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// Copyright 2012 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 DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_
#define DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_
#include "utils.h"
namespace double_conversion {
class StringToDoubleConverter {
public:
// Enumeration for allowing octals and ignoring junk when converting
// strings to numbers.
enum Flags {
NO_FLAGS = 0,
ALLOW_HEX = 1,
ALLOW_OCTALS = 2,
ALLOW_TRAILING_JUNK = 4,
ALLOW_LEADING_SPACES = 8,
ALLOW_TRAILING_SPACES = 16,
ALLOW_SPACES_AFTER_SIGN = 32,
ALLOW_CASE_INSENSITIVITY = 64,
ALLOW_CASE_INSENSIBILITY = 64, // Deprecated
ALLOW_HEX_FLOATS = 128,
};
static const uc16 kNoSeparator = '\0';
// Flags should be a bit-or combination of the possible Flags-enum.
// - NO_FLAGS: no special flags.
// - ALLOW_HEX: recognizes the prefix "0x". Hex numbers may only be integers.
// Ex: StringToDouble("0x1234") -> 4660.0
// In StringToDouble("0x1234.56") the characters ".56" are trailing
// junk. The result of the call is hence dependent on
// the ALLOW_TRAILING_JUNK flag and/or the junk value.
// With this flag "0x" is a junk-string. Even with ALLOW_TRAILING_JUNK,
// the string will not be parsed as "0" followed by junk.
//
// - ALLOW_OCTALS: recognizes the prefix "0" for octals:
// If a sequence of octal digits starts with '0', then the number is
// read as octal integer. Octal numbers may only be integers.
// Ex: StringToDouble("01234") -> 668.0
// StringToDouble("012349") -> 12349.0 // Not a sequence of octal
// // digits.
// In StringToDouble("01234.56") the characters ".56" are trailing
// junk. The result of the call is hence dependent on
// the ALLOW_TRAILING_JUNK flag and/or the junk value.
// In StringToDouble("01234e56") the characters "e56" are trailing
// junk, too.
// - ALLOW_TRAILING_JUNK: ignore trailing characters that are not part of
// a double literal.
// - ALLOW_LEADING_SPACES: skip over leading whitespace, including spaces,
// new-lines, and tabs.
// - ALLOW_TRAILING_SPACES: ignore trailing whitespace.
// - ALLOW_SPACES_AFTER_SIGN: ignore whitespace after the sign.
// Ex: StringToDouble("- 123.2") -> -123.2.
// StringToDouble("+ 123.2") -> 123.2
// - ALLOW_CASE_INSENSITIVITY: ignore case of characters for special values:
// infinity and nan.
// - ALLOW_HEX_FLOATS: allows hexadecimal float literals.
// This *must* start with "0x" and separate the exponent with "p".
// Examples: 0x1.2p3 == 9.0
// 0x10.1p0 == 16.0625
// ALLOW_HEX and ALLOW_HEX_FLOATS are indented.
//
// empty_string_value is returned when an empty string is given as input.
// If ALLOW_LEADING_SPACES or ALLOW_TRAILING_SPACES are set, then a string
// containing only spaces is converted to the 'empty_string_value', too.
//
// junk_string_value is returned when
// a) ALLOW_TRAILING_JUNK is not set, and a junk character (a character not
// part of a double-literal) is found.
// b) ALLOW_TRAILING_JUNK is set, but the string does not start with a
// double literal.
//
// infinity_symbol and nan_symbol are strings that are used to detect
// inputs that represent infinity and NaN. They can be null, in which case
// they are ignored.
// The conversion routine first reads any possible signs. Then it compares the
// following character of the input-string with the first character of
// the infinity, and nan-symbol. If either matches, the function assumes, that
// a match has been found, and expects the following input characters to match
// the remaining characters of the special-value symbol.
// This means that the following restrictions apply to special-value symbols:
// - they must not start with signs ('+', or '-'),
// - they must not have the same first character.
// - they must not start with digits.
//
// If the separator character is not kNoSeparator, then that specific
// character is ignored when in between two valid digits of the significant.
// It is not allowed to appear in the exponent.
// It is not allowed to lead or trail the number.
// It is not allowed to appear twice next to each other.
//
// Examples:
// flags = ALLOW_HEX | ALLOW_TRAILING_JUNK,
// empty_string_value = 0.0,
// junk_string_value = NaN,
// infinity_symbol = "infinity",
// nan_symbol = "nan":
// StringToDouble("0x1234") -> 4660.0.
