(boh_work_d-LONG_MAX-1);
                        boh_work = (long)DISPLAY_AMOUNT;
                }
                else {
                        DISPLAY_AMOUNT = boh_work_d;
                        boh_work = (long) boh_work_d;
                }
        }

        if (!display_error) {

                if (current_base == NB_BINARY)
                        str_size = cvb(display_str,
                                       boh_work,
                                       BOH_SIZE);
                else if (current_base == NB_OCTAL)
                        str_size = sprintf(display_str,
                                           "%lo",
                                           boh_work);
                else if (current_base == NB_DECIMAL) {

                  if(!kcalcdefaults.fixed || last_input == DIGIT
                     || (DISPLAY_AMOUNT > 1.0e+16)){

                    // if I don't guard against the DISPLAY_AMOUNT being too large
                    // kcalc will segfault on larger amount. Such as from typing
                    // from 5*5*******

                    str_size = sprintf(display_str,

#ifdef HAVE_LONG_DOUBLE
                                     "%.*Lg", // was *Lg

                                     kcalcdefaults.precision  +1,
#else
                                           "%.*g",

                                     kcalcdefaults.precision  +1,
#endif
                                             DISPLAY_AMOUNT);
                  }
                  else{//fixed

                  str_size = sprintf(display_str,

#ifdef HAVE_LONG_DOUBLE
                                     "%.*Lf", // was *Lg

                                     kcalcdefaults.fixedprecision  ,
#else
                                           "%.*f",

                                     kcalcdefaults.fixedprecision  ,
#endif
                                             DISPLAY_AMOUNT);

                  }// fixed

                  if ( input_count > 0 && !strpbrk(display_str,"e") &&
                                           last_input == DIGIT   ) {

#ifdef HAVE_LONG_DOUBLE
                    str_size = sprintf(display_str,
                                           "%.*Lf",
                            (kcalcdefaults.precision +1 > input_count)?
                             input_count : kcalcdefaults.precision ,
                             DISPLAY_AMOUNT);
#else
                    str_size = sprintf(display_str,
                                           "%.*f",
                            (kcalcdefaults.precision +1 > input_count)?
                             input_count : kcalcdefaults.precision ,
                             DISPLAY_AMOUNT);
#endif
                  }

                }
                else
                  if (current_base == NB_HEX)
                        str_size = sprintf(display_str,
                                           "%lX",
                                           boh_work);
                  else
                        display_error = 1;
              }

        if (display_error || str_size < 0) {
          display_error = 1;
          strcpy(display_str,"Error");
          if(kcalcdefaults.beep)
            KNotifyClient::beep();
        }
        calc_display->setText(display_str);


  if (inverse){
    statusINVLabel->setText("INV");
  }
  else{
    statusINVLabel->setText("NORM");
  }

  if (hyp_mode){
    statusHYPLabel->setText("HYP");
  }
  else{
    statusHYPLabel->setText("");
  }


}

int cvb(char *out_str, long amount, int max_digits)
{
        /*
         * A routine that converts a long int to
         * binary display format
         */

        char            work_str[(sizeof(amount) * CHAR_BIT) + 1];
        int             work_char = 0,
                        lead_zero = 1,
                        lead_one = 1,
                        lead_one_count = 0,
                        work_size = sizeof(amount) * CHAR_BIT;
        unsigned long   bit_mask = (1 << ((sizeof(amount) * CHAR_BIT) - 1));

        while (bit_mask) {

                if (amount & bit_mask) {
                        if (lead_one)
                                lead_one_count++;
                        lead_zero = 0;
                        work_str[work_char++] = '1';
                } else {
                        lead_one = 0;
                        if (!lead_zero)
                                work_str[work_char++] = '0';
                }
                bit_mask >>= 1;
        }
        if (!work_char)
                work_str[work_char++] = '0';
        work_str[work_char] = '\0';

        if (work_char-lead_one_count < max_digits)
                return strlen(strcpy(out_str,
                                      &work_str[lead_one_count ?
                                      work_size - max_digits :
                                      0]));
        else
           return -1;
}

int UpdateStack(int run_precedence)
{
        item_contents   new_item, *top_item , *top_function;
        CALCAMNT        left_op =0.0 , right_op =0.0;
        int             op_function= 0, return_value = 0;

        new_item.s_item_type = ITEM_AMOUNT;
        while ((top_function = TopTypeStack(ITEM_FUNCTION)) &&
        top_function->s_item_data.item_func_data.item_precedence >=
        run_precedence) {

                return_value = 1;

                if ((top_item = PopStack())->s_item_type != ITEM_AMOUNT){
                  KMessageBox::error( 0, "Stack processing error - right_op");

