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tdeutils/kcalc/knumber/knumber.h

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// -*- c-basic-offset: 2 -*-
/* This file is part of the KDE libraries
Copyright (C) 2005 Klaus Niederkrueger <kniederk@math.uni-koeln.de>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef _KNUMBER_H
#define _KNUMBER_H
#include <tdelibs_export.h>
#include "knumber_priv.h"
class TQString;
/**
*
* @short Class that provides arbitrary precision numbers
*
* KNumber provides access to arbitrary precision numbers from within
* KDE.
*
* KNumber is based on the GMP (GNU Multiprecision) library and
* provides transparent support to integer, fractional and floating
* point number. It contains rudimentary error handling, and also
* includes methods for converting the numbers to TQStrings for
* output, and to read TQStrings to obtain a KNumber.
*
* The different types of numbers that can be represented by objects
* of this class will be described below:
*
* @li @p NumType::SpecialType - This type represents an error that
* has occurred, e.g. trying to divide 1 by 0 gives an object that
* represents infinity.
*
* @li @p NumType::IntegerType - The number is an integer. It can be
* arbitrarily large (restricted by the memory of the system).
*
* @li @p NumType::FractionType - A fraction is a number of the form
* denominator divided by nominator, where both denominator and
* nominator are integers of arbitrary size.
*
* @li @p NumType::FloatType - The number is of floating point
* type. These numbers are usually rounded, so that they do not
* represent precise values.
*
*
* @author Klaus Niederkrueger <kniederk@math.uni-koeln.de>
*/
class KDE_EXPORT KNumber
{
public:
static KNumber const Zero;
static KNumber const One;
static KNumber const MinusOne;
static KNumber const Pi;
static KNumber const Euler;
static KNumber const NotDefined;
/**
* KNumber tries to provide transparent access to the following type
* of numbers:
*
* @li @p NumType::SpecialType - Some type of error has occurred,
* further inspection with @p KNumber::ErrorType
*
* @li @p NumType::IntegerType - the number is an integer
*
* @li @p NumType::FractionType - the number is a fraction
*
* @li @p NumType::FloatType - the number is of floating point type
*
*/
enum NumType {SpecialType, IntegerType, FractionType, FloatType};
/**
* A KNumber that represents an error, i.e. that is of type @p
* NumType::SpecialType can further distinguished:
*
* @li @p ErrorType::UndefinedNumber - This is e.g. the result of
* taking the square root of a negative number or computing
* \f$ \infty - \infty \f$.
*
* @li @p ErrorType::Infinity - Such a number can be e.g. obtained
* by dividing 1 by 0. Some further calculations are still allowed,
* e.g. \f$ \infty + 5 \f$ still gives \f$\infty\f$.
*
* @li @p ErrorType::MinusInfinity - MinusInfinity behaves similarly
* to infinity above. It can be obtained by changing the sign of
* infinity.
*
*/
enum ErrorType {UndefinedNumber, Infinity, MinusInfinity};
KNumber(signed int num = 0);
KNumber(unsigned int num);
KNumber(signed long int num);
KNumber(unsigned long int num);
KNumber(unsigned long long int num);
KNumber(double num);
KNumber(KNumber const & num);
KNumber(TQString const & num);
~KNumber()
{
delete _num;
}
KNumber const & operator=(KNumber const & num);
/**
* Returns the type of the number, as explained in @p KNumber::NumType.
*/
NumType type(void) const;
/**
* Set whether the output of numbers (with KNumber::toTQString)
* should happen as floating point numbers or not. This method has
* in fact only an effect on numbers of type @p
* NumType::FractionType, which can be either displayed as fractions
* or in decimal notation.
*
* The default behavior is not to display fractions in floating
* point notation.
*/
static void setDefaultFloatOutput(bool flag);
/**
* Set whether a number constructed from a TQString should be
* initialized as a fraction or as a float, e.g. "1.01" would be
* treated as 101/100, if this flag is set to true.
*
* The default setting is false.
*/
static void setDefaultFractionalInput(bool flag);
/**
* Set the default precision to be *at least* @p prec (decimal)
* digits. All subsequent initialized floats will use at least this
* precision, but previously initialized variables are unaffected.
