Cope with extraneous whitespace in sexp reader

java/hop/SexpReader.java

@@ -81,6 +81,7 @@ public class SexpReader {
     }
 
     public Object _read(int c) throws IOException {
+        while (true) {
             switch (c) {
                 case -1:
                     return null;
@@ -103,8 +104,13 @@ public class SexpReader {
                 default:
                     if (Character.isDigit(c)) {
                         return new SexpBytes(_readSimpleString(c - '0'));
+                    } else if (Character.isWhitespace(c)) {
+                        // Skip harmless (?) whitespace
+                        c = _input.read();
+                        continue;
                     } else {
-                    throw new SexpSyntaxError("Unexpected character");
+                        throw new SexpSyntaxError("Unexpected character: " + c);
+                    }
             }
         }
     }