more tests

Author: themattchan

test/Test/Data/String.purs

@@ -212,4 +212,8 @@ testString = do
   assert $ slice 0 1   "purescript" == Just "p"
   assert $ slice 3 6   "purescript" == Just "esc"
   assert $ slice (-4) (-1) "purescript" == Just "rip"
-  assert $ slice (-4) 3  "purescript" == Nothing
+  assert $ slice (-4) 3  "purescript" == Nothing -- b' > e'
+  assert $ slice 1000 3  "purescript" == Nothing -- b' > e' (subsumes b > l)
+  assert $ slice 2 (-15) "purescript" == Nothing -- e' < 0
+  assert $ slice (-15) 9 "purescript" == Nothing -- b' < 0
+  assert $ slice 3 1000 "purescript"  == Nothing -- e > l