Quant methods

[dajmcdon]

This is the first of a few possible PRs that our team discussed with @topepo and @EmilHvitfeldt .

Features and bug fixes:

• Allows some standard vec arithmetic on the quantile_pred object.
• Adds vec_ptype2 and vec_cast methods for quantile_pred. Without these, occasional downstream bugs happened on the object.
• Adds functionality to "impute" quantiles by interpolating the quantile function. This is most useful for "extracting" some specific quantile from the quantile_pred object, say the median. This way, rather than trying to "match" doubles, it can just compute it directly. It can also be used to expand the set of quantiles represented by the object.
• Some helper functions for the above: snap() and is_quantile_pred().

[topepo]

Hey @dajmcdon. We'll take a look at this in about 2 weeks. Still in the "open heart surgery" changes to tune and company, trying to make a conference deadline.

[EmilHvitfeldt]

What Max said, i have 2 small things to work on in the meantime:

• Fix the issue in the pkgdown GHA action https://github.com/tidymodels/hardhat/actions/runs/16528113502/job/46746492518?pr=291.
• Avoid using {dplyr}, i don't think it is worth it for just 2 function calls. I would look in {vctrs}, maybe https://vctrs.r-lib.org/reference/vec_unique.html

[dajmcdon]

Thanks both! And no hurry. We'll probably want to handle #282 simultaneously. (FYI @brookslogan is a member of our team).