How do I make a zsh function autocomplet from the middle of a word?

Question

I use zsh and wrote a function to replace cd function. With some help I got it to work like I want it to (mostly). This is a followup to one of my other question. The function almost works like I want it to, but I still have some problems with syntax highlighting and autocompletion.

For the examples, lets say your directories look like this:

/
    a/
        b/
        c/
            d/
        some_dir/

I am also assuming the following code has been sourced:

cl () {
    local first=$( echo $1 | cut -d/ -f1 )
    if [ -d $first ]; then
        pushd $1 >/dev/null # If the first argument is an existing normal directory, move there
    else
        pushd ${PWD%/$first/*}/$1 >/dev/null # Otherwise, move to a parent directory or a child of that parent directory
    fi
}
_cl() {
    _cd
    pth=${words[2]}
    opts=""
    new=${pth##*/}
    local expl
    # Generate the visual formatting and store it in `$expl`
    _description -V ancestor-directories expl 'ancestor directories'
    [[ "$pth" != *"/"*"/"* ]] && middle="" || middle="${${pth%/*}#*/}/"
    if [[ "$pth" != *"/"* ]]; then
        # If this is the start of the path
        # In this case we should also show the parent directories
        local ancestor=$PWD:h
        while (( $#ancestor > 1 )); do
            # -f: Treat this as a file (incl. dirs), so you get proper highlighting.
            # -Q: Don't quote (escape) any of the characters.
            # -W: Specify the parent of the dir we're adding.
            # ${ancestor:h}: The parent ("head") of $ancestor.
            # ${ancestor:t}: The short name ("tail") of $ancestor.
            compadd "$expl[@]" -fQ -W "${ancestor:h}/" - "${ancestor:t}"
            # Move on to the next parent.
            ancestor=$ancestor:h
        done
    else
        # $first is the first part of the path the user typed in.
        # it it is part of the current direoctory, we know the user is trying to go back to a directory
        first=${pth%%/*}
        # $middle is the rest of the provided path
        if [ ! -d $first ]; then
            # path starts with parent directory
            dir=${PWD%/$first/*}/$first
            first=$first/
            # List all sub directories of the $dir/$middle directory
            if [ -d "$dir/$middle" ]; then
                for d in $(ls -a $dir/$middle); do
                    if [ -d $dir/$middle/$d ] && [[ "$d" != "." ]] && [[ "$d" != ".." ]]; then
                        compadd "$expl[@]" -fQ -W $dir/ - $first$middle$d
                    fi
                done
            fi
        fi
    fi
}
compdef _cl cl

The problem:

In my zshrc, I have a line:

zstyle ':completion:*' matcher-list 'm:{a-z}={A-Za-z}' '+l:|=* r:|=*'

This should make autocompletions case insensitive and make sure I can start typing the last part of a directory name, and in will still finnish the full name

Example:

$ cd /a
$ cd di[tab] # replaces 'di' with 'some_dir/'
$ cl di[tab] # this does not do anything. I would like it to replace 'di' with 'some_dir'

How do get it to suggest 'some_dir' when I type 'di'?

Answer 1

The second matcher in your matcher-list never gets called, because _cl() returns "true" (exit status 0, actually) even when it has not added any matches. Returning "true" causes _main_complete() to assume that we're done completing and it will thus not try the next matcher in the list.

To fix this, add the following to the start of _cl():

local -i nmatches=$compstate[nmatches]

and this to the end of _cl():

(( compstate[nmatches] > nmatches ))

That way, _cl() will return "true" only when it has managed to actually add completions.