adjust the syntax coloring so that number-snip% instances

are allowed to pass through the filter (as they are trusted code)

related to racket/racket#1507

gui-lib/framework/private/color.rkt

@@ -27,7 +27,8 @@ added get-regions
         [prefix mode: framework:mode^]
         [prefix text: framework:text^]
         [prefix color-prefs: framework:color-prefs^]
-        [prefix racket: framework:racket^])
+        [prefix racket: framework:racket^]
+        [prefix number-snip: framework:number-snip/int^])
 
 (export (rename framework:color^
                 (-text<%> text<%>)
@@ -337,7 +338,11 @@ added get-regions
            (open-input-text-editor this 
                                    (lexer-state-current-pos ls)
                                    (lexer-state-end-pos ls)
-                                   (λ (x) #f)))
+                                   (λ (x)
+                                     (cond
+                                       [(number-snip:is-number-snip? x)
+                                        x]
+                                       [else #f]))))
          (port-count-lines! in)
          (continue-re-tokenize start-time ok-to-stop? ls in
                                (lexer-state-current-pos ls)

gui-lib/framework/private/number-snip.rkt

@@ -8,7 +8,7 @@
            file/convertible)
   
   (import mred^)
-  (export (rename framework:number-snip^
+  (export (rename framework:number-snip/int^
                   [-snip-class% snip-class%]))
   (init-depend mred^)
   
@@ -91,7 +91,8 @@
                       [(text)
                        (send number-snip get-text 0 1)]
                       [else default]))])))
-  
+
+  (define (is-number-snip? x) (is-a? x number-snip%))
   (define number-snip%
     (class* snip% (readable-snip<%> number-snip-convertible<%>)
       ;; number : number

gui-lib/framework/private/sig.rkt

@@ -10,6 +10,8 @@
   (define-signature number-snip^ extends number-snip-class^
     (make-repeating-decimal-snip
      make-fraction-snip))
+  (define-signature number-snip/int^ extends number-snip^
+    (is-number-snip?))
   
   (define-signature comment-box-class^
     (snip%))