InexactError for parsing/conversion

[chbian]

I am running Julia 0.7.0 on Linus/CentOS and get the following InexactError,

julia> parse(Dec64, "3935767060.093896713")
ERROR: InexactError: parse(Dec64, 3935767060.093896713)
Stacktrace:
 [1] parse(::Type{Dec64}, ::String) at /home/user/.julia/packages/DecFP/3jJW7/src/DecFP.jl:66
 [2] top-level scope at none:0

julia> parse(Float64, "3935767060.093896713")
3.935767060093897e9

Parsing the value to Float64 works fine. But it fails to parse to Dec64. Any idea why it happens? Thanks!

[chbian]

I guess I know the reason. IEEE 754 decimal 64 type may have 16 significant bits or decimal digits. The string I tried to parse in the previous example is too long for Dec64.

[stevengj]

I'm going to re-open this, since it's not clear that we should be throwing an InexactError here, and also for conversion between decimal types:

julia> Dec64(d128"3935767060.093896713")
ERROR: InexactError: convert(Dec64, 3.935767060093896713e9)

We should probably emulate the Float64 behavior here and silently round when parsing/converting values that can't be represented exactly.

julia> Dec64(3935767060.093896713)
3.935767060093897e9