70da367f6b
Review URL: http://codereview.chromium.org/9231009 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10407 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
82 lines
4.0 KiB
C++
82 lines
4.0 KiB
C++
// 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_
|