I have just released a new decimal library for Nim that is based on the IEEE
754-2008 specification.
[https://github.com/JohnAD/decimal128](https://github.com/JohnAD/decimal128)
It has a pending PR for inclusion in the nimble directory.
Examples of use:
let a = newDecimal128("0.00009999999999999999999999999")
let b = newDecimal128("-Infinity")
let c = newDecimal128("1.23E+4023")
let d = newDecimal128("12.3E+4022")
assert c === d # for === to be true, both the numeric value and the
number of significant digits must match
Run
This is the spec used by both the BSON protocol and MongoDB database, which is
why I wrote it. It successfully encodes and decodes NumberDecimal() fields.
I'll be formally adding it to my `bson` and `mongopool` libraries this next
week.
In general, however, it should also work for folks wanting decimal support and
the associated tracking of significant digits.
For me, I pretty much have what I needed: import/export.
But I suspect folks will notice a big glaring problem: **mathematical operators
do not work yet**.
You can't do `a + b` because a
proc `+`*(left, right: Decimal128): Decimal128
Run
procedure has not been written yet.
So, the call-for-help:
If you are interested in having decimal library for Nim, please consider
helping out by writing one of the operator procedures! An issue has been made
for tracking progress:
[https://github.com/JohnAD/decimal128/issues/1](https://github.com/JohnAD/decimal128/issues/1)
Thanks for considering this. I know folks have asked for a decimal library in
Nim in the past. This could be a good opportunity to flush one out based on a
known standard.
