3 files changed, 38 insertions(+), 5 deletions(-)

M src/bare.lisp
M src/package.lisp
M tests/bare-tests.lisp

@@ 142,7 142,17 @@ Set this dynamically in the function calling the DATA defbinary.")
                       (unsigned-byte 8)
                       (*data-length*))))
 
-
 (defbinary void
     ()
     (value nil :type null))
+
+(defun read-optional-type (type stream)
+  (when (read-byte stream)
+    (read-binary type stream)))
+
+(defun write-optional-type (object stream)
+  (when (plusp (slot-value object 'value))
+    (write-byte 1 stream)
+    (write-binary object stream))
+  (when (zerop (slot-value object 'value))
+    (write-byte 0 stream)))

@@ 20,5 20,6 @@
    :data
    :data-fixed
    :void
-
+   :read-optional-type
+   :write-optional-type
    :value))

@@ 147,21 147,43 @@
     :result (ok (string= "こんにちは、世界！"))
     :bytes 28))
 
-(deftest read-data
+(deftest data-test
   (test-binary-type data
     :stream (buf #(#x03 #x13 #x37 #x42))
     :result (ok #(19 55 66))
     :bytes 4))
 
-(deftest read-data-fixed
+(deftest data-fixed-test
   (let ((*data-length* 3))
     (test-binary-type data-fixed
       :stream (buf #(#x13 #x37 #x42))
       :result (ok (equalp #(19 55 66)))
       :bytes 3)))
 
-(deftest read-void
+(deftest void-test
   (test-binary-type void
     :stream (buf #(#xff))
     :result (ok (null))
     :bytes 0))
+
+(deftest optional-type-test
+  (testing "reading and writing optional type when not set"
+    (with-input-from-sequence
+        (in
+         (with-output-to-sequence (out)
+           (write-optional-type
+            (read-binary 'u8 (buf #()))
+            out)))
+      (multiple-value-bind (object) (read-optional-type 'u8 in)
+        (with-slots (value) object
+          (ok (equalp value 0))))))
+  (testing "reading and writing optional type when set"
+    (with-input-from-sequence
+        (in
+         (with-output-to-sequence (out)
+           (write-optional-type
+            (read-binary 'u8 (buf #(#x70)))
+            out)))
+      (multiple-value-bind (object) (read-optional-type 'u8 in)
+        (with-slots (value) object
+          (ok (equalp value 112)))))))