diff --git a/xenomorph/xenomorph/undo/array.rkt b/xenomorph/xenomorph/undo/array.rkt
deleted file mode 100644
index 2fd7d9d6..00000000
--- a/xenomorph/xenomorph/undo/array.rkt
+++ /dev/null
@@ -1,94 +0,0 @@
-#lang racket/base
-(require racket/class
-         sugar/unstable/class
-         sugar/unstable/dict
-         sugar/unstable/js
-         "private/generic.rkt"
-         "private/helper.rkt"
-         "number.rkt"
-         "utils.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
-|#
-
-(define-subclass xenomorph-base% (ArrayT type [len #f] [length-type 'count])
-          
-  (define/augride (decode port [parent #f])
-    (define ctx (if (NumberT? len)
-                    (mhasheq 'parent parent
-                             '_startOffset (pos port)
-                             '_currentOffset 0
-                             '_length len)
-                    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 (+ (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 +inf.0]))
-       (for/list ([i (in-naturals)]
-                  #: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 port ctx))]))
-  
-
-  (define/augride (size [val #f] [ctx #f])
-    (when val (unless (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))
-                                            (values ctx 0))])
-             (+ len-size (for/sum ([item (in-list (countable->list val))])
-                                  (send type size item ctx))))]
-      [else (let ([item-count (resolve-length len #f ctx)]
-                  [item-size (send type size #f ctx)])
-              (* item-size item-count))]))
-  
-
-  (define/augride (encode port array [parent #f])
-    (when array (unless (countable? array)
-                  (raise-argument-error 'Array:encode "list or countable" array)))
-
-    (define (encode-items ctx)
-      (let* ([items (countable->list array)]
-             [item-count (length items)]
-             [max-items (if (number? len) len item-count)])
-        (for ([item (in-list items)])
-             (send type encode port item ctx))))
-
-    (cond
-      [(NumberT? len) (define ctx (mhash 'pointers null
-                                         'startOffset (pos port)
-                                         'parent parent))
-                      (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
-                           (send (· ptr type) encode port (· ptr val)))]
-      [else (encode-items parent)])))
-
-(define-syntax-rule (define-procedures (NEW ...) (OLD ...))
-  (define-values (NEW ...)
-    (values (if (procedure? OLD)
-                (procedure-rename OLD 'NEW)
-                OLD) ...)))
-
-(define-procedures (Array Array? +Array) (ArrayT ArrayT? +ArrayT))
-(define-procedures (array% array? array) (ArrayT ArrayT? +ArrayT))
-
-(test-module
- (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/xenomorph/xenomorph/undo/base.rkt b/xenomorph/xenomorph/undo/base.rkt
deleted file mode 100644
index 10c9d897..00000000
--- a/xenomorph/xenomorph/undo/base.rkt
+++ /dev/null
@@ -1,123 +0,0 @@
-#lang debug racket/base
-(require racket/class
-         sugar/unstable/class
-         racket/generic
-         racket/private/generic-methods
-         "private/generic.rkt"
-         racket/port
-         racket/dict)
-(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])
-  (encode codable [val] [stream] #:parent [parent]))
-
-
-(define codable<%>
-  (interface* ()
-              ([(generic-property gen:codable)
-                (generic-method-table gen:codable
-                                      (define (decode o [port (current-input-port)] #:parent [parent #f])
-                                        (send o decode port parent))
-                                      (define (encode o  [val #f] [port (current-output-port)] #:parent [parent #f])
-                                        (when (port? val)
-                                          (raise-argument-error 'encode "encodable value" val))
-                                        (send o encode port val parent)))])))
-
-
-(define-generics sizable
-  (size sizable [val] [parent]))
-
-(define sizable<%>
-  (interface* ()
-              ([(generic-property gen:sizable)
