[Haskelldb-users] Writing signatures for record-manipulating functions

[Colin P. A. <co...@co...>]

I have the following code:

      
-- | Get list of all top-level galleries from database
topLevelGalleries :: DB.Database -> IO [Gallery]
topLevelGalleries db = do
  let q = do
        t <- DB.table galleryTable
        DB.restrict (DB.isNull $ t DB.! parentGalleryName)
        return t
  rs <- DB.query db q
  return $ map newGallery rs

--newGallery :: DB.Record vr -> Gallery
newGallery rec = Gallery (rec DB.! galleryName) (rec DB.! parentGalleryName) (rec DB.! readImageCapabilityName)  (rec DB.! uploadImageCapabilityName)  (rec DB.! administerGalleryCapabilityName) 


The reason the signature for newGallery is commented out is that it is
very hard to write. I fired up ghci and did a :t newGallery. I got:

newGallery
  :: (Database.HaskellDB.HDBRec.Select
        (Database.HaskellDB.Query.Attr
           Database.GalleryTable.GalleryName String)
        r
        String,
      Database.HaskellDB.HDBRec.Select
        (Database.HaskellDB.Query.Attr
           Database.GalleryTable.ParentGalleryName (Maybe String))
        r
        (Maybe String),
      Database.HaskellDB.HDBRec.Select
        (Database.HaskellDB.Query.Attr
           Database.GalleryTable.ReadImageCapabilityName String)
        r
        String,
      Database.HaskellDB.HDBRec.Select
        (Database.HaskellDB.Query.Attr
           Database.GalleryTable.UploadImageCapabilityName String)
        r
        String,
      Database.HaskellDB.HDBRec.Select
        (Database.HaskellDB.Query.Attr
           Database.GalleryTable.AdministerGalleryCapabilityName String)
        r
        String) =>
     r -> Dragonfly.ImageGallery.ImageGallery.Gallery

Well, that's a bit of a mouthful. I don't really want to type that in.

I would have hoped that somwhere there was a type definition generated
from this from the DBInfo, but I can't find it. Any suggestions as to
where to look?
-- 
Colin Adams
Preston Lancashire