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scuffed-code/icu4c/source/i18n/digitlst.h
Andy Heninger 242e02c388 ICU-12764 icu4c utf-8 source files, update Copyright notices. 
X-SVN-Rev: 39583
2017-01-20 00:20:31 +00:00

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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
*
* Copyright (C) 1997-2015, International Business Machines
* Corporation and others. All Rights Reserved.
*
******************************************************************************
*
* File DIGITLST.H
*
* Modification History:
*
* Date Name Description
* 02/25/97 aliu Converted from java.
* 03/21/97 clhuang Updated per C++ implementation.
* 04/15/97 aliu Changed MAX_COUNT to DBL_DIG. Changed Digit to char.
* 09/09/97 aliu Adapted for exponential notation support.
* 08/02/98 stephen Added nearest/even rounding
* 06/29/99 stephen Made LONG_DIGITS a macro to satisfy SUN compiler
* 07/09/99 stephen Removed kMaxCount (unused, for HP compiler)
******************************************************************************
*/
#ifndef DIGITLST_H
#define DIGITLST_H
#include "unicode/uobject.h"
#if !UCONFIG_NO_FORMATTING
#include "unicode/decimfmt.h"
#include <float.h>
#include "decContext.h"
#include "decNumber.h"
#include "cmemory.h"
// Decimal digits in a 64-bit int
#define INT64_DIGITS 19
typedef enum EDigitListValues {
MAX_DBL_DIGITS = DBL_DIG,
MAX_I64_DIGITS = INT64_DIGITS,
MAX_DIGITS = MAX_I64_DIGITS,
MAX_EXPONENT = DBL_DIG,
DIGIT_PADDING = 3,
DEFAULT_DIGITS = 40, // Initial storage size, will grow as needed.
// "+." + fDigits + "e" + fDecimalAt
MAX_DEC_DIGITS = MAX_DIGITS + DIGIT_PADDING + MAX_EXPONENT
} EDigitListValues;
U_NAMESPACE_BEGIN
class CharString;
class DigitInterval;
// Export an explicit template instantiation of the MaybeStackHeaderAndArray that
// is used as a data member of DigitList.
//
// MSVC requires this, even though it should not be necessary.
// No direct access to the MaybeStackHeaderAndArray leaks out of the i18n library.
//
// Macintosh produces duplicate definition linker errors with the explicit template
// instantiation.
//
#if !U_PLATFORM_IS_DARWIN_BASED
template class U_I18N_API MaybeStackHeaderAndArray<decNumber, char, DEFAULT_DIGITS>;
#endif
enum EStackMode { kOnStack };
enum EFastpathBits { kFastpathOk = 1, kNoDecimal = 2 };
/**
* Digit List is actually a Decimal Floating Point number.
* The original implementation has been replaced by a thin wrapper onto a
* decimal number from the decNumber library.
*
* The original DigitList API has been retained, to minimize the impact of
* the change on the rest of the ICU formatting code.
*
* The change to decNumber enables support for big decimal numbers, and
* allows rounding computations to be done directly in decimal, avoiding
* extra, and inaccurate, conversions to and from doubles.
*
* Original DigitList comments:
*
* Digit List utility class. Private to DecimalFormat. Handles the transcoding
* between numeric values and strings of characters. Only handles
* non-negative numbers. The division of labor between DigitList and
* DecimalFormat is that DigitList handles the radix 10 representation
* issues; DecimalFormat handles the locale-specific issues such as
* positive/negative, grouping, decimal point, currency, and so on.
* <P>
* A DigitList is really a representation of a floating point value.
* It may be an integer value; we assume that a double has sufficient
* precision to represent all digits of a long.
* <P>
* The DigitList representation consists of a string of characters,
* which are the digits radix 10, from '0' to '9'. It also has a radix
* 10 exponent associated with it. The value represented by a DigitList
* object can be computed by mulitplying the fraction f, where 0 <= f < 1,
* derived by placing all the digits of the list to the right of the
* decimal point, by 10^exponent.
*
* --------
*
* DigitList vs. decimalNumber:
*
* DigitList stores digits with the most significant first.
* decNumber stores digits with the least significant first.
