More full fledged version here: https://gist.github.com/evanrelf/d6f55a6db6230f4f30b157ad1fb1b61c

mvp-anon-records.hs

{-# LANGUAGE DataKinds #-}
{-# OPTIONS_GHC -Wall #-}

module X where

import Data.Kind (Type)
import GHC.TypeLits (KnownSymbol, Symbol)

type (:::) :: Symbol -> Type -> Type
data (:::) s a

data Record :: [Type] -> Type where
  RNil :: Record '[]
  RCons :: KnownSymbol s => a -> Record xs -> Record (s ::: a : xs)

example :: Record '["foo" ::: Float, "bar" ::: Bool]
example =
    RCons @"foo" 42.0
  $ RCons @"bar" True
  $ RNil