complete (real C) tags

[Peter Stephenson <pws@xxxxxxxxxxxxxxxxxxxxxxxxx>]

I don't think I ever posted this; it allows the new completion system to
complete tags from a TAGS or tags file (i.e. the tags used by Emacs and vi,
nothing to do with completion tags).  I have it bound to ^Xt.

I was going to send it to zshu, until I realised it didn't use style tags,
and tried to make it by sticking the _wanted stuff in front, which failed,
so I took it off again.  Only one man will know why...

-- 
Peter Stephenson <pws@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cambridge Silicon Radio, Unit 300, Science Park, Milton Road,
Cambridge, CB4 0XL, UK                          Tel: +44 (0)1223 392070

#compdef -k complete-word \C-xt

# Complete tags using either TAGS or tags.  Looks up your directory
# hierarchy to find one.  If both exist, uses TAGS.
#
# You can override the choice of tags file with $TAGSFILE (for TAGS)
# or $tagsfile (for tags).
#
# Could be rewritten by some sed expert to use sed instead of perl.

# setopt localoptions xtrace

# Tags file to look for
local c_Tagsfile=${TAGSFILE:-TAGS} c_tagsfile=${tagsfile:-tags} expl
# Max no. of directories to scan up through
integer c_maxdir=10

local c_path=
integer c_idir
while [[ ! -f $c_path$c_Tagsfile &&
         ! -f $c_path$c_tagsfile && $c_idir -lt $c_maxdir ]]; do
  (( c_idir++ ))
  c_path=../$c_path
done

if [[ -f $c_path$c_Tagsfile ]]; then
  # prefer the more comprehensive TAGS, which unfortunately is a
  # little harder to parse.
  # could do this with sed, just can't be bothered to work out how,
  # after quarter of an hour of trying, except for
  #  rm -f =sed; ln -s /usr/local/bin/perl /usr/bin/sed
  # but that's widely regarded as cheating.
  # _wanted etags expl 'emacs tags'
  compadd - \
    $(perl -ne '/([a-zA-Z_0-9]+)[ \t:;,\(]*\x7f/ &&
	    print "$1\n"' $c_path$c_Tagsfile)
elif [[ -f $c_tagspath ]]; then
  # tags doesn't have as much in, but the tag is easy to find.
  # we can use awk here.
  # _wanted vtags expl 'vi tags'
  compadd - \
    $(awk '{ print $1 }' $c_path$c_Tagsfile)
else
  return 1
fi