85 lines
4.2 KiB
C++
85 lines
4.2 KiB
C++
// Copyright 2010 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef DOUBLE_CONVERSION_BIGNUM_DTOA_H_
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#define DOUBLE_CONVERSION_BIGNUM_DTOA_H_
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#include "utils.h"
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namespace double_conversion {
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enum BignumDtoaMode {
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// Return the shortest correct representation.
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// For example the output of 0.299999999999999988897 is (the less accurate but
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// correct) 0.3.
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BIGNUM_DTOA_SHORTEST,
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// Same as BIGNUM_DTOA_SHORTEST but for single-precision floats.
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BIGNUM_DTOA_SHORTEST_SINGLE,
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// Return a fixed number of digits after the decimal point.
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// For instance fixed(0.1, 4) becomes 0.1000
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// If the input number is big, the output will be big.
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BIGNUM_DTOA_FIXED,
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// Return a fixed number of digits, no matter what the exponent is.
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BIGNUM_DTOA_PRECISION
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};
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// Converts the given double 'v' to ascii.
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// The result should be interpreted as buffer * 10^(point-length).
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// The buffer will be null-terminated.
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//
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// The input v must be > 0 and different from NaN, and Infinity.
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//
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// The output depends on the given mode:
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// - SHORTEST: produce the least amount of digits for which the internal
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// identity requirement is still satisfied. If the digits are printed
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// (together with the correct exponent) then reading this number will give
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// 'v' again. The buffer will choose the representation that is closest to
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// 'v'. If there are two at the same distance, than the number is round up.
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// In this mode the 'requested_digits' parameter is ignored.
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// - FIXED: produces digits necessary to print a given number with
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// 'requested_digits' digits after the decimal point. The produced digits
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// might be too short in which case the caller has to fill the gaps with '0's.
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// Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2.
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// Halfway cases are rounded up. The call toFixed(0.15, 2) thus returns
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// buffer="2", point=0.
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// Note: the length of the returned buffer has no meaning wrt the significance
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// of its digits. That is, just because it contains '0's does not mean that
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// any other digit would not satisfy the internal identity requirement.
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// - PRECISION: produces 'requested_digits' where the first digit is not '0'.
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// Even though the length of produced digits usually equals
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// 'requested_digits', the function is allowed to return fewer digits, in
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// which case the caller has to fill the missing digits with '0's.
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// Halfway cases are again rounded up.
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// 'BignumDtoa' expects the given buffer to be big enough to hold all digits
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// and a terminating null-character.
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void BignumDtoa(double v, BignumDtoaMode mode, int requested_digits,
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Vector<char> buffer, int* length, int* point);
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} // namespace double_conversion
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#endif // DOUBLE_CONVERSION_BIGNUM_DTOA_H_
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