diff --git a/ditto-lucid.cabal b/ditto-lucid.cabal
--- a/ditto-lucid.cabal
+++ b/ditto-lucid.cabal
@@ -1,5 +1,5 @@
 Name:                ditto-lucid
-Version:             0.3.2
+Version:             0.4
 Synopsis:            Add support for using lucid with Ditto
 Description:         Ditto is a library for building and validating forms using applicative functors. This package add support for using ditto with lucid.
 License:             BSD3
@@ -25,7 +25,7 @@
   build-depends:
       base >4.5 && <5
     , lucid < 3.0.0
-    , ditto >= 0.3.1 && <= 0.4
+    , ditto >= 0.4 && <= 0.5
     , text >= 0.11 && < 1.3
     , path-pieces
   hs-source-dirs: src
diff --git a/src/Ditto/Lucid.hs b/src/Ditto/Lucid.hs
--- a/src/Ditto/Lucid.hs
+++ b/src/Ditto/Lucid.hs
@@ -8,14 +8,9 @@
 
 import Data.Foldable (traverse_)
 import Data.Text (Text)
-import Lucid
 import Ditto.Core
-import Ditto.Generalized as G
-import Ditto.Result (FormId)
-import qualified Data.Text as T
-
-encodeFormId :: FormId -> Text
-encodeFormId = T.pack . show
+import Ditto.Generalized.Unnamed as G
+import Lucid
 
 -- | create @\<form action=action method=\"GET\" enctype=\"application/xxx-form-urlencoded\"\>@
 formGenGET
@@ -47,7 +42,7 @@
 
 -- | add an attribute to the 'Html' for a form element.
 setAttr
-  :: (Monad m, Functor m, Applicative f)
+  :: (Environment m input, Functor m, Applicative f)
   => [Attribute]
   -> Form m input error (HtmlT f ()) a 
   -> Form m input error (HtmlT f ()) a
@@ -57,7 +52,7 @@
 --
 -- The @<\ul\>@ will have the attribute @class=\"ditto-error-list\"@.
 errorList
-  :: (Monad m, ToHtml error, Monad f)
+  :: (Environment m input, ToHtml error, Monad f)
   => Form m input error (HtmlT f ()) ()
 errorList = G.errors mkErrors
   where
@@ -73,7 +68,7 @@
 --
 -- The @<\ul\>@ will have the attribute @class=\"ditto-error-list\"@.
 childErrorList
-  :: (Monad m, ToHtml error, Monad f)
+  :: (Environment m input, ToHtml error, Monad f)
   => Form m input error (HtmlT f ()) ()
 childErrorList = G.childErrors mkErrors
   where
@@ -87,41 +82,51 @@
 --
 -- The @<\ul\>@ will have the attribute @class=\"ditto-error-list\"@.
 withErrors
-  :: (Monad m, ToHtml error, Monad f)
+  :: (Environment m input, ToHtml error, Monad f)
   => (HtmlT f () -> [error] -> HtmlT f ())
   -> Form m input error (HtmlT f ()) a
   -> Form m input error (HtmlT f ()) a
 withErrors renderError form = G.withErrors renderError form
 
+-- | create a sibling element to the formlet which includes it and it's childrens' error message
+--
+-- The @<\ul\>@ will have the attribute @class=\"ditto-error-list\"@.
+withChildErrors
+  :: (Environment m input, ToHtml error, Monad f)
+  => (HtmlT f () -> [error] -> HtmlT f ())
+  -> Form m input error (HtmlT f ()) a
+  -> Form m input error (HtmlT f ()) a
+withChildErrors renderError form = G.withChildErrors renderError form
+
 -- | create a @\<br\>@ tag.
-br :: (Monad m, Applicative f) => Form m input error (HtmlT f ()) ()
+br :: (Environment m input, Applicative f) => Form m input error (HtmlT f ()) ()
 br = view (br_ [])
 
