Example.v

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(* This Coq module uses the monad defined in the Monad module to
   describe sequential computations. *)

Require Import Monad Internals.
Open Scope monad_scope.

Definition id (b : bool) : M bool := returnM b.

Definition neg (b : bool) : M bool := if b then returnM false else returnM true.

Fixpoint prepare recBound : M unit :=
  match recBound with
  | O   => emptyM
  | S b => do r <- ready ;
              if r
              then returnM tt
              else do _ <- getReady ;
                      prepare b
  end.

Eval compute in runM (id true) 12.
Eval compute in runM (neg true) 12.
Eval compute in runM (prepare 1) 1.
Eval compute in runM (prepare 2) 1.