Fix non-exhaustive pattern warnings with GHC 9.2.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/lib/Codec/Pesto/Graph.lhs b/src/lib/Codec/Pesto/Graph.lhs
index 5628ec3..b959d59 100644
--- a/src/lib/Codec/Pesto/Graph.lhs
+++ b/src/lib/Codec/Pesto/Graph.lhs
@@ -28,6 +28,7 @@ Language semantics
 > import Data.List (sort, nub, sortOn)
 > import Test.HUnit hiding (test, Node)
 > import Data.Ratio ((%), Ratio)
+> import Data.Either (fromRight)
 >
 > import Codec.Pesto.Parse hiding (test)
 
@@ -158,7 +159,9 @@ These are helper functions:
 > 		consumeStack (_, s, edges) i =
 > 			let
 > 				stack = dropWhile null s
-> 				(top:sx) = if null stack then [[]] else stack
+> 				alwaysStack = if null stack then [[]] else stack
+> 				top = head alwaysStack
+> 				sx = tail alwaysStack
 > 			in (Just i, []:top:sx, edgesTo i top ++ edges)
 > 		edgesTo i = map (\x -> (x, i))
 
@@ -342,8 +345,8 @@ Appendix
 
 > runGraphWith f doc expect = sort edges ~?= sort expect
 > 	where
-> 		(Right op) = (head . extract . snd . unzip) <$> parse ("%pesto " ++ doc)
-> 		nodes = zip [firstNodeId..] op
+> 		op = (head . extract . snd . unzip) <$> parse ("%pesto " ++ doc)
+> 		nodes = zip [firstNodeId..] (fromRight (error "unreachable") op)
 > 		edges = f nodes
 > cmpGraph = runGraphWith toGraph
 > cmpGraphRef = runGraphWith resolveReferences
@@ -363,6 +366,8 @@ Find graph’s root node(s), that is a node without outgoing edges:
 Get all nodes with edges pointing towards nodeid
 
 > incomingEdges edges nodeid = filter ((==) nodeid . snd) edges
+
+> incomingNodes :: Nodes a -> Edges -> NodeId -> Nodes a
 > incomingNodes nodes edges nodeid = map ((!!) nodes . fst) $ incomingEdges edges nodeid
 
 > outgoingEdges edges nodeid = filter ((==) nodeid . fst) edges