printf %s\\n "${value}" \
| sed -rn "2q; /^(${regex})\$/{p;q}; a${default}"
}
+
+invalidate(){
+ # print default if value matches regex; otherwise print value
+ value="$1"
+ regex="$(printf %s\\n "$2" \
+ | sed -r 's;(^|[^\\]+)((\\\\)+)/;\1\2\\/;g; s;(^|[^\\])/;\1\\/;g; s;(^|[^\\]+)((\\\\)+)/;\1\2\\/;g; s;(^|[^\\])/;\1\\/;g;'
+ )" # ^^ escape only unescaped slash characters for later insertion
+ default="$3"
+
+ printf %s\\n "${value}" \
+ | sed -rn "2q; /^(${regex})\$/{bd}; p;q; :d;a${default}"
+}
+
+declare -A item_name
+l10n(){
+ [ -n "${item_name[$1]+x}" ] && printf %s "$item_name[$1]" || printf %s "$1"
+}