Defer is a restricted form of COMEFROM with automatic labels. You COMEFROM the end of the next `defer` block in the same scope, or from the end of the function (before `return`) if there is no more `defer`. The order of execution of defer-blocks is backwards (bottom-to-top) rather than the typical top-to-bottom.
puts("foo");
defer { puts("bar"); }
puts("baz");
defer { puts("qux"); }
puts("corge");
return;
Will evaluate: puts("foo");
puts("baz");
puts("corge");
puts("qux");
puts("bar");
return;
That is the most cursed description I have seen on how defer works. Ever.