[Haskell-cafe] If you'd design a Haskell-like language, what would you do different?

[Conor McBride]

On 23 Dec 2011, at 16:16, MigMit wrote:

>
> On 23 Dec 2011, at 02:11, Conor McBride wrote:
>
>>> So... you are developing a programming language with all  
>>> calculations being automatically lifted to a monad? What if we  
>>> want to do calculations with monadic values themselves, like, for  
>>> example, store a few monadic calculations in a list (without  
>>> joining all there effects as the sequence function does)?
>>
>> The plan is to make a clearer distinction between "being" and  
>> "doing" by
>> splitting types clearly into an effect part and a value part, in a  
>> sort
>> of a Levy-style call-by-push-value way. The notation
>>
>> [<list of effects>]<value type>
>>
>> is a computation type whose inhabitants might *do* some of the  
>> effects in
>> order to produce a value which *is* of the given value type.
>
> Oh, so it's not an arbitrary monad, but a single one. That's a bit  
> disappointing.

The list of effects is arbitrary, and localizable, by means of  
defining handlers.
So it's not a single monad.

It's probably still disappointing.

Cheers

Conor