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

purescript-contrib · Jun 11, 2017 · b89442b · b89442b
1 parent ad4a76c
commit b89442b
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/Text/Parsing/Parser/String.purs b/src/Text/Parsing/Parser/String.purs
@@ -40,7 +40,7 @@ instance charHasUpdatePosition :: HasUpdatePosition Char where
 -- | 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 }