1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/intl/icu/source/i18n/digitlst.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,451 @@
1.4 +/*
1.5 +******************************************************************************
1.6 +*
1.7 +* Copyright (C) 1997-2012, International Business Machines
1.8 +* Corporation and others. All Rights Reserved.
1.9 +*
1.10 +******************************************************************************
1.11 +*
1.12 +* File DIGITLST.H
1.13 +*
1.14 +* Modification History:
1.15 +*
1.16 +* Date Name Description
1.17 +* 02/25/97 aliu Converted from java.
1.18 +* 03/21/97 clhuang Updated per C++ implementation.
1.19 +* 04/15/97 aliu Changed MAX_COUNT to DBL_DIG. Changed Digit to char.
1.20 +* 09/09/97 aliu Adapted for exponential notation support.
1.21 +* 08/02/98 stephen Added nearest/even rounding
1.22 +* 06/29/99 stephen Made LONG_DIGITS a macro to satisfy SUN compiler
1.23 +* 07/09/99 stephen Removed kMaxCount (unused, for HP compiler)
1.24 +******************************************************************************
1.25 +*/
1.26 +
1.27 +#ifndef DIGITLST_H
1.28 +#define DIGITLST_H
1.29 +
1.30 +#include "unicode/uobject.h"
1.31 +
1.32 +#if !UCONFIG_NO_FORMATTING
1.33 +#include "unicode/decimfmt.h"
1.34 +#include <float.h>
1.35 +#include "decContext.h"
1.36 +#include "decNumber.h"
1.37 +#include "cmemory.h"
1.38 +
1.39 +// Decimal digits in a 64-bit int
1.40 +#define INT64_DIGITS 19
1.41 +
1.42 +typedef enum EDigitListValues {
1.43 + MAX_DBL_DIGITS = DBL_DIG,
1.44 + MAX_I64_DIGITS = INT64_DIGITS,
1.45 + MAX_DIGITS = MAX_I64_DIGITS,
1.46 + MAX_EXPONENT = DBL_DIG,
1.47 + DIGIT_PADDING = 3,
1.48 + DEFAULT_DIGITS = 40, // Initial storage size, will grow as needed.
1.49 +
1.50 + // "+." + fDigits + "e" + fDecimalAt
1.51 + MAX_DEC_DIGITS = MAX_DIGITS + DIGIT_PADDING + MAX_EXPONENT
1.52 +} EDigitListValues;
1.53 +
1.54 +U_NAMESPACE_BEGIN
1.55 +
1.56 +class CharString;
1.57 +
1.58 +// Export an explicit template instantiation of the MaybeStackHeaderAndArray that
1.59 +// is used as a data member of DigitList.
1.60 +//
1.61 +// MSVC requires this, even though it should not be necessary.
1.62 +// No direct access to the MaybeStackHeaderAndArray leaks out of the i18n library.
1.63 +//
1.64 +// Macintosh produces duplicate definition linker errors with the explicit template
1.65 +// instantiation.
1.66 +//
1.67 +#if !U_PLATFORM_IS_DARWIN_BASED
1.68 +template class U_I18N_API MaybeStackHeaderAndArray<decNumber, char, DEFAULT_DIGITS>;
1.69 +#endif
1.70 +
1.71 +
1.72 +enum EStackMode { kOnStack };
1.73 +
1.74 +enum EFastpathBits { kFastpathOk = 1, kNoDecimal = 2 };
1.75 +
1.76 +/**
1.77 + * Digit List is actually a Decimal Floating Point number.
1.78 + * The original implementation has been replaced by a thin wrapper onto a
1.79 + * decimal number from the decNumber library.
1.80 + *
1.81 + * The original DigitList API has been retained, to minimize the impact of
1.82 + * the change on the rest of the ICU formatting code.