 -- | wrap a @\<fieldset class=\"ditto\"\>@ around a 'Form'
 --
 fieldset
-  :: (Monad m, Functor m, Applicative f)
+  :: (Environment m input, Functor m, Applicative f)
   => Form m input error (HtmlT f ()) a
   -> Form m input error (HtmlT f ()) a
 fieldset frm = mapView (fieldset_ [class_ "ditto"]) frm
 
 -- | wrap an @\<ol class=\"ditto\"\>@ around a 'Form'
 ol
-  :: (Monad m, Functor m, Applicative f)
+  :: (Environment m input, Functor m, Applicative f)
   => Form m input error (HtmlT f ()) a
   -> Form m input error (HtmlT f ()) a
 ol frm = mapView (ol_ [class_ "ditto"]) frm
 
 -- | wrap a @\<ul class=\"ditto\"\>@ around a 'Form'
 ul
-  :: (Monad m, Functor m, Applicative f)
+  :: (Environment m input, Functor m, Applicative f)
   => Form m input error (HtmlT f ()) a
   -> Form m input error (HtmlT f ()) a
 ul frm = mapView (ul_ [class_ "ditto"]) frm
 
 -- | wrap a @\<li class=\"ditto\"\>@ around a 'Form'
 li
-  :: (Monad m, Functor m, Applicative f)
+  :: (Environment m input, Functor m, Applicative f)
   => Form m input error (HtmlT f ()) a
   -> Form m input error (HtmlT f ()) a
 li frm = mapView (li_ [class_ "ditto"]) frm
diff --git a/src/Ditto/Lucid/Named.hs b/src/Ditto/Lucid/Named.hs
--- a/src/Ditto/Lucid/Named.hs
+++ b/src/Ditto/Lucid/Named.hs
@@ -5,11 +5,12 @@
 module Ditto.Lucid.Named where
 
 import Data.Foldable (traverse_, fold)
+import Data.List.NonEmpty
+import Data.Text (Text)
 import Ditto.Backend
 import Ditto.Core
-import Ditto.Lucid (encodeFormId)
 import Ditto.Generalized.Named as G
-import Ditto.Result (FormId, Result (Ok), unitRange)
+import Ditto.Types
 import Lucid
 import Web.PathPieces
 import qualified Data.Text as T
@@ -18,30 +19,30 @@
 foldTraverse_ f = traverse_ (fold . f)
 
 inputText
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
-  -> String
+  -> Text
   -> text
   -> Form m input err (HtmlT f ()) text
 inputText getInput name initialValue = G.input name getInput inputField initialValue
   where
   inputField i a = input_ [type_ "text", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
-inputTextMReq
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+inputMaybeText
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
-  -> String
+  -> Text
   -> Maybe text
-  -> Form m input err (HtmlT f ()) text
-inputTextMReq getInput name initialValue = G.inputMaybeReq name getInput inputField initialValue
+  -> Form m input err (HtmlT f ()) (Maybe text)
+inputMaybeText getInput name initialValue = G.inputMaybe name getInput inputField initialValue
   where
-  inputField i Nothing = input_ [type_ "text", id_ (encodeFormId i), name_ (encodeFormId i), required_ "required"]
-  inputField i (Just a) = input_ [type_ "text", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a), required_ "required"]
+  inputField i a = let attrs = maybe [] (pure . value_ . toPathPiece) a in 
+    input_ $ type_ "text" : id_ (encodeFormId i) : name_ (encodeFormId i) : attrs
 
 inputPassword
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
-  -> String
+  -> Text
   -> text
   -> Form m input err (HtmlT f ()) text
 inputPassword getInput name initialValue = G.input name getInput inputField initialValue
@@ -49,9 +50,9 @@
   inputField i a = input_ [type_ "password", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
 inputSubmit
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
-  -> String
+  -> Text
   -> text
   -> Form m input err (HtmlT f ()) (Maybe text)
 inputSubmit getInput name initialValue = G.inputMaybe name getInput inputField (Just initialValue)
@@ -59,8 +60,8 @@
   inputField i a = input_ [type_ "submit", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
 inputReset
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
-  => String
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
+  => Text
   -> text
   -> Form m input err (HtmlT f ()) ()
 inputReset name lbl = G.inputNoData name inputField
@@ -68,9 +69,9 @@
   inputField i = input_ [type_ "submit", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece lbl)]
 
