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Re: How to accomplish a method interpolation?

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From:
Brandon Allbery
Date:
December 30, 2017 11:55
Subject:
Re: How to accomplish a method interpolation?
Message ID:
CAKFCL4VSbHKN-inYvtRP-Xb=0-VrzMptMVY=1Ed-SzkoQoi8Kg@mail.gmail.com
I think this is just name collision; this sounds like a dungeon crawler
type thing and it's a "bag of holding".

On Sat, Dec 30, 2017 at 6:45 AM, Elizabeth Mattijsen <liz@dijkmat.nl> wrote:

> > On 30 Dec 2017, at 06:13, clasclin . <clasclin@gmail.com> wrote:
> >
> > I'm reading a book "Make your own python text adventure" and decided to
> give it a try with perl6. So this code works as expected.
> >
> > class Bag {
> >     has %.items;
> >
> >     method show {
> >         say "ropa ", %!items<ropa>.amount
> >             if %!items<ropa>:exists;
> >         say "femur ", %!items<femur>.amount
> >             if %!items<femur>:exists;
> >         say "fósforos ", %!items<fósforos>.amount
> >             if %!items<fósforos>:exists;
> >     }
> > }
> >
> > I'm using a class called bag as my inventory and trying to keep track of
> items in a hash, so the key is just a name and the value is an object and
> just found that a pattern when I try to list the elements on the screen...
> >
> > dd %!items
> > Hash %!items = {:femur(Items::Femur.new(amount => 1)),
> :fósforos(Items::Matches.new(amount => 3)), :ropa(Items::Cloth.new(amount
> => 4))}
> >
> > Items has data and the show method does what I expect, then I change the
> code, so I try to add a private method that handdle the pattern and change
> the show method to use the private one.
> >
> > class Bag {
> >     has %.items;
> >
> >     method !show-item ($msg, $item, $attr) {
> >         # dd $msg; dd $item; dd $attr; # all Str
> >         say "$msg ", %items{$item}.$attr
> >             if %!items{$item}:exists;
> >     }
> >
> >     method show {
> >          self!show-item('Ropa', 'ropa', 'amount');
> >          ...
> >      }
> > }
> >
> > Now I get an error, the line corresponds to the private method
> > No such method 'CALL-ME' for invocant of type 'Str'
> >
> > Try a few variants like return instead of say or things like
> >     say "$msg", "%!items{$item}.$attr"; # output: Ropa
> Items::Cloth<94810994868552>.amount
> >     say "$msg", $!items{$item}.{$attr}; # output: Type Items::Cloth does
> not support associative indexing.
> >     say "$msg", %!items{$item}."{$attr}"; # ouput: gives a compile error
> >
> > The output I'm expecting is: Ropa 4
> > Ropa is the $msg, and 4 corresponds to the value in the attribute amount.
> >
> > Is there a way to refactor my code? Thanks in advance.
>
> Are you aware that Perl 6 has an immutable Bag class (
> https://docs.perl6.org/type/Bag )
>  and mutable BagHash class ( https://docs.perl6.org/type/BagHash ) built
> in ???




-- 
brandon s allbery kf8nh                               sine nomine associates
allbery.b@gmail.com                                  ballbery@sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad        http://sinenomine.net

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