first fix

Author: Maksym Shamrai

src/CFG2TM.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE TupleSections #-}
+{-# OPTIONS_GHC -Wno-incomplete-patterns #-}
 
 module CFG2TM where
 
@@ -24,7 +25,7 @@ iSST = State "q_{1}^{2}"
 first :: [Relation] -> Symbol -> [String]
 first _ (T (Terminal t)) = [t]
 first rels Eps = concatMap (\(Relation (n, _)) -> follow rels (N n)) . filter (\(Relation (_, e : _)) -> e == Eps) $ rels
-first rels (N n) = concatMap (\(Relation (_, h : _)) -> first rels h) . filter (\(Relation (x, _)) -> x == n) $ rels
+first rels s@(N n) = concatMap (\(Relation (_, h : _)) -> first rels h) . filter (\(Relation (x, h : _)) -> x == n && h /= s) $ rels
 
 follow :: [Relation] -> Symbol -> [String]
 follow rels n = concatMap (first rels)

stack.yaml

@@ -19,7 +19,7 @@
 # resolver: ./custom-snapshot.yaml
 # resolver: https://example.com/snapshots/2018-01-01.yaml
 
-resolver: lts-18.9
+resolver: lts-18.5
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.