                }
                right_op = top_item->s_item_data.item_amount;

                if (!((top_item = PopStack()) &&
                top_item->s_item_type == ITEM_FUNCTION)) {
                  KMessageBox::error( 0, "Stack processing error - function");

                }
                op_function =
                        top_item->s_item_data.item_func_data.item_function;

                if (!((top_item = PopStack()) &&
                top_item->s_item_type == ITEM_AMOUNT)) {
                  KMessageBox::error( 0, "Stack processing error - left_op");
                }
                left_op = top_item->s_item_data.item_amount;

                new_item.s_item_data.item_amount =
                        (Arith_ops[op_function])(left_op, right_op);
                PushStack(&new_item);

        }
        if (return_value &&
            percent_mode &&
            !display_error &&
            Prcnt_ops[op_function] != NULL){
                new_item.s_item_data.item_amount =
                        (Prcnt_ops[op_function])(left_op,
                                right_op,
                                new_item.s_item_data.item_amount);
                PushStack(&new_item);
        }
        if (return_value)
                DISPLAY_AMOUNT = new_item.s_item_data.item_amount;

        return return_value;
}

int isoddint(CALCAMNT input)
{
        CALCAMNT        dummy;
        /*
         * Routine to check if CALCAMNT is an Odd integer
         */
        return (MODF(input, &dummy) == 0.0 &&
                MODF(input/2, &dummy) == 0.5);
}

CALCAMNT ExecOr(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecOr\n");
        CALCAMNT        boh_work_d;
        long            boh_work_l, boh_work_r;

        MODF(left_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_l = (long int)boh_work_d;
        MODF(right_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_r = (long int) boh_work_d;
        return (boh_work_l | boh_work_r);
}

CALCAMNT ExecXor(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecXOr\n");
        CALCAMNT        boh_work_d;
        long            boh_work_l, boh_work_r;

        MODF(left_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_l = (long int) boh_work_d;
        MODF(right_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_r = (long int) boh_work_d;
        return (boh_work_l ^ boh_work_r);
}

CALCAMNT ExecAnd(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecAnd\n");
        CALCAMNT        boh_work_d;
        long            boh_work_l, boh_work_r;

        MODF(left_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_l = (long int ) boh_work_d;
        MODF(right_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_r = (long int ) boh_work_d;
        return (boh_work_l & boh_work_r);
}

CALCAMNT ExecLsh(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecLsh\n");
        CALCAMNT        boh_work_d;
        long            boh_work_l, boh_work_r;

        MODF(left_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_l = (long int) boh_work_d;
        MODF(right_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_r = (long int ) boh_work_d;
        return (boh_work_l << boh_work_r);
}

CALCAMNT ExecRsh(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecRsh\n");
        CALCAMNT        boh_work_d;
        long            boh_work_l, boh_work_r;

        MODF(left_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_l = (long int ) boh_work_d;
        MODF(right_op, &boh_work_d);
        if (FABS(boh_work_d) > LONG_MAX) {
                display_error = 1;
                return 0;
        }
        boh_work_r = ( long int ) boh_work_d;
        return (boh_work_l >> boh_work_r);
}

CALCAMNT ExecAdd(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecAdd\n");
        return left_op + right_op;
}

CALCAMNT ExecSubtract(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecSubtract\n");
        return left_op - right_op;
}

CALCAMNT ExecMultiply(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecMulti\n");
        return left_op * right_op;
}

CALCAMNT ExecDivide(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecDivide\n");
        if (right_op == 0) {
                display_error = 1;
                return 0L;
        } else
                return left_op / right_op;
}

CALCAMNT ExecMod(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("ExecMod\n");
  CALCAMNT temp =0.0;

  if (right_op == 0) {
    display_error = 1;
    return 0L;
  } else {

    // x mod y should be the same as x mod -y, thus:
    right_op = FABS(right_op);

    temp = FMOD(left_op, right_op);

    // let's make sure that -7 mod 3 = 2 and NOT -1.
    // In other words we wand x mod 3 to be a _positive_ number
    // that is 0,1 or 2.

    if( temp < 0 ) temp = right_op + temp;
    temp = FABS(temp);

    return temp;
  }
}

CALCAMNT ExecIntDiv(CALCAMNT left_op, CALCAMNT right_op)
{
  // printf("IndDiv\n");
        if (right_op == 0) {
                display_error = 1;
                return 0L;
        } else {
                MODF(left_op / right_op, &left_op);
                return left_op;
        }
}

CALCAMNT ExecPower(CALCAMNT left_op, CALCAMNT right_op)
{

       // printf("ExecPowser %g left_op, %g right_op\n",left_op, right_op);
        if (right_op == 0)
                return 1L;
        if (left_op < 0 && isoddint(1/right_op))
                left_op = -1L * POW((-1L * left_op), right_op);
        else
                left_op = POW(left_op, right_op);
        if (errno == EDOM || errno == ERANGE) {
                display_error = 1;
                return 0;
        } else
                return left_op;
}

