* Is there utility in making hash-table-{keys, values} built-in functions?
@ 2024-11-28 11:53 Shankar Rao
2024-11-28 17:31 ` Mattias Engdegård
2024-11-28 18:40 ` Gerd Möllmann
0 siblings, 2 replies; 3+ messages in thread
From: Shankar Rao @ 2024-11-28 11:53 UTC (permalink / raw)
To: emacs-devel
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Hello all,
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.
Shankar
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Is there utility in making hash-table-{keys, values} built-in functions?
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
2024-11-28 18:40 ` Gerd Möllmann
1 sibling, 0 replies; 3+ messages in thread
From: Mattias Engdegård @ 2024-11-28 17:31 UTC (permalink / raw)
To: Shankar Rao; +Cc: emacs-devel
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.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Is there utility in making hash-table-{keys, values} built-in functions?
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
@ 2024-11-28 18:40 ` Gerd Möllmann
1 sibling, 0 replies; 3+ messages in thread
From: Gerd Möllmann @ 2024-11-28 18:40 UTC (permalink / raw)
To: Shankar Rao; +Cc: emacs-devel
Shankar Rao <shankar.rao@gmail.com> writes:
> Hello all,
>
> 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.
If this is about syntax, cl-loop has support for hash tables. For
example
for x being the hash-keys of something using (hash-value y)
^ permalink raw reply [flat|nested] 3+ messages in thread
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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
2024-11-28 18:40 ` Gerd Möllmann
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