Move files in wtf/ to platform/wtf/ (Part 9).

third_party/WebKit/Source/wtf/dtoa.cpp

-/****************************************************************
- *
- * The author of this software is David M. Gay.
- *
- * Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
- * Copyright (C) 2002, 2005, 2006, 2007, 2008, 2010, 2012 Apple Inc.
- * All rights reserved.
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose without fee is hereby granted, provided that this entire notice
- * is included in all copies of any software which is or includes a copy
- * or modification of this software and in all copies of the supporting
- * documentation for such software.
- *
- * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY
- * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
- * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
- *
- ***************************************************************/
-
-/* Please send bug reports to David M. Gay (dmg at acm dot org,
- * with " at " changed at "@" and " dot " changed to ".").    */
-
-/* On a machine with IEEE extended-precision registers, it is
- * necessary to specify double-precision (53-bit) rounding precision
- * before invoking strtod or dtoa.  If the machine uses (the equivalent
- * of) Intel 80x87 arithmetic, the call
- *    _control87(PC_53, MCW_PC);
- * does this with many compilers.  Whether this or another call is
- * appropriate depends on the compiler; for this to work, it may be
- * necessary to #include "float.h" or another system-dependent header
- * file.
- */
-
-#include "wtf/dtoa.h"
-
-#include "wtf/Vector.h"
-#include <string.h>
-
-namespace WTF {
-
-const char* numberToString(double d, NumberToStringBuffer buffer) {
-  double_conversion::StringBuilder builder(buffer, NumberToStringBufferLength);
-  const double_conversion::DoubleToStringConverter& converter =
-      double_conversion::DoubleToStringConverter::EcmaScriptConverter();
-  converter.ToShortest(d, &builder);
-  return builder.Finalize();
-}
-
-static inline const char* formatStringTruncatingTrailingZerosIfNeeded(
-    NumberToStringBuffer buffer,
-    double_conversion::StringBuilder& builder) {
-  size_t length = builder.position();
-
-  // If there is an exponent, stripping trailing zeros would be incorrect.
-  // FIXME: Zeros should be stripped before the 'e'.
-  if (memchr(buffer, 'e', length))
-    return builder.Finalize();
-
-  size_t decimalPointPosition = 0;
-  for (; decimalPointPosition < length; ++decimalPointPosition) {
-    if (buffer[decimalPointPosition] == '.')
-      break;
-  }
-
-  // No decimal seperator found, early exit.
-  if (decimalPointPosition == length)
-    return builder.Finalize();
-
-  size_t truncatedLength = length - 1;
-  for (; truncatedLength > decimalPointPosition; --truncatedLength) {
-    if (buffer[truncatedLength] != '0')
-      break;
-  }
-
-  // No trailing zeros found to strip.
-  if (truncatedLength == length - 1)
-    return builder.Finalize();
-
-  // If we removed all trailing zeros, remove the decimal point as well.
-  if (truncatedLength == decimalPointPosition) {
-    DCHECK_GT(truncatedLength, 0u);
-    --truncatedLength;
-  }
-
-  // Truncate the StringBuilder, and return the final result.
-  builder.SetPosition(truncatedLength + 1);
-  return builder.Finalize();
-}
-
-const char* numberToFixedPrecisionString(double d,
-                                         unsigned significantFigures,
-                                         NumberToStringBuffer buffer) {
-  // Mimic String::format("%.[precision]g", ...), but use dtoas rounding
-  // facilities.
-  // "g": Signed value printed in f or e format, whichever is more compact for
-  // the given value and precision.
-  // The e format is used only when the exponent of the value is less than -4 or
-  // greater than or equal to the precision argument. Trailing zeros are
-  // truncated, and the decimal point appears only if one or more digits follow
-  // it.
-  // "precision": The precision specifies the maximum number of significant
-  // digits printed.
-  double_conversion::StringBuilder builder(buffer, NumberToStringBufferLength);
-  const double_conversion::DoubleToStringConverter& converter =
-      double_conversion::DoubleToStringConverter::EcmaScriptConverter();
-  converter.ToPrecision(d, significantFigures, &builder);
-  // FIXME: Trailing zeros should never be added in the first place. The
-  // current implementation does not strip when there is an exponent, eg.
-  // 1.50000e+10.
-  return formatStringTruncatingTrailingZerosIfNeeded(buffer, builder);
-}
-
-const char* numberToFixedWidthString(double d,
-                                     unsigned decimalPlaces,
-                                     NumberToStringBuffer buffer) {
-  // Mimic String::format("%.[precision]f", ...), but use dtoas rounding
-  // facilities.
-  // "f": Signed value having the form [ - ]dddd.dddd, where dddd is one or more
-  // decimal digits.  The number of digits before the decimal point depends on
-  // the magnitude of the number, and the number of digits after the decimal
-  // point depends on the requested precision.
-  // "precision": The precision value specifies the number of digits after the
-  // decimal point.  If a decimal point appears, at least one digit appears
-  // before it.  The value is rounded to the appropriate number of digits.
-  double_conversion::StringBuilder builder(buffer, NumberToStringBufferLength);
-  const double_conversion::DoubleToStringConverter& converter =
-      double_conversion::DoubleToStringConverter::EcmaScriptConverter();
-  converter.ToFixed(d, decimalPlaces, &builder);
-  return builder.Finalize();
-}
-
-namespace Internal {
-
-double parseDoubleFromLongString(const UChar* string,
-                                 size_t length,
-                                 size_t& parsedLength) {
-  Vector<LChar> conversionBuffer(length);
-  for (size_t i = 0; i < length; ++i)
-    conversionBuffer[i] = isASCII(string[i]) ? string[i] : 0;
-  return parseDouble(conversionBuffer.data(), length, parsedLength);
-}
-
-}  // namespace Internal
-
-}  // namespace WTF