third_party/double-conversion/src/string-to-double.h - sdk - Git at Google


            
            // 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_
	// 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_