NOTMUCH_OPT_BOOLEAN, /* --verbose */
NOTMUCH_OPT_INT, /* --frob=8 */
NOTMUCH_OPT_KEYWORD, /* --format=raw|json|text */
+ NOTMUCH_OPT_KEYWORD_FLAGS, /* the above with values OR'd together */
NOTMUCH_OPT_STRING, /* --file=/tmp/gnarf.txt */
NOTMUCH_OPT_POSITION /* notmuch dump pos_arg */
};