Script:

     grn=$'\e[32;1m'
     nrm=$'\e[0m'

     var=( "${(@f)$(apt-file search $1)}" )
     targ=
     var2=()

     for ((i=1; i<=$#var; i++ )); do
         if [[ "$targ" != "${${=var[i]}[1]}" ]]; then
             targ="${${=var[i]}[1]}"
             var2+="\n${grn}${${=var[i]}[1]}${nrm}" # Copy first word of 
line.
         fi
         var2+="${${=var[i]}[2,-1]}" # Copy the rest of the line no 
matter how many words.
     done

     print -l "$var2[@]"

---------------------------------------------------

That's my preferred way to look at 'apt-file search' output (Debian and 
derivatives only of course).  It works fine and I think I understand all 
the expansions and splitting.  One you get used to it the nested 
expansions aren't so scary, just read them from inside out, one step at 
a time and it's easy.  But is it optimal?  I've been known to go one 
step to the right by first going three steps to the left, then four 
steps to the right.  I'm guessing it's tight, but ...

BTW, I had a much simpler way of doing this based on a 'two words per 
line of output' assumption, but Debian, in their wisdom, have a very few 
installable files that have spaces in their names, so the above: "   
[2,-1]   " way of doing things is needed.  I have to split on lines and 
then sub-split on words ... I think.  But I do have a talent for making 
things harder than they need be.