Proposal: Amend or patterns (#522) to use p1 ; p2 (#609) Author: Sebastian Graf, David Knothe Rendered proposal: https://github.com/ghc-proposals/ghc-proposals/blob/eb4b67c29282520b2c5c6a49... Discussion: https://github.com/ghc-proposals/ghc-proposals/pull/609 Recommendation: Acceptance ## Summary This proposal refines the syntax of an already accpted proposal (#522) for writing or patterns. The syntax of the old proposal, ```haskell stringOfT :: T -> Maybe String stringOfT (T1 s) = Just s stringOfT (one of T2{}, T3{}) = Nothing ``` is replaced with ```haskell stringOfT :: T -> Maybe String stringOfT (T1 s) = Just s stringOfT (T2{}; T3{}) = Nothing ``` or indeed ```haskell stringOfT :: T -> Maybe String stringOfT x = case x of T1 s -> Just s T2{} T3{} -> Nothing ``` (Beacuse the '(' ... ')' are optional here, we can remove them and naturally exploit layout.) The authors have conducted polls to see what folks preferred, landing on this proposal. The adjustments to the Haskell grammar are really quite minimal requiring one extra production. ## Recommendation The proposal is nondiruptive and as a whole addresses an important practical topic. I recommend that we accept it