Move some JSON/AP codec utils to new Data.Aeson.Local module

src/Data/Aeson/Local.hs

@@ -0,0 +1,51 @@
+{- This file is part of Vervis.
+ -
+ - Written in 2019 by fr33domlover <fr33domlover@riseup.net>.
+ -
+ - ♡ Copying is an act of love. Please copy, reuse and share.
+ -
+ - The author(s) have dedicated all copyright and related and neighboring
+ - rights to this software to the public domain worldwide. This software is
+ - distributed without any warranty.
+ -
+ - You should have received a copy of the CC0 Public Domain Dedication along
+ - with this software. If not, see
+ - <http://creativecommons.org/publicdomain/zero/1.0/>.
+ -}
+
+module Data.Aeson.Local
+    ( frg
+    , parseHttpsURI
+    , renderURI
+    , (.=?)
+    )
+where
+
+import Prelude
+
+import Data.Aeson
+import Data.Aeson.Types (Parser)
+import Data.Text (Text)
+import Network.URI
+
+import qualified Data.Text as T (unpack)
+
+frg :: Text
+frg = "https://forgefed.angeley.es/ns#"
+
+parseHttpsURI :: Text -> Parser URI
+parseHttpsURI t =
+    case parseURI $ T.unpack t of
+        Nothing -> fail "Invalid absolute URI"
+        Just u ->
+            if uriScheme u == "https:"
+                then return u
+                else fail "URI scheme isn't https"
+
+renderURI :: URI -> String
+renderURI u = uriToString id u ""
+
+infixr 8 .=?
+(.=?) :: ToJSON v => Text -> Maybe v -> Series
+k .=? Nothing  = mempty
+k .=? (Just v) = k .= v