diff --git a/pitfall/sugar/js.rkt b/pitfall/sugar/js.rkt
index d994e0de..1827ea76 100644
--- a/pitfall/sugar/js.rkt
+++ b/pitfall/sugar/js.rkt
@@ -51,13 +51,13 @@
 (require sugar/debug)
 (define-macro-cases ·
   [(_ X REF)
-   #'(let loop ([x X])
-       (cond
-         ;; dict first, to catch objects that implement gen:dict
-         [(dict? x) (dict-ref x 'REF #f)]
-         ;; give `send` precedence (presence of method => wants runtime resolution of value)
-         [(object? x) (or (send-or-false x REF) (get-or-false x REF))]
-         [else (raise-argument-error '· (format "~a must be object or dict" 'X) x)]))]
+   (syntax/loc caller-stx (let loop ([x X])
+                             (cond
+                               ;; dict first, to catch objects that implement gen:dict
+                               [(dict? x) (dict-ref x 'REF #f)]
+                               ;; give `send` precedence (presence of method => wants runtime resolution of value)
+                               [(object? x) (or (send-or-false x REF) (get-or-false x REF))]
+                               [else (raise-argument-error '· (format "~a must be object or dict" 'X) x)])))]
   [(_ X REF0 . REFS) #'(· (· X REF0) . REFS)])
 
 #;(module+ test
diff --git a/pitfall/xenomorph/main.rkt b/pitfall/xenomorph/main.rkt
index a7fadebf..233099b2 100644
--- a/pitfall/xenomorph/main.rkt
+++ b/pitfall/xenomorph/main.rkt
@@ -9,7 +9,6 @@
      "optional.rkt"
      "pointer.rkt"
      "reserved.rkt"
-     "stream.rkt"
      "string.rkt"
      "struct.rkt"
      "versioned-struct.rkt")
diff --git a/pitfall/xenomorph/private/array.rkt b/pitfall/xenomorph/private/array.rkt
index 6acfab70..81ab68f5 100644
--- a/pitfall/xenomorph/private/array.rkt
+++ b/pitfall/xenomorph/private/array.rkt
@@ -7,37 +7,37 @@ approximates
 https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
 |#
 
-(define-subclass Streamcoder (ArrayT type [len #f] [length-type 'count])
+(define-subclass xenomorph-base% (ArrayT type [len #f] [length-type 'count])
           
-  (define/augride (decode stream [parent #f])
+  (define/augride (decode port [parent #f])
     (define ctx (if (NumberT? len)
                     (mhasheq 'parent parent
-                             '_startOffset (· stream pos)
+                             '_startOffset (pos port)
                              '_currentOffset 0
                              '_length len)
                     parent))
 
-    (define decoded-len (resolve-length len stream parent))
+    (define decoded-len (resolve-length len port parent))
     (cond
       [(or (not decoded-len) (eq? length-type 'bytes))
        (define end-pos (cond
                          ;; decoded-len is byte length
-                         [decoded-len (+ (· stream pos) decoded-len)]
+                         [decoded-len (+ (pos port) decoded-len)]
                          ;; no decoded-len, but parent has length
                          [(and parent (not (zero? (· parent _length)))) (+ (· parent _startOffset) (· parent _length))]
                          ;; no decoded-len or parent, so consume whole stream
-                         [else (· stream length_)]))
+                         [else +inf.0]))
        (for/list ([i (in-naturals)]
-                  #:break (= (· stream pos) end-pos))
-                 (send type decode stream ctx))]
+                  #:break (or (eof-object? (peek-byte port)) (= (pos port) end-pos)))
+                 (send type decode port ctx))]
       ;; we have decoded-len, which is treated as count of items
       [else (for/list ([i (in-range decoded-len)])
-                      (send type decode stream ctx))]))
+                      (send type decode port ctx))]))
   
 
   (define/augride (size [val #f] [ctx #f])
     (when val (unless (countable? val)
-                (raise-argument-error 'Array:size "list or countable" val)))
+                (raise-argument-error 'Array:size "countable" val)))
     (cond
       [val (let-values ([(ctx len-size) (if (NumberT? len)
                                             (values (mhasheq 'parent ctx) (send len size))
@@ -55,13 +55,13 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
 
     (define (encode-items ctx)
       (for ([item (in-list (countable->list array))])
-                                (send type encode port item ctx)))
+           (send type encode port item ctx)))
 
     (cond
       [(NumberT? len) (define ctx (mhash 'pointers null
-                                         'startOffset (· port pos)
+                                         'startOffset (pos port)
                                          'parent parent))
-                      (ref-set! ctx 'pointerOffset (+ (· port pos) (size array ctx)))
+                      (ref-set! ctx 'pointerOffset (+ (pos port) (size array ctx)))
                       (send len encode port (length array)) ; encode length at front
                       (encode-items ctx)
                       (for ([ptr (in-list (· ctx pointers))]) ; encode pointer data at end
@@ -71,8 +71,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
 (define-values (Array Array? +Array) (values ArrayT ArrayT? +ArrayT))
 
 (test-module
- (define A (+Array uint16be 3))
- (check-equal? (decode A #"ABCDEFG") '(16706 17220 17734))
- (check-equal? (encode A '(16706 17220 17734) #f) #"ABCDEF")
+ (check-equal? (decode (+Array uint16be 3) #"ABCDEF") '(16706 17220 17734))
+ (check-equal? (encode (+Array uint16be 3) '(16706 17220 17734) #f) #"ABCDEF")
  (check-equal? (size (+Array uint16be) '(1 2 3)) 6)
  (check-equal? (size (+Array doublebe) '(1 2 3 4 5)) 40))
diff --git a/pitfall/xenomorph/private/base.rkt b/pitfall/xenomorph/private/base.rkt
index e9464c07..b5ae8bd5 100644
--- a/pitfall/xenomorph/private/base.rkt
+++ b/pitfall/xenomorph/private/base.rkt
@@ -1,7 +1,19 @@
 #lang racket/base
-(require racket/class sugar/class racket/generic racket/private/generic-methods "generic.rkt")
+(require racket/class sugar/class racket/generic racket/private/generic-methods "generic.rkt" racket/port)
 (require sugar/debug)
 (provide (all-defined-out))
+(define-generics posable
+  (pos posable [new-pos])
+  #:defaults
+  ([port? (define (pos p [new-pos #f]) (when new-pos
+                                               (file-position p new-pos))
+                  (file-position p))]))
+
+(define posable<%>
+  (interface* ()
+              ([(generic-property gen:posable)
+                (generic-method-table gen:posable
+                                      (define (pos o [new-pos #f]) (send o pos new-pos)))])))
 
 (define-generics codable
   (decode codable #:parent [parent] [stream])
@@ -27,7 +39,10 @@
 
 
 (define-generics dumpable
-  (dump dumpable))
+  (dump dumpable)
+  #:defaults
+  ([input-port? (define (dump p) (port->bytes p))]
+   [output-port? (define (dump p) (get-output-bytes p))]))
 
 (define dumpable<%>
   (interface* ()
@@ -35,6 +50,8 @@
                 (generic-method-table gen:dumpable
                                       (define (dump o) (send o dump)))])))
 
+(define (symbol-append . syms)
+  (string->symbol (apply string-append (map symbol->string syms))))
 
 (define xenomorph-base%
   (class* object% (codable<%> sizable<%> dumpable<%>)
@@ -44,37 +61,41 @@
 
     (define/pubment (decode port [parent #f])
       (when parent (unless (indexable? parent)
-                     (raise-argument-error 'Xenomorph "indexable" parent)))
+                     (raise-argument-error (symbol-append (get-class-name) ':decode) "indexable" parent)))
       (define ip (cond
                    [(bytes? port) (open-input-bytes port)]
                    [(input-port? port) port]
-                   [else (raise-argument-error 'Xenomorph "bytes or input port" port)]))
-      (post-decode (inner (void) decode ip parent)))
+                   [else (raise-argument-error (symbol-append (get-class-name) ':decode) "bytes or input port" port)]))
+      (post-decode (inner (void) decode ip parent) port parent))
     
     (define/pubment (encode port val-in [parent #f])
       #;(report* port val-in parent)
-      (define val (pre-encode val-in))
+      (define val (pre-encode val-in port))
       (when parent (unless (indexable? parent)
-                     (raise-argument-error 'Xenomorph "indexable" parent)))
+                     (raise-argument-error (symbol-append (get-class-name) ':encode) "indexable" parent)))
       (define op (cond
                    [(output-port? port) port]
                    [(not port) (open-output-bytes)]
                    [else (raise-argument-error 'Xenomorph "output port or #f" port)]))
-      (define encode-result (inner (void) encode op val parent))
+      (define encode-result (inner #"" encode op val parent))
       (when (bytes? encode-result)
         (write-bytes encode-result op))
       (when (not port) (get-output-bytes op)))
     
