Handle strings and byte vectors in query values, and nothing else.

When encoding query values, don't try to convert a value to a string when we
don't know what else to do with it: handle strings and byte vectors, and error
out on anything else.

Fixes #30.

README.markdown

@@ -64,7 +64,7 @@ Create a `uri` object.
 ;=> #<QURI.URI.HTTP:URI-HTTP http://8arrow.org/>
 
 (make-uri :defaults "http://8arrow.org"
-          :query '(("guest" . 1)))
+          :query '(("guest" . "1")))
 ;=> #<QURI.URI.HTTP:URI-HTTP http://8arrow.org?guest=1>
 ```
 

src/encode.lisp

@@ -97,9 +97,10 @@
       (write-string (url-encode field :encoding encoding :space-to-plus space-to-plus) s)
       (when value
         (write-char #\= s)
-        (write-string (url-encode (if (stringp value)
-                                      value
-                                      (write-to-string value))
-                                  :encoding encoding :space-to-plus space-to-plus) s))
+        (check-type value (or string simple-byte-vector))
+        (write-string (url-encode value
+                                  :encoding encoding
+                                  :space-to-plus space-to-plus)
+                      s))
       (when rest
         (write-char #\& s)))))

t/encode.lisp

@@ -17,6 +17,10 @@
 
 (subtest "url-encode-params"
   (is (url-encode-params '(("a" . "b") ("c" . "d")))
-      "a=b&c=d"))
+      "a=b&c=d")
+  (is (url-encode-params
+       `(("a" . ,(make-array 1 :element-type '(unsigned-byte 8)
+                               :initial-contents (list (char-code #\b))))))
+      "a=b"))
 
 (finalize)