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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/FloatingPoint.h"
#include "nsString.h"
#include "txCore.h"
#include "txXMLUtils.h"
#include <math.h>
#include <stdlib.h>
#include <algorithm>
#ifdef WIN32
# include <float.h>
#endif
#include "prdtoa.h"
/*
* Utility class for doubles
*/
/*
* Converts the given String to a double, if the String value does not
* represent a double, NaN will be returned
*/
class txStringToDouble {
public:
txStringToDouble() : mState(eWhitestart), mSign(ePositive) {}
void Parse(const nsAString& aSource) {
if (mState == eIllegal) {
return;
}
uint32_t i = 0;
char16_t c;
auto len = aSource.Length();
for (; i < len; ++i) {
c = aSource[i];
switch (mState) {
case eWhitestart:
if (c == '-') {
mState = eDecimal;
mSign = eNegative;
} else if (c >= '0' && c <= '9') {
mState = eDecimal;
mBuffer.Append((char)c);
} else if (c == '.') {
mState = eMantissa;
mBuffer.Append((char)c);
} else if (!XMLUtils::isWhitespace(c)) {
mState = eIllegal;
return;
}
break;
case eDecimal:
if (c >= '0' && c <= '9') {
mBuffer.Append((char)c);
} else if (c == '.') {
mState = eMantissa;
mBuffer.Append((char)c);
} else if (XMLUtils::isWhitespace(c)) {
mState = eWhiteend;
} else {
mState = eIllegal;
return;
}
break;
case eMantissa:
if (c >= '0' && c <= '9') {
mBuffer.Append((char)c);
} else if (XMLUtils::isWhitespace(c)) {
mState = eWhiteend;
} else {
mState = eIllegal;
return;
}
break;
case eWhiteend:
if (!XMLUtils::isWhitespace(c)) {
mState = eIllegal;
return;
}
break;
default:
break;
}
}
}
double getDouble() {
if (mState == eIllegal || mBuffer.IsEmpty() ||
(mBuffer.Length() == 1 && mBuffer[0] == '.')) {
return mozilla::UnspecifiedNaN<double>();
}
return static_cast<double>(mSign) * PR_strtod(mBuffer.get(), nullptr);
}
private:
nsAutoCString mBuffer;
enum { eWhitestart, eDecimal, eMantissa, eWhiteend, eIllegal } mState;
enum { eNegative = -1, ePositive = 1 } mSign;
};
double txDouble::toDouble(const nsAString& aSrc) {
txStringToDouble sink;
sink.Parse(aSrc);
return sink.getDouble();
}
/*
* Converts the value of the given double to a String, and places
* The result into the destination String.
* @return the given dest string
*/
void txDouble::toString(double aValue, nsAString& aDest) {
// check for special cases
if (std::isnan(aValue)) {
aDest.AppendLiteral("NaN");
return;
}
if (std::isinf(aValue)) {
if (aValue < 0) aDest.Append(char16_t('-'));
aDest.AppendLiteral("Infinity");
return;
}
// Mantissa length is 17, so this is plenty
const int buflen = 20;
char buf[buflen];
int intDigits, sign;
char* endp;
PR_dtoa(aValue, 0, 0, &intDigits, &sign, &endp, buf, buflen - 1);
// compute length
int32_t length = endp - buf;
if (length > intDigits) {
// decimal point needed
++length;
if (intDigits < 1) {
// leading zeros, -intDigits + 1
length += 1 - intDigits;
}
} else {
// trailing zeros, total length given by intDigits
length = intDigits;
}
if (aValue < 0) ++length;
// grow the string
uint32_t oldlength = aDest.Length();
if (!aDest.SetLength(oldlength + length, mozilla::fallible))
return; // out of memory
auto dest = aDest.BeginWriting();
std::advance(dest, oldlength);
if (aValue < 0) {
*dest = '-';
++dest;
}
int i;
// leading zeros
if (intDigits < 1) {
*dest = '0';
++dest;
*dest = '.';
++dest;
for (i = 0; i > intDigits; --i) {
*dest = '0';
++dest;
}
}
// mantissa
int firstlen = std::min<size_t>(intDigits, endp - buf);
for (i = 0; i < firstlen; i++) {
*dest = buf[i];
++dest;
}
if (i < endp - buf) {
if (i > 0) {
*dest = '.';
++dest;
}
for (; i < endp - buf; i++) {
*dest = buf[i];
++dest;
}
}
// trailing zeros
for (; i < intDigits; i++) {
*dest = '0';
++dest;
}
}
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