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Re: How do a pe-salt an array inside an object?

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From:
Fernando Santagata
Date:
July 6, 2021 09:06
Subject:
Re: How do a pe-salt an array inside an object?
Message ID:
CAJ+jyGhaXDgw5dEv+HdFBPS5BCgMLJ8MaCY73fkkvWUs5r0WDA@mail.gmail.com
Hi,
for your last question, let's use again what Norman showed you earlier:

> class AA { has Str @.I is rw }
(AA)
> my $CC = AA.new(I => [Str, Str, 'two', Str, 'four'])
AA.new(I => Array[Str].new(Str, Str, "two", Str, "four"))
> say $CC.I[0]
(Str)
> say $CC.I[2]
two
> say $CC.I[4]
four

In this case undefined values are initialized by their own base class.
Since @.I was declared as a Str array, then Norman used the base class
'Str' as initialization value.

On Tue, Jul 6, 2021 at 10:42 AM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:

> >> On Tue, Jul 6, 2021 at 9:39 AM ToddAndMargo via perl6-users
> >>     I am confused.
> >>
> >>     What I am after it pre-salting $CC.I  with
> >>          $CC.[0] = "abc"
> >>          $CC.[1] = "def"
> >>
> >>     with the ".new" functions when I create $CC
> >>
> >>     -T
>
> On 7/6/21 12:52 AM, Fernando Santagata wrote:
> > Hello,
> >
> > I think that that was exactly what Norman was trying to show. Probably
> > you've been mislead by the first value they assigned in their example:
> >
> >     my $CC = AA.new( I => [Str,"abc"] );
> >
> >
> > Here the 'Str' is the "empty" or "undefined" value, since the array was
> > declared as a Str array.
> >
> > Try this:
> >
> >  > class AA { has Str @.I is rw }
> > (AA)
> >  > my $aa = AA.new: I => ['a','b']
> > AA.new(I => Array[Str].new("a", "b"))
> >  > say $aa.I[0]
> > a
> >  > say $aa.I[1]
> > b
> >
> > or this
> >
> >  > my $bb = AA.new: I => 'a'
> > AA.new(I => Array[Str].new("a"))
> >  > $bb.I[0]
> > a
> >
>
> Hi Fernando,
>
> Thank you!   Now I understand the syntax better.
>
> $ p6 'class AA { has Str @.I is rw; };
>        my $CC = AA.new( I => ["abc","def"] );
>        say $CC.I[1];'
> def
>
>
> Follow up question. Since Raku allows me to assign
> elements to an array in non sequential order:
>
>      $ p6 'my @x; @x[4]=44; say @x;'
>      [(Any) (Any) (Any) (Any) 44]
>
> How to I modify
>       my $CC = AA.new( I => ["abc","def"] );
> such that I can place values in non sequential order?
>
> For example, I wanted to pre-salt
>       $CC.I[4] = "four"
>       $CC.I[2] = "two"
>
> Many thanks,
> -T
>
>
>
>
>

-- 
Fernando Santagata

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