Re: deprecating

On 23/10/12 09:50, I wrote:
> Sorry, you're right. It means "I require at most rank-2 types"
>
> Program A is marked "Rank2Types" and not "RankNTypes" and uses only 
> rank-1 types.
> Program B is marked "Rank2Types" and not "RankNTypes" and uses only 
> rank-1 & rank-2 types.
> Program C is marked "Rank2Types" and not "RankNTypes" and uses rank-3 
> types.
>
> The compiler MUST accept A & B. It SHOULD reject C, but since GHC 
> can't tell the difference, it's acceptable if it accepts it.

"Require at most/least" is ambiguous.

No "Rank2Types" means "I have no rank-2 types" or "I don't require that 
you accept rank-2 types".
"Rank2Types" means "I might have rank-2 types" or "At most, I require 
that you accept at least rank-2 types" which implies "I don't require 
that you accept rank-3 types; I don't require that you reject rank-3 types".

-- Ashley