-    (define/pubment (size [val #f] [parent #f])
+    (define/pubment (size [val #f] [parent #f] . _)
       (when parent (unless (indexable? parent)
-                     (raise-argument-error 'Xenomorph "indexable" parent)))
+                     (raise-argument-error (symbol-append (get-class-name) ':size) "indexable" parent)))
       (define result (inner (void) size val parent))
-      (when result (unless (and (integer? result) (not (negative? result)))
-                     (raise-argument-error 'Xenomorph "integer" result)))
-      result)
+      (cond
+        [(void? result) 0]
+        [(and (integer? result) (not (negative? result))) result]
+        [else (raise-argument-error (symbol-append (get-class-name) ':size) "nonnegative integer" result)]))
+
+    (define/public (get-class-name) (define-values (name _) (object-info this))
+      (or name 'Xenomorph))
     
-    (define/public (post-decode val) val)
-    (define/public (pre-encode val) val)
+    (define/public (post-decode val . _) val)
+    (define/public (pre-encode val . _) val)
     (define/public (dump) (void))))
 
 (define-class-predicates xenomorph-base%)
diff --git a/pitfall/xenomorph/private/bitfield.rkt b/pitfall/xenomorph/private/bitfield.rkt
index 60dc8c16..345a0417 100644
--- a/pitfall/xenomorph/private/bitfield.rkt
+++ b/pitfall/xenomorph/private/bitfield.rkt
@@ -25,11 +25,13 @@ https://github.com/mbutterick/restructure/blob/master/src/Bitfield.coffee
     (define bit-int (for/sum ([(flag i) (in-indexed flags)]
                                        #:when (and flag (ref flag-hash flag)))
                                (arithmetic-shift 1 i)))
-    (send type encode port bit-int)))
+    (send type encode port bit-int))
+
+  (define/override (get-class-name) 'Bitfield))
 
 
 (test-module
- (require "number.rkt" "stream.rkt")
+ (require "number.rkt")
  (define bfer (+Bitfield uint16be '(bold italic underline #f shadow condensed extended)))
  (define bf (send bfer decode #"\0\25"))
  (check-equal? (length (ref-keys bf)) 6) ; omits #f flag
diff --git a/pitfall/xenomorph/private/buffer.rkt b/pitfall/xenomorph/private/buffer.rkt
index 45d78fb8..ecfe49df 100644
--- a/pitfall/xenomorph/private/buffer.rkt
+++ b/pitfall/xenomorph/private/buffer.rkt
@@ -19,7 +19,7 @@ A Restructure RBuffer object is separate.
        string->bytes/utf-8
        list->bytes) xs))
 
-(define-subclass RestructureBase (RBuffer [len #xffff])
+(define-subclass xenomorph-base% (RBuffer [len #xffff])
   
   (define/augment (decode port [parent #f])
     (define decoded-len (resolve-length len port parent))
diff --git a/pitfall/xenomorph/private/enum.rkt b/pitfall/xenomorph/private/enum.rkt
index 9778b7a9..025596f4 100644
--- a/pitfall/xenomorph/private/enum.rkt
+++ b/pitfall/xenomorph/private/enum.rkt
@@ -7,7 +7,7 @@ approximates
 https://github.com/mbutterick/restructure/blob/master/src/Enum.coffee
 |#
 
-(define-subclass Streamcoder (Enum type [options empty])
+(define-subclass xenomorph-base% (Enum type [options empty])
 
   (define/augment (decode stream . _)
     (define index (send type decode stream))
diff --git a/pitfall/xenomorph/private/lazy-array.rkt b/pitfall/xenomorph/private/lazy-array.rkt
index 7c8df20e..a267e9b2 100644
--- a/pitfall/xenomorph/private/lazy-array.rkt
+++ b/pitfall/xenomorph/private/lazy-array.rkt
@@ -8,42 +8,47 @@ https://github.com/mbutterick/restructure/blob/master/src/LazyArray.coffee
 |#
 
 (define (get o i) (send o get i))
+(define (LazyArray->list o) (send o to-list))
 
-(define-subclass object% (InnerLazyArray type [len #f] [stream #f] [ctx #f])
-  (unless stream (raise-argument-error 'LazyArray "stream" stream))
-  (define starting-pos (· stream pos))
+(define-subclass object% (InnerLazyArray type [len #f] [port-in #f] [ctx #f])
+  (field ([port port] (cond
+                        [(bytes? port-in) (open-input-bytes port-in)]
+                        [(port? port-in) port-in]
+                        [else (raise-argument-error 'LazyArray "port" port)])))
+  (define starting-pos (pos port))
   (define item-cache (mhasheqv)) ;  integer-keyed hash, rather than list
+  
 
   (define/public-final (get index)
     (unless (<= 0 index (sub1 len))
       #;(raise-argument-error 'LazyArray:get (format "index in range 0 to ~a" len) index)
       (void))
     (ref! item-cache index (λ ()
-                             (define orig-pos (· stream pos))
-                             (send stream pos (+ starting-pos (* (send type size #f ctx) index)))
-                             (define new-item (send type decode stream ctx))
-                             (send stream pos orig-pos)
+                             (define orig-pos (pos port))
+                             (pos port (+ starting-pos (* (send type size #f ctx) index)))
+                             (define new-item (send type decode port ctx))
+                             (pos port orig-pos)
                              new-item)))
 
   (define/public-final (to-list)
     (for/list ([i (in-range len)])
-      (get i))))
+              (get i))))
 
 
 (define-subclass ArrayT (LazyArray)
   (inherit-field len type)
   
-  (define/override (decode stream [parent #f])
-    (define pos (· stream pos)) ; ! placement matters. `resolve-length` will change `pos`
-    (define decoded-len (resolve-length len stream parent))
+  (define/override (decode port [parent #f])
+    (define starting-pos (pos port)) ; ! placement matters. `resolve-length` will change `pos`
+    (define decoded-len (resolve-length len port parent))
     (let ([parent (if (NumberT? len)
                       (mhasheq 'parent parent
-                               '_startOffset pos
+                               '_startOffset starting-pos
                                '_currentOffset 0
                                '_length len)
                       parent)])
-      (define res (+InnerLazyArray type decoded-len stream parent))
-      (send stream pos (+ (· stream pos) (* decoded-len (send type size #f parent))))
+      (define res (+InnerLazyArray type decoded-len port parent))
+      (pos port (+ (pos port) (* decoded-len (send type size #f parent))))
       res))
 
   (define/override (size [val #f] [ctx #f])
@@ -51,26 +56,23 @@ https://github.com/mbutterick/restructure/blob/master/src/LazyArray.coffee
                     (send val to-list)
                     val) ctx))
 
-  (define/override (encode stream val [ctx #f])
-    (super encode stream (if (InnerLazyArray? val)
-                             (send val to-list)
-                             val) ctx)))    
+  (define/override (encode port val [ctx #f])
+    (super encode port (if (InnerLazyArray? val)
+                           (send val to-list)
+                           val) ctx)))    
 
 (test-module
  (require "stream.rkt")
  (define bstr #"ABCD1234")
- (define ds (+DecodeStream bstr))
+ (define ds (open-input-bytes bstr))
  (define la (+LazyArray uint8 4))
- (define ila (send la decode ds))
- (check-equal? (send ds pos) 4)
- (check-equal? (send ila get 1) 66)
- (check-equal? (send ila get 3) 68)
- (check-equal? (send ds pos) 4)
- (check-equal? (send ila to-list) '(65 66 67 68))
-
- (define la2 (+LazyArray int16be (λ (t) 4)))
- (define es (+EncodeStream))
- (send la2 encode es '(1 2 3 4))
- (check-equal? (send es dump) #"\0\1\0\2\0\3\0\4")
- (check-equal? (send (send la2 decode (+DecodeStream #"\0\1\0\2\0\3\0\4")) to-list) '(1 2 3 4)))
+ (define ila (decode la ds))
+ (check-equal? (pos ds) 4)
+ (check-equal? (get ila 1) 66)
+ (check-equal? (get ila 3) 68)
+ (check-equal? (pos ds) 4)
+ (check-equal? (LazyArray->list ila) '(65 66 67 68))
+ (define la2 (+LazyArray int16be (λ (t) 4))) 
+ (check-equal? (encode la2 '(1 2 3 4) #f) #"\0\1\0\2\0\3\0\4")
+ (check-equal? (send (decode la2 (open-input-bytes #"\0\1\0\2\0\3\0\4")) to-list) '(1 2 3 4)))
 
diff --git a/pitfall/xenomorph/private/number.rkt b/pitfall/xenomorph/private/number.rkt
index f0560b73..6bf44193 100644
--- a/pitfall/xenomorph/private/number.rkt
+++ b/pitfall/xenomorph/private/number.rkt
@@ -50,10 +50,10 @@ https://github.com/mbutterick/restructure/blob/master/src/Number.coffee
                            (arithmetic-shift b (* 8 i))))
     unsigned-int)
 
