From 26a83b4b8e4c367b8c4e0c383de7ed892b39ddd4 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Wed, 25 Mar 2020 09:39:33 -0600
Subject: [PATCH] avoid fold-left on records in compute-size-increments

original commit: 76713b4a708efbe1b3698d9febc9d28225f383c5
---
 s/inspect.ss | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/s/inspect.ss b/s/inspect.ss
index 687fa7d64d..a8c5281390 100644
--- a/s/inspect.ss
+++ b/s/inspect.ss
@@ -2655,12 +2655,15 @@
                          [else (loop (fx+ i 1)
                                      (fx+ size (compute-size ($record-ref x i))))]))]
                      [else
-                      (fold-left (lambda (size fld)
-                                   (if (eq? (fld-type fld) 'scheme-object)
+                      (let loop ([size (fx+ (align (rtd-size rtd)) (compute-size rtd))] [flds flds])
+                        (cond
+                          [(null? flds) size]
+                          [else
+                           (let ([fld (car flds)])
+                             (loop (if (eq? (fld-type fld) 'scheme-object)
                                        (fx+ size (compute-size ($object-ref 'scheme-object x (fld-byte fld))))
-                                       size))
-                        (fx+ (align (rtd-size rtd)) (compute-size rtd))
-                        flds)])))]
+                                       size)
+                                   (cdr flds)))]))])))]
                [(string? x) (align (fx+ (constant header-size-string) (fx* (string-length x) (constant string-char-bytes))))]
                [(box? x) (fx+ (constant size-box) (compute-size (unbox x)))]
                [(flonum? x) (constant size-flonum)]