All languages need some form of "escaping the structured programming fences". Older imperative languages have goto for this, but newer ones try to find some safer alternatives. Here is a (non-comprehensive) list of things to consider as it seems Til doesn't yet have a stabilized polished way to cover all the "escape structured programming use cases".

• exceptions (currently error and error.handler procedures)
• yield (a "highly tamed" form of async/await; untamed forms I personally dislike for objective reasons)
• trap (as from bourne shell) or alike
• Koka's effects on steroids (similar in capabilities as exceptions in Dylan; i.e. combining exceptions as they're now in Til plus yield - i.e. resumption)
• V's ephemeral (!) optionals (I love them - but they require special syntax support and distinction between compile-time and run-time; but they completely avoid introducing none/null/nil value to the langue which is a huge advantage as three-state logic proved to be one of the few worst things in the whole IT industry)