[Ur] using mapR

[Gergely Buday]

Hi,

I would like to fix type constraints for using Monad.mapR so that I
need not pass them when using for creating sources of values. I do not
understand what this error message say, let alone fix the bug. How
should I fix my code?

- Gergely

$ urweb mapr
/home/gergoe/local/sandbox/sandbox/mapr.ur:2:5-2:16: Expression is not
a constructor function
Expression:  Monad.mapR[[<UNIF:R>]] [<UNIF:A::Type -> Type>]
      Type:
((Basis.monad <UNIF:A::Type -> Type>) ->
  tf :: <UNIF:R> -> Type ->
   tr :: <UNIF:R> -> Type ->
    ((nm :: Name ->
       t :: <UNIF:R> -> ((tf t) -> <UNIF:A::Type -> Type+4> (tr t)))
      ->
      r ::: {<UNIF:R>} ->
       ((Top.folder[[<UNIF:R>]] r) ->
         ($(map tf r) -> <UNIF:A::Type -> Type+3> $(map tr r)))))
$ head -3 mapr.ur

fun sourceRecord [ r ::: {Type} ] (fl : folder r) (record : $r) :
(transaction $(map source r)) =
	    @Monad.mapR  [id] [source] fl  (fn [nm :: Name] [t :: Type]  =>
source  ) fl record