zsh-autosuggestions/src/strategies/completion.zsh

#--------------------------------------------------------------------#
# Completion Suggestion Strategy                                     #
#--------------------------------------------------------------------#
# Fetches suggestions from zsh's completion engine
#

# Big thanks to https://github.com/Valodim/zsh-capture-completion
_zsh_autosuggest_capture_completion() {
	zpty $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME zsh -f -i

	# line buffer for pty output
	local line

	setopt rcquotes
	() {
		zpty -w $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME source $1
		repeat 4; do
			zpty -r $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME line
			[[ $line == ok* ]] && return
		done
		echo 'error initializing.' >&2
		exit 2
	} =( <<< '
	# no prompt!
	PROMPT=
	# load completion system
	autoload compinit
	compinit -d ~/.zcompdump_autosuggestions
	# never run a command
	bindkey ''^M'' undefined
	bindkey ''^J'' undefined
	bindkey ''^I'' complete-word
	# send a line with null-byte at the end before and after completions are output
	null-line () {
		echo -E - $''\0''
	}
	compprefuncs=( null-line )
	comppostfuncs=( null-line exit )
	# never group stuff!
	zstyle '':completion:*'' list-grouped false
	# don''t insert tab when attempting completion on empty line
	zstyle '':completion:*'' insert-tab false
	# no list separator, this saves some stripping later on
	zstyle '':completion:*'' list-separator ''''
	# we use zparseopts
	zmodload zsh/zutil
	# override compadd (this our hook)
	compadd () {
		# check if any of -O, -A or -D are given
		if [[ ${@[1,(i)(-|--)]} == *-(O|A|D)\ * ]]; then
			# if that is the case, just delegate and leave
			builtin compadd "$@"
			return $?
		fi
		# ok, this concerns us!
		# echo -E - got this: "$@"
		# be careful with namespacing here, we don''t want to mess with stuff that
		# should be passed to compadd!
		typeset -a __hits __dscr __tmp
		# do we have a description parameter?
		# note we don''t use zparseopts here because of combined option parameters
		# with arguments like -default- confuse it.
		if (( $@[(I)-d] )); then # kind of a hack, $+@[(r)-d] doesn''t work because of line noise overload
			# next param after -d
			__tmp=${@[$[${@[(i)-d]}+1]]}
			# description can be given as an array parameter name, or inline () array
			if [[ $__tmp == \(* ]]; then
				eval "__dscr=$__tmp"
			else
				__dscr=( "${(@P)__tmp}" )
			fi
		fi
		# capture completions by injecting -A parameter into the compadd call.
		# this takes care of matching for us.
		builtin compadd -A __hits -D __dscr "$@"
		# JESUS CHRIST IT TOOK ME FOREVER TO FIGURE OUT THIS OPTION WAS SET AND WAS MESSING WITH MY SHIT HERE
		setopt localoptions norcexpandparam extendedglob
		# extract prefixes and suffixes from compadd call. we can''t do zsh''s cool
		# -r remove-func magic, but it''s better than nothing.
		typeset -A apre hpre hsuf asuf
		zparseopts -E P:=apre p:=hpre S:=asuf s:=hsuf
		# append / to directories? we are only emulating -f in a half-assed way
		# here, but it''s better than nothing.
		integer dirsuf=0
		# don''t be fooled by -default- >.>
		if [[ -z $hsuf && "${${@//-default-/}% -# *}" == *-[[:alnum:]]#f* ]]; then
			dirsuf=1
		fi
		# just drop
		[[ -n $__hits ]] || return
		# this is the point where we have all matches in $__hits and all
		# descriptions in $__dscr!
		# display all matches
		local dsuf dscr
		for i in {1..$#__hits}; do
			# add a dir suffix?
			(( dirsuf )) && [[ -d $__hits[$i] ]] && dsuf=/ || dsuf=
			# description to be displayed afterwards
			(( $#__dscr >= $i )) && dscr=" -- ${${__dscr[$i]}##$__hits[$i] #}" || dscr=
			echo -E - $IPREFIX$apre$hpre$__hits[$i]$dsuf$hsuf$asuf
		done
	}
	# signal success!
	echo ok')

	zpty -w $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME "$*"$'\t'

	integer tog=0
	# read from the pty, and parse linewise
	while zpty -r $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME; do :; done | while IFS= read -r line; do
		if [[ $line == *$'\0\r' ]]; then
			(( tog++ )) && return 0 || continue
		fi
		# display between toggles
		(( tog )) && echo -E - $line
	done

	return 2
}

_zsh_autosuggest_strategy_completion() {
	typeset -g suggestion=$(_zsh_autosuggest_capture_completion "$1" | head -n 1)

	# Strip the trailing carriage return
	suggestion="${suggestion%$'\r'}"

	# Add the completion string to the buffer to build the full suggestion
	local -i i=1
	while [[ "$suggestion" != "${1[$i,-1]}"* ]]; do ((i++)); done
	suggestion="${1[1,$i-1]}$suggestion"
}