Just to clarify: err = catch-all(expr) If your language does not provide a similar tool, you can't just use a function because "expr" is evaluated before

Just to clarify: err = catch-all(expr) If your language does not provide a similar tool, you can't just use a function because "expr" is evaluated before the function is called. I had Lisp macros in mind when writing this. A poor man's approach that is still generic is to wrap the expression in a closure: err = catch-all(() -> expr) Not too cumbersome, but YMMV.