diff --git a/README.md b/README.md
index 20c9943..76c1a23 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,2 @@
 # purescript-yoga-variation
+
diff --git a/spago.dhall b/spago.dhall
index d3e577a..baf03b0 100644
--- a/spago.dhall
+++ b/spago.dhall
@@ -12,7 +12,15 @@ to generate this file without the comments in this block.
 -}
 { name = "my-project"
 , dependencies =
-  [ "arrays", "console", "effect", "prelude", "validation", "variant" ]
+  [ "arrays"
+  , "bifunctors"
+  , "console"
+  , "effect"
+  , "either"
+  , "prelude"
+  , "validation"
+  , "variant"
+  ]
 , packages = ./packages.dhall
 , sources = [ "src/**/*.purs", "test/**/*.purs" ]
 }
diff --git a/src/Yoga/Variation/Variation.purs b/src/Yoga/Variation/Variation.purs
index f16dc8b..c613f40 100644
--- a/src/Yoga/Variation/Variation.purs
+++ b/src/Yoga/Variation/Variation.purs
@@ -1,19 +1,28 @@
 module Yoga.Variation.Variation
   ( Validated
+  , fromEither
   , invalid
+  , invalidM
   , key
+  , mapErrors
+  , module Validation
+  , module Variant
   , valid
-  )
-  where
+  , validM
+  ) where
 
 import Prelude
 
 import Data.Array.NonEmpty (NonEmptyArray)
 import Data.Array.NonEmpty as NonEmpty
+import Data.Bifunctor (class Bifunctor, lmap)
+import Data.Either (Either, either)
 import Data.Symbol (class IsSymbol)
-import Data.Validation.Semigroup as Validation
-import Data.Variant as Variant
-import Prim.Row (class Cons)
+import Data.Validation.Semigroup as ValidationSG
+import Data.Validation.Semigroup hiding (invalid) as Validation
+import Data.Variant (class Contractable, class VariantBounded, class VariantBoundedEnums, class VariantEqs, class VariantMapCases, class VariantMatchCases, class VariantOrds, class VariantShows, class VariantTraverseCases, Unvariant(..), Unvariant', Variant, case_, contract, default, expand, inj, match, on, onMatch, over, overOne, overSome, prj, revariant, traverse, traverseOne, traverseSome, unvariant, variantBounded, variantBoundedEnums, variantEqs, variantOrds, variantShows) as Variant
+import Prim.Row (class Cons, class Union)
+import Prim.RowList (class RowToList)
 import Type.Proxy (Proxy(..))
 
 type Validated err result = Validation.V (NonEmptyArray (Variant.Variant err)) result
@@ -21,14 +30,46 @@ type Validated err result = Validation.V (NonEmptyArray (Variant.Variant err)) r
 valid :: forall err result. result -> Validated err result
 valid = pure
 
+validM :: forall m err result. Applicative m => result -> m (Validated err result)
+validM = valid >>> pure
+
 invalid
-  ∷ ∀ (t63 ∷ Type) (sym ∷ Symbol) (error ∷ Type) (others ∷ Row Type) (errors ∷ Row Type)
+  ∷ ∀ (result ∷ Type) (sym ∷ Symbol) (error ∷ Type) (others ∷ Row Type) (errors ∷ Row Type)
   . Cons sym error others errors
   ⇒ IsSymbol sym
   ⇒ Proxy sym
   → error
-  → Validation.V (NonEmptyArray (Variant.Variant errors)) t63
-invalid proxy value = Validation.invalid $ NonEmpty.singleton $ Variant.inj proxy value
+  → Validation.V (NonEmptyArray (Variant.Variant errors)) result
+invalid proxy value = ValidationSG.invalid $ NonEmpty.singleton $ Variant.inj proxy value
+
+invalidM
+  ∷ ∀ (result ∷ Type) (sym ∷ Symbol) (error ∷ Type) (others ∷ Row Type) (errors ∷ Row Type) m
+   . Applicative m
+  => Cons sym error others errors
+  ⇒ IsSymbol sym
+  ⇒ Proxy sym
+  → error
+  → m (Validation.V (NonEmptyArray (Variant.Variant errors)) result)
+invalidM proxy = invalid proxy >>> pure
+
+fromEither
+  :: ∀ (result ∷ Type) (sym ∷ Symbol) (error ∷ Type) (others ∷ Row Type) (errors ∷ Row Type)
+   . Cons sym error others errors
+  ⇒ IsSymbol sym
+  ⇒ Proxy sym
+  -> Either error result
+  -> Validated errors result
+fromEither proxy = either (invalid proxy) valid
 
 key ∷ ∀ (sym ∷ Symbol). Proxy sym
 key = Proxy
+
+mapErrors
+  :: forall result handlersRl handlers errorsRemaining errorsOut errorsIn
+   . RowToList handlers handlersRl
+  => Variant.VariantMatchCases handlersRl errorsRemaining (Variant.Variant errorsOut)
+  => Union errorsRemaining errorsOut errorsIn
+  => Record handlers
+  -> Validated errorsIn result
+  -> Validated errorsOut result
+mapErrors handlers = lmap (map $ Variant.onMatch handlers identity)