On 8/17/05, Larry Wall <[EMAIL PROTECTED]> wrote:
> You could still reason about it if you can determine what the initial
> value is going to be. But certainly that's not a guarantee, which
> is one of the reasons we're now calling this write/bind-once behavior
> "readonly" and moving true constants to a separate declarator:
>
> my $pi is readonly;
> $pi = 3;
>
> vs
>
> constant $pi = 3;
>
> or
>
> constant Num pi = 3;
>
> or if you like, even
>
> constant π = 3;
Minor detail: when does the right side get evaluated? That is, what
happens here:
constant pi = make_pi();
sub make_pi() { 4*atan2(1,1) }
If you want this to succeed, then this must fail:
constant pi = 4*atan2(1,1);
BEGIN { say "pi = {pi}" }
Is it even possible to evaluate constants at CHECK time and then
constant-fold them in before the program is run?
Luke
