Re: Something wrong with prompt themes

[Adam Spiers <adam@spiers.net>]

Sven Wischnowsky (wischnow@informatik.hu-berlin.de) wrote:
> Andrej Borsenkow wrote:
> > Some prompt themes (e.g. elite) explicitly use characters with 8th
> > bit set. This looks really ugly here - tested on dtterm and
> > console (AT386 terminal - dunno if it specific to SINIX or is in
> > common use) with ISO-8859-1 and ISO-8859-5 charsets.
> 
> Irritating, isn't it? ;-)
> 
> But that reminded me... Adam, have you ever thought about extending
> your prompt themes stuff to include definitions for the format styles
> used by the completion code (so that they look appropriate for the
> prompt style used)?

Eek.  I wasn't really aware that there were any particular conflicts
between completion format styles and prompt themes ... actually that's
not true, since the `adam2' prompt theme, which I use the most, makes
user input bold initially, and I use:

  compstyle '*:descriptions' format "$fg_bold[white]%d$fg_no_bold[white]"

But I suspect I'm missing more significant issues here.  Could you
give a practical example or two where the extension suggested above
would be worthwhile?

> > Or use style(s) to switch them on/off. Themes may look nicely even
> > without these characters - and users may conditionally switch them
> > on/off depending on current terminal.
> 
> Which brings us back to the idea of using a generic package code, sigh.

Yep :-) While I'm not convinced more flexibility is needed in this
(prompt themes) case, there's no denying that a generic customization
system would be very worthwhile.  In my mind, the ideal goal would be
an extension of compstyle for general zsh customization (excepting
options, of course, because they're fine left as is), and then to have
some sort of simple front-end customization program (perhaps something
like the sort of UI the `dialog' program generates?) which harnesses
this in a user-friendly way.  The upshot behind this would be that
someone can download, install and have running very quickly a version
of zsh with all the funky stuff enabled, and actually (roughly)
understand what all the funky bits do, without having to spend hours
uploading the zshcompsys man page to their brain.  That would be
great, IMO.

Back to the topic in hand.  These 8-bit characters seem to be causing
several people to wrinkle up their noses, so I should change something
I guess.  The problem is, I'm not sure what in /every/ case.  In the
`adam2' theme you can already specify `plain' to have 7-bit
replacements for 8-bit characters, so perhaps the default should be
7-bit, and there should be a `solid' option or something which uses
8-bit.  However this approach doesn't always work.  For example, in
the `fade' theme, if you ditch the ability to have stippled
characters, it's difficult to imagine how you could use the theme in a
worthwhile way.  For this reason, I mentioned recommended fonts in the
help texts of all themes which use 8-bit characters.  However, I've
just noticed a bug which prevents most help texts from being displayed
normally: if you haven't used or previewed a particular theme, its
help function won't have been loaded, so `prompt -h foo' won't display
the help.  This problem already cropped up in the previewing code, and
I solved it as following:

      # The next line is a bit ugly.  It (perhaps unnecessarily)
      # runs the prompt theme setup function to ensure that if
      # the theme has a _preview function that it's been autoloaded.
      prompt_${theme_args[1]}_setup

which wasn't too bad, as we needed to run prompt_foo_setup to preview
theme `foo' anyway.  However, it's even messier now I've noticed this
help problem, and so we return to the question, "how best to load an
autoloaded function without actually causing any function within the
autoload file to be run?"  When I last asked this, Bart suggested:

    function loadauto {
        emulate -L zsh
        local f
        f=( $^fpath/$1(N) )
        eval "function $1 {
            $(< $f[1])
        }"
    }

but this won't work, since the files in question are of the autoload
variety which explicitly define the function `foo' (and some other
functions at the same time in fact), and then have a

  foo "$@"

as the last line.  I looked at the autoload -X and +X options, but if
I read the docs and thought about it correctly, they don't help.