 inputHidden
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
-  -> String
+  -> Text
   -> text
   -> Form m input err (HtmlT f ()) text
 inputHidden getInput name initialValue = G.input name getInput inputField initialValue
@@ -78,8 +79,8 @@
   inputField i a = input_ [type_ "hidden", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
 inputButton
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
-  => String
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
+  => Text
   -> text
   -> Form m input err (HtmlT f ()) ()
 inputButton name lbl = G.inputNoData name inputField
@@ -87,11 +88,11 @@
   inputField i = input_ [type_ "button", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece lbl)]
 
 textarea
-  :: (Monad m, FormError input err, ToHtml text, Monad f)
+  :: (Environment m input, FormError input err, ToHtml text, Monad f)
   => (input -> Either err text)
   -> Int -- ^ cols
   -> Int -- ^ rows
-  -> String
+  -> Text
   -> text -- ^ initial text
   -> Form m input err (HtmlT f ()) text
 textarea getInput cols rows name initialValue = G.input name getInput textareaView initialValue
@@ -109,8 +110,8 @@
 --
 -- This control may succeed even if the user does not actually select a file to upload. In that case the uploaded name will likely be \"\" and the file contents will be empty as well.
 inputFile
-  :: (Monad m, FormError input err, FormInput input, Applicative f)
-  => String
+  :: (Environment m input, FormError input err, FormInput input, Applicative f, ft ~ FileType input, Monoid ft)
+  => Text
   -> Form m input err (HtmlT f ()) (FileType input)
 inputFile name = G.inputFile name fileView
   where
@@ -118,9 +119,9 @@
 
 -- | Create a @\<button type=\"submit\"\>@ element
 buttonSubmit
-  :: (Monad m, FormError input err, PathPiece text, ToHtml children, Monad f)
+  :: (Environment m input, FormError input err, PathPiece text, ToHtml children, Monad f)
   => (input -> Either err text)
-  -> String
+  -> Text
   -> text
   -> children
   -> Form m input err (HtmlT f ()) (Maybe text)
@@ -132,8 +133,8 @@
 --
 -- This element does not add any data to the form data set.
 buttonReset
-  :: (Monad m, FormError input err, Monad f)
-  => String
+  :: (Environment m input, FormError input err, Monad f)
+  => Text
   -> HtmlT f ()
   -> Form m input err (HtmlT f ()) ()
 buttonReset name c = G.inputNoData name inputField
@@ -144,8 +145,8 @@
 --
 -- This element does not add any data to the form data set.
 button
-  :: (Monad m, FormError input err, Monad f)
-  => String
+  :: (Environment m input, FormError input err, Monad f)
+  => Text
   -> HtmlT f ()
   -> Form m input err (HtmlT f ()) ()
 button name c = G.inputNoData name inputField
@@ -158,21 +159,21 @@
 --
 -- > label "some input field: " ++> inputText ""
 label
-  :: (Monad m, Monad f)
+  :: (Environment m input, Monad f)
   => HtmlT f ()
-  -> String
+  -> Text
   -> Form m input err (HtmlT f ()) ()
 label c name = G.label name mkLabel
   where
   mkLabel i = label_ [for_ (encodeFormId i)] c
 
-arbitraryHtml :: Monad m => view -> Form m input err view ()
+arbitraryHtml :: Environment m input => view -> Form m input err view ()
 arbitraryHtml = view
 
 inputInt
-  :: (Monad m, FormError input err, Applicative f)
+  :: (Environment m input, FormError input err, Applicative f)
   => (input -> Either err Int)
-  -> String
+  -> Text
   -> Int
   -> Form m input err (HtmlT f ()) Int
 inputInt getInput name initialValue = G.input name getInput inputField initialValue
@@ -186,9 +187,9 @@
       ]
 
