From 8381e149a3883fff20dc965894b9702390af09e3 Mon Sep 17 00:00:00 2001
From: Josh Berdine <jjb@fb.com>
Date: Thu, 29 Oct 2020 13:27:20 -0700
Subject: [PATCH] [sledge] Add Trm.fv

Reviewed By: da319

Differential Revision: D24532353

fbshipit-source-id: 506105bd1
---
 sledge/src/trm.ml  | 4 ++++
 sledge/src/trm.mli | 1 +
 2 files changed, 5 insertions(+)

diff --git a/sledge/src/trm.ml b/sledge/src/trm.ml
index 381ccf61b..93ad112e4 100644
--- a/sledge/src/trm.ml
+++ b/sledge/src/trm.ml
@@ -492,3 +492,7 @@ let iter_subtrms e ~f =
   | Concat xs | Record xs | Apply (_, xs) -> Array.iter ~f xs
 
 let subtrms e = Iter.from_labelled_iter (iter_subtrms e)
+
+(** Query *)
+
+let fv e = Var.Set.of_iter (vars e)
diff --git a/sledge/src/trm.mli b/sledge/src/trm.mli
index f9b453b6b..67120bfe0 100644
--- a/sledge/src/trm.mli
+++ b/sledge/src/trm.mli
@@ -95,6 +95,7 @@ val map : t -> f:(t -> t) -> t
 
 val seq_size_exn : t -> t
 val seq_size : t -> t option
+val fv : t -> Var.Set.t
 
 (** Traverse *)