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Re: [nongnu] elpa/geiser bb9d5cb200: geiser-impl--normalize-method: quic

From: Stefan Monnier
Subject: Re: [nongnu] elpa/geiser bb9d5cb200: geiser-impl--normalize-method: quick fix for previous change
Date: Fri, 28 Jan 2022 16:16:54 -0500
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux)

> yes, that works, but i find it ugly to use eval explictly for the sake
> of not using "a list-that-looks-like-a-function":

To me, it's being more honest: we have a variable that holds an ELisp
expression, so we need `eval` somwehere.

> what are the downsides of the latter?  i understand that i'd be just
> hiding an implicit eval, but is that all, or am i missing
> other drawbacks?

There's no serious drawback, no.  Here are some minor drawbacks:
- In Common-Lisp and Scheme '(lambda () 5) does not evaluate to
  something recognized as a function.  Currently ELisp does, but I think
  it's something better avoided.  I hope in some distant future we can
  make the types `function` and `cons` be a mutually-exclusive.
- the function value `(lambda () ,v) returns a function that will
  evaluate v using the old dynamically-scoped dialect which we're trying
  to phase out.

> (isn't, loosely speaking, hiding evals one of things macros
> buy us?

`eval` is used sometimes in macros, but most macros neither use nor hide
`eval`, AFAIK, no.

> ... the version without eval looks more readable to me).

My own taste is reflects in the fact that my local Emacs rejects
(lambda ...) as a valid function value ;-)


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