From e7e2038d4de425817f3730770c50f05aa09dedf4 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Fri, 14 Dec 2018 16:37:35 -0800
Subject: [PATCH] nits

---
 xenomorph/xenomorph/helper.rkt            |  5 +++++
 xenomorph/xenomorph/test/pointer-test.rkt | 18 ++++++++----------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/xenomorph/xenomorph/helper.rkt b/xenomorph/xenomorph/helper.rkt
index 98d3ffbf..50484423 100644
--- a/xenomorph/xenomorph/helper.rkt
+++ b/xenomorph/xenomorph/helper.rkt
@@ -10,6 +10,11 @@
     [(input-port? arg) arg]
     [else (raise-argument-error '->input-port "byte string or input port" arg)]))
 
+(define (dict-ref* d . keys)
+  (for/fold ([d d])
+            ([k (in-list keys)])
+    (dict-ref d k)))
+
 (define private-keys '(parent _startOffset _currentOffset _length))
 (define (dict->mutable-hash x)
   (define h (make-hasheq))
diff --git a/xenomorph/xenomorph/test/pointer-test.rkt b/xenomorph/xenomorph/test/pointer-test.rkt
index 5f7fe1f8..3e1d319f 100644
--- a/xenomorph/xenomorph/test/pointer-test.rkt
+++ b/xenomorph/xenomorph/test/pointer-test.rkt
@@ -72,13 +72,13 @@ https://github.com/mbutterick/restructure/blob/master/test/Pointer.coffee
  "size should add to parent pointerSize"
  (let ([parent (mhash 'parent (mhash 'pointerSize 0))])
    (check-equal? (size (+xpointer #:relative-to 'parent) 10 #:parent parent) 1)
-   (check-equal? (dict-ref (dict-ref parent 'parent) 'pointerSize) 1)))
+   (check-equal? (dict-ref* parent 'parent 'pointerSize) 1)))
 
 (test-case
  "size should add to global pointerSize"
  (let ([parent (mhash 'parent (mhash 'parent (mhash 'parent (mhash 'pointerSize 0))))])
    (check-equal? (size (+xpointer #:relative-to 'global) 10 #:parent parent) 1)
-   (check-equal? (dict-ref (dict-ref (dict-ref (dict-ref parent 'parent) 'parent) 'parent) 'pointerSize) 1)))
+   (check-equal? (dict-ref* parent 'parent 'parent 'parent 'pointerSize) 1)))
 
 (test-case
  "size should handle void pointers"
@@ -142,8 +142,8 @@ https://github.com/mbutterick/restructure/blob/master/test/Pointer.coffee
                                      'pointerOffset 5
                                      'pointers null)))
    (encode (+xpointer #:relative-to 'parent) 10 #:parent parent)
-   (check-equal? (dict-ref (dict-ref parent 'parent) 'pointerOffset) 6)
-   (check-equal? (dict-ref (dict-ref parent 'parent) 'pointers) (list (mhasheq 'type uint8
+   (check-equal? (dict-ref* parent 'parent 'pointerOffset) 6)
+   (check-equal? (dict-ref* parent 'parent 'pointers) (list (mhasheq 'type uint8
                                                                             'val 10
                                                                             'parent parent)))
    (check-equal? (get-output-bytes (current-output-port)) (bytes 2))))
@@ -158,8 +158,8 @@ https://github.com/mbutterick/restructure/blob/master/test/Pointer.coffee
                                                    'pointerOffset 5
                                                    'pointers null)))))
    (encode (+xpointer #:relative-to 'global) 10 #:parent parent)
-   (check-equal? (dict-ref (dict-ref (dict-ref (dict-ref parent 'parent) 'parent) 'parent) 'pointerOffset) 6)
-   (check-equal? (dict-ref (dict-ref (dict-ref (dict-ref parent 'parent) 'parent) 'parent) 'pointers)
+   (check-equal? (dict-ref* parent 'parent 'parent 'parent 'pointerOffset) 6)
+   (check-equal? (dict-ref* parent 'parent 'parent 'parent 'pointers)
                  (list (mhasheq 'type uint8
                                 'val 10
                                 'parent parent)))
@@ -172,11 +172,9 @@ https://github.com/mbutterick/restructure/blob/master/test/Pointer.coffee
                       'startOffset 0
                       'pointerOffset 1
                       'pointers null))
-   (encode (+xpointer uint8 'void) (+xvoid-pointer uint8 55) #:parent  parent)
+   (encode (+xpointer uint8 'void) (+xvoid-pointer uint8 55) #:parent parent)
    (check-equal? (dict-ref parent 'pointerOffset) 2)
-   (check-equal? (dict-ref parent 'pointers) (list (mhasheq 'type uint8
-                                                         'val 55
-                                                         'parent parent)))
+   (check-equal? (dict-ref parent 'pointers) (list (mhasheq 'type uint8 'val 55 'parent parent)))
    (check-equal? (get-output-bytes (current-output-port)) (bytes 1))))
 
 (test-case