1.83 + *
1.84 + * The change to decNumber enables support for big decimal numbers, and
1.85 + * allows rounding computations to be done directly in decimal, avoiding
1.86 + * extra, and inaccurate, conversions to and from doubles.
1.87 + *
1.88 + * Original DigitList comments:
1.89 + *
1.90 + * Digit List utility class. Private to DecimalFormat. Handles the transcoding
1.91 + * between numeric values and strings of characters. Only handles
1.92 + * non-negative numbers. The division of labor between DigitList and
1.93 + * DecimalFormat is that DigitList handles the radix 10 representation
1.94 + * issues; DecimalFormat handles the locale-specific issues such as
1.95 + * positive/negative, grouping, decimal point, currency, and so on.
1.96 + * <P>
1.97 + * A DigitList is really a representation of a floating point value.
1.98 + * It may be an integer value; we assume that a double has sufficient
1.99 + * precision to represent all digits of a long.
1.100 + * <P>
1.101 + * The DigitList representation consists of a string of characters,
1.102 + * which are the digits radix 10, from '0' to '9'. It also has a radix
1.103 + * 10 exponent associated with it. The value represented by a DigitList
1.104 + * object can be computed by mulitplying the fraction f, where 0 <= f < 1,
1.105 + * derived by placing all the digits of the list to the right of the
1.106 + * decimal point, by 10^exponent.
1.107 + *
1.108 + * --------
1.109 + *
1.110 + * DigitList vs. decimalNumber:
1.111 + *
1.112 + * DigitList stores digits with the most significant first.
1.113 + * decNumber stores digits with the least significant first.
1.114 + *
1.115 + * DigitList, decimal point is before the most significant.
1.116 + * decNumber, decimal point is after the least signficant digit.
1.117 + *
1.118 + * digitList: 0.ddddd * 10 ^ exp
1.119 + * decNumber: ddddd. * 10 ^ exp
1.120 + *
1.121 + * digitList exponent = decNumber exponent + digit count
1.122 + *
1.123 + * digitList, digits are platform invariant chars, '0' - '9'
1.124 + * decNumber, digits are binary, one per byte, 0 - 9.
1.125 + *
1.126 + * (decNumber library is configurable in how digits are stored, ICU has configured
1.127 + * it this way for convenience in replacing the old DigitList implementation.)
1.128 + */
1.129 +class U_I18N_API DigitList : public UMemory { // Declare external to make compiler happy
1.130 +public:
1.131 +
1.132 + DigitList();
1.133 + ~DigitList();
1.134 +
1.135 + /* copy constructor
1.136 + * @param DigitList The object to be copied.
1.137 + * @return the newly created object.
1.138 + */
1.139 + DigitList(const DigitList&); // copy constructor
1.140 +
1.141 + /* assignment operator
1.142 + * @param DigitList The object to be copied.
1.143 + * @return the newly created object.
1.144 + */
1.145 + DigitList& operator=(const DigitList&); // assignment operator
1.146 +
1.147 + /**
1.148 + * Return true if another object is semantically equal to this one.
1.149 + * @param other The DigitList to be compared for equality
1.150 + * @return true if another object is semantically equal to this one.
1.151 + * return false otherwise.
1.152 + */
1.153 + UBool operator==(const DigitList& other) const;
1.154 +
1.155 + int32_t compare(const DigitList& other);
1.156 +
1.157 +
1.158 + inline UBool operator!=(const DigitList& other) const { return !operator==(other); }
1.159 +
1.160 + /**
1.161 + * Clears out the digits.
1.162 + * Use before appending them.
1.163 + * Typically, you set a series of digits with append, then at the point
1.164 + * you hit the decimal point, you set myDigitList.fDecimalAt = myDigitList.fCount;
1.165 + * then go on appending digits.
1.166 + */
1.167 + void clear(void);
1.168 +
1.169 + /**
1.170 + * Remove, by rounding, any fractional part of the decimal number,
1.171 + * leaving an integer value.
