Commit 649f7c76 authored by Robbert Krebbers's avatar Robbert Krebbers

Document list_remove and list_remove_list.

parent 4fd8d550
...@@ -285,18 +285,20 @@ Inductive contains {A} : relation (list A) := ...@@ -285,18 +285,20 @@ Inductive contains {A} : relation (list A) :=
Infix "`contains`" := contains (at level 70) : C_scope. Infix "`contains`" := contains (at level 70) : C_scope.
Hint Extern 0 (_ `contains` _) => reflexivity. Hint Extern 0 (_ `contains` _) => reflexivity.
Section contains_dec_help. (** Removes [x] from the list [l]. The function returns a [Some] when the
Context `{EqDecision A}. +removal succeeds and [None] when [x] is not in [l]. *)
Fixpoint list_remove (x : A) (l : list A) : option (list A) := Fixpoint list_remove `{EqDecision A} (x : A) (l : list A) : option (list A) :=
match l with match l with
| [] => None | [] => None
| y :: l => if decide (x = y) then Some l else (y ::) <$> list_remove x l | y :: l => if decide (x = y) then Some l else (y ::) <$> list_remove x l
end. end.
Fixpoint list_remove_list (k : list A) (l : list A) : option (list A) :=
match k with (** Removes all elements in the list [k] from the list [l]. The function returns
| [] => Some l | x :: k => list_remove x l = list_remove_list k a [Some] when the removal succeeds and [None] some element of [k] is not in [l]. *)
end. Fixpoint list_remove_list `{EqDecision A} (k : list A) (l : list A) : option (list A) :=
End contains_dec_help. match k with
| [] => Some l | x :: k => list_remove x l = list_remove_list k
end.
Inductive Forall3 {A B C} (P : A B C Prop) : Inductive Forall3 {A B C} (P : A B C Prop) :
list A list B list C Prop := list A list B list C Prop :=
......
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