Problems with defining a class

[Kevin Pye]

Hi,

The following fairly simple code works well:

   class A {
 has num $!a is required is built;
};

  dd A.new(a => 1e0);

producing "A.new(a => 1e0)".

However, if we make a slight change:

   class A {
 has num $!a is required is built;
};

  dd A.new(a => 0e0);

(i.e. initialising to 0 instead of 1), we get

   The attribute '$!a' is required, but you did not provide a value for it. 
   in block  at test.raku line 5

Any value except 0 seems to work fine.

Am I doing something stupid, or is this a problem with rakudo?

Kevin.

Re: Problems with defining a class

[William Michels via perl6-users]

It seems to work okay if I change `num` to `Num`:

class A {
 has Num $!a is required is built;
};

  dd A.new(a => 0e0);


#returns:

A.new(a => 0e0)

Note, I'm on a fairly old version of Rakudo [moar (2021.06).

HTH, Bill.


On Tue, Aug 23, 2022 at 6:47 PM Kevin Pye  wrote:
>
> Hi,
>
> The following fairly simple code works well:
>
>class A {
>  has num $!a is required is built;
> };
>
>   dd A.new(a => 1e0);
>
> producing "A.new(a => 1e0)".
>
> However, if we make a slight change:
>
>class A {
>  has num $!a is required is built;
> };
>
>   dd A.new(a => 0e0);
>
> (i.e. initialising to 0 instead of 1), we get
>
>The attribute '$!a' is required, but you did not provide a value for it.
>in block  at test.raku line 5
>
> Any value except 0 seems to work fine.
>
> Am I doing something stupid, or is this a problem with rakudo?
>
> Kevin.

Re: Problems with defining a class

[Kevin Pye]

That makes some reasonable sense. I guess "is required" and native attributes 
are more-or-less incompatible.

Kevin.

On Wed, 24 Aug 2022, at 12:45, William Michels via perl6-users wrote:
> It seems to work okay if I change `num` to `Num`:
>
> class A {
>  has Num $!a is required is built;
> };
>
>   dd A.new(a => 0e0);
>
>
> #returns:
>
> A.new(a => 0e0)
>
> Note, I'm on a fairly old version of Rakudo [moar (2021.06).
>
> HTH, Bill.
>
>
> On Tue, Aug 23, 2022 at 6:47 PM Kevin Pye  wrote:
>>
>> Hi,
>>
>> The following fairly simple code works well:
>>
>>class A {
>>  has num $!a is required is built;
>> };
>>
>>   dd A.new(a => 1e0);
>>
>> producing "A.new(a => 1e0)".
>>
>> However, if we make a slight change:
>>
>>class A {
>>  has num $!a is required is built;
>> };
>>
>>   dd A.new(a => 0e0);
>>
>> (i.e. initialising to 0 instead of 1), we get
>>
>>The attribute '$!a' is required, but you did not provide a value for it.
>>in block  at test.raku line 5
>>
>> Any value except 0 seems to work fine.
>>
>> Am I doing something stupid, or is this a problem with rakudo?
>>
>> Kevin.