-                (generic-method-table gen:sizable
-                                      (define (size o [val #f] [parent #f]) (send o size val parent)))])))
-
-(define (dump x)
-  (define (dump-dict x)
-    (for/list ([(k v) (in-dict x)])
-              (cons (dump k) (dump v))))
-  (let loop ([x x])
-    (cond
-      [(input-port? x) (port->bytes x)]
-      [(output-port? x) (get-output-bytes x)]
-      [(and (object? x)
-            (memq 'dump (interface->method-names (object-interface x)))) (send x dump)]
-      [(dict? x) (dump-dict x)]
-      [(list? x) (map loop x)]
-      [else x])))
-
-#;(define dumpable<%>
-    (interface* ()
-                ([(generic-property gen:dumpable)
-                  (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<%>)
-    (super-new)
-    (field [_hash (make-hash)]
-           [_list null])
-
-    (define/pubment (decode port [parent #f] . args)
-      ;; todo: is `indexable?` really a necessary condition? doesn't seem to break anything withou it
-      #;(when parent (unless (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 (symbol-append (get-class-name) ':decode) "bytes or input port" port)]))
-      (post-decode (inner (void) decode ip parent) port parent . args))
-    
-    (define/pubment (encode port val-in [parent #f] . args)
-      #;(report* port val-in parent)
-      (define val (pre-encode val-in port))
-      #;(when parent (unless (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 . args))
-      (when (bytes? encode-result)
-        (write-bytes encode-result op))
-      (when (not port) (get-output-bytes op)))
-    
-    (define/pubment (size [val #f] [parent #f] . args)
-      (when parent (unless (indexable? parent)
-                     (raise-argument-error (symbol-append (get-class-name) ':size) "indexable" parent)))
-      (define result (inner (void) size val parent . args))
-      (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 (dump) (void))))
-
-(define-class-predicates xenomorph-base%)
-
-(define-subclass xenomorph-base% (RestructureBase))
-(define-subclass RestructureBase (Streamcoder))
-
diff --git a/xenomorph/xenomorph/undo/bitfield.rkt b/xenomorph/xenomorph/undo/bitfield.rkt
deleted file mode 100644
index 78c2b267..00000000
--- a/xenomorph/xenomorph/undo/bitfield.rkt
+++ /dev/null
@@ -1,49 +0,0 @@
-#lang racket/base
-(require racket/class
-         racket/list
-         sugar/unstable/class
-         sugar/unstable/dict
-         "private/generic.rkt"
-         "private/helper.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Bitfield.coffee
-|#
-
-(define-subclass Streamcoder (Bitfield type [flags empty])
-  (unless (andmap (λ (f) (or (key? f) (not f))) flags)
-    (raise-argument-error 'Bitfield "list of keys" flags))
-          
-  (define/augment (decode stream . _)
-    (define flag-hash (mhasheq))
-    (for* ([val (in-value (send type decode stream))]
-           [(flag i) (in-indexed flags)]
-           #:when flag)
-      (hash-set! flag-hash flag (bitwise-bit-set? val i)))
-    flag-hash)
-
-  (define/augment (size . _) (send type size))
-
-  (define/augment (encode port flag-hash [ctx #f])
-    (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))
-
-  (define/override (get-class-name) 'Bitfield))
-
-
-(test-module
- (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
- (check-true (ref bf 'bold))
- (check-true (ref bf 'underline))
- (check-true (ref bf 'shadow))
- (check-false (ref bf 'italic))
- (check-false (ref bf 'condensed))
- (check-false (ref bf 'extended))
- (check-equal? (encode bfer bf #f) #"\0\25"))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/buffer.rkt b/xenomorph/xenomorph/undo/buffer.rkt
deleted file mode 100644
index bb4ebc1e..00000000
--- a/xenomorph/xenomorph/undo/buffer.rkt
+++ /dev/null
@@ -1,60 +0,0 @@
-#lang racket/base
-(require racket/class
-         sugar/unstable/class
-         "private/generic.rkt"
-         "private/helper.rkt"
-         "number.rkt"
-         "utils.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Buffer.coffee
-|#
-
-#|
-A Buffer is a container object for any data object that supports random access
-A Node Buffer object is basically a byte string.
