257 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			257 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
| // © 2018 and later: Unicode, Inc. and others.
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| // License & terms of use: http://www.unicode.org/copyright.html
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| //
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| // From the double-conversion library. Original license:
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| //
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| // Copyright 2012 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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| 
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| // ICU PATCH: ifdef around UCONFIG_NO_FORMATTING
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| #include "unicode/utypes.h"
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| #if !UCONFIG_NO_FORMATTING
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| 
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| #ifndef DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_
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| #define DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_
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| 
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| // ICU PATCH: Customize header file paths for ICU.
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| 
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| #include "double-conversion-utils.h"
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| 
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| // ICU PATCH: Wrap in ICU namespace
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| U_NAMESPACE_BEGIN
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| 
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| namespace double_conversion {
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| 
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| class StringToDoubleConverter {
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|  public:
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|   // Enumeration for allowing octals and ignoring junk when converting
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|   // strings to numbers.
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|   enum Flags {
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|     NO_FLAGS = 0,
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|     ALLOW_HEX = 1,
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|     ALLOW_OCTALS = 2,
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|     ALLOW_TRAILING_JUNK = 4,
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|     ALLOW_LEADING_SPACES = 8,
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|     ALLOW_TRAILING_SPACES = 16,
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|     ALLOW_SPACES_AFTER_SIGN = 32,
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|     ALLOW_CASE_INSENSITIVITY = 64,
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|     ALLOW_CASE_INSENSIBILITY = 64,  // Deprecated
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|     ALLOW_HEX_FLOATS = 128,
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|   };
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| 
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|   static const uc16 kNoSeparator = '\0';
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| 
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|   // Flags should be a bit-or combination of the possible Flags-enum.
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|   //  - NO_FLAGS: no special flags.
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|   //  - ALLOW_HEX: recognizes the prefix "0x". Hex numbers may only be integers.
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|   //      Ex: StringToDouble("0x1234") -> 4660.0
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|   //          In StringToDouble("0x1234.56") the characters ".56" are trailing
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|   //          junk. The result of the call is hence dependent on
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|   //          the ALLOW_TRAILING_JUNK flag and/or the junk value.
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|   //      With this flag "0x" is a junk-string. Even with ALLOW_TRAILING_JUNK,
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|   //      the string will not be parsed as "0" followed by junk.
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|   //
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|   //  - ALLOW_OCTALS: recognizes the prefix "0" for octals:
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|   //      If a sequence of octal digits starts with '0', then the number is
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|   //      read as octal integer. Octal numbers may only be integers.
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|   //      Ex: StringToDouble("01234") -> 668.0
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|   //          StringToDouble("012349") -> 12349.0  // Not a sequence of octal
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|   //                                               // digits.
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|   //          In StringToDouble("01234.56") the characters ".56" are trailing
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|   //          junk. The result of the call is hence dependent on
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|   //          the ALLOW_TRAILING_JUNK flag and/or the junk value.
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|   //          In StringToDouble("01234e56") the characters "e56" are trailing
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|   //          junk, too.
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|   //  - ALLOW_TRAILING_JUNK: ignore trailing characters that are not part of
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|   //      a double literal.
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|   //  - ALLOW_LEADING_SPACES: skip over leading whitespace, including spaces,
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|   //                          new-lines, and tabs.
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|   //  - ALLOW_TRAILING_SPACES: ignore trailing whitespace.
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|   //  - ALLOW_SPACES_AFTER_SIGN: ignore whitespace after the sign.
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|   //       Ex: StringToDouble("-   123.2") -> -123.2.
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|   //           StringToDouble("+   123.2") -> 123.2
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|   //  - ALLOW_CASE_INSENSITIVITY: ignore case of characters for special values:
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|   //      infinity and nan.
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|   //  - ALLOW_HEX_FLOATS: allows hexadecimal float literals.
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|   //      This *must* start with "0x" and separate the exponent with "p".
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|   //      Examples: 0x1.2p3 == 9.0
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|   //                0x10.1p0 == 16.0625
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|   //      ALLOW_HEX and ALLOW_HEX_FLOATS are indented.
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|   //
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|   // empty_string_value is returned when an empty string is given as input.
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|   // If ALLOW_LEADING_SPACES or ALLOW_TRAILING_SPACES are set, then a string
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|   // containing only spaces is converted to the 'empty_string_value', too.
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|   //
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|   // junk_string_value is returned when
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|   //  a) ALLOW_TRAILING_JUNK is not set, and a junk character (a character not
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|   //     part of a double-literal) is found.
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|   //  b) ALLOW_TRAILING_JUNK is set, but the string does not start with a
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|   //     double literal.
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|   //
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|   // infinity_symbol and nan_symbol are strings that are used to detect
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|   // inputs that represent infinity and NaN. They can be null, in which case
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|   // they are ignored.
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|   // The conversion routine first reads any possible signs. Then it compares the
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|   // following character of the input-string with the first character of
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|   // the infinity, and nan-symbol. If either matches, the function assumes, that
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|   // a match has been found, and expects the following input characters to match
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|   // the remaining characters of the special-value symbol.
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|   // This means that the following restrictions apply to special-value symbols:
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|   //  - they must not start with signs ('+', or '-'),
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|   //  - they must not have the same first character.
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|   //  - they must not start with digits.
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|   //
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|   // If the separator character is not kNoSeparator, then that specific
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|   // character is ignored when in between two valid digits of the significant.
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|   // It is not allowed to appear in the exponent.
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|   // It is not allowed to lead or trail the number.
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|   // It is not allowed to appear twice next to each other.
