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From: "Mattias Engdegård" <mattias.engdegard@gmail.com>
To: Shankar Rao <shankar.rao@gmail.com>
Cc: emacs-devel@gnu.org
Subject: Re: Is there utility in making hash-table-{keys, values} built-in functions?
Date: Thu, 28 Nov 2024 18:31:06 +0100	[thread overview]
Message-ID: <B0916A03-E1CC-4936-965A-12DCDE9CBE73@gmail.com> (raw)
In-Reply-To: <CAGEgU=gaGaN4QOt1s83xmJEJ1eJW1xqd94pE544ecPVuNb6Hew@mail.gmail.com>

28 nov. 2024 kl. 12.53 skrev Shankar Rao <shankar.rao@gmail.com>:

> I noticed that the functions hash-table-keys and hash-table-values are just wrappers around maphash. This means that there is no way to iterate over a hash-table without using a lambda.
> 
> Would it be useful or worthwhile to implement these directly in C? I don't know much about low-level Emacs development, but having these as built-ins could make iteration of a hash-table a little faster and easier to debug.

It's unlikely that it would be faster to make a list just for the purpose of a single iteration; the allocation costs alone would be too high. Other ways of iterating through hash-tables have been tried with mostly disappointing results, although there might be some value in avoiding use of the C stack in some cases.

If you tell us what you are trying to accomplish, it would be easier for us to help you.




  reply	other threads:[~2024-11-28 17:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-28 11:53 Is there utility in making hash-table-{keys, values} built-in functions? Shankar Rao
2024-11-28 17:31 ` Mattias Engdegård [this message]
2024-11-28 18:40 ` Gerd Möllmann

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