isordered

[Nosferican]

This function is defined in CategoricalArrays.jl.

CategoricalArrays.isordered(x::CategoricalValue) = isordered(x.pool)

However, it is quite generic and would be beneficial to have it defined in DataAPI.jl as something like

DataAPI.isordered(::Any) = false
DataAPI.isordered(obj::AbstractVector) = issorted(obj)

Thoughts?

[bkamins]

Indeed it would be good to add it and it was discussed. Note that isordered is not the same as issorted.

This is related to JuliaLang/julia#37239 and Ordered trait

[quinnj]

Yes, I'm in favor of this; in Arrow.jl, a dict-encoded column can define whether it's isOrdered as well, so it could leverage this as well.

[bkamins]

This should be added also for DataFrames.jl

[nalimilan]

@Nosferican Could you develop the use case do you have in mind? This is important to decide how to define the trait IMO. See #26.