Avoiding construction of dead dictionaries

[Claude Heiland-Allen]

Hi all,

On 09/08/2021 16:31, Brandon Allbery wrote:
> We haven't figured out what they did, but the other day we had someone 
> in #haskell with an infinite loop evaluating a dictionary. So 
> apparently it is possible for a dictionary to be bottom somehow.

I managed to do something like this once: I was using type level natural 
numbers to parameterize my type, and through carelessness my dictionary 
for `T n` depended on the dictionary for `T (Succ n)`.  My heap profile 
was a triangular wedge with space taken up by dictionaries growing 
linearly without bound.


Claude

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