Dear old literal history

["Bart Schaefer" <schaefer@candle.brasslantern.com>]

Does anyone else ever get nostalgic for "literal history"?  This used to be
turned on by `setopt HIST_LIT' (or `set -j' for those wondering why the
single-letter options skip from -i to -k).  Occasionally this was useful if
one wrote a complicated history substitution which failed in some small way,
and one therefore wanted to edit the line from *before* history was expanded.

I was about to suggest that it would be pretty easy now to reinstate the
literal history via ZLE widgets, when I discovered by an accident of search
terms that I already did so back in zsh-workers/4269.  Except that now it's
possible to do a much better job, and widgets don't work quite like they
did a year and a half ago anyway.

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typeset -A zle_lines
typeset -i zle_hist

precmd() {
    zle_hist=${(%%):-%h}	# The one icky bit
    ((zle_hist > HISTSIZE)) && unset zle_lines\[$[zle_hist-HISTSIZE]\]
}

zle-store () {
    zle_lines[$zle_hist]=$BUFFER 
    zle .accept-line
}

zle-fetch-previous () {
    zle .up-history || return 1 
    (($+zle_lines[$HISTNO])) && BUFFER=$zle_lines[$HISTNO] 
    return 0
}

zle-fetch-next () {
    NUMERIC=-${NUMERIC:-1}
    zle-fetch-previous
}

zle -N zle-store
zle -N zle-fetch-next
zle -N zle-fetch-previous

zle -A zle-store accept-line

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An exercise for someone (maybe me, not tonight):  Implement LITHISTSIZE.
(That means one can't use .up-history and HISTNO, which gets ugly.)

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com