I resubscribed to this mailing list three seconds later. I am not good
at letting go of things.

Marc Nieper-Wißkirchen <xxxxxx@nieper-wisskirchen.de> writes:
> It should be between
>
> (=? x y)
>
> and
>
> (=? comparator-specific-to-the-arguments x y).

Since the code is generic it is not known what types those arguments are.

>> Again, which generic code do you have in mind where you want to code
>> > something like (map =? xs ys) and where using a user-supplied comparator
>> > argument is not the better solution?
>>
>> For example (count =? xs ys) to see how many two objects in the same
>> position match. Monster sprites vs player sprites in a video game for
>> example.
>>
>
> In that case, use your specific sprite-comparator.

And then the next day I needed to write code to see how many two objects
in same position match in another context, for example people and their
hats. I could reuse the same code.

Which I also could if every procedure from top-level and on in had been
passing along an appropriate comparator.

CPS: comparator passing style.

(video-game sprite-comparator)

(theatre-attendance-record sprite-comparator)

But the same would be true for any queriable datum, such as in the
apply-default-discount example (that queried for a default discount
factor) as opposed to (define apply-discount *) that expects a discount
factor to be passed in.

> Note that you would always be able to import =?/default as =? through the
> renaming mechanism of the library system.

An argument both sides can make as easily.

> You have raised a lot of interesting points, so I don't think that your
> participation is useless quite the contrary. While I may not subscribe to
> your POV, this doesn't make it invalid.
>
> SRFIs can be revised, so nothing which is specified by SRFI 128 has to be
> set in stone for eternity.

I appreciate this very, very much. I am not used to discussing these
topics in this format. I am a thin-skinned, short-tempered, emotional,
salty being.