Subject: Re: bug#53518: 29.0.50; em-extpipe breaks input of sharp-quoted Lisp symbols

From: Sean Whitton <[email-masked]>
Date: Tue, 25 Jan 2022 13:01:51 -0700

Hello,

On Tue 25 Jan 2022 at 10:14AM -08, Jim Porter wrote:

> It becomes more relevant with my WIP patches to support piping to Lisp
> functions, but it means something different today too.

Indeed.

> Just for the sake of completeness, in my WIP patches, "echo hi |
> #'upcase" and "echo hi | upcase" will also do different things,
> following the above precedent. The former pipes the output of echo to
> the function upcase. The latter pipes the output of echo to the *result*
> of calling the function upcase with no arguments.

Okay, thanks.  I asked because I thought you were only planning support
the former case.

> In addition to being consistent with how Eshell currently works, this
> allows you to do things like "echo hi | less -N", where "less -N" is
> evaluated as an Eshell command and then returns a pseudo-pipe for echo
> to connect to.

It's not quite clear to me how this is consistent with how Eshell
currently works.  When you type "echo hi | cat" is it right to say that
"cat" is evaluated to produce the thing to which the output of the first
command is piped?  Perhaps I'm not thinking broadly enough.

-- 
Sean Whitton