scuffed-code/icu4c/source/i18n/number_utils.cpp
2018-04-14 08:10:45 +00:00

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// © 2018 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
#include <stdlib.h>
#include <cmath>
#include "unicode/utypes.h"
#if !UCONFIG_NO_FORMATTING && !UPRV_INCOMPLETE_CPP11_SUPPORT
// Allow implicit conversion from char16_t* to UnicodeString for this file:
// Helpful in toString methods and elsewhere.
#define UNISTR_FROM_STRING_EXPLICIT
#include "number_types.h"
#include "number_utils.h"
#include "charstr.h"
#include "decContext.h"
#include "decNumber.h"
#include "double-conversion.h"
#include "uresimp.h"
#include "ureslocs.h"
using namespace icu;
using namespace icu::number;
using namespace icu::number::impl;
using icu::double_conversion::DoubleToStringConverter;
namespace {
const char16_t*
doGetPattern(UResourceBundle* res, const char* nsName, const char* patternKey, UErrorCode& publicStatus,
UErrorCode& localStatus) {
// Construct the path into the resource bundle
CharString key;
key.append("NumberElements/", publicStatus);
key.append(nsName, publicStatus);
key.append("/patterns/", publicStatus);
key.append(patternKey, publicStatus);
if (U_FAILURE(publicStatus)) {
return u"";
}
return ures_getStringByKeyWithFallback(res, key.data(), nullptr, &localStatus);
}
}
const char16_t* utils::getPatternForStyle(const Locale& locale, const char* nsName, CldrPatternStyle style,
UErrorCode& status) {
const char* patternKey;
switch (style) {
case CLDR_PATTERN_STYLE_DECIMAL:
patternKey = "decimalFormat";
break;
case CLDR_PATTERN_STYLE_CURRENCY:
patternKey = "currencyFormat";
break;
case CLDR_PATTERN_STYLE_ACCOUNTING:
patternKey = "accountingFormat";
break;
case CLDR_PATTERN_STYLE_PERCENT:
patternKey = "percentFormat";
break;
case CLDR_PATTERN_STYLE_SCIENTIFIC:
patternKey = "scientificFormat";
break;
default:
U_ASSERT(false);
}
LocalUResourceBundlePointer res(ures_open(nullptr, locale.getName(), &status));
if (U_FAILURE(status)) { return u""; }
// Attempt to get the pattern with the native numbering system.
UErrorCode localStatus = U_ZERO_ERROR;
const char16_t* pattern;
pattern = doGetPattern(res.getAlias(), nsName, patternKey, status, localStatus);
if (U_FAILURE(status)) { return u""; }
// Fall back to latn if native numbering system does not have the right pattern
if (U_FAILURE(localStatus) && uprv_strcmp("latn", nsName) != 0) {
localStatus = U_ZERO_ERROR;
pattern = doGetPattern(res.getAlias(), "latn", patternKey, status, localStatus);
if (U_FAILURE(status)) { return u""; }
}
return pattern;
}
DecNum::DecNum() {
uprv_decContextDefault(&fContext, DEC_INIT_BASE);
uprv_decContextSetRounding(&fContext, DEC_ROUND_HALF_EVEN);
fContext.traps = 0; // no traps, thank you (what does this even mean?)
}
DecNum::DecNum(const DecNum& other, UErrorCode& status)
: fContext(other.fContext) {
// Allocate memory for the new DecNum.
U_ASSERT(fContext.digits == other.fData.getCapacity());
if (fContext.digits > kDefaultDigits) {
void* p = fData.resize(fContext.digits, 0);
if (p == nullptr) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
}
// Copy the data from the old DecNum to the new one.
uprv_memcpy(fData.getAlias(), other.fData.getAlias(), sizeof(decNumber));
uprv_memcpy(fData.getArrayStart(),
other.fData.getArrayStart(),
other.fData.getArrayLimit() - other.fData.getArrayStart());
}
void DecNum::setTo(StringPiece str, UErrorCode& status) {
// We need NUL-terminated for decNumber; CharString guarantees this, but not StringPiece.
CharString cstr(str, status);
if (U_FAILURE(status)) { return; }
_setTo(cstr.data(), str.length(), status);
}
void DecNum::setTo(const char* str, UErrorCode& status) {
_setTo(str, static_cast<int32_t>(uprv_strlen(str)), status);
}
void DecNum::setTo(double d, UErrorCode& status) {
// Need to check for NaN and Infinity before going into DoubleToStringConverter
if (std::isnan(d) != 0 || std::isfinite(d) == 0) {
status = U_UNSUPPORTED_ERROR;
return;
}
// First convert from double to string, then string to DecNum.