-  (define/override (post-decode unsigned-val)
+  (define/override (post-decode unsigned-val . _)
     (if _signed? (unsigned->signed unsigned-val bits) unsigned-val))
 
-  (define/override (pre-encode val)
+  (define/override (pre-encode val . _)
     (exact-if-possible val))
 
   (define/augment (encode port val [parent #f])
@@ -75,7 +75,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Number.coffee
     (define bs (read-bytes byte-size port))
     (floating-point-bytes->real bs (eq? endian 'be)))
 
-  (define/augment (encode val [parent #f]) ; convert float to int
+  (define/augment (encode port val [parent #f]) ; convert float to int
     (define bs (real->floating-point-bytes val byte-size (eq? endian 'be)))
     bs)
 
@@ -95,10 +95,10 @@ https://github.com/mbutterick/restructure/blob/master/src/Number.coffee
   (super-make-object (string->symbol (format "int~a" size)) fixed-endian)
   (define _point (arithmetic-shift 1 fracBits))
 
-  (define/override (post-decode int)
+  (define/override (post-decode int . _)
     (exact-if-possible (/ int _point 1.0)))
 
-  (define/override (pre-encode fixed)
+  (define/override (pre-encode fixed . _)
     (exact-if-possible (floor (* fixed _point)))))
 
 (define-instance fixed16 (make-object Fixed 16))
diff --git a/pitfall/xenomorph/private/optional.rkt b/pitfall/xenomorph/private/optional.rkt
index a1b59e6f..4f8f2057 100644
--- a/pitfall/xenomorph/private/optional.rkt
+++ b/pitfall/xenomorph/private/optional.rkt
@@ -7,7 +7,7 @@ approximates
 https://github.com/mbutterick/restructure/blob/master/src/Optional.coffee
 |#
 
-(define-subclass Streamcoder (Optional type [condition #t])
+(define-subclass xenomorph-base% (Optional type [condition #t])
 
   (define (resolve-condition parent)
     (if (procedure? condition)
@@ -18,10 +18,9 @@ https://github.com/mbutterick/restructure/blob/master/src/Optional.coffee
     (when (resolve-condition parent)
       (send type decode stream parent)))
 
-  (define/override (size [val #f] [parent #f])
-    (if (resolve-condition parent)
-        (send type size val parent)
-        0))
+  (define/augment (size val parent)
+    (when (resolve-condition parent)
+      (send type size val parent)))
 
   (define/augment (encode stream val parent)
     (when (resolve-condition parent)
diff --git a/pitfall/xenomorph/private/pointer.rkt b/pitfall/xenomorph/private/pointer.rkt
index 4b16a963..64577ad8 100644
--- a/pitfall/xenomorph/private/pointer.rkt
+++ b/pitfall/xenomorph/private/pointer.rkt
@@ -18,7 +18,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
     [(· ctx parent) => find-top-ctx]
     [else ctx]))
 
-(define-subclass RestructureBase (Pointer offset-type type-in [options (mhasheq)])
+(define-subclass xenomorph-base% (Pointer offset-type type-in [options (mhasheq)])
   (field [type (and (not (eq? type-in 'void)) type-in)])
   (define pointer-style (or (· options type) 'local))
   (define allow-null (or (· options allowNull) #t)) 
@@ -26,7 +26,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
   (define lazy (· options lazy))
   (define relative-getter-or-0 (or (· options relativeTo) (λ (ctx) 0))) ; changed this to a simple lambda
 
-  (define/override (decode stream [ctx #f])
+  (define/augment (decode stream [ctx #f])
     (define offset (send offset-type decode stream ctx))
     (cond
       [(and allow-null (= offset null-value)) #f] ; handle null pointers
@@ -56,7 +56,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
          [else ptr])]))
 
   
-  (define/override (size [val #f] [ctx #f])
+  (define/augment (size [val #f] [ctx #f])
     (let*-values ([(parent) ctx]
                   [(ctx) (caseq pointer-style
                                 [(local immediate) ctx]
@@ -70,7 +70,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
       (send offset-type size)))
                  
 
-  (define/override (encode stream val [ctx #f])
+  (define/augment (encode stream val [ctx #f])
     (if (not val)
         (send offset-type encode stream null-value)
         (let* ([parent ctx]
diff --git a/pitfall/xenomorph/private/stream.rkt b/pitfall/xenomorph/private/stream.rkt
index a275683f..af6a8720 100644
--- a/pitfall/xenomorph/private/stream.rkt
+++ b/pitfall/xenomorph/private/stream.rkt
@@ -102,14 +102,7 @@ https://github.com/mbutterick/restructure/blob/master/src/DecodeStream.coffee
                 (generic-method-table gen:countable
                                       (define (length o) (get-field length_ o)))])))
 
-(define-generics posable
-  (pos posable [new-pos]))
 
-(define posable<%>
-  (interface* ()
-              ([(generic-property gen:posable)
-                (generic-method-table gen:posable
-                                      (define (pos o [new-pos #f]) (send o pos new-pos)))])))
 
 (define DecodeStreamT
   (class* PortWrapper
diff --git a/pitfall/xenomorph/private/struct.rkt b/pitfall/xenomorph/private/struct.rkt
index 3578520c..6d87d269 100644
--- a/pitfall/xenomorph/private/struct.rkt
+++ b/pitfall/xenomorph/private/struct.rkt
@@ -44,17 +44,17 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
                         (define/override (dump) _kv)))
 
 
-(define-subclass Streamcoder (Struct [fields (dictify)])
-  (field [[_process process] (λ (res stream ctx) res)]
-         [[_preEncode preEncode] void]) ; store as field so it can be mutated from outside
+(define-subclass xenomorph-base% (Struct [fields (dictify)])
+  (field [[_process process] (λ (res port ctx) res)]
+         [[_pre-encode pre-encode] (λ (val port) val)]) ; store as field so it can be mutated from outside
   
-  (define/overment (process res stream [ctx #f])
+  (define/overment (post-decode res stream [ctx #f])
     (let* ([res (_process res stream ctx)]
-           [res (inner res process res stream ctx)])
+           [res (inner res post-decode res stream ctx)])
       (unless (dict? res) (raise-result-error 'Struct:process "dict" res))
       res))
   
-  (define/override (preEncode . args) (apply _preEncode args))
+  (define/override (pre-encode . args) (apply _pre-encode args))
   
   (unless ((disjoin assocs? Struct?) fields) ; should be Versioned Struct but whatever
     (raise-argument-error 'Struct "assocs or Versioned Struct" fields))
@@ -62,33 +62,32 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
   (define/augride (decode stream [parent #f] [len 0])
     ;; _setup and _parse-fields are separate to cooperate with VersionedStruct
     (let* ([res (_setup stream parent len)]
-           [res (_parse-fields stream res fields)]
-           [res (process res stream)])
+           [res (_parse-fields stream res fields)])
       res))
 
-  (define/public-final (_setup stream parent len)
+  (define/public-final (_setup port parent len)
     (define res (make-object StructDictRes)) ; not mere hash
     (dict-set*! res 'parent parent
-                '_startOffset (· stream pos)
+                '_startOffset (pos port)
                 '_currentOffset 0
                 '_length len)
     res)
 
-  (define/public-final (_parse-fields stream res fields)
+  (define/public-final (_parse-fields port res fields)
     (unless (assocs? fields)
       (raise-argument-error '_parse-fields "assocs" fields))
     (for/fold ([res res])
               ([(key type) (in-dict fields)])
       (define val (if (procedure? type)
                       (type res)
-                      (send type decode stream res)))
+                      (send type decode port res)))
       (unless (void? val)
         (ref-set! res key val))
-      (ref-set! res '_currentOffset (- (· stream pos) (· res _startOffset)))
+      (ref-set! res '_currentOffset (- (pos port) (· res _startOffset)))
       res))
   
 
-  (define/override (size [val #f] [parent #f] [include-pointers #t])
+  (define/augride (size [val #f] [parent #f] [include-pointers #t])
     (define ctx (mhasheq 'parent parent
                          'val val
                          'pointerSize 0))
@@ -96,25 +95,25 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
                 (send type size (and val (ref val key)) ctx))
        (if include-pointers (· ctx pointerSize) 0)))
 
-  (define/augride (encode stream val [parent #f])
+  (define/augride (encode port val [parent #f])
     (unless (dict? val)
       (raise-argument-error 'Struct:encode "dict" val))
 