 inputDouble
-  :: (Monad m, FormError input err, Applicative f)
+  :: (Environment m input, FormError input err, Applicative f)
   => (input -> Either err Double)
-  -> String
+  -> Text
   -> Double
   -> Form m input err (HtmlT f ()) Double
 inputDouble getInput name initialValue = G.input name getInput inputField initialValue
@@ -201,12 +202,12 @@
 --
 -- see also 'inputCheckboxes'
 inputCheckbox
-  :: forall err input m f. (Monad m, FormError input err, Applicative f)
+  :: forall err input m f. (Environment m input, FormError input err, Applicative f)
   => Bool -- ^ initially checked
-  -> String -- ^
+  -> Text -- ^
   -> Form m input err (HtmlT f ()) Bool
 inputCheckbox initiallyChecked name =
-  Form $ do
+  Form (successDecode True) (pure initiallyChecked) $ do
     i <- getNamedFormId name
     v <- getFormInput' i
     case v of
@@ -221,8 +222,7 @@
               [type_ "checkbox", id_ (encodeFormId i), name_ (encodeFormId i), value_ (encodeFormId i)]
      in pure
           ( View $ const $ checkbox
-          , pure $
-            Ok
+          , Ok
               ( Proved
                 { pos = unitRange i
                 , unProved = if checked then True else False
@@ -233,15 +233,16 @@
 -- | Create a group of @\<input type=\"checkbox\"\>@ elements
 --
 inputCheckboxes
-  :: (Functor m, Monad m, FormError input err, FormInput input, ToHtml lbl, Monad f)
-  => String
+  :: (Functor m, Environment m input, FormError input err, FormInput input, ToHtml lbl, Monad f, PathPiece a, Eq a)
+  => Text
   -> [(a, lbl)] -- ^ value, label, initially checked
+  -> (input -> Either err [a])
   -> (a -> Bool) -- ^ function which indicates if a value should be checked initially
   -> Form m input err (HtmlT f ()) [a]
-inputCheckboxes name choices isChecked = G.inputMulti name choices mkCheckboxes isChecked
+inputCheckboxes name choices fromInput isChecked = G.inputMulti name choices fromInput mkCheckboxes isChecked
   where
   mkCheckboxes nm choices' = foldTraverse_ (mkCheckbox nm) choices'
-  mkCheckbox nm (i, val, lbl, checked) =
+  mkCheckbox nm (Choice i lbl checked val) =
     [ input_ $
         ( (if checked then (checked_ :) else id)
           [type_ "checkbox", id_ (encodeFormId i), name_ (encodeFormId nm), value_ (toPathPiece val)]
@@ -251,16 +252,17 @@
 