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|   //
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|   // Examples:
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|   //  flags = ALLOW_HEX | ALLOW_TRAILING_JUNK,
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|   //  empty_string_value = 0.0,
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|   //  junk_string_value = NaN,
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|   //  infinity_symbol = "infinity",
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|   //  nan_symbol = "nan":
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|   //    StringToDouble("0x1234") -> 4660.0.
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|   //    StringToDouble("0x1234K") -> 4660.0.
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|   //    StringToDouble("") -> 0.0  // empty_string_value.
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|   //    StringToDouble(" ") -> NaN  // junk_string_value.
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|   //    StringToDouble(" 1") -> NaN  // junk_string_value.
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|   //    StringToDouble("0x") -> NaN  // junk_string_value.
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|   //    StringToDouble("-123.45") -> -123.45.
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|   //    StringToDouble("--123.45") -> NaN  // junk_string_value.
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|   //    StringToDouble("123e45") -> 123e45.
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|   //    StringToDouble("123E45") -> 123e45.
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|   //    StringToDouble("123e+45") -> 123e45.
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|   //    StringToDouble("123E-45") -> 123e-45.
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|   //    StringToDouble("123e") -> 123.0  // trailing junk ignored.
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|   //    StringToDouble("123e-") -> 123.0  // trailing junk ignored.
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|   //    StringToDouble("+NaN") -> NaN  // NaN string literal.
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|   //    StringToDouble("-infinity") -> -inf.  // infinity literal.
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|   //    StringToDouble("Infinity") -> NaN  // junk_string_value.
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|   //
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|   //  flags = ALLOW_OCTAL | ALLOW_LEADING_SPACES,
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|   //  empty_string_value = 0.0,
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|   //  junk_string_value = NaN,
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|   //  infinity_symbol = NULL,
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|   //  nan_symbol = NULL:
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|   //    StringToDouble("0x1234") -> NaN  // junk_string_value.
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|   //    StringToDouble("01234") -> 668.0.
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|   //    StringToDouble("") -> 0.0  // empty_string_value.
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|   //    StringToDouble(" ") -> 0.0  // empty_string_value.
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|   //    StringToDouble(" 1") -> 1.0
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|   //    StringToDouble("0x") -> NaN  // junk_string_value.
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|   //    StringToDouble("0123e45") -> NaN  // junk_string_value.
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|   //    StringToDouble("01239E45") -> 1239e45.
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|   //    StringToDouble("-infinity") -> NaN  // junk_string_value.
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|   //    StringToDouble("NaN") -> NaN  // junk_string_value.
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|   //
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|   //  flags = NO_FLAGS,
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|   //  separator = ' ':
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|   //    StringToDouble("1 2 3 4") -> 1234.0
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|   //    StringToDouble("1  2") -> NaN // junk_string_value
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|   //    StringToDouble("1 000 000.0") -> 1000000.0
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|   //    StringToDouble("1.000 000") -> 1.0
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|   //    StringToDouble("1.0e1 000") -> NaN // junk_string_value
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|   StringToDoubleConverter(int flags,
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|                           double empty_string_value,
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|                           double junk_string_value,
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|                           const char* infinity_symbol,
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|                           const char* nan_symbol,
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|                           uc16 separator = kNoSeparator)
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|       : flags_(flags),
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|         empty_string_value_(empty_string_value),
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|         junk_string_value_(junk_string_value),
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|         infinity_symbol_(infinity_symbol),
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|         nan_symbol_(nan_symbol),
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|         separator_(separator) {
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|   }
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| 
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|   // Performs the conversion.
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|   // The output parameter 'processed_characters_count' is set to the number
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|   // of characters that have been processed to read the number.
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|   // Spaces than are processed with ALLOW_{LEADING|TRAILING}_SPACES are included
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|   // in the 'processed_characters_count'. Trailing junk is never included.
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|   double StringToDouble(const char* buffer,
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|                         int length,
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|                         int* processed_characters_count) const;
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| 
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|   // Same as StringToDouble above but for 16 bit characters.
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|   double StringToDouble(const uc16* buffer,
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|                         int length,
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|                         int* processed_characters_count) const;
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| 
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|   // Same as StringToDouble but reads a float.
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|   // Note that this is not equivalent to static_cast<float>(StringToDouble(...))
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|   // due to potential double-rounding.
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|   float StringToFloat(const char* buffer,
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|                       int length,
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|                       int* processed_characters_count) const;
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| 
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|   // Same as StringToFloat above but for 16 bit characters.
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|   float StringToFloat(const uc16* buffer,
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|                       int length,
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|                       int* processed_characters_count) const;
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| 
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|   // Same as StringToDouble for T = double, and StringToFloat for T = float.
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|   template <typename T>
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|   T StringTo(const char* buffer,
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|              int length,
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|              int* processed_characters_count) const;
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| 
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|   // Same as StringTo above but for 16 bit characters.
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|   template <typename T>
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|   T StringTo(const uc16* buffer,
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|              int length,
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|              int* processed_characters_count) const;
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| 
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|  private:
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|   const int flags_;
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|   const double empty_string_value_;
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|   const double junk_string_value_;
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|   const char* const infinity_symbol_;
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|   const char* const nan_symbol_;
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|   const uc16 separator_;
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| 
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|   template <class Iterator>
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|   double StringToIeee(Iterator start_pointer,
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|                       int length,
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|                       bool read_as_double,
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|                       int* processed_characters_count) const;
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| 
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|   DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS(StringToDoubleConverter);
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| };
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| 
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| }  // namespace double_conversion
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| 
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| // ICU PATCH: Close ICU namespace
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| U_NAMESPACE_END
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| 
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| #endif  // DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_
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| #endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING
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