*
* DigitList, decimal point is before the most significant.
* decNumber, decimal point is after the least signficant digit.
*
* digitList: 0.ddddd * 10 ^ exp
* decNumber: ddddd. * 10 ^ exp
*
* digitList exponent = decNumber exponent + digit count
*
* digitList, digits are platform invariant chars, '0' - '9'
* decNumber, digits are binary, one per byte, 0 - 9.
*
* (decNumber library is configurable in how digits are stored, ICU has configured
* it this way for convenience in replacing the old DigitList implementation.)
*/
class U_I18N_API DigitList : public UMemory { // Declare external to make compiler happy
public:
DigitList();
~DigitList();
/* copy constructor
* @param DigitList The object to be copied.
* @return the newly created object.
*/
DigitList(const DigitList&); // copy constructor
/* assignment operator
* @param DigitList The object to be copied.
* @return the newly created object.
*/
DigitList& operator=(const DigitList&); // assignment operator
/**
* Return true if another object is semantically equal to this one.
* @param other The DigitList to be compared for equality
* @return true if another object is semantically equal to this one.
* return false otherwise.
*/
UBool operator==(const DigitList& other) const;
int32_t compare(const DigitList& other);
inline UBool operator!=(const DigitList& other) const { return !operator==(other); }
/**
* Clears out the digits.
* Use before appending them.
* Typically, you set a series of digits with append, then at the point
* you hit the decimal point, you set myDigitList.fDecimalAt = myDigitList.fCount;
* then go on appending digits.
*/
void clear(void);
/**
* Remove, by rounding, any fractional part of the decimal number,
* leaving an integer value.
*/
void toIntegralValue();
/**
* Appends digits to the list.
* CAUTION: this function is not recommended for new code.
* In the original DigitList implementation, decimal numbers were
* parsed by appending them to a digit list as they were encountered.
* With the revamped DigitList based on decNumber, append is very
* inefficient, and the interaction with the exponent value is confusing.
* Best avoided.
* TODO: remove this function once all use has been replaced.
* TODO: describe alternative to append()
* @param digit The digit to be appended.
*/
void append(char digit);
/**
* Utility routine to get the value of the digit list
* Returns 0.0 if zero length.
* @return the value of the digit list.
*/
double getDouble(void) const;
/**
* Utility routine to get the value of the digit list
* Make sure that fitsIntoLong() is called before calling this function.
* Returns 0 if zero length.
* @return the value of the digit list, return 0 if it is zero length
*/
int32_t getLong(void) /*const*/;
/**
* Utility routine to get the value of the digit list
* Make sure that fitsIntoInt64() is called before calling this function.
* Returns 0 if zero length.
* @return the value of the digit list, return 0 if it is zero length
*/
int64_t getInt64(void) /*const*/;
/**
* Utility routine to get the value of the digit list as a decimal string.
*/
void getDecimal(CharString &str, UErrorCode &status);
/**
* Return true if the number represented by this object can fit into
* a long.
* @param ignoreNegativeZero True if negative zero is ignored.
* @return true if the number represented by this object can fit into
* a long, return false otherwise.
*/
UBool fitsIntoLong(UBool ignoreNegativeZero) /*const*/;
/**
* Return true if the number represented by this object can fit into
* an int64_t.
* @param ignoreNegativeZero True if negative zero is ignored.
* @return true if the number represented by this object can fit into
* a long, return false otherwise.
*/
UBool fitsIntoInt64(UBool ignoreNegativeZero) /*const*/;
/**
* Utility routine to set the value of the digit list from a double.
* @param source The value to be set
*/
void set(double source);
/**
* Utility routine to set the value of the digit list from a long.
* If a non-zero maximumDigits is specified, no more than that number of
* significant digits will be produced.
* @param source The value to be set
*/
void set(int32_t source);
/**
* Utility routine to set the value of the digit list from an int64.
* If a non-zero maximumDigits is specified, no more than that number of
* significant digits will be produced.
* @param source The value to be set
*/
void set(int64_t source);
/**
* Utility routine to set the value of the digit list from an int64.
* Does not set the decnumber unless requested later
* If a non-zero maximumDigits is specified, no more than that number of
* significant digits will be produced.
