You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

323 lines
10 KiB

// Copyright (C) 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2015, International Business Machines
* Corporation and others. All Rights Reserved.
*******************************************************************************
* precision.h
*
* created on: 2015jan06
* created by: Travis Keep
*/
#ifndef __PRECISION_H__
#define __PRECISION_H__
#include "unicode/uobject.h"
#if !UCONFIG_NO_FORMATTING
#include "unicode/utypes.h"
#include "digitinterval.h"
#include "digitlst.h"
#include "significantdigitinterval.h"
U_NAMESPACE_BEGIN
class VisibleDigits;
class VisibleDigitsWithExponent;
/**
* A precision manager for values to be formatted as fixed point.
* Handles rounding of number to prepare it for formatting.
*/
class U_I18N_API FixedPrecision : public UMemory {
public:
/**
* The smallest format interval allowed. Default is 1 integer digit and no
* fraction digits.
*/
DigitInterval fMin;
/**
* The largest format interval allowed. Must contain fMin.
* Default is all digits.
*/
DigitInterval fMax;
/**
* Min and max significant digits allowed. The default is no constraints.
*/
SignificantDigitInterval fSignificant;
/**
* The rounding increment or zero if there is no rounding increment.
* Default is zero.
*/
DigitList fRoundingIncrement;
/**
* If set, causes round() to set status to U_FORMAT_INEXACT_ERROR if
* any rounding is done. Default is FALSE.
*/
UBool fExactOnly;
/**
* If set, causes round() to set status to U_ILLEGAL_ARGUMENT_ERROR if
* rounded number has more than maximum integer digits. Default is FALSE.
*/
UBool fFailIfOverMax;
/**
* Controls the rounding mode that initVisibleDigits uses.
* Default is DecimalFormat::kRoundHalfEven
*/
DecimalFormat::ERoundingMode fRoundingMode;
FixedPrecision();
/**
* Returns TRUE if this object equals rhs.
*/
UBool equals(const FixedPrecision &rhs) const {
return (fMin.equals(rhs.fMin) &&
fMax.equals(rhs.fMax) &&
fSignificant.equals(rhs.fSignificant) &&
(fRoundingIncrement == rhs.fRoundingIncrement) &&
fExactOnly == rhs.fExactOnly &&
fFailIfOverMax == rhs.fFailIfOverMax &&
fRoundingMode == rhs.fRoundingMode);
}
/**
* Rounds value in place to prepare it for formatting.
* @param value The value to be rounded. It is rounded in place.
* @param exponent Always pass 0 for fixed decimal formatting. scientific
* precision passes the exponent value. Essentially, it divides value by
* 10^exponent, rounds and then multiplies by 10^exponent.
* @param status error returned here.
* @return reference to value.
*/
DigitList &round(DigitList &value, int32_t exponent, UErrorCode &status) const;
/**
* Returns the interval to use to format the rounded value.
* @param roundedValue the already rounded value to format.
* @param interval modified in place to be the interval to use to format
* the rounded value.
* @return a reference to interval.
*/
DigitInterval &getInterval(
const DigitList &roundedValue, DigitInterval &interval) const;
/**
* Returns TRUE if this instance allows for fast formatting of integers.
*/
UBool isFastFormattable() const;
/**
* Initializes a VisibleDigits.
* @param value value for VisibleDigits
* Caller must not assume that the value of this parameter will remain
* unchanged.
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigits &initVisibleDigits(
DigitList &value,
VisibleDigits &digits,
UErrorCode &status) const;
/**
* Initializes a VisibleDigits.
* @param value value for VisibleDigits
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigits &initVisibleDigits(
double value,
VisibleDigits &digits,
UErrorCode &status) const;
/**
* Initializes a VisibleDigits.
* @param value value for VisibleDigits
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigits &initVisibleDigits(
int64_t value,
VisibleDigits &digits,
UErrorCode &status) const;
/**
* Initializes a VisibleDigitsWithExponent.
* @param value value for VisibleDigits
* Caller must not assume that the value of this parameter will remain
* unchanged.