-First argument must be a string, Buffer, ArrayBuffer, Array, or array-like object.
-A Restructure RBuffer object is separate.
-|#
-
-(define (+Buffer xs [type #f])
-  ((if (string? xs)
-       string->bytes/utf-8
-       list->bytes) xs))
-
-(define-subclass xenomorph-base% (RBuffer [len #xffff])
-  
-  (define/augment (decode port [parent #f])
-    (define decoded-len (resolve-length len port parent))
-    (read-bytes decoded-len port))
-
-  (define/augment (size [val #f] [parent #f])
-    (when val (unless (bytes? val)
-                (raise-argument-error 'Buffer:size "bytes" val)))
-    (if val
-        (bytes-length val)
-        (resolve-length len val parent)))
-
-  (define/augment (encode port buf [parent #f])
-    (unless (bytes? buf)
-      (raise-argument-error 'Buffer:encode "bytes" buf))
-    (define op (or port (open-output-bytes)))
-    (when (NumberT? len)
-      (send len encode op (length buf)))
-    (write-bytes buf op)
-    (unless port (get-output-bytes op))))
-
-(define-subclass RBuffer (BufferT))
-
-
-#;(test-module
-   (require "stream.rkt")
-   (define stream (+DecodeStream #"\2BCDEF"))
-   (define S (+String uint8 'utf8))
-   (check-equal? (send S decode stream) "BC")
-   (define os (+EncodeStream))
-   (send S encode os "Mike")
-   (check-equal? (send os dump) #"\4Mike")
-   (check-equal? (send (+String) size "foobar") 6))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/enum.rkt b/xenomorph/xenomorph/undo/enum.rkt
deleted file mode 100644
index 8913d6d0..00000000
--- a/xenomorph/xenomorph/undo/enum.rkt
+++ /dev/null
@@ -1,26 +0,0 @@
-#lang racket/base
-(require racket/class
-         racket/list
-         sugar/unstable/class
-         "private/helper.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Enum.coffee
-|#
-
-(define-subclass xenomorph-base% (Enum type [options empty])
-
-  (define/augment (decode stream . _)
-    (define index (send type decode stream))
-    (or (list-ref options index) index))
-
-  (define/augment (size . _) (send type size))
-
-  (define/augment (encode stream val [ctx #f])
-    (define index (index-of options val))
-    (unless index
-      (raise-argument-error 'Enum:encode "valid option" val))
-    (send type encode stream index)))
-
diff --git a/xenomorph/xenomorph/undo/info.rkt b/xenomorph/xenomorph/undo/info.rkt
deleted file mode 100644
index f238d403..00000000
--- a/xenomorph/xenomorph/undo/info.rkt
+++ /dev/null
@@ -1,4 +0,0 @@
-#lang info
-
-(define scribblings '(("scribblings/xenomorph.scrbl" ())))
-(define compile-omit-paths '("test/"))
diff --git a/xenomorph/xenomorph/undo/lazy-array.rkt b/xenomorph/xenomorph/undo/lazy-array.rkt
deleted file mode 100644
index e8cd6528..00000000
--- a/xenomorph/xenomorph/undo/lazy-array.rkt
+++ /dev/null
@@ -1,83 +0,0 @@
-#lang racket/base
-(require racket/class
-         sugar/unstable/class
-         sugar/unstable/dict
-         "private/generic.rkt"
-         "private/helper.rkt"
-         "utils.rkt"
-         "array.rkt"
-         "number.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-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] [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" (sub1 len)) index))
-    (ref! item-cache index (λ ()
-                             (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))))
-
-
-(define-subclass ArrayT (LazyArray)
-  (inherit-field len type)
-  
-  (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 starting-pos
-                               '_currentOffset 0
-                               '_length len)
-                      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])
-    (super size (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
- (define bstr #"ABCD1234")
- (define ds (open-input-bytes bstr))
- (define la (+LazyArray uint8 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/xenomorph/xenomorph/undo/main.rkt b/xenomorph/xenomorph/undo/main.rkt
deleted file mode 100644
index 00e28a92..00000000
--- a/xenomorph/xenomorph/undo/main.rkt
+++ /dev/null
@@ -1,18 +0,0 @@
-#lang racket/base
-
-(define-syntax-rule (r+p ID ...)