1.172 + */
1.173 + void toIntegralValue();
1.174 +
1.175 + /**
1.176 + * Appends digits to the list.
1.177 + * CAUTION: this function is not recommended for new code.
1.178 + * In the original DigitList implementation, decimal numbers were
1.179 + * parsed by appending them to a digit list as they were encountered.
1.180 + * With the revamped DigitList based on decNumber, append is very
1.181 + * inefficient, and the interaction with the exponent value is confusing.
1.182 + * Best avoided.
1.183 + * TODO: remove this function once all use has been replaced.
1.184 + * TODO: describe alternative to append()
1.185 + * @param digit The digit to be appended.
1.186 + */
1.187 + void append(char digit);
1.188 +
1.189 + /**
1.190 + * Utility routine to get the value of the digit list
1.191 + * Returns 0.0 if zero length.
1.192 + * @return the value of the digit list.
1.193 + */
1.194 + double getDouble(void) const;
1.195 +
1.196 + /**
1.197 + * Utility routine to get the value of the digit list
1.198 + * Make sure that fitsIntoLong() is called before calling this function.
1.199 + * Returns 0 if zero length.
1.200 + * @return the value of the digit list, return 0 if it is zero length
1.201 + */
1.202 + int32_t getLong(void) /*const*/;
1.203 +
1.204 + /**
1.205 + * Utility routine to get the value of the digit list
1.206 + * Make sure that fitsIntoInt64() is called before calling this function.
1.207 + * Returns 0 if zero length.
1.208 + * @return the value of the digit list, return 0 if it is zero length
1.209 + */
1.210 + int64_t getInt64(void) /*const*/;
1.211 +
1.212 + /**
1.213 + * Utility routine to get the value of the digit list as a decimal string.
1.214 + */
1.215 + void getDecimal(CharString &str, UErrorCode &status);
1.216 +
1.217 + /**
1.218 + * Return true if the number represented by this object can fit into
1.219 + * a long.
1.220 + * @param ignoreNegativeZero True if negative zero is ignored.
1.221 + * @return true if the number represented by this object can fit into
1.222 + * a long, return false otherwise.
1.223 + */
1.224 + UBool fitsIntoLong(UBool ignoreNegativeZero) /*const*/;
1.225 +
1.226 + /**
1.227 + * Return true if the number represented by this object can fit into
1.228 + * an int64_t.
1.229 + * @param ignoreNegativeZero True if negative zero is ignored.
1.230 + * @return true if the number represented by this object can fit into
1.231 + * a long, return false otherwise.
1.232 + */
1.233 + UBool fitsIntoInt64(UBool ignoreNegativeZero) /*const*/;
1.234 +
1.235 + /**
1.236 + * Utility routine to set the value of the digit list from a double.
1.237 + * @param source The value to be set
1.238 + */
1.239 + void set(double source);
1.240 +
1.241 + /**
1.242 + * Utility routine to set the value of the digit list from a long.
1.243 + * If a non-zero maximumDigits is specified, no more than that number of
1.244 + * significant digits will be produced.
1.245 + * @param source The value to be set
1.246 + */
1.247 + void set(int32_t source);
1.248 +
1.249 + /**
1.250 + * Utility routine to set the value of the digit list from an int64.
1.251 + * If a non-zero maximumDigits is specified, no more than that number of
1.252 + * significant digits will be produced.
1.253 + * @param source The value to be set
1.254 + */
1.255 + void set(int64_t source);
1.256 +
1.257 + /**
1.258 + * Utility routine to set the value of the digit list from an int64.
1.259 + * Does not set the decnumber unless requested later
1.260 + * If a non-zero maximumDigits is specified, no more than that number of
1.261 + * significant digits will be produced.
1.262 + * @param source The value to be set
1.263 + */
1.264 + void setInteger(int64_t source);
1.265 +
1.266 + /**
1.267 + * Utility routine to set the value of the digit list from a decimal number
1.268 + * string.
