case package:ghc

Match the scrutinee of a case and potentially return a new scrutinee and a function to apply to each literal alternative.

Case rules It's important that occurrence info are present, hence the use of In* types.

The x in case scrut of x { (y,z) -> ... }

The y,z in case scrut of x { (y,z) -> ... }

Patterns and guards in a case alternative

Threshold for LiberateCase