$(lens 'foo) -- handy one-off lens maker for record fields

FieldTH.hs

{-# LANGUAGE TemplateHaskell #-}
-- | For when you have a record that doesn't have lenses derived for
-- it and you need a lens, just use @$(lens 'thefield)@ and away you go.
module Control.Lens.FieldTH where
import Language.Haskell.TH
lens :: Name -> Q Exp
lens name = do
  [|\f r ->
      fmap
        $(lamE
            [varP (mkName "a")]
            (recUpdE (varE (mkName "r")) [return (name, VarE (mkName "a"))]))
        (f ($(varE name) r))|]

REPL.hs

> data X = X { field1 :: Int} deriving Show
> import Control.Lens.Basic
> view $(lens 'field1) (X 123)
123
> over $(lens 'field1) (*2) (X 123)
X {field1 = 246}

> data Y a = Y { field2 :: a} deriving Show
> over $(lens 'field2) (*2) (Y 123)
Y {field2 = 246}
> over $(lens 'field2) show (Y 123)
Y {field2 = "123"}

This is awesome! Would you be able to make this available on hackage?