GHC.Ix.indexError no longer exported
As of base
4.14, the Ix
typeclass's definition has been moved from GHC.Arr
to GHC.Ix
. However, the move didn't preserve the old GHC.Arr
API; in particular, the indexError
function is no longer exported.
indexError
is useful when writing your own Ix
instances, so it should be available to third-party code that creates new instances.