-  (begin (require ID ...) (provide (all-from-out ID ...))))
-
-(r+p "array.rkt"
-     "base.rkt"
-     "bitfield.rkt"
-     "buffer.rkt"
-     "enum.rkt"
-     "lazy-array.rkt"
-     "number.rkt"
-     "optional.rkt"
-     "pointer.rkt"
-     "reserved.rkt"
-     "string.rkt"
-     "struct.rkt"
-     "versioned-struct.rkt")
diff --git a/xenomorph/xenomorph/undo/number.rkt b/xenomorph/xenomorph/undo/number.rkt
deleted file mode 100644
index b555c926..00000000
--- a/xenomorph/xenomorph/undo/number.rkt
+++ /dev/null
@@ -1,197 +0,0 @@
-#lang racket/base
-(require (for-syntax racket/base
-                     racket/syntax
-                     "sizes.rkt"
-                     racket/match)
-         racket/class
-         sugar/unstable/class
-         "private/helper.rkt"
-         "sizes.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Number.coffee
-|#
-
-(define (ends-with-8? type)
-  (define str (symbol->string type))
-  (equal? (substring str (sub1 (string-length str))) "8"))
-
-(define (signed-type? type)
-  (not (equal? "u" (substring (symbol->string type) 0 1))))
-
-(test-module
- (check-false (signed-type? 'uint16))
- (check-true (signed-type? 'int16)))
-
-(define (exact-if-possible x) (if (integer? x) (inexact->exact x) x))
-(define system-endian (if (system-big-endian?) 'be 'le))
-
-(define-subclass xenomorph-base% (Integer [type 'uint16] [endian system-endian])
-  (getter-field [number-type (string->symbol (format "~a~a" type (if (ends-with-8? type) "" endian)))])
-  (define _signed? (signed-type? type))
-
-  ;; `get-type-size` will raise error if number-type is invalid: use this as check of input
-  ;; size of a number doesn't change, so we can stash it as `_size`
-  (define _size (with-handlers ([exn:fail:contract?
-                                 (λ (exn) 
-                                   (raise-argument-error 'Integer "valid type and endian" (format "~v ~v" type endian)))])
-                  (get-type-size number-type)))
-
-  (define bits (* _size 8))
-  
-  (define/augment (size . args) _size)
-
-  (define-values (bound-min bound-max)
-    ;; if a signed integer has n bits, it can contain a number
-    ;; between - (expt 2 (sub1 n)) and (sub1 (expt 2 (sub1 n)).
