[kazinator]

Wouldn't the handlers for exception handling by dynamically scoped, not lexically?

If we have a try block, and call a function, and if that function throws, we want the try block to be able to catch that. The function is not understood as having magic access to an environment; it's a pervasive dynamic environment that is visible to the current execution context at all times, in which exit points for non-local transfers are established.

That's almost the entire point since an error situation that is entirely confined to a lexical scope can be dealt with using some local control flow (some form of goto, or structured derivative thereof).

[simcop2387]

So with perl 5 there isn't a real exception handler like you'd expect from other languages (I'm unsure of perl 6). It works like the following (program output available at [1]):

    use v5.24.0;
    my $x = 1;
    my $y = "bar";
    
    sub foo { # this sub fails fatally
       die "what is going on here";
    }
    
    say "x is $x, y is $y"; # 1 and bar
    
    eval { # similar to try
      my $y = "baz"; # we have a new lexical scope in here too.
      $x = 2; # but this will change the outside scope since it's also available to us
      say "x is $x, y is $y"; # 2 and baz
      foo();
      $x = 3; # this never happens
    };
    
    if ($@) { # check for an error, similar to catch
       say "CAUGHT ERROR: ", $@; # just parrot the error out for now.
    }
    
    say "x is $x, y is $y"; # 2 and bar

Inside the eval the lexical scope outside is still available and a new one is also available. The error that happens gets stuffed into a special variable and you can choose to handle it or not later. This works the same way if you give eval a string to run also.

[1] https://perlbot.pl/pastebin/pl5u9w