From 8fa2f86b7e9994f31ef5214ab5254135826b45cd Mon Sep 17 00:00:00 2001
From: Josh Berdine <jjb@fb.com>
Date: Thu, 28 Feb 2019 06:45:34 -0800
Subject: [PATCH] [sledge] Fix order of Exp.fold args

Reviewed By: ngorogiannis

Differential Revision: D14251654

fbshipit-source-id: 8d1e22da7
---
 sledge/src/llair/exp.ml           | 12 ++++--------
 sledge/src/llair/exp.mli          |  2 +-
 sledge/src/symbheap/congruence.ml |  2 +-
 3 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/sledge/src/llair/exp.ml b/sledge/src/llair/exp.ml
index 83ec1cf4e..f13d518e7 100644
--- a/sledge/src/llair/exp.ml
+++ b/sledge/src/llair/exp.ml
@@ -1039,17 +1039,13 @@ let iter e ~f =
 
 let fold e ~init:s ~f =
   match e with
-  | App {op; arg} ->
-      let s = f s op in
-      let s = f s arg in
-      s
+  | App {op; arg} -> f op (f arg s)
   | Add {args} | Mul {args} ->
-      let s = Qset.fold ~f:(fun e _ s -> f s e) args ~init:s in
-      s
+      Qset.fold ~f:(fun e _ s -> f e s) args ~init:s
   | _ -> s
 
-let for_all e ~f = fold ~f:(fun so_far a -> so_far && f a) ~init:true e
-let exists e ~f = fold ~f:(fun found a -> found || f a) ~init:false e
+let for_all e ~f = fold ~f:(fun a so_far -> so_far && f a) ~init:true e
+let exists e ~f = fold ~f:(fun a found -> found || f a) ~init:false e
 
 let app1 ?(partial = false) op arg =
   ( match (op, arg) with
diff --git a/sledge/src/llair/exp.mli b/sledge/src/llair/exp.mli
index 216b5274a..d55e8fee4 100644
--- a/sledge/src/llair/exp.mli
+++ b/sledge/src/llair/exp.mli
@@ -204,7 +204,7 @@ val offset : t -> (Q.t * Typ.t) option
 val iter : t -> f:(t -> unit) -> unit
 val fold_vars : t -> init:'a -> f:('a -> Var.t -> 'a) -> 'a
 val fold_exps : t -> init:'a -> f:('a -> t -> 'a) -> 'a
-val fold : t -> init:'a -> f:('a -> t -> 'a) -> 'a
+val fold : t -> init:'a -> f:(t -> 'a -> 'a) -> 'a
 val for_all : t -> f:(t -> bool) -> bool
 val exists : t -> f:(t -> bool) -> bool
 
diff --git a/sledge/src/symbheap/congruence.ml b/sledge/src/symbheap/congruence.ml
index 6095740e4..7292d463b 100644
--- a/sledge/src/symbheap/congruence.ml
+++ b/sledge/src/symbheap/congruence.ml
@@ -551,7 +551,7 @@ let rec norm_extend r ek =
           ~default:e
           ~if_added:(fun lkp ->
             let use =
-              Exp.fold e_' ~init:r.use ~f:(fun use b'j ->
+              Exp.fold e_' ~init:r.use ~f:(fun b'j use ->
                   let b' = Exp.base b'j in
                   Map.update use b' ~f:(function
                     | Some b_use -> Use.add b_use e