* @param source The value to be set
*/
void setInteger(int64_t source);
/**
* Utility routine to set the value of the digit list from a decimal number
* string.
* @param source The value to be set. The string must be nul-terminated.
* @param fastpathBits special flags for fast parsing
*/
void set(StringPiece source, UErrorCode &status, uint32_t fastpathBits = 0);
/**
* Multiply this = this * arg
* This digitlist will be expanded if necessary to accomodate the result.
* @param arg the number to multiply by.
*/
void mult(const DigitList &arg, UErrorCode &status);
/**
* Divide this = this / arg
*/
void div(const DigitList &arg, UErrorCode &status);
// The following functions replace direct access to the original DigitList implmentation
// data structures.
void setRoundingMode(DecimalFormat::ERoundingMode m);
/** Test a number for zero.
* @return TRUE if the number is zero
*/
UBool isZero(void) const;
/** Test for a Nan
* @return TRUE if the number is a NaN
*/
UBool isNaN(void) const {return decNumberIsNaN(fDecNumber);}
UBool isInfinite() const {return decNumberIsInfinite(fDecNumber);}
/** Reduce, or normalize. Removes trailing zeroes, adjusts exponent appropriately. */
void reduce();
/** Remove trailing fraction zeros, adjust exponent accordingly. */
void trim();
/** Set to zero */
void setToZero() {uprv_decNumberZero(fDecNumber);}
/** get the number of digits in the decimal number */
int32_t digits() const {return fDecNumber->digits;}
/**
* Round the number to the given number of digits.
* @param maximumDigits The maximum number of digits to be shown.
* Upon return, count will be less than or equal to maximumDigits.
* result is guaranteed to be trimmed.
*/
void round(int32_t maximumDigits);
void roundFixedPoint(int32_t maximumFractionDigits);
/** Ensure capacity for digits. Grow the storage if it is currently less than
* the requested size. Capacity is not reduced if it is already greater
* than requested.
*/
void ensureCapacity(int32_t requestedSize, UErrorCode &status);
UBool isPositive(void) const { return decNumberIsNegative(fDecNumber) == 0;}
void setPositive(UBool s);
void setDecimalAt(int32_t d);
int32_t getDecimalAt();
void setCount(int32_t c);
int32_t getCount() const;
/**
* Set the digit in platform (invariant) format, from '0'..'9'
* @param i index of digit
* @param v digit value, from '0' to '9' in platform invariant format
*/
void setDigit(int32_t i, char v);
/**
* Get the digit in platform (invariant) format, from '0'..'9' inclusive
* @param i index of digit
* @return invariant format of the digit
*/
char getDigit(int32_t i);
/**
* Get the digit's value, as an integer from 0..9 inclusive.
* Note that internally this value is a decNumberUnit, but ICU configures it to be a uint8_t.
* @param i index of digit
* @return value of that digit
*/
uint8_t getDigitValue(int32_t i);
/**
* Gets the upper bound exponent for this value. For 987, returns 3
* because 10^3 is the smallest power of 10 that is just greater than
* 987.
*/
int32_t getUpperExponent() const;
/**
* Gets the lower bound exponent for this value. For 98.7, returns -1
* because the right most digit, is the 10^-1 place.
*/
int32_t getLowerExponent() const { return fDecNumber->exponent; }
/**
* Sets result to the smallest DigitInterval needed to display this
* DigitList in fixed point form and returns result.
*/
DigitInterval& getSmallestInterval(DigitInterval &result) const;
/**
* Like getDigitValue, but the digit is identified by exponent.
* For example, getDigitByExponent(7) returns the 10^7 place of this
* DigitList. Unlike getDigitValue, there are no upper or lower bounds
* for passed parameter. Instead, getDigitByExponent returns 0 if
* the exponent falls outside the interval for this DigitList.
*/
uint8_t getDigitByExponent(int32_t exponent) const;
/**
* Appends the digits in this object to a CharString.
* 3 is appended as (char) 3, not '3'
*/
void appendDigitsTo(CharString &str, UErrorCode &status) const;
/**
* Equivalent to roundFixedPoint(-digitExponent) except unlike
* roundFixedPoint, this works for any digitExponent value.
