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/*
* Copyright (C) 2012 Google 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:
*
* * 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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_DECIMAL_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_DECIMAL_H_
#include <cstdint>
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace blink {
// This class represents decimal base floating point number.
//
// FIXME: Once all C++ compiler support decimal type, we should replace this
// class to compiler supported one. See below URI for current status of decimal
// type for C++:
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1977.html
class WTF_EXPORT Decimal {
USING_FAST_MALLOC(Decimal);
public:
enum Sign {
kPositive,
kNegative,
};
// You should not use EncodedData other than unit testing.
class EncodedData {
DISALLOW_NEW();
// For accessing FormatClass.
friend class Decimal;
public:
EncodedData(Sign, int exponent, uint64_t coefficient);
bool operator==(const EncodedData&) const;
bool operator!=(const EncodedData& another) const {
return !operator==(another);
}
uint64_t Coefficient() const { return coefficient_; }
int CountDigits() const;
int Exponent() const { return exponent_; }
bool IsFinite() const { return !IsSpecial(); }
bool IsInfinity() const { return format_class_ == kClassInfinity; }
bool IsNaN() const { return format_class_ == kClassNaN; }
bool IsSpecial() const {
return format_class_ == kClassInfinity || format_class_ == kClassNaN;
}
bool IsZero() const { return format_class_ == kClassZero; }
Sign GetSign() const { return sign_; }
void SetSign(Sign sign) { sign_ = sign; }
private:
enum FormatClass {
kClassInfinity,
kClassNormal,
kClassNaN,
kClassZero,
};
EncodedData(Sign, FormatClass);
FormatClass GetFormatClass() const { return format_class_; }
uint64_t coefficient_;
int16_t exponent_;
FormatClass format_class_;
Sign sign_;
};
Decimal(int32_t = 0);
Decimal(Sign, int exponent, uint64_t coefficient);
Decimal(const Decimal&);
Decimal& operator=(const Decimal&);
Decimal& operator+=(const Decimal&);
Decimal& operator-=(const Decimal&);
Decimal& operator*=(const Decimal&);
Decimal& operator/=(const Decimal&);
Decimal operator-() const;
bool operator==(const Decimal&) const;
bool operator!=(const Decimal&) const;
bool operator<(const Decimal&) const;
bool operator<=(const Decimal&) const;
bool operator>(const Decimal&) const;
bool operator>=(const Decimal&) const;
Decimal operator+(const Decimal&) const;
Decimal operator-(const Decimal&) const;
Decimal operator*(const Decimal&)const;
Decimal operator/(const Decimal&) const;
int Exponent() const {
DCHECK(IsFinite());
return data_.Exponent();
}
bool IsFinite() const { return data_.IsFinite(); }
bool IsInfinity() const { return data_.IsInfinity(); }
bool IsNaN() const { return data_.IsNaN(); }
bool IsNegative() const { return GetSign() == kNegative; }
bool IsPositive() const { return GetSign() == kPositive; }
bool IsSpecial() const { return data_.IsSpecial(); }
bool IsZero() const { return data_.IsZero(); }
Decimal Abs() const;
Decimal Ceil() const;
Decimal Floor() const;
Decimal Remainder(const Decimal&) const;
Decimal Round() const;
double ToDouble() const;
// Note: toString method supports infinity and nan but fromString not.
String ToString() const;
static Decimal FromDouble(double);
// fromString supports following syntax EBNF:
// number ::= sign? digit+ ('.' digit*) (exponent-marker sign? digit+)?
// | sign? '.' digit+ (exponent-marker sign? digit+)?
// sign ::= '+' | '-'
// exponent-marker ::= 'e' | 'E'
// digit ::= '0' | '1' | ... | '9'
// Note: fromString doesn't support "infinity" and "nan".
static Decimal FromString(const String&);
static Decimal Infinity(Sign);
static Decimal Nan();
static Decimal Zero(Sign);
// You should not use below methods. We expose them for unit testing.
explicit Decimal(const EncodedData&);
const EncodedData& Value() const { return data_; }
private:
struct AlignedOperands {
uint64_t lhs_coefficient;
uint64_t rhs_coefficient;
int exponent;
};
Decimal(double);
Decimal CompareTo(const Decimal&) const;
static AlignedOperands AlignOperands(const Decimal& lhs, const Decimal& rhs);
static inline Sign InvertSign(Sign sign) {
return sign == kNegative ? kPositive : kNegative;
}
Sign GetSign() const { return data_.GetSign(); }
EncodedData data_;
};
WTF_EXPORT std::ostream& operator<<(std::ostream&, const Decimal&);
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_DECIMAL_H_
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