Consider adding Raku compiler "worry" hints when encountering syntax similar to "my Hash %h" or "my Array @arr"

[tbrowder]

As suggested by @ab5tract on IRC #raku on 2025-09-28, the worry would not appear with equivalent use of syntax 'my %h of Hash' or 'my @arr of Array'.

[tbrowder]

I wonder if we might use an environment variable, like those currently defined, to affect the compilation process regarding report levels of problems

[jubilatious1]

Valid syntax doesn't usually warrant a message.

Noobs are often told they "don't understand" the Raku language--hence no changes are warranted in response to their requests.

If we are not catering to Raku noobs, is it fair to cater to Raku experts?

Regards.

@thoughtstream
@TimToady
@pmichaud

[thoughtstream]

There's already a run-time error if they attempt to assign the wrong type of value
to a my Hash %h or my Array @arr:

Type check failed for an element of %h; expected Hash but got Str ("ceci n'est pas un hachage")

If that explanation insufficiently awesome, perhaps the error mechanism could add some extra exposition,
but only for explicitly declared hash-of-hashes and array-of-arrays:

Type check failed for an element of %h; expected Hash but got Str ("ceci n'est pas un hachage")
Note: the declaration "my Hash %h" requires each element of %h to be a hash. 
Did you mean "my Str %h" or just  "my %h" instead?

[ab5tract]

Noobs are often told they "don't understand" the Raku language--hence no changes are warranted in response to their requests.

We have an entire category of error explicitly for helping new (and old) users, called Less Than Awesome.

I would like to understand more where we are emitting this anti newcomer attitude so that it can be corrected.

[ab5tract]

but only for explicitly declared hash-of-hashes and array-of-arrays:

This is a fine suggestion that matches the intent of the proposed change perfectly well.

Thanks for chiming in Damien.

[librasteve]

@jubilatious1 fwiw I strongly support catering to newcomers at all levels … web resources, tools, example and learning materials

for example I came to Raku after a 10 year break from professional coding and Think Raku (it was Think Perl6 at that time) was a great way to learn OO, functional, grammars, types from first principles … Raku has an awesome OO syntax and gradual types and repl for first timers imo

and by newcomers, i am thinking of both experienced coders in (say) Python, PHP, Go and so on and of first time coders who are learning to code for the first time