Language level heads-up warnings

[David Luposchainsky]

On 2013-05-22 15:42, Simon Peyton-Jones wrote:
> Yes, I think that if the libraries community thought it was
> important, I (or indeed someone else) could add a couple of ad-hoc
> warnings to GHC without much work. But you'd all need to be clear and
> specific about what warnings were wanted, and they'd need to be easy
> to check (ie no global program analysis).

Simon,

good to hear that it's worth thinking about.

I'm not sure what exactly "no global program analysis" means here. Where
would the boundaries of such warnings be? I could imagine problems if
Applicative/Monad are defined in separate packages/modules (although
that may be rare in practice).

Greetings,
David