* Better dealing with errors in eval-string and read-from-string/-all

* Made them work with byte strings too
* Added tests to the above

svn: r5081

original commit: a772fa8c8407386a2279c4d6ea2d6294de7c83c0

collects/mrlib/cache-image-snip.ss

@@ -139,20 +139,18 @@
   ;;
   ;; snip-class
   ;;
-  
+
   (define cache-image-snip-class%
     (class snip-class%
       (define/override (read f)
-        (let ([data (read-from-string (bytes->string/utf-8 (send f get-bytes))
-                                      void
-                                      (lambda (x) #f))])
+        (let ([data (read-from-string (send f get-bytes) (lambda () #f))])
           (if data
-              (argb->cache-image-snip (make-argb (first data) (second data))
-                                      (third data)
-                                      (fourth data))
-              (make-null-cache-image-snip))))
+            (argb->cache-image-snip (make-argb (first data) (second data))
+                                    (third data)
+                                    (fourth data))
+            (make-null-cache-image-snip))))
       (super-new)))
-  
+
   (define snip-class (new cache-image-snip-class%))
   (send snip-class set-version 1)
   (send snip-class set-classname (format "~s" `(lib "cache-image-snip.ss" "mrlib")))
@@ -655,4 +653,4 @@ for b3, we have:
    [argb? (any/c . -> . boolean?)]
    [make-argb ((vectorof (integer-in 0 255)) integer? . -> . argb?)]
    [argb-vector (argb? . -> . (vectorof (integer-in 0 255)))]
-   [argb-width (argb? . -> . integer?)]))
+   [argb-width (argb? . -> . integer?)]))

collects/mrlib/syntax-browser.ss

@@ -36,8 +36,8 @@ needed to really make this work:
   (define syntax-snipclass%
     (class snip-class%
       (define/override (read stream)
-        (let ([str (send stream get-bytes)])
-          (make-object syntax-snip% (unmarshall-syntax (read-from-string (bytes->string/utf-8 str))))))
+        (make-object syntax-snip%
+          (unmarshall-syntax (read-from-string (send stream get-bytes)))))
       (super-instantiate ())))
   
   (define snip-class (make-object syntax-snipclass%))