Re: dynamic reset of completion widget

[Peter Stephenson <pws@csr.com>]

Francisco Borges wrote:
> 2. Have a default widget for my python script, say _optparse, that makes
> a new custom widget and rebinds the completion of foo.py to _foo.py

This sounds quite a reasonable way of doing it.

You might want to make it a bit more flexible about possible
enchancements by providing a few extra support functions in parallel to
_optparse (just put #autoload at the top of each function) and then make
_foo.py use those.  It gives you a little bit more decoupling between
the versions of zsh and the versions of the python script.  It depends
how complicated _foo.py is going to be; if you're simply going to call
_arguments, for example, maybe there's no point.  However, having your
own _optparse_arguments as a front-end whose initial implementation is
simply

_optparse_arguments() { _arguments "$@"; }

allows you a bit of future-proofing.

> # I start with
> compdef _optparse foo.py 
> compdef _optparse bozo.py
> [etc]
> 
> # I'm not a zsh programmer, so please have patience here...
> _optparse(){
> 
> # discover the name of the command we are completing
> set bar=`give the command name I'm completing`

$service ought to give you this immediately.  In general it's
a completion context, but if you know you're complete for
command arguments, as you will here, it's the name of the command
you're completing for.

> eval "`$bar --make-zsh-widget`"
> # which would return something like:
> # "_foo.py() { compadd Scooby Dooby Doo; }"
> 
> compdef _$bar $bar
> }
> 
> Is this possible? Can I just rebind like this?

Yes, you can, however the newly defined function won't get called the
first time.  So you should add

_$bar "$@"

to the end of _optparse.

Before that you might want to check that the specific completion
function has actually been defined for safety, e.g.

if [[ -z $functions[_$bar] ]]; the
  _message "$bar --make-zsh-widget didn't define _$bar"
  return 1
fi

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070


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