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bug#56641: Deprecate `lsh`
From: |
Mattias Engdegård |
Subject: |
bug#56641: Deprecate `lsh` |
Date: |
Thu, 21 Jul 2022 09:47:52 +0200 |
21 juli 2022 kl. 03.43 skrev Po Lu <luangruo@yahoo.com>:
> Which is the obvious use? For compatibility with programs (not
> necessarily within Emacs) that expect different values based on the
> number of VALBITs in the Emacs machine file?
Honestly I don't know. Even before Emacs 27, `lsh` seems a bit questionable
since the width is both platform-dependent and unlike C, say, isn't a
particularly useful size. It doesn't correspond to anything in hardware, isn't
a power of two or anything like that.
It could be code that expects (lsh x -29) to return the sign bit as 1 or 0, as
some kind of 'optimisation', what do I know.
Also see bug#32463 for some discussion about lsh during the transition to
bignums. Basically everyone agreed that it's useless but that it probably needs
to be kept for compatibility in some way.
- bug#56641: Deprecate `lsh`, (continued)
- bug#56641: Deprecate `lsh`, Eli Zaretskii, 2022/07/19
- bug#56641: Deprecate `lsh`, Po Lu, 2022/07/19
- bug#56641: Deprecate `lsh`, Eli Zaretskii, 2022/07/19
- bug#56641: Deprecate `lsh`, Po Lu, 2022/07/19
- bug#56641: Deprecate `lsh`, Eli Zaretskii, 2022/07/20
- bug#56641: Deprecate `lsh`, Mattias Engdegård, 2022/07/20
- bug#56641: Deprecate `lsh`, Po Lu, 2022/07/20
- bug#56641: Deprecate `lsh`, Eli Zaretskii, 2022/07/20
- bug#56641: Deprecate `lsh`, Mattias Engdegård, 2022/07/20
- bug#56641: Deprecate `lsh`, Po Lu, 2022/07/20
- bug#56641: Deprecate `lsh`,
Mattias Engdegård <=
bug#56641: Deprecate `lsh`, Lars Ingebrigtsen, 2022/07/23
bug#56641: Deprecate `lsh`, Basil L. Contovounesios, 2022/07/23
bug#56641: Deprecate `lsh`, Mattias Engdegård, 2022/07/23
bug#56641: Deprecate `lsh`, Basil L. Contovounesios, 2022/07/23