about summary refs log tree commit diff
path: root/users/Profpatsch/my-prelude/src/ValidationParseT.hs
diff options
context:
space:
mode:
Diffstat (limited to 'users/Profpatsch/my-prelude/src/ValidationParseT.hs')
-rw-r--r--users/Profpatsch/my-prelude/src/ValidationParseT.hs16
1 files changed, 16 insertions, 0 deletions
diff --git a/users/Profpatsch/my-prelude/src/ValidationParseT.hs b/users/Profpatsch/my-prelude/src/ValidationParseT.hs
new file mode 100644
index 0000000000..593b7ebf39
--- /dev/null
+++ b/users/Profpatsch/my-prelude/src/ValidationParseT.hs
@@ -0,0 +1,16 @@
+module ValidationParseT where
+
+import Control.Selective (Selective)
+import Data.Functor.Compose (Compose (..))
+import PossehlAnalyticsPrelude
+
+-- | A simple way to create an Applicative parser that parses from some environment.
+--
+-- Use with DerivingVia. Grep codebase for examples.
+newtype ValidationParseT env m a = ValidationParseT {unValidationParseT :: env -> m (Validation (NonEmpty Error) a)}
+  deriving
+    (Functor, Applicative, Selective)
+    via ( Compose
+            ((->) env)
+            (Compose m (Validation (NonEmpty Error)))
+        )