introduce prettyValidateFail, fixing issue NorfairKing#112

hapytex · Jun 3, 2023 · 9f805a9 · 9f805a9
1 parent 20ddbd6
commit 9f805a9
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/validity/src/Data/Validity.hs b/validity/src/Data/Validity.hs
@@ -85,6 +85,7 @@ module Data.Validity
     checkValidity,
     validationIsValid,
     prettyValidate,
+    prettyValidateFail,
     prettyValidation,
 
     -- * Re-exports
@@ -679,3 +680,10 @@ prettyValidation v =
           case i of
             0 -> segment
             _ -> replicate i ' ' ++ "\\ " ++ segment
+
+-- | Validate a given value and fail the monadic computation if so.
+
+-- This function will fail the moand with a nice error if the value is invalid.
+-- It will return the original value wrapped in the monadic context if it was valid.
+prettyValidateFail :: (Validity a, MonadFail m) => a -> m a
+prettyValidateFail = either fail pure . prettyValidate