 -- | Create a group of @\<input type=\"radio\"\>@ elements
 inputRadio
-  :: (Functor m, Monad m, FormError input err, FormInput input, Monad f)
-  => String
-  -> [(a, Html ())] -- ^ value, label, initially checked
+  :: (Functor m, Environment m input, FormError input err, FormInput input, Monad f, PathPiece a, Eq a)
+  => Text
+  -> NonEmpty (a, Html ()) -- ^ value, label, initially checked
+  -> (input -> Either err a)
   -> (a -> Bool) -- ^ isDefault
   -> Form m input err (HtmlT f ()) a
-inputRadio name choices isDefault =
-  G.inputChoice name isDefault choices mkRadios
+inputRadio name choices fromInput isDefault =
+  G.inputChoice name isDefault choices fromInput mkRadios
   where
   mkRadios nm choices' = foldTraverse_ (mkRadio nm) choices'
-  mkRadio nm (i, val, lbl, checked) =
+  mkRadio nm (Choice i lbl checked val) =
     [ input_ $
         (if checked then (checked_ :) else id)
           [type_ "radio", id_ (encodeFormId i), name_ (encodeFormId nm), value_ (toPathPiece val)]
@@ -272,19 +274,20 @@
 --
 -- see also: 'selectMultiple'
 select
-  :: (Functor m, Monad m, FormError input err, FormInput input, Monad f)
-  => String
-  -> [(a, Html ())] -- ^ value, label
+  :: (Functor m, Environment m input, FormError input err, FormInput input, Monad f, PathPiece a, Eq a)
+  => Text
+  -> NonEmpty (a, Html ()) -- ^ value, label
+  -> (input -> Either err a)
   -> (a -> Bool) -- ^ isDefault, must match *exactly one* element in the list of choices
   -> Form m input err (HtmlT f ()) a
-select name choices isDefault = G.inputChoice name isDefault choices mkSelect
+select name choices fromInput isDefault = G.inputChoice name isDefault choices fromInput mkSelect
   where
-  mkSelect :: (ToHtml lbl, Monad f) => FormId -> [(a, Int, lbl, Bool)] -> HtmlT f ()
+  mkSelect :: (ToHtml lbl, Monad f, PathPiece a) => FormId -> [Choice lbl a] -> HtmlT f ()
   mkSelect nm choices' =
     select_ [name_ (encodeFormId nm)] $
       traverse_ mkOption choices'
-  mkOption :: (ToHtml lbl, Monad f) => (a, Int, lbl, Bool) -> HtmlT f ()
-  mkOption (_, val, lbl, selected) =
+  mkOption :: (ToHtml lbl, Monad f, PathPiece a) => Choice lbl a -> HtmlT f ()
+  mkOption (Choice _ lbl selected val) =
     option_
       ( (if selected then ((:) (selected_ "selected")) else id)
         [value_ (toPathPiece val)]
@@ -295,19 +298,20 @@
 --
 -- This creates a @\<select\>@ element which allows more than one item to be selected.
 selectMultiple
-  :: (Functor m, Monad m, FormError input err, FormInput input, Monad f)
-  => String
+  :: (Functor m, Environment m input, FormError input err, FormInput input, Monad f, PathPiece a, Eq a)
+  => Text
   -> [(a, Html ())] -- ^ value, label, initially checked
+  -> (input -> Either err [a])
   -> (a -> Bool) -- ^ isSelected initially
   -> Form m input err (HtmlT f ()) [a]
-selectMultiple name choices isSelected = G.inputMulti name choices mkSelect isSelected
+selectMultiple name choices fromInput isSelected = G.inputMulti name choices fromInput mkSelect isSelected
   where
-  mkSelect :: (ToHtml lbl, Monad f) => FormId -> [(a, Int, lbl, Bool)] -> HtmlT f ()
+  mkSelect :: (ToHtml lbl, Monad f, PathPiece a) => FormId -> [Choice lbl a] -> HtmlT f ()
   mkSelect nm choices' =
     select_ [name_ (encodeFormId nm), multiple_ "multiple"] $
       traverse_ mkOption choices'
-  mkOption :: (ToHtml lbl, Monad f) => (a, Int, lbl, Bool) -> HtmlT f ()
-  mkOption (_, val, lbl, selected) =
+  mkOption :: (ToHtml lbl, Monad f, PathPiece a) => Choice lbl a -> HtmlT f ()
+  mkOption (Choice _ lbl selected val) =
     option_
       ( (if selected then ((:) (selected_ "selected")) else id)
         [value_ (toPathPiece val)]
diff --git a/src/Ditto/Lucid/Unnamed.hs b/src/Ditto/Lucid/Unnamed.hs
--- a/src/Ditto/Lucid/Unnamed.hs
+++ b/src/Ditto/Lucid/Unnamed.hs
@@ -7,18 +7,18 @@
 import Data.Foldable (traverse_, fold)
 import Ditto.Backend
 import Ditto.Core
-import Ditto.Generalized as G
-import Ditto.Lucid
-import Ditto.Result (FormId, Result (Ok), unitRange)
+import Ditto.Generalized.Unnamed as G
+import Ditto.Types
 import Lucid
 import Web.PathPieces
+import Data.List.NonEmpty
 import qualified Data.Text as T
 
 foldTraverse_ :: (Foldable t, Applicative f, Monoid (f b)) => (a -> t (f b)) -> t a -> f ()
 foldTraverse_ f = traverse_ (fold . f)
 
