swift does it wrong

[Raoul Duke]

if let

and 

guard else

quickly become just as terrible in real use when there's any complexity to the state or any non-throwing style error handling and logging. 

solving the small use cases was a nice try and is great when it works but quickly falls apart usability wise. 

[David Barbour]

My Glas language uses conditionals based on backtracking, i.e. `try/then/else`. If the `try` clause succeeds, we proceed to `then`, otherwise we backtrack (undoing effects of 'try') then proceed to `else`. In this design, it is not a problem for the `try` clause to adjust the environment (i.e. stack type, var types, etc.) locally for the `then` clause, i.e. similar to `if let` of swift. But without undoing effects, this pattern easily becomes very troublesome IMO because the system state received by the 'else' clause would be very unclear.

[Raoul Duke]

another thing i end up doing is wrapping some chunks of n existing bit of code that has conditionals into an iife lambda, especially when trying to emulate something like a clojure transient mutable block.