-    (send this preEncode val stream) ; preEncode goes first, because it might bring input dict into compliance
+    (send this pre-encode val port) ; preEncode goes first, because it might bring input dict into compliance
     (define ctx (mhash 'pointers empty
-                       'startOffset (· stream pos)
+                       'startOffset (pos port)
                        'parent parent
                        'val val
                        'pointerSize 0))
-    (ref-set! ctx 'pointerOffset (+ (· stream pos) (size val ctx #f)))
+    (ref-set! ctx 'pointerOffset (+ (pos port) (size val ctx #f)))
 
     (unless (andmap (λ (key) (memq key (dict-keys val))) (dict-keys fields))
       (raise-argument-error 'Struct:encode
                             (format "dict that contains superset of Struct keys: ~a" (dict-keys fields)) (dict-keys val)))
     (for ([(key type) (in-dict fields)])
-         (send type encode stream (ref val key) ctx))
+         (send type encode port (ref val key) ctx))
     (for ([ptr (in-list (· ctx pointers))])
-         (send (· ptr type) encode stream (· ptr val) (· ptr parent)))))
+         (send (· ptr type) encode port (· ptr val) (· ptr parent)))))
 
 
 (test-module
diff --git a/pitfall/xenomorph/private/versioned-struct.rkt b/pitfall/xenomorph/private/versioned-struct.rkt
index dcc90dad..d3b3c55e 100644
--- a/pitfall/xenomorph/private/versioned-struct.rkt
+++ b/pitfall/xenomorph/private/versioned-struct.rkt
@@ -15,7 +15,7 @@ https://github.com/mbuttrackerick/restructure/blob/master/src/VersionedStruct.co
   (unless (and (dict? versions) (andmap (λ (val) (or (dict? val) (Struct? val))) (map cdr versions)))
     (raise-argument-error 'VersionedStruct "dict of dicts or Structs" versions))
 
-  (inherit _setup  _parse-fields process)
+  (inherit _setup  _parse-fields post-decode)
   (inherit-field fields)
   (field [forced-version #f]
          [versionGetter void]
@@ -51,7 +51,6 @@ https://github.com/mbuttrackerick/restructure/blob/master/src/VersionedStruct.co
       [(VersionedStruct? fields) (send fields decode stream parent)]
       [else
        (_parse-fields stream res fields)
-       (process res stream)
        res]))
   
   (define/public-final (force-version! version)
diff --git a/pitfall/xenomorph/test/enum-test.rkt b/pitfall/xenomorph/test/enum-test.rkt
index 74d14885..3692fa53 100644
--- a/pitfall/xenomorph/test/enum-test.rkt
+++ b/pitfall/xenomorph/test/enum-test.rkt
@@ -14,40 +14,21 @@ https://github.com/mbutterick/restructure/blob/master/test/Enum.coffee
 (check-equal? (size e) 1)
 
 
-;
 ;  it 'should decode', ->
-;    stream = new DecodeStream new Buffer [1, 2, 0]
-;    e.decode(stream).should.equal 'bar'
-;    e.decode(stream).should.equal 'baz'
-;    e.decode(stream).should.equal 'foo'
+(parameterize ([current-input-port (open-input-bytes (bytes 1 2 0))])
+  (check-equal? (decode e) "bar")
+  (check-equal? (decode e) "baz")
+  (check-equal? (decode e) "foo"))
 
-(let ([stream (+DecodeStream (+Buffer '(1 2 0)))])
-  (check-equal? (decode e stream) "bar")
-  (check-equal? (decode e stream) "baz")
-  (check-equal? (decode e stream) "foo"))
 
-;
 ;  it 'should encode', (done) ->
-;    stream = new EncodeStream
-;    stream.pipe concat (buf) ->
-;      buf.should.deep.equal new Buffer [1, 2, 0]
-;      done()
-;
-;    e.encode stream, 'bar'
-;    e.encode stream, 'baz'
-;    e.encode stream, 'foo'
-;    stream.end()
-
-(let ([stream (+EncodeStream)])
-  (encode e stream "bar")
-  (encode e stream "baz")
-  (encode e stream "foo")
-  (check-equal? (send stream dump) (+Buffer '(1 2 0))))
-
-;
+(parameterize ([current-output-port (open-output-bytes)])
+  (encode e "bar")
+  (encode e "baz")
+  (encode e "foo")
+  (check-equal? (dump (current-output-port)) (bytes 1 2 0)))
+
+
 ;  it 'should throw on unknown option', ->
-;    stream = new EncodeStream
-;    should.throw ->
-;      e.encode stream, 'unknown'
 
-(check-exn exn:fail:contract? (λ () (encode e (+EncodeStream) "unknown")))
\ No newline at end of file
+(check-exn exn:fail:contract? (λ () (encode e "unknown" (open-output-bytes))))
\ No newline at end of file
diff --git a/pitfall/xenomorph/test/lazy-array-test.rkt b/pitfall/xenomorph/test/lazy-array-test.rkt
index 31a9ac57..3278d3cf 100644
--- a/pitfall/xenomorph/test/lazy-array-test.rkt
+++ b/pitfall/xenomorph/test/lazy-array-test.rkt
@@ -8,104 +8,51 @@ https://github.com/mbutterick/restructure/blob/master/test/LazyArray.coffee
 ;describe 'LazyArray', ->
 ;  describe 'decode', ->
 ;    it 'should decode items lazily', ->
-;      stream = new DecodeStream new Buffer [1, 2, 3, 4, 5]
-;      array = new LazyArray uint8, 4
-;      
-;      arr = array.decode(stream)
-;      arr.should.not.be.an.instanceof Array
-;      arr.should.have.length 4
-;      stream.pos.should.equal 4
-;      
-;      arr.get(0).should.equal 1
-;      arr.get(1).should.equal 2
-;      arr.get(2).should.equal 3
-;      arr.get(3).should.equal 4
-;      
-;      should.not.exist arr.get(-1)
-;      should.not.exist arr.get(5)
 
-(let* ([stream (+DecodeStream (+Buffer '(1 2 3 4 5)))]
-       [array (+LazyArray uint8 4)])
-  (define arr (decode array stream))
+(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
+  (define array (+LazyArray uint8 4))
+  (define arr (decode array))
   (check-false (Array? arr))
   (check-equal? (ref arr 'len) 4)
-  (check-equal? (pos stream) 4)
+  (check-equal? (pos (current-input-port)) 4)
   (check-equal? (get arr 0) 1)
   (check-equal? (get arr 1) 2)
   (check-equal? (get arr 2) 3)
   (check-equal? (get arr 3) 4))
-
-
-
-;      
+      
 ;    it 'should be able to convert to an array', ->
-;      stream = new DecodeStream new Buffer [1, 2, 3, 4, 5]
-;      array = new LazyArray uint8, 4
-;      
-;      arr = array.decode(stream)
-;      arr.toArray().should.deep.equal [1, 2, 3, 4]
 
-(let* ([stream (+DecodeStream (+Buffer '(1 2 3 4 5)))]
-       [array (+LazyArray uint8 4)])
-  (define arr (decode array stream))
-  (check-equal? (send arr to-list) '(1 2 3 4)))
+(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
+  (define array (+LazyArray uint8 4))
+  (define arr (decode array))
+  (check-equal? (LazyArray->list arr) '(1 2 3 4)))
 
-;      
+     
 ;    it 'should have an inspect method', ->
-;      stream = new DecodeStream new Buffer [1, 2, 3, 4, 5]
-;      array = new LazyArray uint8, 4
-;      
-;      arr = array.decode(stream)
-;      arr.inspect().should.equal '[ 1, 2, 3, 4 ]'
+;    [skipped]
 
-#;(let* ([stream (+DecodeStream (+Buffer '(1 2 3 4 5)))]
-       [array (+LazyArray uint8 4)])
-  (define arr (decode array stream))
-  (check-equal? (send arr inspect) (format "~a" '(1 2 3 4))))
 
-;      
 ;    it 'should decode length as number before array', ->
-;      stream = new DecodeStream new Buffer [4, 1, 2, 3, 4, 5]
-;      array = new LazyArray uint8, uint8
-;      arr = array.decode(stream)
-;      
-;      arr.toArray().should.deep.equal [1, 2, 3, 4]
 
-(let* ([stream (+DecodeStream (+Buffer '(4 1 2 3 4 5)))]
-       [array (+LazyArray uint8 uint8)])
-  (define arr (decode array stream))
-  (check-equal? (send arr to-list) '(1 2 3 4)))
+(parameterize ([current-input-port (open-input-bytes (bytes 4 1 2 3 4 5))])
+  (define array (+LazyArray uint8 uint8))
+  (define arr (decode array))
+  (check-equal? (LazyArray->list arr) '(1 2 3 4)))
 
