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4 // From the double-conversion library. Original license:
5 //
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32 
33 // ICU PATCH: ifdef around UCONFIG_NO_FORMATTING
34 #include "unicode/utypes.h"
35 #if !UCONFIG_NO_FORMATTING
36 
37 #ifndef DOUBLE_CONVERSION_BIGNUM_DTOA_H_
38 #define DOUBLE_CONVERSION_BIGNUM_DTOA_H_
39 
40 // ICU PATCH: Customize header file paths for ICU.
41 
42 #include "double-conversion-utils.h"
43 
44 // ICU PATCH: Wrap in ICU namespace
45 U_NAMESPACE_BEGIN
46 
47 namespace double_conversion {
48 
49 enum BignumDtoaMode {
50   // Return the shortest correct representation.
51   // For example the output of 0.299999999999999988897 is (the less accurate but
52   // correct) 0.3.
53   BIGNUM_DTOA_SHORTEST,
54   // Same as BIGNUM_DTOA_SHORTEST but for single-precision floats.
55   BIGNUM_DTOA_SHORTEST_SINGLE,
56   // Return a fixed number of digits after the decimal point.
57   // For instance fixed(0.1, 4) becomes 0.1000
58   // If the input number is big, the output will be big.
59   BIGNUM_DTOA_FIXED,
60   // Return a fixed number of digits, no matter what the exponent is.
61   BIGNUM_DTOA_PRECISION
62 };
63 
64 // Converts the given double 'v' to ascii.
65 // The result should be interpreted as buffer * 10^(point-length).
66 // The buffer will be null-terminated.
67 //
68 // The input v must be > 0 and different from NaN, and Infinity.
69 //
70 // The output depends on the given mode:
71 //  - SHORTEST: produce the least amount of digits for which the internal
72 //   identity requirement is still satisfied. If the digits are printed
73 //   (together with the correct exponent) then reading this number will give
74 //   'v' again. The buffer will choose the representation that is closest to
75 //   'v'. If there are two at the same distance, than the number is round up.
76 //   In this mode the 'requested_digits' parameter is ignored.
77 //  - FIXED: produces digits necessary to print a given number with
78 //   'requested_digits' digits after the decimal point. The produced digits
79 //   might be too short in which case the caller has to fill the gaps with '0's.
80 //   Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2.
81 //   Halfway cases are rounded up. The call toFixed(0.15, 2) thus returns
82 //     buffer="2", point=0.
83 //   Note: the length of the returned buffer has no meaning wrt the significance
84 //   of its digits. That is, just because it contains '0's does not mean that
85 //   any other digit would not satisfy the internal identity requirement.
86 //  - PRECISION: produces 'requested_digits' where the first digit is not '0'.
87 //   Even though the length of produced digits usually equals
88 //   'requested_digits', the function is allowed to return fewer digits, in
89 //   which case the caller has to fill the missing digits with '0's.
90 //   Halfway cases are again rounded up.
91 // 'BignumDtoa' expects the given buffer to be big enough to hold all digits
92 // and a terminating null-character.
93 void BignumDtoa(double v, BignumDtoaMode mode, int requested_digits,
94                 Vector<char> buffer, int* length, int* point);
95 
96 }  // namespace double_conversion
97 
98 // ICU PATCH: Close ICU namespace
99 U_NAMESPACE_END
100 
101 #endif  // DOUBLE_CONVERSION_BIGNUM_DTOA_H_
102 #endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING
103