 inputText
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
   -> text
   -> Form m input err (HtmlT f ()) text
@@ -26,18 +26,18 @@
   where
   inputField i a = input_ [type_ "text", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
-inputTextMReq
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+inputMaybeText
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
   -> Maybe text
-  -> Form m input err (HtmlT f ()) text
-inputTextMReq getInput initialValue = G.inputMaybeReq getInput inputField initialValue
+  -> Form m input err (HtmlT f ()) (Maybe text)
+inputMaybeText getInput initialValue = G.inputMaybe getInput inputField initialValue
   where
-  inputField i Nothing = input_ [type_ "text", id_ (encodeFormId i), name_ (encodeFormId i), required_ "required"]
-  inputField i (Just a) = input_ [type_ "text", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a), required_ "required"]
+  inputField i a = let attrs = maybe [] (pure . value_ . toPathPiece) a in 
+    input_ $ type_ "text" : id_ (encodeFormId i) : name_ (encodeFormId i) : attrs
 
 inputPassword
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
   -> text
   -> Form m input err (HtmlT f ()) text
@@ -46,7 +46,7 @@
   inputField i a = input_ [type_ "password", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
 inputSubmit
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
   -> text
   -> Form m input err (HtmlT f ()) (Maybe text)
@@ -55,7 +55,7 @@
   inputField i a = input_ [type_ "submit", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
 inputReset
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => text
   -> Form m input err (HtmlT f ()) ()
 inputReset lbl = G.inputNoData inputField
@@ -63,7 +63,7 @@
   inputField i = input_ [type_ "submit", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece lbl)]
 
 inputHidden
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => (input -> Either err text)
   -> text
   -> Form m input err (HtmlT f ()) text
@@ -72,7 +72,7 @@
   inputField i a = input_ [type_ "hidden", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece a)]
 
 inputButton
-  :: (Monad m, FormError input err, PathPiece text, Applicative f)
+  :: (Environment m input, FormError input err, PathPiece text, Applicative f)
   => text
   -> Form m input err (HtmlT f ()) ()
 inputButton lbl = G.inputNoData inputField
@@ -80,7 +80,7 @@
   inputField i = input_ [type_ "button", id_ (encodeFormId i), name_ (encodeFormId i), value_ (toPathPiece lbl)]
 
 textarea
-  :: (Monad m, FormError input err, ToHtml text, Monad f)
+  :: (Environment m input, FormError input err, ToHtml text, Monad f)
   => (input -> Either err text)
   -> Int -- ^ cols
   -> Int -- ^ rows
@@ -101,7 +101,7 @@
 --
 -- This control may succeed even if the user does not actually select a file to upload. In that case the uploaded name will likely be \"\" and the file contents will be empty as well.
 inputFile
-  :: (Monad m, FormError input err, FormInput input, Applicative f)
+  :: (Environment m input, FormError input err, FormInput input, Applicative f, ft ~ FileType input, Monoid ft)
   => Form m input err (HtmlT f ()) (FileType input)
 inputFile = G.inputFile fileView
   where
@@ -109,7 +109,7 @@
 
 -- | Create a @\<button type=\"submit\"\>@ element
 buttonSubmit
-  :: (Monad m, FormError input err, PathPiece text, ToHtml children, Monad f)
+  :: (Environment m input, FormError input err, PathPiece text, ToHtml children, Monad f)
   => (input -> Either err text)
   -> text
   -> children
@@ -122,7 +122,7 @@
 --
 -- This element does not add any data to the form data set.
 buttonReset
-  :: (Monad m, FormError input err, ToHtml children, Monad f)
+  :: (Environment m input, FormError input err, ToHtml children, Monad f)
   => children
   -> Form m input err (HtmlT f ()) ()
 buttonReset c = G.inputNoData inputField 
@@ -133,7 +133,7 @@
 --
 -- This element does not add any data to the form data set.
 button
-  :: (Monad m, FormError input err, ToHtml children, Monad f)
+  :: (Environment m input, FormError input err, ToHtml children, Monad f)
   => children
   -> Form m input err (HtmlT f ()) ()
 button c = G.inputNoData inputField
@@ -146,21 +146,20 @@
 --
 -- > label "some input field: " ++> inputText ""
 label
-  :: (Monad m, Monad f)
+  :: (Environment m input, Monad f)
   => HtmlT f ()
   -> Form m input err (HtmlT f ()) ()
 label c = G.label mkLabel
   where
   mkLabel i = label_ [for_ (encodeFormId i)] c
 
