Question regarding es and coercion

[davidgarland]

Is it safe to use unsafeCoerce to turn Eff '[] a into Eff es a? I would expect that the two have the same runtime representation, but I'm just making sure.

I know in general I should just avoid unifying es with '[] for as long as possible, but due to a design problem out of my control I cannot avoid this. (In specific, I'm trying to write a sort of iterator library, and implementing IsList for those iterators requires that there are no effects present, because IsList has toList as a member rather than that being its own class, making the type of fromList unnecessarily restrictive-- being allowed to cast Eff '[] a to Eff es a would at least allow users to get effectual code that uses list literals to work)

[arybczak]

You don't have to use unsafeCoerce, you can use inject, but you need a version from master, i.e. yet unreleased 2.2.2.0.

I'll release it in a couple of days.

[davidgarland]

Thank you for the help, it is much appreciated :)