@(defex u0)
@(defex u1)
@(define baz (x))
@  (cases)
@    (bind x "0")
@    (throw u0 "text0")
@  (or)
@    (bind x "1")
@    (throw u1 "text1")
@  (end)
@(end)
@(define bar (x))
@  (baz x)
@(end)
@(define foo ())
@  (next :list ("0" "1"))
@  (collect)
@num
@    (try)
@      (bar num)
@    (catch u0 (arg))
@      (output)
caught u0: @arg
@      (end)
@    (catch u1 (arg))
@      (output)
caught u1: @arg
@      (end)
@    (end)
@  (end)
@(end)
@(foo)