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[bug#50878] [PATCH] union: Resolve collisions by stable-sort'ing them.


From: Attila Lendvai
Subject: [bug#50878] [PATCH] union: Resolve collisions by stable-sort'ing them.
Date: Thu, 30 Sep 2021 14:12:31 +0000

> > the hash also needs to be dropped from the path for sorting to be
> > useful, but the return value must be the full path, hence the
> > complexity with sorting the indices, pointing both to the full paths
> > and the cut parts.
>
> You can replace the 'less' argument of 'stable-sort'.

> Example sorting by the second character of a string:
>
> (sort '("za" "yb" "xc") (lambda (x y)
> (char>? (string-ref x 1)
>                                   (string-ref y 1)))))

i don't know about the expected size of the collision list here, but
that would cons much more, because that would cons up two substrings
at each comparison, i.e. O(n^2) vs O(n) at least in GC load, probably
in time also.

i think it's not worth it, but let me know, and then i can simplify
the code somewhat at the cost of more consing.

sorting lists is probably also much slower than sorting vectors, but
there may be some tricks i don't know about.

random note: civodul said on IRC that there's a certain reluctancy to
update the opaque binary blobs, and the bootstrap guile will be
replaced by mes anyway.

so, if we want to have this merged, then we will need to give up on
testing it until mes becomes the bootstrap scheme (and assuming it
will have srfi vectors).

in the lights of the above, i think i'll stop pursuing this patch, but
i'd be happy to implement something if you can give me highlevel
guidance.

with the above pointed out, are you still happy with the list sorting?

i'd love to have idris packaged so that it has bin/idris symlinked to
bin/idris-1.2.3, and installing multiple versions of it would pick the
newest one for bin/idris.

--
• attila lendvai
• PGP: 963F 5D5F 45C7 DFCD 0A39
--
“Have the courage to take your own thoughts seriously, for they will shape you.”
        — Albert Einstein (1879–1955)






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