#haskell #type-families
In GHC, a type family that can’t reduce is considered “stuck”. Such a type is effectively a new type, equal only to itself, like empty datatypes a programmer might declare.
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What are type families? | Types and Kindst1 :: Int -> SillyGadt (F1 Char)
> MkSillyGadt2 :: Float -> SillyGadt (F1 Double)
Now, even though F1 Char is nonsense, SillyGadt (F1 Char) is inhabited. And GHC distinguishes between F1 Char and F1 Double .
<span>In GHC, a type family that can’t reduce is considered “stuck”. Such a type is effectively a new type, equal only to itself, like empty datatypes a programmer might declare. The only thing different about something like F1 Char from something like Maybe Char is that F1 Char cannot be used in a type pattern (that is, the left-hand side of a type family Summary
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