report errors betterly

pitfall/pitfall/check-pdf.rkt

@@ -128,7 +128,7 @@
                (cons idx (car (parse-pdf-bytes (peek-bytes (- end start) start))))))
    < #:key car))
 
-(define (dict-compare arg1 arg2)
+(define (dict-compare arg1 arg2 [obj-idx #f])
   (define d1 (if (dict? arg1) arg1 (pdf->dict arg1)))
   (define d2 (if (dict? arg2) arg2 (pdf->dict arg2)))
   (unless (dict? d1)
@@ -139,13 +139,14 @@
     (error (format "dict lengths different in d1 (~a) and d2 (~a)" (length d1) (length d2))))
   (for/and ([(k1 v1) (in-dict d1)]
             [(k2 v2) (in-dict d2)])
-    (unless (equal? k1 k2)
+           (define current-object-idx (or obj-idx k1))
-      (error (format "keys unequal in ~e and ~e: ~a ≠ ~a" arg1 arg2 k1 k2)))
+           (cond
-    (unless (equal? v1 v2)
+             [(dict? v1) (dict-compare v1 v2 current-object-idx)]
-      (error (format "values unequal in ~e and ~e: ~e ≠ ~e" arg1 arg2 v1 v2)))
+             [(not (equal? k1 k2))
-    (when (dict? v1)
+              (error (format "keys unequal in object ~a: ~a ≠ ~a" current-object-idx k1 k2))]
-      (dict-compare v1 v2))
+             [(not (equal? v1 v2))
-    #true))
+              (error (format "values unequal in object ~a for key ~e: ~e ≠ ~e" current-object-idx k1 v1 v2))]
+             [else #true])))
 
 (define-simple-check (check-headers-equal? ps1 ps2)
   (equal? (peek-bytes 14 0 (open-input-file ps1))