add publication date (only year)

src/ISTEX.hs

@@ -16,4 +16,8 @@ runIstexAPIClient cmd = do
 
 basicSearch :: Maybe T.Text -> IO (Either ClientError Documents)
 basicSearch rq = do
-  runIstexAPIClient $ search (Just "author,title,abstract") (Just 5000) rq
+  runIstexAPIClient $
+    search
+    (Just "author,title,abstract,publicationDate")
+    (Just 5)
+    rq

src/ISTEX/Client.hs

@@ -32,7 +32,8 @@ data Document = Document
     _id :: T.Text,
     _title :: Maybe T.Text,
     _authors :: [Author],
-    _abstract :: Maybe T.Text
+    _abstract :: Maybe T.Text,
+    _publicationDate :: Maybe Int
   } deriving (Show, Generic)
 L.makeLenses ''Document
 
@@ -43,6 +44,8 @@ instance FromJSON Document where
     <*> (o .:? "title")
     <*> (o .: "author" <|> pure [])
     <*> (o .:? "abstract")
+    <*> do pPubDate <- (o .:? "publicationDate")
+           return $ (read . T.unpack) <$> pPubDate
 
 data Documents = Documents
   {