 ;      
 ;  describe 'size', ->
 ;    it 'should work with LazyArrays', ->
-;      stream = new DecodeStream new Buffer [1, 2, 3, 4, 5]
-;      array = new LazyArray uint8, 4
-;      arr = array.decode(stream)
-;      
-;      array.size(arr).should.equal 4
 
-(let* ([stream (+DecodeStream (+Buffer '(1 2 3 4 5)))]
-       [array (+LazyArray uint8 4)])
-  (define arr (decode array stream))
+(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
+  (define array (+LazyArray uint8 4))
+  (define arr (decode array))
   (check-equal? (size array arr) 4))
 
-;      
+
 ;  describe 'encode', ->
 ;    it 'should work with LazyArrays', (done) ->
-;      stream = new DecodeStream new Buffer [1, 2, 3, 4, 5]
-;      array = new LazyArray uint8, 4
-;      arr = array.decode(stream)
-;      
-;      enc = new EncodeStream
-;      enc.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [1, 2, 3, 4]
-;        done()
-;      
-;      array.encode(enc, arr)
-;      enc.end()
 
-(let* ([stream (+DecodeStream (+Buffer '(1 2 3 4 5)))]
-       [array (+LazyArray uint8 4)])
-  (define arr (decode array stream))  
-  (check-equal? (encode array #f arr) (+Buffer '(1 2 3 4))))
\ No newline at end of file
+(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
+  (define array (+LazyArray uint8 4))
+  (define arr (decode array))  
+  (check-equal? (encode array arr #f) (bytes 1 2 3 4)))
\ No newline at end of file
diff --git a/pitfall/xenomorph/test/number-test.rkt b/pitfall/xenomorph/test/number-test.rkt
index 843874bb..8d4edb7c 100644
--- a/pitfall/xenomorph/test/number-test.rkt
+++ b/pitfall/xenomorph/test/number-test.rkt
@@ -9,228 +9,118 @@ https://github.com/mbutterick/restructure/blob/master/test/Number.coffee
 ;describe 'Number', ->
 ;  describe 'uint8', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xab, 0xff]
-;      uint8.decode(stream).should.equal 0xab
-;      uint8.decode(stream).should.equal 0xff
-;
 ;    it 'should have a size', ->
-;      uint8.size().should.equal 1
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xab, 0xff]
-;        done()
-;
-;      uint8.encode(stream, 0xab)
-;      uint8.encode(stream, 0xff)
-;      stream.end()
-
-(let ([stream (+DecodeStream (bytes #xab #xff))])
-  (check-equal? (decode uint8 stream) #xab)
-  (check-equal? (decode uint8 stream) #xff))
+(parameterize ([current-input-port (open-input-bytes (bytes #xab #xff))])
+  (check-equal? (decode uint8) #xab)
+  (check-equal? (decode uint8) #xff))
 
 (check-equal? (size uint8) 1)
 
-(let ([stream (+EncodeStream)])
-  (encode uint8 stream #xab)
-  (encode uint8 stream #xff)
-  (check-equal? (dump stream) (bytes #xab #xff)))
+(let ([port (open-output-bytes)])
+  (encode uint8 #xab port)
+  (encode uint8 #xff port)
+  (check-equal? (dump port) (bytes #xab #xff)))
 
 
-;
 ;  describe 'uint16', ->
 ;    it 'is an alias for uint16be', ->
-;      uint16.should.equal uint16be
-
-;; modified test: `uint16` is the same endianness as the platform
+; modified test: `uint16` is the same endianness as the platform
 (check-equal? (decode uint16 (bytes 0 1)) (send (if (system-big-endian?)
-                                                         uint16be
-                                                         uint16le) decode (bytes 0 1)))
+                                                    uint16be
+                                                    uint16le) decode (bytes 0 1)))
 
-;
 ;  describe 'uint16be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xab, 0xff]
-;      uint16be.decode(stream).should.equal 0xabff
-;
 ;    it 'should have a size', ->
-;      uint16be.size().should.equal 2
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xab, 0xff]
-;        done()
-;
-;      uint16be.encode(stream, 0xabff)
-;      stream.end()
 
-(check-equal? (decode uint16be (+DecodeStream (bytes #xab #xff))) #xabff)
+(check-equal? (decode uint16be (open-input-bytes (bytes #xab #xff))) #xabff)
 (check-equal? (size uint16be) 2)
-(check-equal? (encode uint16be #f #xabff) (bytes #xab #xff))
+(check-equal? (encode uint16be #xabff #f) (bytes #xab #xff))
 
 ;
 ;  describe 'uint16le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xff, 0xab]
-;      uint16le.decode(stream).should.equal 0xabff
-;
 ;    it 'should have a size', ->
-;      uint16le.size().should.equal 2
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xff, 0xab]
-;        done()
-;
-;      uint16le.encode(stream, 0xabff)
-;      stream.end()
 
-(check-equal? (decode uint16le (+DecodeStream (bytes #xff #xab))) #xabff)
+(check-equal? (decode uint16le (open-input-bytes (bytes #xff #xab))) #xabff)
 (check-equal? (size uint16le) 2)
-(check-equal? (encode uint16le #f #xabff) (bytes #xff #xab))
+(check-equal? (encode uint16le #xabff #f) (bytes #xff #xab))
 
 ;
 ;  describe 'uint24', ->
 ;    it 'is an alias for uint24be', ->
-;      uint24.should.equal uint24be
-
 ;; modified test: `uint24` is the same endianness as the platform
 (check-equal? (decode uint24 (bytes 0 1 2)) (send (if (system-big-endian?)
-                                                           uint24be
-                                                           uint24le) decode (bytes 0 1 2)))
+                                                      uint24be
+                                                      uint24le) decode (bytes 0 1 2)))
 
 ;
 ;  describe 'uint24be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xff, 0xab, 0x24]
-;      uint24be.decode(stream).should.equal 0xffab24
-;
 ;    it 'should have a size', ->
-;      uint24be.size().should.equal 3
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xff, 0xab, 0x24]
-;        done()
-;
-;      uint24be.encode(stream, 0xffab24)
-;      stream.end()
 
-(check-equal? (decode uint24be (+DecodeStream (bytes #xff #xab #x24))) #xffab24)
+(check-equal? (decode uint24be (open-input-bytes (bytes #xff #xab #x24))) #xffab24)
 (check-equal? (size uint24be) 3)
-(check-equal? (encode uint24be #f #xffab24) (bytes #xff #xab #x24))
+(check-equal? (encode uint24be #xffab24 #f) (bytes #xff #xab #x24))
 
 ;
 ;  describe 'uint24le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x24, 0xab, 0xff]
-;      uint24le.decode(stream).should.equal 0xffab24
-;
 ;    it 'should have a size', ->
-;      uint24le.size().should.equal 3
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x24, 0xab, 0xff]
-;        done()
-;
-;      uint24le.encode(stream, 0xffab24)
-;      stream.end()
 
-(check-equal? (decode uint24le (+DecodeStream (bytes #x24 #xab #xff))) #xffab24)
+(check-equal? (decode uint24le (open-input-bytes (bytes #x24 #xab #xff))) #xffab24)
 (check-equal? (size uint24le) 3)
-(check-equal? (encode uint24le #f #xffab24) (bytes #x24 #xab #xff))
+(check-equal? (encode uint24le #xffab24 #f) (bytes #x24 #xab #xff))
 
 ;
 ;  describe 'uint32', ->
 ;    it 'is an alias for uint32be', ->
-;      uint32.should.equal uint32be
-
 ;; modified test: `uint32` is the same endianness as the platform
 (check-equal? (decode uint32 (bytes 0 1 2 3)) (send (if (system-big-endian?)
-                                                             uint32be
-                                                             uint32le) decode (bytes 0 1 2 3)))
+                                                        uint32be
+                                                        uint32le) decode (bytes 0 1 2 3)))
 
 ;
 ;  describe 'uint32be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xff, 0xab, 0x24, 0xbf]
-;      uint32be.decode(stream).should.equal 0xffab24bf
-;
 ;    it 'should have a size', ->
-;      uint32be.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xff, 0xab, 0x24, 0xbf]
-;        done()
-;
-;      uint32be.encode(stream, 0xffab24bf)
-;      stream.end()
 
-(check-equal? (decode uint32be (+DecodeStream (bytes #xff #xab #x24 #xbf))) #xffab24bf)
+(check-equal? (decode uint32be (open-input-bytes (bytes #xff #xab #x24 #xbf))) #xffab24bf)
 (check-equal? (size uint32be) 4)
-(check-equal? (encode uint32be #f #xffab24bf) (bytes #xff #xab #x24 #xbf))
+(check-equal? (encode uint32be #xffab24bf #f) (bytes #xff #xab #x24 #xbf))
 
