The Tor Browser: intl/icu/source/i18n/digitlst.h@6474c204b198 (annotated)

intl/icu/source/i18n/digitlst.h@6474c204b198 (annotated)

intl/icu/source/i18n/digitlst.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
 ******************************************************************************
 *
 *   Copyright (C) 1997-2012, 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;
 // 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(const 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.
      */
     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);
 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,
       kInt64
     } fHave;
     UBool shouldRoundUp(int32_t maximumDigits) const;
  public:
     using UMemory::operator new;
     using UMemory::operator delete;
     /**
      * 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 internalSetInt64(int64_t d) {
       fHave = kInt64;
       fUnion.fInt64=d;
     }
     inline void internalClear() {
       fHave = kNone;
     }
 };
 U_NAMESPACE_END
 #endif // #if !UCONFIG_NO_FORMATTING
 #endif // _DIGITLST
 //eof

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intl/icu/source/i18n/digitlst.h@6474c204b198 (annotated)

intl/icu/source/i18n/digitlst.h