Ticket #595 (new task: None)
Overhaul GHC's overlapping/non-exhaustive pattern checking
|Reported by:||simonmar||Owned by:|
|Keywords:||warnings||Cc:||marcot@…, ryani.spam@…, benjross@…|
|Type of failure:||Incorrect warning at compile-time||Difficulty:||Difficult (2-5 days)|
|Test Case:||N/A||Blocked By:|
Description (last modified by simonmar) (diff)
GHC has a module in the desugarer (Check) which checks whether patterns are overlapping and/or exhaustive, to support the flags -fwarn-overlapping-patterns and -fwarn-non-exhaustive-patterns. The code is old and crufty, and has several outstanding bugs. A rewrite is needed.