 ;
 ;  describe 'uint32le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xbf, 0x24, 0xab, 0xff]
-;      uint32le.decode(stream).should.equal 0xffab24bf
-;
-;    it 'should have a size', ->
-;      uint32le.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xbf, 0x24, 0xab, 0xff]
-;        done()
-;
-;      uint32le.encode(stream, 0xffab24bf)
-;      stream.end()
 
-(check-equal? (decode uint32le (+DecodeStream (bytes #xbf #x24 #xab #xff))) #xffab24bf)
+(check-equal? (decode uint32le (open-input-bytes (bytes #xbf #x24 #xab #xff))) #xffab24bf)
 (check-equal? (size uint32le) 4)
-(check-equal? (encode uint32le #f #xffab24bf) (bytes #xbf #x24 #xab #xff))
+(check-equal? (encode uint32le #xffab24bf #f) (bytes #xbf #x24 #xab #xff))
 
 
 ;
 ;  describe 'int8', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x7f, 0xff]
-;      int8.decode(stream).should.equal 127
-;      int8.decode(stream).should.equal -1
-;
 ;    it 'should have a size', ->
-;      int8.size().should.equal 1
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x7f, 0xff]
-;        done()
-;
-;      int8.encode(stream, 127)
-;      int8.encode(stream, -1)
-;      stream.end()
 
-(let ([stream (+DecodeStream (bytes #x7f #xff))])
-  (check-equal? (decode int8 stream) 127)
-  (check-equal? (decode int8 stream) -1))
+(let ([port (open-input-bytes (bytes #x7f #xff))])
+  (check-equal? (decode int8 port) 127)
+  (check-equal? (decode int8 port) -1))
 
 (check-equal? (size int8) 1)
 
-(let ([stream (+EncodeStream)])
-  (encode int8 stream 127)
-  (encode int8 stream -1)
-  (check-equal? (dump stream) (bytes #x7f #xff)))
+(let ([port (open-output-bytes)])
+  (encode int8 127 port)
+  (encode int8 -1 port)
+  (check-equal? (dump port) (bytes #x7f #xff)))
 
 
 ;
@@ -240,59 +130,34 @@ https://github.com/mbutterick/restructure/blob/master/test/Number.coffee
 
 ;; modified test: `int16` is the same endianness as the platform
 (check-equal? (decode int16 (bytes 0 1)) (send (if (system-big-endian?)
-                                                        int16be
-                                                        int16le) decode (bytes 0 1)))
+                                                   int16be
+                                                   int16le) decode (bytes 0 1)))
 
 
 ;
 ;  describe 'int16be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xff, 0xab]
-;      int16be.decode(stream).should.equal -85
-;
 ;    it 'should have a size', ->
-;      int16be.size().should.equal 2
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xff, 0xab]
-;        done()
-;
-;      int16be.encode(stream, -85)
-;      stream.end()
 
-(let ([stream (+DecodeStream (bytes #xff #xab))])
-  (check-equal? (decode int16be stream) -85))
+(let ([port (open-input-bytes (bytes #xff #xab))])
+  (check-equal? (decode int16be port) -85))
 
 (check-equal? (size int16be) 2)
 
-(let ([stream (+EncodeStream)])
-  (encode int16be stream -85)
-  (check-equal? (dump stream) (bytes #xff #xab)))
+(let ([port (open-output-bytes)])
+  (encode int16be -85 port)
+  (check-equal? (dump port) (bytes #xff #xab)))
+
 
-;
 ;  describe 'int16le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xab, 0xff]
-;      int16le.decode(stream).should.equal -85
-;
 ;    it 'should have a size', ->
-;      int16le.size().should.equal 2
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xab, 0xff]
-;        done()
-;
-;      int16le.encode(stream, -85)
-;      stream.end()
-
 
-(check-equal? (decode int16le (+DecodeStream (bytes #xab #xff))) -85)
+(check-equal? (decode int16le (open-input-bytes (bytes #xab #xff))) -85)
 (check-equal? (size int16le) 2)
-(check-equal? (encode int16le #f -85) (bytes #xab #xff))
+(check-equal? (encode int16le -85 #f) (bytes #xab #xff))
 
 
 ;
@@ -302,325 +167,169 @@ https://github.com/mbutterick/restructure/blob/master/test/Number.coffee
 
 ;; modified test: `int24` is the same endianness as the platform
 (check-equal? (decode int24 (bytes 0 1 2)) (send (if (system-big-endian?)
-                                                          int24be
-                                                          int24le) decode (bytes 0 1 2)))
+                                                     int24be
+                                                     int24le) decode (bytes 0 1 2)))
 
 
 ;
 ;  describe 'int24be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xff, 0xab, 0x24]
-;      int24be.decode(stream).should.equal -21724
-;
 ;    it 'should have a size', ->
-;      int24be.size().should.equal 3
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xff, 0xab, 0x24]
-;        done()
-;
-;      int24be.encode(stream, -21724)
-;      stream.end()
 
-(check-equal? (decode int24be (+DecodeStream (bytes #xff #xab #x24))) -21724)
+(check-equal? (decode int24be (open-input-bytes (bytes #xff #xab #x24))) -21724)
 (check-equal? (size int24be) 3)
-(check-equal? (encode int24be #f -21724) (bytes #xff #xab #x24))
+(check-equal? (encode int24be -21724 #f) (bytes #xff #xab #x24))
 
 ;
 ;  describe 'int24le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x24, 0xab, 0xff]
-;      int24le.decode(stream).should.equal -21724
-;
 ;    it 'should have a size', ->
-;      int24le.size().should.equal 3
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x24, 0xab, 0xff]
-;        done()
-;
-;      int24le.encode(stream, -21724)
-;      stream.end()
-;
 
-(check-equal? (decode int24le (+DecodeStream (bytes #x24 #xab #xff))) -21724)
+(check-equal? (decode int24le (open-input-bytes (bytes #x24 #xab #xff))) -21724)
 (check-equal? (size int24le) 3)
-(check-equal? (encode int24le #f -21724) (bytes #x24 #xab #xff))
+(check-equal? (encode int24le -21724 #f) (bytes #x24 #xab #xff))
 
 
 
 ;  describe 'int32', ->
 ;    it 'is an alias for int32be', ->
-;      int32.should.equal int32be
-
-;; modified test: `int32` is the same endianness as the platform
+; modified test: `int32` is the same endianness as the platform
 (check-equal? (decode int32 (bytes 0 1 2 3)) (send (if (system-big-endian?)
-                                                            int32be
-                                                            int32le) decode (bytes 0 1 2 3)))
+                                                       int32be
+                                                       int32le) decode (bytes 0 1 2 3)))
 
 
 
 ;
 ;  describe 'int32be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xff, 0xab, 0x24, 0xbf]
-;      int32be.decode(stream).should.equal -5561153
-;
 ;    it 'should have a size', ->
-;      int32be.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xff, 0xab, 0x24, 0xbf]
-;        done()
-;
-;      int32be.encode(stream, -5561153)
-;      stream.end()
 
-(check-equal? (decode int32be (+DecodeStream (bytes #xff #xab #x24 #xbf))) -5561153)
+(check-equal? (decode int32be (open-input-bytes (bytes #xff #xab #x24 #xbf))) -5561153)
 (check-equal? (size int32be) 4)
-(check-equal? (encode int32be #f -5561153) (bytes #xff #xab #x24 #xbf))
+(check-equal? (encode int32be -5561153 #f) (bytes #xff #xab #x24 #xbf))
 
 ;
 ;  describe 'int32le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xbf, 0x24, 0xab, 0xff]
-;      int32le.decode(stream).should.equal -5561153
-;
 ;    it 'should have a size', ->
-;      int32le.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xbf, 0x24, 0xab, 0xff]
-;        done()
-;
-;      int32le.encode(stream, -5561153)
-;      stream.end()
 
-(check-equal? (decode int32le (+DecodeStream (bytes #xbf #x24 #xab #xff))) -5561153)
+(check-equal? (decode int32le (open-input-bytes (bytes #xbf #x24 #xab #xff))) -5561153)
 (check-equal? (size int32le) 4)
-(check-equal? (encode int32le #f -5561153) (bytes #xbf #x24 #xab #xff))
+(check-equal? (encode int32le -5561153 #f) (bytes #xbf #x24 #xab #xff))
 
 ;
 ;  describe 'float', ->
 ;    it 'is an alias for floatbe', ->
-;      float.should.equal floatbe
-
-;; modified test: `float` is the same endianness as the platform
+; modified test: `float` is the same endianness as the platform
 (check-equal? (decode float (bytes 0 1 2 3)) (send (if (system-big-endian?)
-                                                            floatbe
-                                                            floatle) decode (bytes 0 1 2 3)))
+                                                       floatbe
+                                                       floatle) decode (bytes 0 1 2 3)))
 
