Merge pull request #401 from zsh-users/features/completion-suggestions

Features/completion suggestions

zsh-autosuggestions.zsh

@@ -25,16 +25,6 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 # OTHER DEALINGS IN THE SOFTWARE.
 
-#--------------------------------------------------------------------#
-# Setup                                                              #
-#--------------------------------------------------------------------#
-
-# Precmd hooks for initializing the library and starting pty's
-autoload -Uz add-zsh-hook
-
-# Asynchronous suggestions are generated in a pty
-zmodload zsh/zpty
-
 #--------------------------------------------------------------------#
 # Global Configuration Variables                                     #
 #--------------------------------------------------------------------#
@@ -122,6 +112,10 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 	)
 }
 
+# Pty name for capturing completions for completion suggestion strategy
+(( ! ${+ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME} )) &&
+typeset -g ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME=zsh_autosuggest_completion_pty
+
 #--------------------------------------------------------------------#
 # Utility Functions                                                  #
 #--------------------------------------------------------------------#
@@ -486,6 +480,115 @@ _zsh_autosuggest_partial_accept() {
 	zle -N autosuggest-toggle _zsh_autosuggest_widget_toggle
 }
 
+#--------------------------------------------------------------------#
+# Completion Suggestion Strategy                                     #
+#--------------------------------------------------------------------#
+# Fetches a suggestion from the completion engine
+#
+
+_zsh_autosuggest_capture_postcompletion() {
+	# Always insert the first completion into the buffer
+	compstate[insert]=1
+
+	# Don't list completions
+	unset compstate[list]
+}
+
+_zsh_autosuggest_capture_completion_widget() {
+	local -a +h comppostfuncs
+	comppostfuncs=(_zsh_autosuggest_capture_postcompletion)
+
+	# Only capture completions at the end of the buffer
+	CURSOR=$#BUFFER
+
+	# Run the original widget wrapping `.complete-word` so we don't
+	# recursively try to fetch suggestions, since our pty is forked
+	# after autosuggestions is initialized.
+	zle -- ${(k)widgets[(r)completion:.complete-word:_main_complete]}
+
+	# The completion has been added, print the buffer as the suggestion
+	echo -nE - $'\0'$BUFFER$'\0'
+}
+
+zle -N autosuggest-capture-completion _zsh_autosuggest_capture_completion_widget
+
+_zsh_autosuggest_capture_setup() {
+	# There is a bug in zpty module in older zsh versions by which a
+	# zpty that exits will kill all zpty processes that were forked
+	# before it. Here we set up a zsh exit hook to SIGKILL the zpty
+	# process immediately, before it has a chance to kill any other
+	# zpty processes.
+	if ! is-at-least 5.4; then
+		zshexit() {
+			kill -KILL $$
+			sleep 1 # Block for long enough for the signal to come through
+		}
+	fi
+
+	# Try to avoid any suggestions that wouldn't match the prefix
+	zstyle ':completion:*' matcher-list ''
+	zstyle ':completion:*' path-completion false
+	zstyle ':completion:*' max-errors 0 not-numeric
+
+	bindkey '^I' autosuggest-capture-completion
+}
+
+_zsh_autosuggest_capture_completion_sync() {
+	_zsh_autosuggest_capture_setup
+
+	zle autosuggest-capture-completion
+}
+
+_zsh_autosuggest_capture_completion_async() {
+	_zsh_autosuggest_capture_setup
+
+	zmodload zsh/parameter 2>/dev/null || return # For `$functions`
+
+	# Make vared completion work as if for a normal command line
+	# https://stackoverflow.com/a/7057118/154703
+	autoload +X _complete
+	functions[_original_complete]=$functions[_complete]
+	_complete () {
+		unset 'compstate[vared]'
+		_original_complete "$@"
+	}
+
+	# Open zle with buffer set so we can capture completions for it
+	vared 1
+}
+
+_zsh_autosuggest_strategy_completion() {
+	typeset -g suggestion
+	local line REPLY
+
+	# Exit if we don't have completions
+	whence compdef >/dev/null || return
+
+	# Exit if we don't have zpty
+	zmodload zsh/zpty 2>/dev/null || return
+
+	# Zle will be inactive if we are in async mode
+	if zle; then
+		zpty $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME _zsh_autosuggest_capture_completion_sync
+	else
+		zpty $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME _zsh_autosuggest_capture_completion_async "\$1"
+		zpty -w $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME $'\t'
+	fi
+
+	{
+		# The completion result is surrounded by null bytes, so read the
+		# content between the first two null bytes.
+		zpty -r $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME line '*'$'\0''*'$'\0'
+
+		# On older versions of zsh, we sometimes get extra bytes after the
+		# second null byte, so trim those off the end
+		suggestion="${${${(M)line:#*$'\0'*$'\0'*}#*$'\0'}%%$'\0'*}"
+	} always {
+		# Destroy the pty
+		zpty -d $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME
+	}
+}
+
 #--------------------------------------------------------------------#
 # History Suggestion Strategy                                        #
 #--------------------------------------------------------------------#
@@ -589,7 +692,10 @@ _zsh_autosuggest_fetch_suggestion() {
 		# Try to get a suggestion from this strategy
 		_zsh_autosuggest_strategy_$strategy "$1"
 
-		# Break once we've found a suggestion
+		# Ensure the suggestion matches the prefix
+		[[ "$suggestion" != "$1"* ]] && unset suggestion
+
+		# Break once we've found a valid suggestion
 		[[ -n "$suggestion" ]] && break
 	done
 }
@@ -683,4 +789,5 @@ _zsh_autosuggest_start() {
 }
 
 # Start the autosuggestion widgets on the next precmd
+autoload -Uz add-zsh-hook
 add-zsh-hook precmd _zsh_autosuggest_start