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(*
* Vericert: Verified high-level synthesis.
* Copyright (C) 2020 Yann Herklotz <yann@yannherklotz.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*)
From Coq Require Import Lists.List.
Declare Scope monad_scope.
Module Type Monad.
Parameter mon : Type -> Type.
Parameter ret : forall (A : Type) (x : A), mon A.
Arguments ret [A].
Parameter bind : forall (A B : Type) (f : mon A) (g : A -> mon B), mon B.
Arguments bind [A B].
Parameter bind2 : forall (A B C: Type) (f: mon (A * B)) (g: A -> B -> mon C), mon C.
Arguments bind2 [A B C].
End Monad.
Module MonadExtra(M : Monad).
Import M.
Module Import MonadNotation.
Notation "'do' X <- A ; B" :=
(bind A (fun X => B))
(at level 200, X name, A at level 100, B at level 200) : monad_scope.
Notation "'do' ( X , Y ) <- A ; B" :=
(bind2 A (fun X Y => B))
(at level 200, X name, Y name, A at level 100, B at level 200) : monad_scope.
End MonadNotation.
#[local] Open Scope monad_scope.
Fixpoint traverselist {A B: Type} (f: A -> mon B) (l: list A) {struct l}: mon (list B) :=
match l with
| nil => ret nil
| x::xs =>
do r <- f x;
do rs <- traverselist f xs;
ret (r::rs)
end.
Fixpoint collectlist {A : Type} (f : A -> mon unit) (l : list A) {struct l} : mon unit :=
match l with
| nil => ret tt
| x::xs => do _ <- f x; collectlist f xs
end.
End MonadExtra.
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