diff options
Diffstat (limited to 'dom/xslt/base/txDouble.cpp')
| -rw-r--r-- | dom/xslt/base/txDouble.cpp | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/dom/xslt/base/txDouble.cpp b/dom/xslt/base/txDouble.cpp new file mode 100644 index 000000000..f52d1b885 --- /dev/null +++ b/dom/xslt/base/txDouble.cpp @@ -0,0 +1,215 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* 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: + typedef char16_t input_type; + typedef char16_t value_type; + txStringToDouble(): mState(eWhitestart), mSign(ePositive) {} + + void + write(const input_type* aSource, uint32_t aSourceLength) + { + if (mState == eIllegal) { + return; + } + uint32_t i = 0; + char16_t c; + for ( ; i < aSourceLength; ++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 mSign*PR_strtod(mBuffer.get(), 0); + } +private: + nsAutoCString mBuffer; + enum { + eWhitestart, + eDecimal, + eMantissa, + eWhiteend, + eIllegal + } mState; + enum { + eNegative = -1, + ePositive = 1 + } mSign; +}; + +double txDouble::toDouble(const nsAString& aSrc) +{ + txStringToDouble sink; + nsAString::const_iterator fromBegin, fromEnd; + copy_string(aSrc.BeginReading(fromBegin), aSrc.EndReading(fromEnd), sink); + 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 (mozilla::IsNaN(aValue)) { + aDest.AppendLiteral("NaN"); + return; + } + if (mozilla::IsInfinite(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 + nsAString::iterator dest; + aDest.BeginWriting(dest).advance(int32_t(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; + } +} |