Re: case-insensitive string comparison

[Roland Winkler]

On Tue, Jul 19 2022, Sam Steingold wrote:
> Specifically, I would like to add
>
> (defun string-equal-ignore-case (s1 s2)
>   "Like `string-equal', but case-insensitive.
> Upper-case and lower-case letters are treated as equal.
> Unibyte strings are converted to multibyte for comparison."
>   (eq t (compare-strings s1 0 nil s2 0 nil t)))
>
> to subr.el next to `string-prefix-p' - is this okay?

I have run into this problem fairly often that I needed case-insensitive
string comparison, and I believe various elisp packages include a
"private" version of the above.  I always felt that
`(eq t (compare-strings s1 0 nil s2 0 nil t))' was a crutch for this
common problem.  Would it make sense to give the built-in function
string-equal an optional arg ignore-case?