sorting function and strings

[seblemaguer]

Hello,

I am currently facing the issue described in radian-software/prescient.el#73

As it causes me a lot of trouble lately, I would like to try to fix this. However, before I go further, I would like to know what is your approach concerning the items: should I consider that items passed to the sorting function should be strings or can be anything?

Thanks

[basil-conto]

Unfortunately, third-party completion "frontends" (including Ivy) seem to define their own notions of sorting.

The standard means of sorting completion candidates are the metadata display-sort-function and cycle-sort-function (see (info "(elisp) Programmed Completion")), each of which accepts a list of completion strings. But I don't even know how well Ivy handles these, let alone other completion frontends.

Ivy provides two user options for customising sorting: ivy-sort-functions-alist and ivy-sort-matches-functions-alist. Sorting functions in the former take two arguments (as with the built-in sort function) and return nil or non-nil depending on which argument should come first. Functions in the latter take a string and a list of candidates containing that string and return the list of candidates in the desired order.

Functions in ivy-sort-functions-alist have to support the different types of completion collections they might be used for. For example, the default Ivy sort function ivy-string< is like string< but handles both strings and cons cells (in the case of alist collections) as arguments.

I don't know what Prescient does, so without a backtrace of the error you run into, there's not much more I can say. HTH.

[seblemaguer]

I see. Thanks for the answer. I have a look to see if I can get something minimal which makes sense as I am not sure that the current backtrace will be useful.

[seblemaguer]

I switched to something else. So I won't have time to deal with this issue. I close it for now but if someone else wants to solve it I am interested in the solution