[parser] fix abstract/authors type (no Maybe for lists)

Also, use deepContent to get article title and abstracts' contents.

src/PUBMED/Parser.hs

@@ -20,6 +20,8 @@ contentWithChildren :: Prism' Node T.Text
 contentWithChildren = prism' NodeContent $ \case { NodeContent c -> Just c
                                                  ; NodeElement e -> Just $ e ^. TTL.children . traverse . contentWithChildren }
 
+deepContent = TTL.children . traverse . contentWithChildren
+
 parseDocIds :: TL.Text -> [Integer]
 parseDocIds txt = map (\s -> read (T.unpack s) :: Integer) parsed
   where
@@ -33,8 +35,8 @@ data PubMed =
 data PubMedArticle =
      PubMedArticle { pubmed_title   :: Maybe T.Text
                    , pubmed_journal :: Maybe T.Text
-                   , pubmed_abstract :: Maybe [T.Text]  -- TODO No Maybe?
-                   , pubmed_authors :: Maybe [Author]  -- TODO No Maybe?
+                   , pubmed_abstract :: [T.Text]
+                   , pubmed_authors :: [Author]
                    }
                    deriving (Show)
 
@@ -76,12 +78,14 @@ parsePubMed txt = catMaybes $ txt ^.. pubmedArticle . to pubMed
         d = read $ T.unpack $ el ^. namedEl "Day" . TTL.contents
     pubMedArticle el = PubMedArticle { pubmed_title = Just $ el ^. title
                                      , pubmed_journal = el ^? journalTitle
-                                     , pubmed_abstract = Just $ el ^.. abstract
-                                     , pubmed_authors = Just $ el ^.. authors . to author }
+                                     , pubmed_abstract = el ^.. abstract
+                                     , pubmed_authors = el ^.. authors . to author }
       where
         journalTitle = namedEl "Journal" . namedEl "Title" . TTL.contents
-        title = namedEl "ArticleTitle" . TTL.children . traverse . contentWithChildren
-        abstract = namedEl "Abstract" . namedEl "AbstractText" . TTL.contents
+        title = namedEl "ArticleTitle" . deepContent
+        abstract = namedEl "Abstract" . TTL.allNamed (only "AbstractText") . to abstractContent
+          where
+            abstractContent el = el ^. deepContent
         authors = namedEl "AuthorList" . TTL.allNamed (only "Author")
     author el = Author { lastName = el ^? lastName
                        , foreName = el ^? firstName