Floating point issue with NaN values

Hi, there. Thanks for providing this nice library!

I found myself in a problem here that is related to the following lines:

from strictyaml import Map, Float, load

schema = Map(
    {
        "number_one": Float(),
        "not_a_number": Float(),
    }
)

yaml_string = (
    "number_one: 1.0\n"
    "not_a_number: .nan"
)

load(yaml_string=yaml_string, schema=schema)

and I got this:

strictyaml.exceptions.YAMLValidationError: when expecting a float
found arbitrary text
  in "<unicode string>", line 2, column 1:
    not_a_number: '.nan'
    ^ (line: 2)

According to https://yaml.org/spec/1.2/spec.html#id2804092, .nan, .inf or -.inf are part of the canonical form of the floating point representation.

(In fact, I would like to do that using dirty_load, as I need a readable representation for my matrices (I’m using Seq(Seq(Float))), but that’s another story, as dirty_load seems to be just another way of calling generic_load with allow_flow_style.)

Am I missing something here or is there a workaround for it?

Thank you

[shoogle]

I would say accept only INF and NaN (think this form is least likely to be mistaken for a standard string). StrictYAML aims to be fully roundtripable, which means there should only be one valid representation. It is a restricted subset of YAML, so no need to support every variation. You could check for other variations and print an error saying to use INF or NaN.

[crdoconnor]

Yes, please do. I’ll merge and release a new version on pypi once you’re done.

Thank you for doing this.