 ;
 ;  describe 'floatbe', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x43, 0x7a, 0x8c, 0xcd]
-;      floatbe.decode(stream).should.be.closeTo 250.55, 0.005
-;
 ;    it 'should have a size', ->
-;      floatbe.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x43, 0x7a, 0x8c, 0xcd]
-;        done()
-;
-;      floatbe.encode(stream, 250.55)
-;      stream.end()
 
-(check-= (decode floatbe (+DecodeStream (bytes #x43 #x7a #x8c #xcd))) 250.55 0.01)
+(check-= (decode floatbe (open-input-bytes (bytes #x43 #x7a #x8c #xcd))) 250.55 0.01)
 (check-equal? (size floatbe) 4)
-(check-equal? (encode floatbe #f 250.55) (bytes #x43 #x7a #x8c #xcd))
+(check-equal? (encode floatbe 250.55 #f) (bytes #x43 #x7a #x8c #xcd))
 
 ;
 ;  describe 'floatle', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xcd, 0x8c, 0x7a, 0x43]
-;      floatle.decode(stream).should.be.closeTo 250.55, 0.005
-;
 ;    it 'should have a size', ->
-;      floatle.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xcd, 0x8c, 0x7a, 0x43]
-;        done()
-;
-;      floatle.encode(stream, 250.55)
-;      stream.end()
 
-
-(check-= (decode floatle (+DecodeStream (bytes #xcd #x8c #x7a #x43))) 250.55 0.01)
+(check-= (decode floatle (open-input-bytes (bytes #xcd #x8c #x7a #x43))) 250.55 0.01)
 (check-equal? (size floatle) 4)
-(check-equal? (encode floatle #f 250.55) (bytes #xcd #x8c #x7a #x43))
+(check-equal? (encode floatle 250.55 #f) (bytes #xcd #x8c #x7a #x43))
 
 ;
 ;  describe 'double', ->
 ;    it 'is an alias for doublebe', ->
-;      double.should.equal doublebe
-
-;; modified test: `double` is the same endianness as the platform
+; modified test: `double` is the same endianness as the platform
 (check-equal? (decode double (bytes 0 1 2 3 4 5 6 7)) (send (if (system-big-endian?)
-                                                            doublebe
-                                                            doublele) decode (bytes 0 1 2 3 4 5 6 7)))
+                                                                doublebe
+                                                                doublele) decode (bytes 0 1 2 3 4 5 6 7)))
 
 ;
 ;  describe 'doublebe', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x40, 0x93, 0x4a, 0x3d, 0x70, 0xa3, 0xd7, 0x0a]
-;      doublebe.decode(stream).should.be.equal 1234.56
-;
 ;    it 'should have a size', ->
-;      doublebe.size().should.equal 8
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x40, 0x93, 0x4a, 0x3d, 0x70, 0xa3, 0xd7, 0x0a]
-;        done()
-;
-;      doublebe.encode(stream, 1234.56)
-;      stream.end()
 
-(check-equal? (decode doublebe (+DecodeStream (bytes #x40 #x93 #x4a #x3d #x70 #xa3 #xd7 #x0a))) 1234.56)
+(check-equal? (decode doublebe (open-input-bytes (bytes #x40 #x93 #x4a #x3d #x70 #xa3 #xd7 #x0a))) 1234.56)
 (check-equal? (size doublebe) 8)
-(check-equal? (encode doublebe #f 1234.56) (bytes #x40 #x93 #x4a #x3d #x70 #xa3 #xd7 #x0a))
+(check-equal? (encode doublebe 1234.56 #f) (bytes #x40 #x93 #x4a #x3d #x70 #xa3 #xd7 #x0a))
 
 ;
 ;  describe 'doublele', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x0a, 0xd7, 0xa3, 0x70, 0x3d, 0x4a, 0x93, 0x40]
-;      doublele.decode(stream).should.be.equal 1234.56
-;
 ;    it 'should have a size', ->
-;      doublele.size().should.equal 8
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x0a, 0xd7, 0xa3, 0x70, 0x3d, 0x4a, 0x93, 0x40]
-;        done()
-;
-;      doublele.encode(stream, 1234.56)
-;      stream.end()
 
-(check-equal? (decode doublele (+DecodeStream (bytes #x0a #xd7 #xa3 #x70 #x3d #x4a #x93 #x40))) 1234.56)
+(check-equal? (decode doublele (open-input-bytes (bytes #x0a #xd7 #xa3 #x70 #x3d #x4a #x93 #x40))) 1234.56)
 (check-equal? (size doublele) 8)
-(check-equal? (encode doublele #f 1234.56) (bytes #x0a #xd7 #xa3 #x70 #x3d #x4a #x93 #x40))
+(check-equal? (encode doublele 1234.56 #f) (bytes #x0a #xd7 #xa3 #x70 #x3d #x4a #x93 #x40))
 
 ;
 ;  describe 'fixed16', ->
 ;    it 'is an alias for fixed16be', ->
-;      fixed16.should.equal fixed16be
-
-;; modified test: `fixed16` is the same endianness as the platform
+; modified test: `fixed16` is the same endianness as the platform
 (check-equal? (decode fixed16 (bytes 0 1)) (send (if (system-big-endian?)
-                                                            fixed16be
-                                                            fixed16le) decode (bytes 0 1)))
+                                                     fixed16be
+                                                     fixed16le) decode (bytes 0 1)))
 
 ;
 ;  describe 'fixed16be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x19, 0x57]
-;      fixed16be.decode(stream).should.be.closeTo 25.34, 0.005
-;
 ;    it 'should have a size', ->
-;      fixed16be.size().should.equal 2
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x19, 0x57]
-;        done()
-;
-;      fixed16be.encode(stream, 25.34)
-;      stream.end()
 
-(check-= (decode fixed16be (+DecodeStream (bytes #x19 #x57))) 25.34 0.01)
+(check-= (decode fixed16be (open-input-bytes (bytes #x19 #x57))) 25.34 0.01)
 (check-equal? (size fixed16be) 2)
-(check-equal? (encode fixed16be #f 25.34) (bytes #x19 #x57))
+(check-equal? (encode fixed16be 25.34 #f) (bytes #x19 #x57))
 
 ;
 ;  describe 'fixed16le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x57, 0x19]
-;      fixed16le.decode(stream).should.be.closeTo 25.34, 0.005
-;
 ;    it 'should have a size', ->
-;      fixed16le.size().should.equal 2
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x57, 0x19]
-;        done()
-;
-;      fixed16le.encode(stream, 25.34)
-;      stream.end()
 
-(check-= (decode fixed16le (+DecodeStream (bytes #x57 #x19))) 25.34 0.01)
+(check-= (decode fixed16le (open-input-bytes (bytes #x57 #x19))) 25.34 0.01)
 (check-equal? (size fixed16le) 2)
-(check-equal? (encode fixed16le #f 25.34) (bytes #x57 #x19))
+(check-equal? (encode fixed16le 25.34 #f) (bytes #x57 #x19))
 
 ;
 ;  describe 'fixed32', ->
 ;    it 'is an alias for fixed32be', ->
-;      fixed32.should.equal fixed32be
+; modified test: `fixed32` is the same endianness as the platform
 
-;; modified test: `fixed32` is the same endianness as the platform
 (check-equal? (decode fixed32 (bytes 0 1 2 3)) (send (if (system-big-endian?)
-                                                            fixed32be
-                                                            fixed32le) decode (bytes 0 1 2 3)))
+                                                         fixed32be
+                                                         fixed32le) decode (bytes 0 1 2 3)))
 
 ;
 ;  describe 'fixed32be', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0x00, 0xfa, 0x8c, 0xcc]
-;      fixed32be.decode(stream).should.be.closeTo 250.55, 0.005
-;
 ;    it 'should have a size', ->
-;      fixed32be.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0x00, 0xfa, 0x8c, 0xcc]
-;        done()
-;
-;      fixed32be.encode(stream, 250.55)
-;      stream.end()
-
-(check-= (decode fixed32be (+DecodeStream (bytes #x00 #xfa #x8c #xcc))) 250.55 0.01)
+(check-= (decode fixed32be (open-input-bytes (bytes #x00 #xfa #x8c #xcc))) 250.55 0.01)
 (check-equal? (size fixed32be) 4)
-(check-equal? (encode fixed32be #f 250.55) (bytes #x00 #xfa #x8c #xcc))
+(check-equal? (encode fixed32be 250.55 #f) (bytes #x00 #xfa #x8c #xcc))
 
