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// © 2017 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
#include "unicode/utypes.h"
#if !UCONFIG_NO_FORMATTING
#include <cstdlib>
#include "number_scientific.h"
#include "number_utils.h"
#include "formatted_string_builder.h"
#include "unicode/unum.h"
#include "number_microprops.h"
using namespace icu;
using namespace icu::number;
using namespace icu::number::impl;
// NOTE: The object lifecycle of ScientificModifier and ScientificHandler differ greatly in Java and C++.
//
// During formatting, we need to provide an object with state (the exponent) as the inner modifier.
//
// In Java, where the priority is put on reducing object creations, the unsafe code path re-uses the
// ScientificHandler as a ScientificModifier, and the safe code path pre-computes 25 ScientificModifier
// instances. This scheme reduces the number of object creations by 1 in both safe and unsafe.
//
// In C++, MicroProps provides a pre-allocated ScientificModifier, and ScientificHandler simply populates
// the state (the exponent) into that ScientificModifier. There is no difference between safe and unsafe.
ScientificModifier::ScientificModifier() : fExponent(0), fHandler(nullptr) {}
void ScientificModifier::set(int32_t exponent, const ScientificHandler *handler) {
// ScientificModifier should be set only once.
U_ASSERT(fHandler == nullptr);
fExponent = exponent;
fHandler = handler;
}
int32_t ScientificModifier::apply(FormattedStringBuilder &output, int32_t /*leftIndex*/, int32_t rightIndex,
UErrorCode &status) const {
// FIXME: Localized exponent separator location.
int i = rightIndex;
// Append the exponent separator and sign
i += output.insert(
i,
fHandler->fSymbols->getSymbol(DecimalFormatSymbols::ENumberFormatSymbol::kExponentialSymbol),
UNUM_EXPONENT_SYMBOL_FIELD,
status);
if (fExponent < 0 && fHandler->fSettings.fExponentSignDisplay != UNUM_SIGN_NEVER) {
i += output.insert(
i,
fHandler->fSymbols
->getSymbol(DecimalFormatSymbols::ENumberFormatSymbol::kMinusSignSymbol),
UNUM_EXPONENT_SIGN_FIELD,
status);
} else if (fExponent >= 0 && fHandler->fSettings.fExponentSignDisplay == UNUM_SIGN_ALWAYS) {
i += output.insert(
i,
fHandler->fSymbols
->getSymbol(DecimalFormatSymbols::ENumberFormatSymbol::kPlusSignSymbol),
UNUM_EXPONENT_SIGN_FIELD,
status);
}
// Append the exponent digits (using a simple inline algorithm)
int32_t disp = std::abs(fExponent);
for (int j = 0; j < fHandler->fSettings.fMinExponentDigits || disp > 0; j++, disp /= 10) {
auto d = static_cast<int8_t>(disp % 10);
i += utils::insertDigitFromSymbols(
output,
i - j,
d,
*fHandler->fSymbols,
UNUM_EXPONENT_FIELD,
status);
}
return i - rightIndex;
}
int32_t ScientificModifier::getPrefixLength() const {
// TODO: Localized exponent separator location.
return 0;
}
int32_t ScientificModifier::getCodePointCount() const {
// NOTE: This method is only called one place, NumberRangeFormatterImpl.
// The call site only cares about != 0 and != 1.
// Return a very large value so that if this method is used elsewhere, we should notice.
return 999;
}
bool ScientificModifier::isStrong() const {
// Scientific is always strong
return true;
}
bool ScientificModifier::containsField(UNumberFormatFields field) const {
(void)field;
// This method is not used for inner modifiers.
UPRV_UNREACHABLE;
}
void ScientificModifier::getParameters(Parameters& output) const {
// Not part of any plural sets
output.obj = nullptr;
}
bool ScientificModifier::semanticallyEquivalent(const Modifier& other) const {
auto* _other = dynamic_cast<const ScientificModifier*>(&other);
if (_other == nullptr) {
return false;
}
// TODO: Check for locale symbols and settings as well? Could be less efficient.
return fExponent == _other->fExponent;
}
// Note: Visual Studio does not compile this function without full name space. Why?
icu::number::impl::ScientificHandler::ScientificHandler(const Notation *notation, const DecimalFormatSymbols *symbols,
const MicroPropsGenerator *parent) :
fSettings(notation->fUnion.scientific), fSymbols(symbols), fParent(parent) {}
void ScientificHandler::processQuantity(DecimalQuantity &quantity, MicroProps µs,
UErrorCode &status) const {
fParent->processQuantity(quantity, micros, status);
if (U_FAILURE(status)) { return; }
// Do not apply scientific notation to special doubles
if (quantity.isInfinite() || quantity.isNaN()) {
micros.modInner = µs.helpers.emptyStrongModifier;
return;
}
// Treat zero as if it had magnitude 0
int32_t exponent;
if (quantity.isZeroish()) {
if (fSettings.fRequireMinInt && micros.rounder.isSignificantDigits()) {
// Show "00.000E0" on pattern "00.000E0"
micros.rounder.apply(quantity, fSettings.fEngineeringInterval, status);
exponent = 0;
} else {
micros.rounder.apply(quantity, status);
exponent = 0;
}
} else {
exponent = -micros.rounder.chooseMultiplierAndApply(quantity, *this, status);
}
// Use MicroProps's helper ScientificModifier and save it as the modInner.
ScientificModifier &mod = micros.helpers.scientificModifier;
mod.set(exponent, this);
micros.modInner = &mod;
// We already performed rounding. Do not perform it again.
micros.rounder = RoundingImpl::passThrough();
}
int32_t ScientificHandler::getMultiplier(int32_t magnitude) const {
int32_t interval = fSettings.fEngineeringInterval;
int32_t digitsShown;
if (fSettings.fRequireMinInt) {
// For patterns like "000.00E0" and ".00E0"
digitsShown = interval;
} else if (interval <= 1) {
// For patterns like "0.00E0" and "@@@E0"
digitsShown = 1;
} else {
// For patterns like "##0.00"
digitsShown = ((magnitude % interval + interval) % interval) + 1;
}
return digitsShown - magnitude - 1;
}
#endif /* #if !UCONFIG_NO_FORMATTING */
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