Introducing zsh-hints

[Joep van Delft <joepvandelft@xs4all.nl>]

Hi there, 

In order to gradually acquaint myself with zsh's possibilities and
idioms, I have written a zle function that displays definition files
nicely under the current buffer with zle -M.  Intended use is to
provide a quick help on these things that are hard to complete like
parameter expansion flags. The original idea I found in feh's
zshrc[1], I tried to make it as generally usable and configurable as
possible. 

Because of its intended use is closely tied with zsh itself, I
decided to {shamelessly,humbly} bring it to your attention. As I am
pretty new to programming, I would appreciate any comments on style
and function. 

You can find the main repository here: 
https://github.com/joepvd/zsh-hints/settings

I hope some will find it useful! :) 

Kind regards, 

Joep 



[1] http://git.plenz.com/configs/plain/.zsh/zshrc


.. code:: zsh

# zsh-hints
# Easily display non-completable information below the buffer. 
# Written by Joep van Delft, 2014. 

emulate -L zsh
setopt extended_glob

name=${WIDGET#zsh-hints-}

# Locate the library file by explicit setting or guesswork: 
zstyle -s ":zsh-hints:$name:" file hintfile || {
    zstyle -s ":zsh-hints:$name:" dir hintdir || \
        hintdir="${XDG_DATA_HOME:-~/.local/share}/zsh"
    zstyle -s ":zsh-hints:$name:" ext hintext || \
        hintext="hints"
    hintfile="$hintdir/${name}${hintext:+.$hintext}"
}
if [[ ! -r "$~hintfile" ]]; then
    print "Library file $~hintfile not found for $WIDGET." >&2
    return 1
fi

# Get the configuration for the styles: 
zstyle -b ":zsh-hints:$name:" verbose verbose || verbose=yes
zstyle -s ":zsh-hints:$name:" pri_sep pri_sep || pri_sep='#'
zstyle -s ":zsh-hints:$name:" sec_sep sec_sep || sec_sep="$pri_sep"
zstyle -s ":zsh-hints:$name:" margin  margin  || margin=6

# Establish the available lines for display: 
if [[ $verbose == "yes" ]]; then
    dl=$((${LINES}-${margin}-1))
else
    dl=$((${LINES}-$margin))
fi

# Store the contents of the help file in an array. The reason that
# this is separated from the output generation, is because the 
# output depends on the longest 'key', or first word of a line. 
# As ZSH does not support multidimensional arrays, an emulation
# of multidimensional arrays is attempted by the names of the
# keys of the associative array txt, with the keys of the form 
# 02_03. Pattern matching on the keys makes it work like an 
# associative array. 
declare -A txt      # The main data structure. 
declare -Z 2 i j    # Counters with leading zeros. 
len_k=0
i=0

for line in "${(f)$(<${~hintfile})}"; do
    i=$(($i+1))
    for j in {1..${#${(s: :)line}}}; do
        txt[${i}_${j}]=${${(s: :)line}[$j]}
    done
    # Get a reasonable estimate len_k of the maximum length 
    # of the relevant keys:
    #print $i, $dl
    (( $i<=$dl )) && (( $#txt[${i}_01]>$len_k )) &&
len_k=$#txt[${i}_01] done

output_txt() {
    for hint_no in ${(ou)${(k)txt[@]}%_*}; do
        # Looping over the (unique and ordered) numerical part before 
        # the underscore of the keys of txt-array. A.K.A. the hint_no
        # identifying a line. 
        v=$(($v+1))
        if (( $v > $dl )); then
            [[ "$verbose" == "yes" ]] && print "   ...$(( $i-$hint_no
)) hints omitted." break
        fi
        # Get the ordered indexes of words belonging matching the
current line: for word in ${(oM)${(k)txt[@]}:#$hint_no*}; do
            if [[ -z ${word:#*01} ]]; then
                # It is the first word: Special treatment. 
                printf "%-${len_k}s %s" "$txt[$word]" "$pri_sep"
                d=$(($len_k+2))
            elif (( $d+1+$#txt[$word] <= $COLUMNS )); then
                # It is not a key, and it fits on the current line.
                printf " %s" "$txt[$word]"
                d=$(($d+1+$#txt[$word]))
            else
                # It is not a key and does not fit on current line.
                printf "\n%-${len_k}s %s %s" " " "$sec_sep"
"$txt[$word]" d=$(($len_k+$#txt[$word]))
                v=$(($v+1))
            fi
        done
        printf "\n"
    done
}

zle -M "$(output_txt)"

# vim: ft=zsh

.... end of code