-arbitraryHtml :: Monad m => view -> Form m input err view ()
+arbitraryHtml :: Environment m input => view -> Form m input err view ()
 arbitraryHtml wrap =
-  Form $ do
+  Form (successDecode ()) (pure ()) $ do
     id' <- getFormId
     pure
       ( View (const $ wrap)
-      , pure
-        ( Ok $ Proved
+      , ( Ok $ Proved
           { pos = unitRange id'
           , unProved = ()
           }
@@ -168,7 +167,7 @@
       )
 
 inputInt
-  :: (Monad m, FormError input err, Applicative f)
+  :: (Environment m input, FormError input err, Applicative f)
   => (input -> Either err Int)
   -> Int
   -> Form m input err (HtmlT f ()) Int
@@ -183,7 +182,7 @@
       ]
 
 inputDouble
-  :: (Monad m, FormError input err, Applicative f)
+  :: (Environment m input, FormError input err, Applicative f)
   => (input -> Either err Double)
   -> Double
   -> Form m input err (HtmlT f ()) Double
@@ -197,11 +196,11 @@
 --
 -- see also 'inputCheckboxes'
 inputCheckbox
-  :: forall err input m f. (Monad m, FormError input err, Applicative f)
+  :: forall err input m f. (Environment m input, FormError input err, Applicative f)
   => Bool -- ^ initially checked
   -> Form m input err (HtmlT f ()) Bool
 inputCheckbox initiallyChecked =
-  Form $ do
+  Form (successDecode True) (pure initiallyChecked) $ do
     i <- getFormId
     v <- getFormInput' i
     case v of
@@ -216,8 +215,7 @@
               [type_ "checkbox", id_ (encodeFormId i), name_ (encodeFormId i), value_ (encodeFormId i)]
      in pure
           ( View $ const $ checkbox
-          , pure $
-            Ok
+          , Ok
               ( Proved
                 { pos = unitRange i
                 , unProved = if checked then True else False
@@ -228,16 +226,16 @@
 -- | Create a group of @\<input type=\"checkbox\"\>@ elements
 --
 inputCheckboxes
-  :: (Functor m, Monad m, FormError input err, FormInput input, Monad f)
+  :: (Functor m, Environment m input, FormError input err, FormInput input, Monad f, PathPiece a, Eq a)
   => [(a, Html ())] -- ^ value, label, initially checked
+  -> (input -> Either err [a])
   -> (a -> Bool) -- ^ function which indicates if a value should be checked initially
   -> Form m input err (HtmlT f ()) [a]
-inputCheckboxes choices isChecked =
-  G.inputMulti choices mkCheckboxes isChecked
+inputCheckboxes choices fromInput isChecked =
+  G.inputMulti choices fromInput mkCheckboxes isChecked
   where
-  mkCheckboxes :: Monad f => FormId -> [(FormId, Int, Html (), Bool)] -> HtmlT f ()
   mkCheckboxes nm choices' = foldTraverse_ (mkCheckbox nm) choices'
-  mkCheckbox nm (i, val, lbl, checked) =
+  mkCheckbox nm (Choice i lbl checked val) =
     [ input_ $
         ( (if checked then (checked_ :) else id)
           [type_ "checkbox", id_ (encodeFormId i), name_ (encodeFormId nm), value_ (toPathPiece val)]
@@ -247,15 +245,16 @@
 
