Ivy-sort-functions-alist can no longer handle lambda functions

[dieggsy]

Not sure why, but recent changes have made it so that

(add-to-list 'ivy-sort-functions-alist (lambda (str1 str2) (string< (downcase str1) (downcase str2)))

Results in an error saying lambda is an invalid function.

[basil-conto]

Not only can I not reproduce this (please try to provide a detailed set of steps starting from make plain); but doing this makes no sense. ivy-sort-functions-alist is an alist mapping collection functions (i.e. :callers) to sorting functions:

ivy-sort-functions-alist is a variable defined in ‘ivy.el’.
Its value is
((read-file-name-internal . ivy-sort-file-function-default)
 (internal-complete-buffer)
 (ivy-completion-in-region)
 (counsel-git-grep-function)
 (Man-goto-section)
 (org-refile)
 (t . ivy-string<))

Documentation:
An alist of sorting functions for each collection function.
Interactive functions that call completion fit in here as well.

Nil means no sorting, which is useful to turn off the sorting for
functions that have candidates in the natural buffer order, like
‘org-refile’ or ‘Man-goto-section’.

A list can be used to associate multiple sorting functions with a
collection.  The car of the list is the current sort
function.  This list can be rotated with ‘ivy-rotate-sort’.

The entry associated with t is used for all fall-through cases.

See also ‘ivy-sort-max-size’.

So, what you probably want is:

(add-to-list 'ivy-sort-functions-alist
	     (cons t (lambda (x y)
		       (> 0 (compare-strings x nil nil y nil nil t)))))

[dieggsy]

Yeah, that was me typing it out incorrectly instead of copy pasting. I meant:

(add-to-list 'ivy-sort-functions-alist
             '(ivy-completion-in-region . (lambda (str1 str2)
                                            (string< (downcase str1) (downcase str2)))))

With this, trying to use completion in region results in Invalid function: lambda.

[basil-conto]

Thanks, I can reproduce this now (and was the one who introduced the issue in the first place, while trying to fix another issue).

FWIW, it is inadvisable to quote lambdas, and case-insensitive string comparison is better done with compare-strings:

(add-to-list 'ivy-sort-functions-alist
             (cons #'ivy-completion-in-region
                   (lambda (str1 str2)
                     (> 0 (compare-strings str1 nil nil str2 nil nil t)))))

or

(add-to-list 'ivy-sort-functions-alist
             `(ivy-completion-in-region
               . ,(lambda (str1 str2)
                    (> 0 (compare-strings str1 nil nil str2 nil nil t)))))

[dieggsy]

Cool, thanks for the tips