Re: valid values?
The `where` clause is already a smart-match, adding `~~` to it is not
only redundant, it can cause confusing action at a distance.
(By that I mean the right side of `where` is exactly the same as the
right side of `~~`)
You wouldn't write this:
* ~~ (* ~~ 1|2|4|8|16)
So don't write this either:
… where * ~~ 1|2|4|8|16
---
It should be
sub mysub(Int $value where 1|2|4|8|16)
{
say "Got $value"
}
On Sun, Mar 3, 2019 at 4:16 AM Fernando Santagata
wrote:
>
> Hi Todd,
> is this what you're looking for?
>
> sub mysub(Int $value where * ~~ 1|2|4|8|16)
> {
> say "Got $value"
> }
>
> mysub 2; # Got 2
> mysub 3; # Constraint type check failed in binding to parameter '$value';
> expected anonymous constraint to be met but got Int (3)
>
> On Sun, Mar 3, 2019 at 11:09 AM ToddAndMargo via perl6-users
> wrote:
>>
>> Hi All,
>>
>> I want to pass an integer to a sub. The only
>> valid values of the integer are 1, 2, 4, 8, and 16.
>>
>> Other than using "if" to test their values, is
>> there a way to state that an integer can only
>> have certain predefined values?
>>
>> Many thanks,
>> -T
>>
>> --
>> ~~~
>> Having been erased,
>> The document you're seeking
>> Must now be retyped.
>> ~~~
>
>
>
> --
> Fernando Santagata
Re: valid values?
On Sun, Mar 3, 2019 at 11:41 AM ToddAndMargo via perl6-users < perl6-users@perl.org> wrote: > That way I can catch bad values at compile time and not have > to wait and see what it gets fed. > The snippet I showed you doesn't intercepts wrong values at compile time, but rather at run time. -- Fernando Santagata
Re: valid values?
Hi Todd,
is this what you're looking for?
sub mysub(Int $value where * ~~ 1|2|4|8|16)
{
say "Got $value"
}
mysub 2; # Got 2
mysub 3; # Constraint type check failed in binding to parameter '$value';
expected anonymous constraint to be met but got Int (3)
On Sun, Mar 3, 2019 at 11:09 AM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:
> Hi All,
>
> I want to pass an integer to a sub. The only
> valid values of the integer are 1, 2, 4, 8, and 16.
>
> Other than using "if" to test their values, is
> there a way to state that an integer can only
> have certain predefined values?
>
> Many thanks,
> -T
>
> --
> ~~~
> Having been erased,
> The document you're seeking
> Must now be retyped.
> ~~~
>
--
Fernando Santagata
valid values?
Hi All, I want to pass an integer to a sub. The only valid values of the integer are 1, 2, 4, 8, and 16. Other than using "if" to test their values, is there a way to state that an integer can only have certain predefined values? Many thanks, -T -- ~~~ Having been erased, The document you're seeking Must now be retyped. ~~~
