michael@0: // Copyright 2010 the V8 project authors. All rights reserved.
michael@0: // Redistribution and use in source and binary forms, with or without
michael@0: // modification, are permitted provided that the following conditions are
michael@0: // met:
michael@0: //
michael@0: //     * Redistributions of source code must retain the above copyright
michael@0: //       notice, this list of conditions and the following disclaimer.
michael@0: //     * Redistributions in binary form must reproduce the above
michael@0: //       copyright notice, this list of conditions and the following
michael@0: //       disclaimer in the documentation and/or other materials provided
michael@0: //       with the distribution.
michael@0: //     * Neither the name of Google Inc. nor the names of its
michael@0: //       contributors may be used to endorse or promote products derived
michael@0: //       from this software without specific prior written permission.
michael@0: //
michael@0: // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0: // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0: // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0: // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
michael@0: // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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michael@0: // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0: // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0: // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0: // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0: // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: 
michael@0: #ifndef DOUBLE_CONVERSION_FAST_DTOA_H_
michael@0: #define DOUBLE_CONVERSION_FAST_DTOA_H_
michael@0: 
michael@0: #include "utils.h"
michael@0: 
michael@0: namespace double_conversion {
michael@0: 
michael@0: enum FastDtoaMode {
michael@0:   // Computes the shortest representation of the given input. The returned
michael@0:   // result will be the most accurate number of this length. Longer
michael@0:   // representations might be more accurate.
michael@0:   FAST_DTOA_SHORTEST,
michael@0:   // Same as FAST_DTOA_SHORTEST but for single-precision floats.
michael@0:   FAST_DTOA_SHORTEST_SINGLE,
michael@0:   // Computes a representation where the precision (number of digits) is
michael@0:   // given as input. The precision is independent of the decimal point.
michael@0:   FAST_DTOA_PRECISION
michael@0: };
michael@0: 
michael@0: // FastDtoa will produce at most kFastDtoaMaximalLength digits. This does not
michael@0: // include the terminating '\0' character.
michael@0: static const int kFastDtoaMaximalLength = 17;
michael@0: // Same for single-precision numbers.
michael@0: static const int kFastDtoaMaximalSingleLength = 9;
michael@0: 
michael@0: // Provides a decimal representation of v.
michael@0: // The result should be interpreted as buffer * 10^(point - length).
michael@0: //
michael@0: // Precondition:
michael@0: //   * v must be a strictly positive finite double.
michael@0: //
michael@0: // Returns true if it succeeds, otherwise the result can not be trusted.
michael@0: // There will be *length digits inside the buffer followed by a null terminator.
michael@0: // If the function returns true and mode equals
michael@0: //   - FAST_DTOA_SHORTEST, then
michael@0: //     the parameter requested_digits is ignored.
michael@0: //     The result satisfies
michael@0: //         v == (double) (buffer * 10^(point - length)).
michael@0: //     The digits in the buffer are the shortest representation possible. E.g.
michael@0: //     if 0.099999999999 and 0.1 represent the same double then "1" is returned
michael@0: //     with point = 0.
michael@0: //     The last digit will be closest to the actual v. That is, even if several
michael@0: //     digits might correctly yield 'v' when read again, the buffer will contain
michael@0: //     the one closest to v.
michael@0: //   - FAST_DTOA_PRECISION, then
michael@0: //     the buffer contains requested_digits digits.
michael@0: //     the difference v - (buffer * 10^(point-length)) is closest to zero for
michael@0: //     all possible representations of requested_digits digits.
michael@0: //     If there are two values that are equally close, then FastDtoa returns
michael@0: //     false.
michael@0: // For both modes the buffer must be large enough to hold the result.
michael@0: bool FastDtoa(double d,
michael@0:               FastDtoaMode mode,
michael@0:               int requested_digits,
michael@0:               Vector<char> buffer,
michael@0:               int* length,
michael@0:               int* decimal_point);
michael@0: 
michael@0: }  // namespace double_conversion
michael@0: 
michael@0: #endif  // DOUBLE_CONVERSION_FAST_DTOA_H_