1.269 + * @param source The value to be set. The string must be nul-terminated.
1.270 + * @param fastpathBits special flags for fast parsing
1.271 + */
1.272 + void set(const StringPiece &source, UErrorCode &status, uint32_t fastpathBits = 0);
1.273 +
1.274 + /**
1.275 + * Multiply this = this * arg
1.276 + * This digitlist will be expanded if necessary to accomodate the result.
1.277 + * @param arg the number to multiply by.
1.278 + */
1.279 + void mult(const DigitList &arg, UErrorCode &status);
1.280 +
1.281 + /**
1.282 + * Divide this = this / arg
1.283 + */
1.284 + void div(const DigitList &arg, UErrorCode &status);
1.285 +
1.286 + // The following functions replace direct access to the original DigitList implmentation
1.287 + // data structures.
1.288 +
1.289 + void setRoundingMode(DecimalFormat::ERoundingMode m);
1.290 +
1.291 + /** Test a number for zero.
1.292 + * @return TRUE if the number is zero
1.293 + */
1.294 + UBool isZero(void) const;
1.295 +
1.296 + /** Test for a Nan
1.297 + * @return TRUE if the number is a NaN
1.298 + */
1.299 + UBool isNaN(void) const {return decNumberIsNaN(fDecNumber);}
1.300 +
1.301 + UBool isInfinite() const {return decNumberIsInfinite(fDecNumber);}
1.302 +
1.303 + /** Reduce, or normalize. Removes trailing zeroes, adjusts exponent appropriately. */
1.304 + void reduce();
1.305 +
1.306 + /** Remove trailing fraction zeros, adjust exponent accordingly. */
1.307 + void trim();
1.308 +
1.309 + /** Set to zero */
1.310 + void setToZero() {uprv_decNumberZero(fDecNumber);}
1.311 +
1.312 + /** get the number of digits in the decimal number */
1.313 + int32_t digits() const {return fDecNumber->digits;}
1.314 +
1.315 + /**
1.316 + * Round the number to the given number of digits.
1.317 + * @param maximumDigits The maximum number of digits to be shown.
1.318 + * Upon return, count will be less than or equal to maximumDigits.
1.319 + */
1.320 + void round(int32_t maximumDigits);
1.321 +
1.322 + void roundFixedPoint(int32_t maximumFractionDigits);
1.323 +
1.324 + /** Ensure capacity for digits. Grow the storage if it is currently less than
1.325 + * the requested size. Capacity is not reduced if it is already greater
1.326 + * than requested.
1.327 + */
1.328 + void ensureCapacity(int32_t requestedSize, UErrorCode &status);
1.329 +
1.330 + UBool isPositive(void) const { return decNumberIsNegative(fDecNumber) == 0;}
1.331 + void setPositive(UBool s);
1.332 +
1.333 + void setDecimalAt(int32_t d);
1.334 + int32_t getDecimalAt();
1.335 +
1.336 + void setCount(int32_t c);
1.337 + int32_t getCount() const;
1.338 +
1.339 + /**
1.340 + * Set the digit in platform (invariant) format, from '0'..'9'
1.341 + * @param i index of digit
1.342 + * @param v digit value, from '0' to '9' in platform invariant format
1.343 + */
1.344 + void setDigit(int32_t i, char v);
1.345 +
1.346 + /**
1.347 + * Get the digit in platform (invariant) format, from '0'..'9' inclusive
1.348 + * @param i index of digit
1.349 + * @return invariant format of the digit
1.350 + */
1.351 + char getDigit(int32_t i);
1.352 +
1.353 +
1.354 + /**
1.355 + * Get the digit's value, as an integer from 0..9 inclusive.
1.356 + * Note that internally this value is a decNumberUnit, but ICU configures it to be a uint8_t.
