All~

On 6/7/05, Luke Palmer <lrpalmer@[...].com>  wrote:
>  On 6/7/05, Matt Fowles <ubermatt@[...].com> wrote:
>  > On 6/7/05, Ingo Blechschmidt <iblech@[...].de> wrote:
>  > > Hi,
>  > >
>  > >   sub foo (Code $code) {
>  > >     my $return_to_caller = -> $ret { return $ret };
>  > >
>  > >     $code($return_to_caller);
>  > >     return 23;
>  > >   }
>  > >
>  > >   sub bar (Code $return) { $return(42) }
>  > >
>  > >   say foo &bar; # 42 or 23?
>  > >
>  > > I think it should output 42, as the return() in the pointy
>  > > block $return_to_caller affects &foo, not the pointy block.
>  > > To leave a pointy block, one would have to use leave(), right?
>  >
>  > I don't like this because the function bar is getting oddly
>  > prematurely halted.
>  
>  Then let's put it this way:
>  
>     sub foo () {
>         for 0..10 {
>             when 6 { return 42 }
>         }
>         return 26;
>     }
>  
>  And if that didn't do it, then let's write it equivalently as:
>  
>     sub foo () {
>         &map(-> $_ { return 42 }, 0..10);
>         return 26;
>     }
>  
>  Do you see why the return binds to the sub rather than the pointy now?
>  
>  Also, we're going to be avoiding the return continuation problem with:
>  
>     sub foo() {
>         return -> { return 42 };
>     }
>  
>     my $code = foo();
>     say "Boo!";
>     $code();
>  
>  Says not:
>  
>     Boo
>     Boo
>     Boo
>     ...
>  
>  But:
>  
>     Boo
>     Can't return from subroutine that already returned at <eval> line 2.

You are right.  I yield... It just made by brain hurt, now that it is
somewhat fortified with caffeine I see.

Matt
-- 
"Computer Science is merely the post-Turing Decline of Formal Systems Theory."
-???