At Wed, 13 Nov 2019 20:57:04 +0100, David Fetter <da...@fetter.org> wrote in > On Wed, Nov 13, 2019 at 03:58:38PM -0300, Alvaro Herrera wrote: > > On 2019-Nov-13, David Fetter wrote: > > > > > On Wed, Nov 13, 2019 at 03:06:08PM -0300, Alvaro Herrera wrote: > > > > 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? > > > > > > 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. > > > > > So something like %w[...%w] where people could put things like PROMPT1 > > > inside? > > > > Hmm, (I'm not sure your proposed syntax works, but let's assume that > > it does.) I'm saying you'd define > > \set PROMPT1 '%a%b%c ' > > \set PROMPT2 '%w[%a%b%c %w]' > > > > and you'd end up with matching indentation on multiline queries.
This seems assuming %x are a kind of stable (until semicolon) function. But at least %`..` can be volatile. So, I think the %w thing in PROMPT2 should be able to refer the actual prompt string resulted from PROMPT1. > > I'm not sure that we'd need to make something like this work: > > PROMPT1="%w[$PROMPT1%w]" > > which I think is what you're saying. > > PROMPT2="%w[$PROMPT1%w]", and basically yes. Like this. Or may be a bit too-much and I don't came up with a lialistic use-case, but I think of the following syntax. \set PROMPT1 '%w[%a%b%c%w] ' \set PROMPT2 '%w ' where %w in PROMPT2 is replaced by a whitespace with the same length to the output of %w[..%w] part in PROMPT1. > > We already have "%:PROMPT1:" but that expands to the literal value of > > prompt1, not to the value that prompt1 would expand to: > > Yeah, that's not so great for this usage. I guess "expand variables" > could be a separate useful feature (and patch) all by itself... +1. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
