reserved done

xenomorph/xenomorph/redo/reserved.rkt

@@ -0,0 +1,30 @@
+#lang racket/base
+(require "helper.rkt" "util.rkt")
+(provide (all-defined-out))
+
+#|
+approximates
+https://github.com/mbutterick/restructure/blob/master/src/Reserved.coffee
+|#
+
+(define (xreserved-decode xo [port-arg (current-input-port)] #:parent [parent #f])
+  (define port (->input-port port-arg))
+  (pos port (+ (pos port) (size xo #f parent)))
+  (void))
+
+(define (xreserved-encode xo val [port-arg (current-output-port)] #:parent [parent #f])
+  (define port (if (output-port? port-arg) port-arg (open-output-bytes)))
+  (write-bytes (make-bytes (size xo val parent) 0))
+  (unless port-arg (get-output-bytes port)))
+
+(define (xreserved-size xo [val #f] [parent #f])
+  (* (size (xreserved-type xo)) (resolve-length (xreserved-count xo) #f parent)))
+
+(struct xreserved (type count) #:transparent
+  #:methods gen:xenomorphic
+  [(define decode xreserved-decode)
+   (define encode xreserved-encode)
+   (define size xreserved-size)])
+
+(define (+xreserved type [count 1])
+  (xreserved type count))

xenomorph/xenomorph/redo/test/main.rkt

@@ -6,9 +6,9 @@
          "enum-test.rkt"
          ;"lazy-array-test.rkt"
          "number-test.rkt"
-         ;"optional-test.rkt"
+         "optional-test.rkt"
          "pointer-test.rkt"
-         ;"reserved-test.rkt"
+         "reserved-test.rkt"
          "string-test.rkt"
          "struct-test.rkt"
          ;"versioned-struct-test.rkt"

xenomorph/xenomorph/redo/test/reserved-test.rkt

@@ -0,0 +1,32 @@
+#lang racket/base
+(require rackunit
+         "../number.rkt"
+         "../helper.rkt"
+         "../reserved.rkt")
+
+#|
+approximates
+https://github.com/mbutterick/restructure/blob/master/test/Reserved.coffee
+|#
+
+(test-case
+ "size should have a default count of 1"
+ (check-equal? (size (+xreserved uint8)) 1))
+
+(test-case
+ "size should allow custom counts and types"
+ (check-equal? (size (+xreserved uint16be 10)) 20))
+
+(test-case
+ "should decode"
+ (parameterize ([current-input-port (open-input-bytes (bytes 0 0))])
+   (define reserved (+xreserved uint16be))
+   (check-equal? (decode reserved) (void))
+   (check-equal? (pos (current-input-port)) 2)))
+
+(test-case
+ "should encode"
+ (parameterize ([current-output-port (open-output-bytes)])
+   (define reserved (+xreserved uint16be))
+   (encode reserved #f)
+   (check-equal? (dump (current-output-port)) (bytes 0 0))))