* If maxSigDigits is set then this instance is rounded to have no more
* than maxSigDigits. The end result is guaranteed to be trimmed.
*/
void roundAtExponent(int32_t digitExponent, int32_t maxSigDigits=INT32_MAX);
/**
* Quantizes according to some amount and rounds according to the
* context of this instance. Quantizing 3.233 with 0.05 gives 3.25.
*/
void quantize(const DigitList &amount, UErrorCode &status);
/**
* Like toScientific but only returns the exponent
* leaving this instance unchanged.
*/
int32_t getScientificExponent(
int32_t minIntDigitCount, int32_t exponentMultiplier) const;
/**
* Converts this instance to scientific notation. This instance
* becomes the mantissa and the exponent is returned.
* @param minIntDigitCount minimum integer digits in mantissa
* Exponent is set so that the actual number of integer digits
* in mantissa is as close to the minimum as possible.
* @param exponentMultiplier The exponent is always a multiple of
* This number. Usually 1, but set to 3 for engineering notation.
* @return exponent
*/
int32_t toScientific(
int32_t minIntDigitCount, int32_t exponentMultiplier);
/**
* Shifts decimal to the right.
*/
void shiftDecimalRight(int32_t numPlaces);
private:
/*
* These data members are intentionally public and can be set directly.
*<P>
* The value represented is given by placing the decimal point before
* fDigits[fDecimalAt]. If fDecimalAt is < 0, then leading zeros between
* the decimal point and the first nonzero digit are implied. If fDecimalAt
* is > fCount, then trailing zeros between the fDigits[fCount-1] and the
* decimal point are implied.
* <P>
* Equivalently, the represented value is given by f * 10^fDecimalAt. Here
* f is a value 0.1 <= f < 1 arrived at by placing the digits in fDigits to
* the right of the decimal.
* <P>
* DigitList is normalized, so if it is non-zero, fDigits[0] is non-zero. We
* don't allow denormalized numbers because our exponent is effectively of
* unlimited magnitude. The fCount value contains the number of significant
* digits present in fDigits[].
* <P>
* Zero is represented by any DigitList with fCount == 0 or with each fDigits[i]
* for all i <= fCount == '0'.
*
* int32_t fDecimalAt;
* int32_t fCount;
* UBool fIsPositive;
* char *fDigits;
* DecimalFormat::ERoundingMode fRoundingMode;
*/
public:
decContext fContext; // public access to status flags.
private:
decNumber *fDecNumber;
MaybeStackHeaderAndArray<decNumber, char, DEFAULT_DIGITS> fStorage;
/* Cached double value corresponding to this decimal number.
* This is an optimization for the formatting implementation, which may
* ask for the double value multiple times.
*/
union DoubleOrInt64 {
double fDouble;
int64_t fInt64;
} fUnion;
enum EHave {
kNone=0,
kDouble
} fHave;
UBool shouldRoundUp(int32_t maximumDigits) const;
public:
#if U_OVERRIDE_CXX_ALLOCATION
using UMemory::operator new;
using UMemory::operator delete;
#else
static inline void * U_EXPORT2 operator new(size_t size) U_NO_THROW { return ::operator new(size); };
static inline void U_EXPORT2 operator delete(void *ptr ) U_NO_THROW { ::operator delete(ptr); };
#endif
static double U_EXPORT2 decimalStrToDouble(char *decstr, char **end);
/**
* Placement new for stack usage
* @internal
*/
static inline void * U_EXPORT2 operator new(size_t /*size*/, void * onStack, EStackMode /*mode*/) U_NO_THROW { return onStack; }
/**
* Placement delete for stack usage
* @internal
*/
static inline void U_EXPORT2 operator delete(void * /*ptr*/, void * /*onStack*/, EStackMode /*mode*/) U_NO_THROW {}
private:
inline void internalSetDouble(double d) {
fHave = kDouble;
fUnion.fDouble=d;
}
inline void internalClear() {
fHave = kNone;
}
};
U_NAMESPACE_END
#endif // #if !UCONFIG_NO_FORMATTING
#endif // _DIGITLST
//eof
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