--- /dev/null
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "DecimalNumber.h"
+#include <math.h>
+#include <wtf/MathExtras.h>
+#include <wtf/text/WTFString.h>
+
+namespace WTF {
+
+unsigned DecimalNumber::bufferLengthForStringDecimal() const
+{
+ unsigned length = 0;
+ // if the exponent is negative the number decimal representation is of the form:
+ // [<sign>]0.[<zeros>]<significand>
+ if (m_exponent < 0) {
+ if (m_sign)
+ ++length;
+ length += 2; // for "0."
+ length += -m_exponent - 1;
+ length += m_precision;
+ return length;
+ }
+
+ unsigned digitsBeforeDecimalPoint = m_exponent + 1;
+
+ // If the precision is <= than the number of digits to get up to the decimal
+ // point, then there is no fractional part, number is of the form:
+ // [<sign>]<significand>[<zeros>]
+ if (m_precision <= digitsBeforeDecimalPoint) {
+ if (m_sign)
+ ++length;
+ length += m_precision;
+ length += digitsBeforeDecimalPoint - m_precision;
+ return length;
+ }
+
+ // If we get here, number starts before the decimal point, and ends after it,
+ // as such is of the form:
+ // [<sign>]<significand-begin>.<significand-end>
+ if (m_sign)
+ ++length;
+ length += digitsBeforeDecimalPoint;
+ ++length; // for decimal point
+ length += m_precision - digitsBeforeDecimalPoint;
+
+ return length;
+}
+
+unsigned DecimalNumber::bufferLengthForStringExponential() const
+{
+ unsigned length = 0;
+ if (m_sign)
+ ++length;
+
+ // Add the significand
+ ++length;
+
+ if (m_precision > 1) {
+ ++length; // for decimal point
+ length += m_precision - 1;
+ }
+
+ // Add "e+" or "e-"
+ length += 2;
+
+ int exponent = (m_exponent >= 0) ? m_exponent : -m_exponent;
+
+ // Add the exponent
+ if (exponent >= 100)
+ ++length;
+ if (exponent >= 10)
+ ++length;
+ ++length;
+
+ return length;
+}
+
+unsigned DecimalNumber::toStringDecimal(UChar* buffer, unsigned bufferLength) const
+{
+ ASSERT_UNUSED(bufferLength, bufferLength >= bufferLengthForStringDecimal());
+
+ // Should always be at least one digit to add to the string!
+ ASSERT(m_precision);
+ UChar* next = buffer;
+
+ // if the exponent is negative the number decimal representation is of the form:
+ // [<sign>]0.[<zeros>]<significand>
+ if (m_exponent < 0) {
+ unsigned zeros = -m_exponent - 1;
+
+ if (m_sign)
+ *next++ = '-';
+ *next++ = '0';
+ *next++ = '.';
+ for (unsigned i = 0; i < zeros; ++i)
+ *next++ = '0';
+ for (unsigned i = 0; i < m_precision; ++i)
+ *next++ = m_significand[i];
+
+ return next - buffer;
+ }
+
+ unsigned digitsBeforeDecimalPoint = m_exponent + 1;
+
+ // If the precision is <= than the number of digits to get up to the decimal
+ // point, then there is no fractional part, number is of the form:
+ // [<sign>]<significand>[<zeros>]
+ if (m_precision <= digitsBeforeDecimalPoint) {
+ if (m_sign)
+ *next++ = '-';
+ for (unsigned i = 0; i < m_precision; ++i)
+ *next++ = m_significand[i];
+ for (unsigned i = 0; i < (digitsBeforeDecimalPoint - m_precision); ++i)
+ *next++ = '0';
+
+ return next - buffer;
+ }
+
+ // If we get here, number starts before the decimal point, and ends after it,
+ // as such is of the form:
+ // [<sign>]<significand-begin>.<significand-end>
+
+ if (m_sign)
+ *next++ = '-';
+ for (unsigned i = 0; i < digitsBeforeDecimalPoint; ++i)
+ *next++ = m_significand[i];
+ *next++ = '.';
+ for (unsigned i = digitsBeforeDecimalPoint; i < m_precision; ++i)
+ *next++ = m_significand[i];
+
+ return next - buffer;
+}
+
+unsigned DecimalNumber::toStringExponential(UChar* buffer, unsigned bufferLength) const
+{
+ ASSERT_UNUSED(bufferLength, bufferLength >= bufferLengthForStringExponential());
+
+ // Should always be at least one digit to add to the string!
+ ASSERT(m_precision);
+ UChar* next = buffer;
+
+ // Add the sign
+ if (m_sign)
+ *next++ = '-';
+
+ // Add the significand
+ *next++ = m_significand[0];
+ if (m_precision > 1) {
+ *next++ = '.';
+ for (unsigned i = 1; i < m_precision; ++i)
+ *next++ = m_significand[i];
+ }
+
+ // Add "e+" or "e-"
+ *next++ = 'e';
+ int exponent;
+ if (m_exponent >= 0) {
+ *next++ = '+';
+ exponent = m_exponent;
+ } else {
+ *next++ = '-';
+ exponent = -m_exponent;
+ }
+
+ // Add the exponent
+ if (exponent >= 100)
+ *next++ = '0' + exponent / 100;
+ if (exponent >= 10)
+ *next++ = '0' + (exponent % 100) / 10;
+ *next++ = '0' + exponent % 10;
+
+ return next - buffer;
+}
+
+} // namespace WTF
projects / apple / javascriptcore.git / blobdiff