[Ur] row.T

[Adam Chlipala]

Gergely Buday wrote:
> val queryX : tables ::: {{Type}} ->  exps ::: {Type} ->  ctx ::: {Unit}
> ->  inp ::: {Type}
>     192              ->  [tables ~ exps] =>
>     193              sql_query [] [] tables exps
>     194              ->  ($(exps ++ map (fn fields :: {Type} =>  $fields) tables)
>     195                  ->  xml ctx inp [])
>     196              ->  transaction (xml ctx inp [])
>
> Do I understand correctly that the compiler extracts tables, exps, ctx
> and inp from the sql query?
>    

The answer is probably "yes," though I'm not 100% sure I know what 
you're asking.  Just like with parametric polymorphism in ML or Haskell, 
the constructor parameters are inferred from the types of the value 
parameters.