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// Copyright 2010 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "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 THE COPYRIGHT
// OWNER 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.

#ifndef V8_BIGNUM_DTOA_H_
#define V8_BIGNUM_DTOA_H_

namespace v8 {
namespace internal {

enum BignumDtoaMode {
  // Return the shortest correct representation.
  // For example the output of 0.299999999999999988897 is (the less accurate but
  // correct) 0.3.
  BIGNUM_DTOA_SHORTEST,
  // Return a fixed number of digits after the decimal point.
  // For instance fixed(0.1, 4) becomes 0.1000
  // If the input number is big, the output will be big.
  BIGNUM_DTOA_FIXED,
  // Return a fixed number of digits, no matter what the exponent is.
  BIGNUM_DTOA_PRECISION
};

// Converts the given double 'v' to ASCII.
// The result should be interpreted as buffer * 10^(point-length).
// The buffer will be null-terminated.
//
// The input v must be > 0 and different from NaN, and Infinity.
//
// The output depends on the given mode:
// - SHORTEST: produce the least amount of digits for which the internal
// identity requirement is still satisfied. If the digits are printed
// (together with the correct exponent) then reading this number will give
// 'v' again. The buffer will choose the representation that is closest to
// 'v'. If there are two at the same distance, than the number is round up.
// In this mode the 'requested_digits' parameter is ignored.
// - FIXED: produces digits necessary to print a given number with
// 'requested_digits' digits after the decimal point. The produced digits
// might be too short in which case the caller has to fill the gaps with '0's.
// Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2.
// Halfway cases are rounded up. The call toFixed(0.15, 2) thus returns
// buffer="2", point=0.
// Note: the length of the returned buffer has no meaning wrt the significance
// of its digits. That is, just because it contains '0's does not mean that
// any other digit would not satisfy the internal identity requirement.
// - PRECISION: produces 'requested_digits' where the first digit is not '0'.
// Even though the length of produced digits usually equals
// 'requested_digits', the function is allowed to return fewer digits, in
// which case the caller has to fill the missing digits with '0's.
// Halfway cases are again rounded up.
// 'BignumDtoa' expects the given buffer to be big enough to hold all digits
// and a terminating null-character.
void BignumDtoa(double v, BignumDtoaMode mode, int requested_digits,
                Vector<char> buffer, int* length, int* point);

} } // namespace v8::internal

#endif // V8_BIGNUM_DTOA_H_
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