add 'drop (Prefix a) a >>= uncons = Nothing' law

purescript-contrib · Jun 11, 2017 · 3a7d083 · 3a7d083
1 parent ad4a76c
commit 3a7d083
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/src/Text/Parsing/Parser/String.purs b/src/Text/Parsing/Parser/String.purs
@@ -38,9 +38,9 @@ instance charHasUpdatePosition :: HasUpdatePosition Char where
 
 -- | This class exists to abstract over streams which support the string-like
 -- | operations which this modules needs.
--- |
+-- | 
 -- | Instances must satisfy the following laws:
--- |
+-- | - `drop (Prefix a) a >>= uncons = Nothing`
 class StreamLike f c | f -> c where
   uncons :: f -> Maybe { head :: c, tail :: f, updatePos :: Position -> Position }
   drop :: Prefix f -> f -> Maybe {  rest :: f, updatePos :: Position -> Position }