 -- | Create a group of @\<input type=\"radio\"\>@ elements
 inputRadio
-  :: (Functor m, Monad m, FormError input err, FormInput input, Monad f)
-  => [(a, Html ())] -- ^ value, label, initially checked
+  :: (Functor m, Environment m input, FormError input err, FormInput input, Monad f, PathPiece a, Eq a)
+  => NonEmpty (a, Html ()) -- ^ value, label, initially checked
+  -> (input -> Either err a)
   -> (a -> Bool) -- ^ isDefault
   -> Form m input err (HtmlT f ()) a
-inputRadio choices isDefault =
-  G.inputChoice isDefault choices mkRadios
+inputRadio choices fromInput isDefault =
+  G.inputChoice isDefault choices fromInput mkRadios
   where
   mkRadios nm choices' = foldTraverse_ (mkRadio nm) choices'
-  mkRadio nm (i, val, lbl, checked) =
+  mkRadio nm (Choice i lbl checked val) =
     [ input_ $
         (if checked then (checked_ :) else id)
           [type_ "radio", id_ (encodeFormId i), name_ (encodeFormId nm), value_ (toPathPiece val)]
@@ -267,19 +266,20 @@
 --
 -- see also: 'selectMultiple'
 select
-  :: (Functor m, Monad m, FormError input err, FormInput input, Monad f)
-  => [(a, Html ())] -- ^ value, label
+  :: (Functor m, Environment m input, FormError input err, FormInput input, Monad f, PathPiece a, Eq a)
+  => NonEmpty (a, Html ()) -- ^ value, label
+  -> (input -> Either err a)
   -> (a -> Bool) -- ^ isDefault, must match *exactly one* element in the list of choices
   -> Form m input err (HtmlT f ()) a
-select choices isDefault =
-  G.inputChoice isDefault choices mkSelect
+select choices fromInput isDefault =
+  G.inputChoice isDefault choices fromInput mkSelect
   where
-  mkSelect :: (ToHtml lbl, Monad f) => FormId -> [(a, Int, lbl, Bool)] -> HtmlT f ()
+  mkSelect :: (ToHtml lbl, Monad f, PathPiece a) => FormId -> [Choice lbl a] -> HtmlT f ()
   mkSelect nm choices' =
     select_ [name_ (encodeFormId nm)] $
       traverse_ mkOption choices'
-  mkOption :: (ToHtml lbl, Monad f) => (a, Int, lbl, Bool) -> HtmlT f ()
-  mkOption (_, val, lbl, selected) =
+  mkOption :: (ToHtml lbl, Monad f, PathPiece a) => Choice lbl a -> HtmlT f ()
+  mkOption (Choice _ lbl selected val) =
     option_
       ( (if selected then ((:) (selected_ "selected")) else id)
         [value_ (toPathPiece val)]
@@ -290,23 +290,23 @@
 --
 -- This creates a @\<select\>@ element which allows more than one item to be selected.
 selectMultiple
-  :: (Functor m, Monad m, FormError input err, FormInput input, Monad f)
+  :: (Functor m, Environment m input, FormError input err, FormInput input, Monad f, PathPiece a, Eq a)
   => [(a, Html ())] -- ^ value, label, initially checked
+  -> (input -> Either err [a])
   -> (a -> Bool) -- ^ isSelected initially
   -> Form m input err (HtmlT f ()) [a]
-selectMultiple choices isSelected =
-  G.inputMulti choices mkSelect isSelected
+selectMultiple choices fromInput isSelected =
+  G.inputMulti choices fromInput mkSelect isSelected
   where
-  mkSelect :: (ToHtml lbl, Monad f) => FormId -> [(a, Int, lbl, Bool)] -> HtmlT f ()
+  mkSelect :: (ToHtml lbl, Monad f, PathPiece a) => FormId -> [Choice lbl a] -> HtmlT f ()
   mkSelect nm choices' =
     select_ [name_ (encodeFormId nm), multiple_ "multiple"] $
       traverse_ mkOption choices'
-  mkOption :: (ToHtml lbl, Monad f) => (a, Int, lbl, Bool) -> HtmlT f ()
-  mkOption (_, val, lbl, selected) =
+  mkOption :: (ToHtml lbl, Monad f, PathPiece a) => Choice lbl a -> HtmlT f ()
+  mkOption (Choice _ lbl selected val) =
     option_
       ( (if selected then ((:) (selected_ "selected")) else id)
         [value_ (toPathPiece val)]
       )
       (toHtml lbl)
-