CALCAMNT ExecPwrRoot(CALCAMNT left_op, CALCAMNT right_op)
{

       // printf("ExecPwrRoot  %g left_op, %g right_op\n", left_op, right_op);
        if (right_op == 0) {
                display_error = 1;
                return 0L;
        }
        if (left_op < 0 && isoddint(right_op))
                left_op = -1L * POW((-1L * left_op), (1L)/right_op);
        else
                left_op = POW(left_op, (1L)/right_op);
        if (errno == EDOM || errno == ERANGE) {
          display_error = 1;
          return 0;
        }
        else
          return left_op;
}


CALCAMNT ExecAddSubP(CALCAMNT left_op, CALCAMNT right_op, CALCAMNT result)
{
  // printf("ExecAddsubP\n");
  (void) left_op;

        if (result == 0) {
                display_error = 1;
                return 0;
        } else
                return (result * 100L) / right_op;
}

CALCAMNT ExecMultiplyP(CALCAMNT left_op, CALCAMNT right_op, CALCAMNT result)
{
  // printf("ExecMultiplyP\n");
  (void) left_op;
  (void) right_op;

        return (result / 100L);
}

CALCAMNT ExecDivideP(CALCAMNT left_op, CALCAMNT right_op, CALCAMNT result)
{
  // printf("ExecDivideP\n");
  (void) left_op;
  (void) right_op;

        return (result * 100L);
}

CALCAMNT ExecPowerP(CALCAMNT left_op, CALCAMNT right_op, CALCAMNT result)
{
  // printf("ExecPowerP\n");
  (void) result;
        return ExecPower(left_op, (right_op / 100L));
}

CALCAMNT ExecPwrRootP(CALCAMNT left_op, CALCAMNT right_op, CALCAMNT result)
{
  // printf("ExePwrRootP\n");
  (void) result;

        if (right_op == 0) {
                display_error = 1;
                return 0;
        } else
                return ExecPower(left_op, (100L / right_op));
}



stack_ptr AllocStackItem (void) {

        if (stack_next <= stack_last) {

                process_stack[stack_next].prior_item = NULL;
                process_stack[stack_next].prior_type = NULL;
                return &process_stack[stack_next++];
        }

        KMessageBox::error( 0, "Stack Error !");
        return &process_stack[stack_next];
}

void UnAllocStackItem (stack_ptr return_item) {

        if (return_item != &process_stack[--stack_next]) {

          KMessageBox::error( 0, "Stack Error !");
        }

}
void PushStack(item_contents *add_item)
{
        /*
         * Add an item to the stack
         */

        stack_ptr new_item = top_of_stack;

        if (!(new_item &&
        new_item->item_value.s_item_type == add_item->s_item_type)) {

                new_item = AllocStackItem();    /* Get a new item    */

                /*
                 * Chain new item to existing stacks
                 */

                new_item->prior_item = top_of_stack;
                top_of_stack         = new_item;
                new_item->prior_type = top_type_stack[add_item->s_item_type];
                top_type_stack[add_item->s_item_type] = new_item;
        }

        new_item->item_value  = *add_item;      /* assign contents*/

}

item_contents *PopStack(void)
{
        /*
         * Remove and return the top item in the stack
         */

        static item_contents return_item;
        item_contents *return_item_ptr = NULL;
        stack_ptr return_stack_ptr;

        if ((return_stack_ptr = top_of_stack)) {
                return_item = top_of_stack->item_value;

                top_type_stack[return_item.s_item_type]
                             = top_of_stack->prior_type;
                top_of_stack = top_of_stack->prior_item;

                UnAllocStackItem(return_stack_ptr);
                return_item_ptr = &return_item;
        }

        return return_item_ptr;
}

item_contents *TopOfStack(void)
{
        /*
         * Return the top item in the stack without removing
         */

        item_contents *return_item_ptr = NULL;

        if (top_of_stack) {
                return_item_ptr = &top_of_stack->item_value;
        }

        return return_item_ptr;
}

item_contents *TopTypeStack(item_type rqstd_type)
{
        /*
         * Return the top item in the stack without removing
         */

        item_contents *return_item_ptr = NULL;

        if (top_type_stack[rqstd_type]) {
                return_item_ptr = &top_type_stack[rqstd_type]->item_value;
        }

        return return_item_ptr;
}


/*
 * Stack storage management Data and Functions
 */



void InitStack (void) {

        stack_next = 0;
        stack_last = STACK_SIZE - 1;
        top_of_stack = top_type_stack[0] = top_type_stack[1] = NULL;
}