 ;
 ;  describe 'fixed32le', ->
 ;    it 'should decode', ->
-;      stream = new DecodeStream new Buffer [0xcc, 0x8c, 0xfa, 0x00]
-;      fixed32le.decode(stream).should.be.closeTo 250.55, 0.005
-;
 ;    it 'should have a size', ->
-;      fixed32le.size().should.equal 4
-;
 ;    it 'should encode', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [0xcc, 0x8c, 0xfa, 0x00]
-;        done()
-;
-;      fixed32le.encode(stream, 250.55)
-;      stream.end()
 
-(check-= (decode fixed32le (+DecodeStream (bytes #xcc #x8c #xfa #x00))) 250.55 0.01)
+(check-= (decode fixed32le (open-input-bytes (bytes #xcc #x8c #xfa #x00))) 250.55 0.01)
 (check-equal? (size fixed32le) 4)
-(check-equal? (encode fixed32le #f 250.55) (bytes #xcc #x8c #xfa #x00))
\ No newline at end of file
+(check-equal? (encode fixed32le 250.55 #f) (bytes #xcc #x8c #xfa #x00))
\ No newline at end of file
diff --git a/pitfall/xenomorph/test/optional-test.rkt b/pitfall/xenomorph/test/optional-test.rkt
index 34e29f93..7b48392b 100644
--- a/pitfall/xenomorph/test/optional-test.rkt
+++ b/pitfall/xenomorph/test/optional-test.rkt
@@ -8,193 +8,106 @@ https://github.com/mbutterick/restructure/blob/master/test/Optional.coffee
 ;describe 'Optional', ->
 ;  describe 'decode', ->
 ;    it 'should not decode when condition is falsy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, false
-;      should.not.exist optional.decode(stream)
-;      stream.pos.should.equal 0
-
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 #f)])
-  (check-equal? (decode optional stream) (void))
-  (check-equal? (· stream pos) 0))
 
+(parameterize ([current-input-port (open-input-bytes (bytes 0))])
+  (define optional (+Optional uint8 #f))
+  (check-equal? (decode optional) (void))
+  (check-equal? (pos (current-input-port)) 0))
 
 ;    it 'should not decode when condition is a function and falsy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, -> false
-;      should.not.exist optional.decode(stream)
-;      stream.pos.should.equal 0
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 (λ _ #f))])
-  (check-equal? (decode optional stream) (void))
-  (check-equal? (· stream pos) 0))
+(parameterize ([current-input-port (open-input-bytes (bytes 0))])
+  (define optional (+Optional uint8 (λ _ #f)))
+  (check-equal? (decode optional) (void))
+  (check-equal? (pos (current-input-port)) 0))
+
 
-;
 ;    it 'should decode when condition is omitted', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8
-;      should.exist optional.decode(stream)
-;      stream.pos.should.equal 1
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8)])
-  (check-not-equal? (decode optional stream) (void))
-  (check-equal? (· stream pos) 1))
+(parameterize ([current-input-port (open-input-bytes (bytes 0))])
+  (define optional (+Optional uint8))
+  (check-not-equal? (decode optional) (void))
+  (check-equal? (pos (current-input-port)) 1))
 
 ;
 ;    it 'should decode when condition is truthy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, true
-;      should.exist optional.decode(stream)
-;      stream.pos.should.equal 1
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 #t)])
-  (check-not-equal? (decode optional stream) (void))
-  (check-equal? (· stream pos) 1))
+(parameterize ([current-input-port (open-input-bytes (bytes 0))])
+  (define optional (+Optional uint8 #t))
+  (check-not-equal? (decode optional) (void))
+  (check-equal? (pos (current-input-port)) 1))
+
 
-;
 ;    it 'should decode when condition is a function and truthy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, -> true
-;      should.exist optional.decode(stream)
-;      stream.pos.should.equal 1
 
+(parameterize ([current-input-port (open-input-bytes (bytes 0))])
+  (define optional (+Optional uint8 (λ _ #t)))
+  (check-not-equal? (decode optional) (void))
+  (check-equal? (pos (current-input-port)) 1))
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 (λ _ #t))])
-  (check-not-equal? (decode optional stream) (void))
-  (check-equal? (· stream pos) 1))
 
-;
 ;  describe 'size', ->
-;    it 'should return 0 when condition is falsy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, false
-;      optional.size().should.equal 0
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 #f)])
-  (check-equal? (· optional size) 0))
+(check-equal? (size (+Optional uint8 #f)) 0)
 
 ;
 ;    it 'should return 0 when condition is a function and falsy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, -> false
-;      optional.size().should.equal 0
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 (λ _ #f))])
-  (check-equal? (· optional size) 0))
+(check-equal? (size (+Optional uint8 (λ _ #f))) 0)
+
 
-;
 ;    it 'should return given type size when condition is omitted', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8
-;      optional.size().should.equal 1
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8)])
-  (check-equal? (· optional size) 1))
-;
+(check-equal? (size (+Optional uint8)) 1)
+
+
 ;    it 'should return given type size when condition is truthy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, true
-;      optional.size().should.equal 1
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 #t)])
-  (check-equal? (· optional size) 1))
+(check-equal? (size (+Optional uint8 #t)) 1)
+
 
-;
 ;    it 'should return given type size when condition is a function and truthy', ->
-;      stream = new DecodeStream new Buffer [0]
-;      optional = new Optional uint8, -> true
-;      optional.size().should.equal 1
 
-(let ([stream (+DecodeStream (+Buffer '(0)))]
-      [optional (+Optional uint8 (λ _ #t))])
-  (check-equal? (· optional size) 1))
+(check-equal? (size (+Optional uint8 (λ _ #t))) 1)
+
 
-;
 ;  describe 'encode', ->
 ;    it 'should not encode when condition is falsy', (done) ->
-;      stream = new EncodeStream
-;      optional = new Optional uint8, false
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal []
-;        done()
-;
-;      optional.encode stream, 128
-;      stream.end()
 
-(let ([stream (+EncodeStream)]
-      [optional (+Optional uint8 #f)])
-  (encode optional stream 128)
-  (check-equal? (dump stream) (+Buffer empty)))
+(parameterize ([current-output-port (open-output-bytes)])
+  (define optional (+Optional uint8 #f))
+  (encode optional 128)
+  (check-equal? (dump (current-output-port)) (bytes)))
+
 
-;
 ;    it 'should not encode when condition is a function and falsy', (done) ->
-;      stream = new EncodeStream
-;      optional = new Optional uint8, -> false
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal []
-;        done()
-;
-;      optional.encode stream, 128
-;      stream.end()
 
-(let ([stream (+EncodeStream)]
-      [optional (+Optional uint8 (λ _ #f))])
-  (encode optional stream 128)
-  (check-equal? (dump stream) (+Buffer empty)))
+(parameterize ([current-output-port (open-output-bytes)])
+  (define optional (+Optional uint8 (λ _ #f)))
+  (encode optional 128)
+  (check-equal? (dump (current-output-port)) (bytes)))
 
 
 ;
 ;    it 'should encode when condition is omitted', (done) ->
-;      stream = new EncodeStream
-;      optional = new Optional uint8
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [128]
-;        done()
-;
-;      optional.encode stream, 128
-;      stream.end()
 
-(let ([stream (+EncodeStream)]
-      [optional (+Optional uint8)])
-  (encode optional stream 128)
-  (check-equal? (dump stream) (+Buffer '(128))))
+(parameterize ([current-output-port (open-output-bytes)])
+  (define optional (+Optional uint8))
+  (encode optional 128)
+  (check-equal? (dump (current-output-port)) (bytes 128)))
+
 
-;
 ;    it 'should encode when condition is truthy', (done) ->
-;      stream = new EncodeStream
-;      optional = new Optional uint8, true
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [128]
-;        done()
-;
-;      optional.encode stream, 128
-;      stream.end()
 
-(let ([stream (+EncodeStream)]
-      [optional (+Optional uint8 #t)])
-  (encode optional stream 128)
-  (check-equal? (dump stream) (+Buffer '(128))))
+(parameterize ([current-output-port (open-output-bytes)])
+  (define optional (+Optional uint8 #t))
+  (encode optional 128)
+  (check-equal? (dump (current-output-port)) (bytes 128)))
+
 
-;
 ;    it 'should encode when condition is a function and truthy', (done) ->
-;      stream = new EncodeStream
-;      optional = new Optional uint8, -> true
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer [128]
-;        done()
-;
-;      optional.encode stream, 128
-;      stream.end()
 
-(let ([stream (+EncodeStream)]
-      [optional (+Optional uint8 (λ _ #t))])
-  (encode optional stream 128)
-  (check-equal? (dump stream) (+Buffer '(128))))
\ No newline at end of file
+(parameterize ([current-output-port (open-output-bytes)])
+  (define optional (+Optional uint8 (λ _ #t)))
+  (encode optional 128)
+  (check-equal? (dump (current-output-port)) (bytes 128)))
\ No newline at end of file