Hey everyone,
So excited to finally announce we can correctly parse
floating-point numbers according to IEEE round half-to-even
(bankers) rule like in C/C++, Rust, and others.
@nogc, optionally nothrow API is provided as part of Mir
Algorithm v3.9.0 [0].
The documentation is available [1].
In case you are surprised, you can be sure that neither D
compilers can correctly parse decimal FP literals [2, 3, 4], nor
Phobos can correctly parse decimal FP strings [6].
Mir decimal parsing supports up-to quadruple precision.
The conversion error is 0 ULP for normal numbers.
Subnormal numbers with a decimal exponent greater than or equal
to -512 have upper error bound equal to 1 ULP. Zero error
bound for subnormal numbers can be supported in the future when
Mir Ion, the ASDF successor, is ready.
The implementation is based on the paper [7].
The error bounds above are valid for LDC. DMD may have slightly
larger errors because of the wrong code generation for ulong to
double conversion [5].
This work has been sponsored by Symmetry Investments and Kaleidic
Associates.
Best regards,
Ilya
[0] https://github.com/libmir/mir-algorithm
[1] http://mir-algorithm.libmir.org/mir_parse.html#.fromString[2]
https://issues.dlang.org/show_bug.cgi?id=20951
[3] https://issues.dlang.org/show_bug.cgi?id=20952
[4] https://issues.dlang.org/show_bug.cgi?id=20953
[5] https://issues.dlang.org/show_bug.cgi?id=20963
[6] https://issues.dlang.org/show_bug.cgi?id=20967
[7]
https://www.researchgate.net/publication/2295884_How_to_Read_Floating_Point_Numbers_Accurately