1.357 + * @param i index of digit
1.358 + * @return value of that digit
1.359 + */
1.360 + uint8_t getDigitValue(int32_t i);
1.361 +
1.362 +
1.363 +private:
1.364 + /*
1.365 + * These data members are intentionally public and can be set directly.
1.366 + *<P>
1.367 + * The value represented is given by placing the decimal point before
1.368 + * fDigits[fDecimalAt]. If fDecimalAt is < 0, then leading zeros between
1.369 + * the decimal point and the first nonzero digit are implied. If fDecimalAt
1.370 + * is > fCount, then trailing zeros between the fDigits[fCount-1] and the
1.371 + * decimal point are implied.
1.372 + * <P>
1.373 + * Equivalently, the represented value is given by f * 10^fDecimalAt. Here
1.374 + * f is a value 0.1 <= f < 1 arrived at by placing the digits in fDigits to
1.375 + * the right of the decimal.
1.376 + * <P>
1.377 + * DigitList is normalized, so if it is non-zero, fDigits[0] is non-zero. We
1.378 + * don't allow denormalized numbers because our exponent is effectively of
1.379 + * unlimited magnitude. The fCount value contains the number of significant
1.380 + * digits present in fDigits[].
1.381 + * <P>
1.382 + * Zero is represented by any DigitList with fCount == 0 or with each fDigits[i]
1.383 + * for all i <= fCount == '0'.
1.384 + *
1.385 + * int32_t fDecimalAt;
1.386 + * int32_t fCount;
1.387 + * UBool fIsPositive;
1.388 + * char *fDigits;
1.389 + * DecimalFormat::ERoundingMode fRoundingMode;
1.390 + */
1.391 +
1.392 +public:
1.393 + decContext fContext; // public access to status flags.
1.394 +
1.395 +private:
1.396 + decNumber *fDecNumber;
1.397 + MaybeStackHeaderAndArray<decNumber, char, DEFAULT_DIGITS> fStorage;
1.398 +
1.399 + /* Cached double value corresponding to this decimal number.
1.400 + * This is an optimization for the formatting implementation, which may
1.401 + * ask for the double value multiple times.
1.402 + */
1.403 + union DoubleOrInt64 {
1.404 + double fDouble;
1.405 + int64_t fInt64;
1.406 + } fUnion;
1.407 + enum EHave {
1.408 + kNone=0,
1.409 + kDouble,
1.410 + kInt64
1.411 + } fHave;
1.412 +
1.413 +
1.414 +
1.415 + UBool shouldRoundUp(int32_t maximumDigits) const;
1.416 +
1.417 + public:
1.418 +
1.419 + using UMemory::operator new;
1.420 + using UMemory::operator delete;
1.421 +
1.422 + /**
1.423 + * Placement new for stack usage
1.424 + * @internal
1.425 + */
1.426 + static inline void * U_EXPORT2 operator new(size_t /*size*/, void * onStack, EStackMode /*mode*/) U_NO_THROW { return onStack; }
1.427 +
1.428 + /**
1.429 + * Placement delete for stack usage
1.430 + * @internal
1.431 + */
1.432 + static inline void U_EXPORT2 operator delete(void * /*ptr*/, void * /*onStack*/, EStackMode /*mode*/) U_NO_THROW {}
1.433 +
1.434 + private:
1.435 + inline void internalSetDouble(double d) {
1.436 + fHave = kDouble;
1.437 + fUnion.fDouble=d;
1.438 + }
1.439 + inline void internalSetInt64(int64_t d) {
1.440 + fHave = kInt64;
1.441 + fUnion.fInt64=d;
1.442 + }
1.443 + inline void internalClear() {
1.444 + fHave = kNone;
1.445 + }
1.446 +};
1.447 +
1.448 +
1.449 +U_NAMESPACE_END
1.450 +
1.451 +#endif // #if !UCONFIG_NO_FORMATTING
1.452 +#endif // _DIGITLST
1.453 +
1.454 +//eof
