rnf should work for any value or rnf should be implemented in the compiler

Currently rnf is implemented in a type class NFData in Control.Parallel.Strategies. This is not general enough, since it doesn't work for values that only exist in a monad. E.g. something built in the ST monad that uses unsafeInterleaveST cannot be converted to head normal form via rnf, since it cannot return a "Done" value, only a ST s Done value.

A solution would be to have the function rnf implemented in the compiler. Its specification would be to evaluate its argument to head normal form and then return it. This is much more convenient to users, since they don't need to implement the boiler-plate code for every data type encountered.

Trac metadata

Trac field	Value
Version	6.7
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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Operating system	Unknown
Architecture	Unknown