Re: Invisible PROMPT2 - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Invisible PROMPT2
Date
Msg-id 20191113180608.GA24000@alvherre.pgsql
Whole thread Raw
In response to Re: Invisible PROMPT2  (David Fetter <david@fetter.org>)
Responses Re: Invisible PROMPT2  (David Fetter <david@fetter.org>)
List pgsql-hackers
On 2019-Nov-13, David Fetter wrote:

> On Wed, Nov 13, 2019 at 09:47:01AM -0500, Tom Lane wrote:

> > > How about a circumfix directive (like the existing %[ ... %])
> > > that replaces everything inside with whitespace, but keeps the width?
> > 
> > Or just define %w as meaning "whitespace of the same width as
> > PROMPT1".  You couldn't use it *in* PROMPT1, then, but I see
> > no use-case for that anyway.
> 
> +1 for doing it this way.  Would it make more sense to error out if
> somebody tried to set that in PROMPT1, or ignore it, or...?

This seems way too specific to me.  I like the "circumfix" directive
better, because it allows one to do more things.  I don't have any
immediate use for it, but it doesn't seem completely far-fetched that
there are some.

BTW the psql manual says that %[ and %] were plagiarized from tcsh, but
that's a lie: tcsh does not contain such a feature.  Bash does, however.
(I guess not many people read the tcsh manual.)

Neither bash nor tcsh have a feature to return whitespace of anything;
we're in a green field here ISTM.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



pgsql-hackers by date:

Previous
From: Mark Dilger
Date:
Subject: Re: Using multiple extended statistics for estimates
Next
From: David Fetter
Date:
Subject: Re: Invisible PROMPT2