mapAndUnzip, mapAndUnzip3,
nOfThem, filterOut,
lengthExceeds, lengthIs, lengthAtLeast, listLengthCmp, atLength,
- isSingleton, only,
+ isSingleton, only, singleton,
notNull, snocView,
isIn, isn'tIn,
atLen [] = EQ
atLen _ = GT
+singleton :: a -> [a]
+singleton x = [x]
+
isSingleton :: [a] -> Bool
isSingleton [x] = True
isSingleton _ = False