Thank you. It really helps. Then I go further to understand and I find interesting. The same applies to int 3. > 3.WHERE 94821123453912 As expected, is different from str 3 > "3".WHERE 139904951827592 But the same to $a. > my $a = 3; 3
I suppose that the constant 3 is created only when called. AFAIK the Raku store the $b from your example as a math expression (eager evaluation?). That might explain why your $b has a different memory location. Your answer was very helpful. Thanks again On Wed, Feb 12, 2020 at 11:29 AM Patrick R. Michaud <pmich...@pobox.com> wrote: > On Wed, Feb 12, 2020 at 10:27:20AM -0300, Aureliano Guedes wrote: > > So, I'd like to find a way to test if two variables are bound or not, > > especially concerning their memory address. > > > > If the address is not fixed for a lifetime, I must be able to test it in > > just one cycle. > > > $a.WHERE == $b.WHERE # I expected FALSE > > True > > > > To a bound variable, I expect the same address, but to an unbounded > > variable, this garbage collector behavior seams assing to the same memory > > location two unbounded variables with the same value. It is right? Must > > reduce memory usage but is a quiet weirdo. > > I don't know that it's "weirdo" that two variables containing the same > (constant, immutable) value end up at the same address. It's just the > compiler treating constants as proper objects and being smart about memory > allocation. > > In particular: > > > my $a = 3; say $a.WHERE > 94659198947472 > > $a = 4; say $a.WHERE > 94659198947432 > > $a = 3; say $a.WHERE > 94659198947472 > > What's likely happened is that the compiler has created an Int > representing the constant "3", and keeps track of that for future > compilations. Whenever the compiler encounters another "3", rather than > build a new Int object in memory it re-uses the Int it already established > if it can. > > So, with > > > my $b = 3; say $b.WHERE > 94659198947472 > > The compiler lets $b use the same constant 3 object that was created the > first time it was encountered, even though $a coincidentally also uses it. > > > $b = 6 div 2; say $b; say $b.WHERE > 3 > 139719166700504 > > The compiler has gone ahead and used "6 div 2" to produce a new Int > object, which has the same value as the constant 3 but is in a different > memory location. If we then do > > > $b = 3; say $b.WHERE > 94659198947472 > > you can see that the constant "3" Int is still hanging around to be used > wherever it's later mentioned in the code. > > Hope this helps, > > Pm > -- Aureliano Guedes skype: aureliano.guedes contato: (11) 94292-6110 whatsapp +5511942926110