// StringToDouble("0x1234K") -> 4660.0.
// StringToDouble("") -> 0.0 // empty_string_value.
// StringToDouble(" ") -> NaN // junk_string_value.
// StringToDouble(" 1") -> NaN // junk_string_value.
// StringToDouble("0x") -> NaN // junk_string_value.
// StringToDouble("-123.45") -> -123.45.
// StringToDouble("--123.45") -> NaN // junk_string_value.
// StringToDouble("123e45") -> 123e45.
// StringToDouble("123E45") -> 123e45.
// StringToDouble("123e+45") -> 123e45.
// StringToDouble("123E-45") -> 123e-45.
// StringToDouble("123e") -> 123.0 // trailing junk ignored.
// StringToDouble("123e-") -> 123.0 // trailing junk ignored.
// StringToDouble("+NaN") -> NaN // NaN string literal.
// StringToDouble("-infinity") -> -inf. // infinity literal.
// StringToDouble("Infinity") -> NaN // junk_string_value.
//
// flags = ALLOW_OCTAL | ALLOW_LEADING_SPACES,
// empty_string_value = 0.0,
// junk_string_value = NaN,
// infinity_symbol = NULL,
// nan_symbol = NULL:
// StringToDouble("0x1234") -> NaN // junk_string_value.
// StringToDouble("01234") -> 668.0.
// StringToDouble("") -> 0.0 // empty_string_value.
// StringToDouble(" ") -> 0.0 // empty_string_value.
// StringToDouble(" 1") -> 1.0
// StringToDouble("0x") -> NaN // junk_string_value.
// StringToDouble("0123e45") -> NaN // junk_string_value.
// StringToDouble("01239E45") -> 1239e45.
// StringToDouble("-infinity") -> NaN // junk_string_value.
// StringToDouble("NaN") -> NaN // junk_string_value.
//
// flags = NO_FLAGS,
// separator = ' ':
// StringToDouble("1 2 3 4") -> 1234.0
// StringToDouble("1 2") -> NaN // junk_string_value
// StringToDouble("1 000 000.0") -> 1000000.0
// StringToDouble("1.000 000") -> 1.0
// StringToDouble("1.0e1 000") -> NaN // junk_string_value
StringToDoubleConverter(int flags,
double empty_string_value,
double junk_string_value,
const char* infinity_symbol,
const char* nan_symbol,
uc16 separator = kNoSeparator)
: flags_(flags),
empty_string_value_(empty_string_value),
junk_string_value_(junk_string_value),
infinity_symbol_(infinity_symbol),
nan_symbol_(nan_symbol),
separator_(separator) {
}
// Performs the conversion.
// The output parameter 'processed_characters_count' is set to the number
// of characters that have been processed to read the number.
// Spaces than are processed with ALLOW_{LEADING|TRAILING}_SPACES are included
// in the 'processed_characters_count'. Trailing junk is never included.
double StringToDouble(const char* buffer,
int length,
int* processed_characters_count) const;
// Same as StringToDouble above but for 16 bit characters.
double StringToDouble(const uc16* buffer,
int length,
int* processed_characters_count) const;
// Same as StringToDouble but reads a float.
// Note that this is not equivalent to static_cast<float>(StringToDouble(...))
// due to potential double-rounding.
float StringToFloat(const char* buffer,
int length,
int* processed_characters_count) const;
// Same as StringToFloat above but for 16 bit characters.
float StringToFloat(const uc16* buffer,
int length,
int* processed_characters_count) const;
// Same as StringToDouble for T = double, and StringToFloat for T = float.
template <typename T>
T StringTo(const char* buffer,
int length,
int* processed_characters_count) const;
// Same as StringTo above but for 16 bit characters.
template <typename T>
T StringTo(const uc16* buffer,
int length,
int* processed_characters_count) const;
private:
const int flags_;
const double empty_string_value_;
const double junk_string_value_;
const char* const infinity_symbol_;
const char* const nan_symbol_;
const uc16 separator_;
template <class Iterator>
double StringToIeee(Iterator start_pointer,
int length,
bool read_as_double,
int* processed_characters_count) const;
DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS(StringToDoubleConverter);
};
} // namespace double_conversion
#endif // DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_
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