Add autocomplete for gas. Based on the rvm plugin.

plugins/gas/_gas

+#compdef gas
+
+local curcontext="$curcontext" state line cmds ret=1
+
+_arguments -C \
+	'(- 1 *)'{-v,--version}'[display version information]' \
+	'(-h|--help)'{-h,--help}'[show help information]' \
+	'1: :->cmds' \
+	'*: :->args' && ret=0
+
+case $state in
+	cmds)
+		cmds=(
+            "version:Prints Gas's version"
+            "use:Uses author"
+            "show:Shows your current user"
+            "list:Lists your authors"
+            "import:Imports current user to gasconfig"
+            "help:Describe available tasks or one specific task"
+            "delete:Deletes author"
+            "add:Adds author to gasconfig"
+        )
+		_describe -t commands 'gas command' cmds && ret=0
+		;;
+	args)
+		case $line[1] in
+			(use|delete)
+				_values -S , 'rubies' $(cat ~/.gas | sed -n -e 's/^\[\(.*\)\]/\1/p') && ret=0
+				;;
+		esac
+		;;
+esac
+
+return ret