Add regex to the query language

src/Data/Query.hs

@@ -21,6 +21,9 @@ import Data.Buuka
 import Data.List
        (isPrefixOf, isSuffixOf)
 
+import Text.Regex.TDFA
+       ((=~))
+
 import Data.Functor.Foldable
        (Fix(..))
 
@@ -31,6 +34,7 @@ data Field a where
 data QueryF f where
   StartsWith :: Field String -> String -> QueryF f
   EndsWith :: Field String -> String -> QueryF f
+  Regex :: Field String -> String -> QueryF f
   And :: f -> f -> QueryF f
 
 deriving instance Functor QueryF
@@ -52,4 +56,6 @@ evaluate = \case
   EndsWith Url x -> \BuukaEntry{url=URL u} -> x `isSuffixOf` u
   StartsWith Title x -> \BuukaEntry{title=t} -> maybe False (x `isPrefixOf`) t
   EndsWith Title x -> \BuukaEntry{title=t} -> maybe False (x `isSuffixOf`) t
+  Regex Url x -> \BuukaEntry{url=URL u} -> u =~ x
+  Regex Title x -> \BuukaEntry{title=t} -> maybe False (=~ x) t
   And a b -> \e -> a e && b e