Re: [vim9script] Behavior of has_key()

> The help entry for has_key() says that the key must be a string. In
> legacy Vim script, however, this works fine:
>
> let dd = {42: '42', v:true: 'T', 3.14: '3.14'}
> echo dd->has_key(42)
> echo dd->has_key(v:true)
> echo dd->has_key(3.14)
>
> In Vim 9 script, the behavior is different:
>
> vim9script
> const dd = {42: '42', true: 'T', [3.14]: '3.14'}
> echo dd->has_key(42) # OK
> echo dd->has_key(v:true) # Error, must be string(v:true)
> echo dd->has_key(3.14) # Error, must be string(3.14)
>
> This seems a bit inconsistent to me. I don't have a problem with Vim
> 9 script being different from legacy script, but I think that either all
> the three cases should raise an error, or none of them.
>
> Besides, the documentation does not make it clear that implicit type
> casting may happen.

I'll add a note to the help.

In Vim9 script there is no automatic conversion to string, but an
exception is made for a number. I don't recall the discussion, but I
think this was because it is rather common. Perhaps not totally
consistent, but I don't want to change it now, it would cause obscure
problems.

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