Two Proposals

Manuel M T Chakravarty chak at
Thu Oct 6 13:08:22 CEST 2011

Roman Leshchinskiy:
> Manuel M T Chakravarty wrote:
>> Roman Leshchinskiy:
>>> What data structures other than lists do we want to construct using list
>>> literals? I'm not really sure what the use cases are.
>> Parallel arrays! (I want to get rid of our custom syntax.)
> Why? Don't you think it is useful to have a visual indication of which
> data structure you are using and what is going to be evaluated in
> parallel?

Whether a computation is parallel depends on the type.  That is still the case.

In Haskell, it is usually hard to reason about performance without a good understanding of the involved types and their representation.  Syntax alone is usually not very helpful.  I think it is fine if that is the same for data parallelism.

> In any case, if we want to get rid of the parallel array syntax, we have
> to overload list literals, enumerations and list comprehensions. We have
> the generic monadic desugaring for the latter but recovering an efficient
> DPH program from that sn't trivial.

At ICFP, George suggested that we might use RULES to transform the patterns of generic monadic desugaring into the form that we need for parallel arrays.  We need to check whether that really works out, of course.


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