*/
static void setDefaultFloatPrecision(unsigned int prec);
/**
* What a terrible method name!! When displaying a fraction, the
* default mode gives @p "nomin/denom". With this method one can
* choose to display a fraction as @p "integer nomin/denom".
*
* Examples: Default representation mode is 47/17, but if @p flag is
* @p true, then the result is 2 13/17.
*/
static void setSplitoffIntegerForFractionOutput(bool flag);
/**
* Return a TQString representing the KNumber.
*
* @param width This number specifies the maximal length of the
* output, before the method switches to exponential notation and
* does rounding. For negative numbers, this option is ignored.
*
* @param prec This parameter controls the number of digits
* following the decimal point. For negative numbers, this option
* is ignored.
*
*/
TQString const toTQString(int width = -1, int prec = -1) const;
/**
* Compute the absolute value, i.e. @p x.abs() returns the value
*
* \f[ \left\{\begin{array}{cl} x, & x \ge 0 \\ -x, & x <
* 0\end{array}\right.\f]
* This method works for \f$ x = \infty \f$ and \f$ x = -\infty \f$.
*/
KNumber const abs(void) const;
/**
* Compute the square root. If \f$ x < 0 \f$ (including \f$
* x=-\infty \f$), then @p x.sqrt() returns @p
* ErrorType::UndefinedNumber.
*
* If @p x is an integer or a fraction, then @p x.sqrt() tries to
* compute the exact square root. If the square root is not a
* fraction, then a float with the default precision is returned.
*
* This method works for \f$ x = \infty \f$ giving \f$ \infty \f$.
*/
KNumber const sqrt(void) const;
/**
* Compute the cube root.
*
* If @p x is an integer or a fraction, then @p x.cbrt() tries to
* compute the exact cube root. If the cube root is not a fraction,
* then a float is returned, but
*
* WARNING: A float cube root is computed as a standard @p double
* that is later transformed back into a @p KNumber.
*
* This method works for \f$ x = \infty \f$ giving \f$ \infty \f$,
* and for \f$ x = -\infty \f$ giving \f$ -\infty \f$.
*/
KNumber const cbrt(void) const;
/**
* Truncates a @p KNumber to its integer type returning a number of
* type @p NumType::IntegerType.
*
* If \f$ x = \pm\infty \f$, integerPart leaves the value unchanged,
* i.e. it returns \f$ \pm\infty \f$.
*/
KNumber const integerPart(void) const;
KNumber const power(KNumber const &exp) const;
KNumber const operator+(KNumber const & arg2) const;
KNumber const operator -(void) const;
KNumber const operator-(KNumber const & arg2) const;
KNumber const operator*(KNumber const & arg2) const;
KNumber const operator/(KNumber const & arg2) const;
KNumber const operator%(KNumber const & arg2) const;
KNumber const operator&(KNumber const & arg2) const;
KNumber const operator|(KNumber const & arg2) const;
KNumber const operator<<(KNumber const & arg2) const;
KNumber const operator>>(KNumber const & arg2) const;
operator bool(void) const;
operator signed long int(void) const;
operator unsigned long int(void) const;
operator unsigned long long int(void) const;
operator double(void) const;
bool const operator==(KNumber const & arg2) const
{ return (compare(arg2) == 0); }
bool const operator!=(KNumber const & arg2) const
{ return (compare(arg2) != 0); }
bool const operator>(KNumber const & arg2) const
{ return (compare(arg2) > 0); }
bool const operator<(KNumber const & arg2) const
{ return (compare(arg2) < 0); }
bool const operator>=(KNumber const & arg2) const
{ return (compare(arg2) >= 0); }
bool const operator<=(KNumber const & arg2) const
{ return (compare(arg2) <= 0); }
KNumber & operator +=(KNumber const &arg);
KNumber & operator -=(KNumber const &arg);
//KNumber const toFloat(void) const;
private:
void simplifyRational(void);
int const compare(KNumber const & arg2) const;
_knumber *_num;
static bool _float_output;
static bool _fraction_input;
static bool _splitoffinteger_output;
};
#endif // _KNUMBER_H