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigitsWithExponent &initVisibleDigitsWithExponent(
DigitList &value,
VisibleDigitsWithExponent &digits,
UErrorCode &status) const;
/**
* Initializes a VisibleDigitsWithExponent.
* @param value value for VisibleDigits
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigitsWithExponent &initVisibleDigitsWithExponent(
double value,
VisibleDigitsWithExponent &digits,
UErrorCode &status) const;
/**
* Initializes a VisibleDigitsWithExponent.
* @param value value for VisibleDigits
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigitsWithExponent &initVisibleDigitsWithExponent(
int64_t value,
VisibleDigitsWithExponent &digits,
UErrorCode &status) const;
private:
/**
* Attempts to initialize 'digits' using simple mod 10 arithmetic.
* Returns FALSE if this is not possible such as when rounding
* would change the value. Otherwise returns TRUE.
*
* If the method returns FALSE, caller should create a DigitList
* and use it to initialize 'digits'. If this method returns TRUE,
* caller should accept the value stored in 'digits'. If this
* method returns TRUE along with a non zero error, caller must accept
* the error and not try again with a DigitList.
*
* Before calling this method, caller must verify that this object
* has no rounding increment set.
*
* The value that 'digits' is initialized to is mantissa * 10^exponent.
* For example mantissa = 54700 and exponent = -3 means 54.7. The
* properties of this object (such as min and max fraction digits),
* not the number of trailing zeros in the mantissa, determine whether or
* not the result contains any trailing 0's after the decimal point.
*
* @param mantissa the digits. May be positive or negative. May contain
* trailing zeros.
* @param exponent must always be zero or negative. An exponent > 0
* yields undefined results!
* @param digits result stored here.
* @param status any error returned here.
*/
UBool
initVisibleDigits(
int64_t mantissa,
int32_t exponent,
VisibleDigits &digits,
UErrorCode &status) const;
UBool isRoundingRequired(
int32_t upperExponent, int32_t lowerExponent) const;
DigitInterval &getIntervalForZero(DigitInterval &interval) const;
DigitInterval &getInterval(
int32_t upperExponent, DigitInterval &interval) const;
static UBool handleNonNumeric(DigitList &value, VisibleDigits &digits);
friend class ScientificPrecision;
};
/**
* A precision manager for values to be expressed as scientific notation.
*/
class U_I18N_API ScientificPrecision : public UMemory {
public:
FixedPrecision fMantissa;
int32_t fMinExponentDigits;
ScientificPrecision();
/**
* rounds value in place to prepare it for formatting.
* @param value The value to be rounded. It is rounded in place.
* @param status error returned here.
* @return reference to value.
*/
DigitList &round(DigitList &value, UErrorCode &status) const;
/**
* Converts value to a mantissa and exponent.
*
* @param value modified in place to be the mantissa. Depending on
* the precision settings, the resulting mantissa may not fall
* between 1.0 and 10.0.
* @return the exponent of value.
*/
int32_t toScientific(DigitList &value) const;
/**
* Returns TRUE if this object equals rhs.
*/
UBool equals(const ScientificPrecision &rhs) const {
return fMantissa.equals(rhs.fMantissa) && fMinExponentDigits == rhs.fMinExponentDigits;
}
/**
* Initializes a VisibleDigitsWithExponent.
* @param value the value
* Caller must not assume that the value of this parameter will remain
* unchanged.
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigitsWithExponent &initVisibleDigitsWithExponent(
DigitList &value,
VisibleDigitsWithExponent &digits,
UErrorCode &status) const;
/**
* Initializes a VisibleDigitsWithExponent.
* @param value the value
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigitsWithExponent &initVisibleDigitsWithExponent(
double value,
VisibleDigitsWithExponent &digits,
UErrorCode &status) const;
/**
* Initializes a VisibleDigitsWithExponent.
* @param value the value
* @param digits This is the value that is initialized.
* @param status any error returned here.
* @return digits
*/
VisibleDigitsWithExponent &initVisibleDigitsWithExponent(
int64_t value,
VisibleDigitsWithExponent &digits,
UErrorCode &status) const;
private:
int32_t getMultiplier() const;
};
U_NAMESPACE_END
#endif // #if !UCONFIG_NO_FORMATTING
#endif // __PRECISION_H__