Rounding errors when parsing floats

[abaco]

I was running some generative tests on my code and I ran into an issue with high precision floats. For example:

> x = 0.7531531167929774
> runParser (show x) testTokenParser.float
(Right 0.7531531167929775)

Note the final 5 instead of 4. The problem seems to be in the code that parses the decimal part of a number. Indeed, the following equivalent code gives the same erroneous result:

> digits = [7,5,3,1,5,3,1,1,6,7,9,2,9,7,7,4]
> foldr (\d f -> (f + toNumber d) / 10.0) 0.0 digits
0.7531531167929775

I'm not sure about the best way to modify fraction so as to avoid rounding errors. Maybe using the native parseFloat?

[jamesdbrock]

Oh yeah that looks like a bug, thanks for the bug report.

[jamesdbrock]

Hi @abaco I hope #142 solves your problem. Please reopen this issue if it doesn't.