experiment for testing gcloud completion

src/_gcloud

@@ -0,0 +1,64 @@
+autoload -U +X bashcompinit && bashcompinit
+zmodload -i zsh/parameter
+if ! (( $+functions[compdef] )) ; then
+    autoload -U +X compinit && compinit
+fi
+
+_python_argcomplete() {
+    local prefix=
+    if [[ $COMP_LINE == 'gcloud '* ]]; then
+        if [[ $3 == ssh  && $2 == *@* ]] ;then
+            # handle ssh user@instance specially
+            prefix=${2%@*}@
+            COMP_LINE=${COMP_LINE%$2}"${2#*@}"
+        elif [[ $2 == *'='* ]] ; then
+            # handle --flag=value
+            prefix=${2%=*}'='
+            COMP_LINE=${COMP_LINE%$2}${2/'='/' '}
+        fi
+    fi
+    local IFS=''
+    COMPREPLY=( $(IFS="$IFS"                   COMP_LINE="$COMP_LINE"                   COMP_POINT="$COMP_POINT"                   _ARGCOMPLETE_COMP_WORDBREAKS="$COMP_WORDBREAKS"                   _ARGCOMPLETE=1                   "$1" 8>&1 9>&2 1>/dev/null 2>/dev/null) )
+    if [[ $? != 0 ]]; then
+        unset COMPREPLY
+        return
+    fi
+    # if one completion without a trailing space, add the space
+    if [[ ${#COMPREPLY[@]} == 1 && $COMPREPLY != *[=' '] ]]; then
+        COMPREPLY+=' '
+    fi
+    if [[ $prefix != '' ]]; then
+        typeset -i n
+        for ((n=0; n < ${#COMPREPLY[@]}; n++));do
+            COMPREPLY[$n]=$prefix${COMPREPLY[$n]}
+        done
+    fi
+}
+complete -o nospace -o default -F _python_argcomplete "gcloud"
+
+_completer() {
+    command=$1
+    name=$2
+    eval '[[ -n "$'"${name}"'_COMMANDS" ]] || '"${name}"'_COMMANDS="$('"${command}"')"'
+    set -- $COMP_LINE
+    shift
+    while [[ $1 == -* ]]; do
+          shift
+    done
+    [[ -n "$2" ]] && return
+    grep -q "${name}\s*$" <<< $COMP_LINE &&
+        eval 'COMPREPLY=($'"${name}"'_COMMANDS)' &&
+        return
+    [[ "$COMP_LINE" == *" " ]] && return
+    [[ -n "$1" ]] &&
+        eval 'COMPREPLY=($(echo "$'"${name}"'_COMMANDS" | grep ^'"$1"'))'
+}
+
+unset bq_COMMANDS
+_bq_completer() {
+    _completer "CLOUDSDK_COMPONENT_MANAGER_DISABLE_UPDATE_CHECK=1 bq help | grep '^[^ ][^ ]*  ' | sed 's/ .*//'" bq
+}
+
+complete -o default -F _bq_completer bq
+complete -o nospace -F _python_argcomplete gsutil
+