// Allocate enough room for: all digits, "E-324", and NUL-terminator.
char buffer[DoubleToStringConverter::kBase10MaximalLength + 6];
bool sign; // unused; always positive
int32_t length;
int32_t point;
DoubleToStringConverter::DoubleToAscii(
d,
DoubleToStringConverter::DtoaMode::SHORTEST,
0,
buffer,
sizeof(buffer),
&sign,
&length,
&point
);
// Read initial result as a string.
_setTo(buffer, length, status);
// Set exponent and bitmask. Note that DoubleToStringConverter does not do negatives.
fData.getAlias()->exponent += point - length;
fData.getAlias()->bits |= static_cast<uint8_t>(std::signbit(d) ? DECNEG : 0);
}
void DecNum::_setTo(const char* str, int32_t maxDigits, UErrorCode& status) {
if (maxDigits > kDefaultDigits) {
fData.resize(maxDigits, 0);
fContext.digits = maxDigits;
} else {
fContext.digits = kDefaultDigits;
}
static_assert(DECDPUN == 1, "Assumes that DECDPUN is set to 1");
uprv_decNumberFromString(fData.getAlias(), str, &fContext);
// Check for invalid syntax and set the corresponding error code.
if ((fContext.status & DEC_Conversion_syntax) != 0) {
status = U_DECIMAL_NUMBER_SYNTAX_ERROR;
return;
} else if (fContext.status != 0) {
// Not a syntax error, but some other error, like an exponent that is too large.
status = U_UNSUPPORTED_ERROR;
return;
}
// For consistency with Java BigDecimal, no support for DecNum that is NaN or Infinity!
if (decNumberIsSpecial(fData.getAlias())) {
status = U_UNSUPPORTED_ERROR;
return;
}
}
void
DecNum::setTo(const uint8_t* bcd, int32_t length, int32_t scale, bool isNegative, UErrorCode& status) {
if (length > kDefaultDigits) {
fData.resize(length, 0);
fContext.digits = length;
} else {
fContext.digits = kDefaultDigits;
}
// "digits is of type int32_t, and must have a value in the range 1 through 999,999,999."
if (length < 1 || length > 999999999) {
// Too large for decNumber
status = U_UNSUPPORTED_ERROR;
return;
}
// "The exponent field holds the exponent of the number. Its range is limited by the requirement that
// "the range of the adjusted exponent of the number be balanced and fit within a whole number of
// "decimal digits (in this implementation, be 999,999,999 through +999,999,999). The adjusted
// "exponent is the exponent that would result if the number were expressed with a single digit before
// "the decimal point, and is therefore given by exponent+digits-1."
if (scale > 999999999 - length + 1 || scale < -999999999 - length + 1) {
// Too large for decNumber
status = U_UNSUPPORTED_ERROR;
return;
}
fData.getAlias()->digits = length;
fData.getAlias()->exponent = scale;
fData.getAlias()->bits = static_cast<uint8_t>(isNegative ? DECNEG : 0);
uprv_decNumberSetBCD(fData, bcd, static_cast<uint32_t>(length));
if (fContext.status != 0) {
// Some error occured while constructing the decNumber.
status = U_INTERNAL_PROGRAM_ERROR;
}
}
void DecNum::normalize() {
uprv_decNumberReduce(fData, fData, &fContext);
}
void DecNum::multiplyBy(const DecNum& rhs, UErrorCode& status) {
uprv_decNumberMultiply(fData, fData, rhs.fData, &fContext);
if (fContext.status != 0) {
status = U_INTERNAL_PROGRAM_ERROR;
}
}
void DecNum::divideBy(const DecNum& rhs, UErrorCode& status) {
uprv_decNumberDivide(fData, fData, rhs.fData, &fContext);
if (fContext.status != 0) {
status = U_INTERNAL_PROGRAM_ERROR;
}
}
bool DecNum::isNegative() const {
return decNumberIsNegative(fData.getAlias());
}
bool DecNum::isZero() const {
return decNumberIsZero(fData.getAlias());
}
#endif /* #if !UCONFIG_NO_FORMATTING */