-    (let* ([signed-max (sub1 (arithmetic-shift 1 (sub1 bits)))]
-           [signed-min (sub1 (- signed-max))]
-           [delta (if _signed? 0 signed-min)])
-      (values (- signed-min delta) (- signed-max delta))))
-
-  (define/augment (decode port [parent #f])
-    (define bstr (read-bytes _size port))
-    (define bs ((if (eq? endian system-endian) values reverse) (bytes->list bstr)))
-    (define unsigned-int (for/sum ([(b i) (in-indexed bs)])
-                                  (arithmetic-shift b (* 8 i))))
-    unsigned-int)
-
-  (define/override (post-decode unsigned-val . _)
-    (if _signed? (unsigned->signed unsigned-val bits) unsigned-val))
-
-  (define/override (pre-encode val . _)
-    (exact-if-possible val))
-
-  (define/augment (encode port val [parent #f])
-    (unless (<= bound-min val bound-max)
-      (raise-argument-error 'Integer:encode (format "value within range of ~a ~a-byte int (~a to ~a)" (if _signed? "signed" "unsigned") _size bound-min bound-max) val))
-    (define-values (bs _) (for/fold ([bs null] [n val])
-                                    ([i (in-range _size)])
-                            (values (cons (bitwise-and n #xff) bs) (arithmetic-shift n -8))))
-    (apply bytes ((if (eq? endian 'be) values reverse) bs))))
-
-(define-values (NumberT NumberT? +NumberT) (values Integer Integer? +Integer))
-(define-values (Number Number? +Number) (values Integer Integer? +Integer))
-
-
-(define-subclass xenomorph-base% (Float _size [endian system-endian])
-  (define byte-size (/ _size 8))
-  
-  (define/augment (decode port [parent #f]) ;  convert int to float
-    (define bs (read-bytes byte-size port))
-    (floating-point-bytes->real bs (eq? endian 'be)))
-
-  (define/augment (encode port val [parent #f]) ; convert float to int
-    (define bs (real->floating-point-bytes val byte-size (eq? endian 'be)))
-    bs)
-
-  (define/augment (size . args) byte-size))
-
-
-(define-instance float (make-object Float 32))
-(define-instance floatbe (make-object Float 32 'be))
-(define-instance floatle (make-object Float 32 'le))
-
-(define-instance double (make-object Float 64))
-(define-instance doublebe (make-object Float 64 'be))
-(define-instance doublele (make-object Float 64 'le))
-
-
-(define-subclass* Integer (Fixed size [fixed-endian system-endian] [fracBits (floor (/ size 2))])
-  (super-make-object (string->symbol (format "int~a" size)) fixed-endian)
-  (define _point (arithmetic-shift 1 fracBits))
-
-  (define/override (post-decode int . _)
-    (exact-if-possible (/ int _point 1.0)))
-
-  (define/override (pre-encode fixed . _)
-    (exact-if-possible (floor (* fixed _point)))))
-
-(define-instance fixed16 (make-object Fixed 16))
-(define-instance fixed16be (make-object Fixed 16 'be))
-(define-instance fixed16le (make-object Fixed 16 'le))
-(define-instance fixed32 (make-object Fixed 32))
-(define-instance fixed32be (make-object Fixed 32 'be))
-(define-instance fixed32le (make-object Fixed 32 'le))
-
-
-(test-module
- (check-exn exn:fail:contract? (λ () (+Integer 'not-a-valid-type)))
- (check-exn exn:fail:contract? (λ () (encode uint8 256 #f)))
- (check-not-exn (λ () (encode uint8 255 #f)))
- (check-exn exn:fail:contract? (λ () (encode int8 256 #f)))
- (check-exn exn:fail:contract? (λ () (encode int8 255 #f)))
- (check-not-exn (λ () (encode int8 127 #f)))
- (check-not-exn (λ () (encode int8 -128 #f )))
- (check-exn exn:fail:contract? (λ () (encode int8 -129 #f)))
- (check-exn exn:fail:contract? (λ () (encode uint16 (add1 #xffff) #f)))
- (check-not-exn (λ () (encode uint16 #xffff #f)))
- 
- (let ([o (+Integer 'uint16 'le)]
-       [ip (open-input-bytes (bytes 1 2 3 4))]
-       [op (open-output-bytes)])
-   (check-equal? (send o decode ip) 513) ;; 1000 0000  0100 0000
-   (check-equal? (send o decode ip) 1027)  ;; 1100 0000 0010 0000
-   (encode o 513 op)
-   (check-equal? (get-output-bytes op) (bytes 1 2))
-   (encode o 1027 op)
-   (check-equal? (get-output-bytes op) (bytes 1 2 3 4)))
-
- (let ([o (+Integer 'uint16 'be)]
-       [ip (open-input-bytes (bytes 1 2 3 4))]
-       [op (open-output-bytes)])
-   (check-equal? (send o decode ip) 258) ;; 0100 0000 1000 0000 
-   (check-equal? (send o decode ip) 772) ;; 0010 0000 1100 0000
-   (encode o 258 op)
-   (check-equal? (get-output-bytes op) (bytes 1 2))
-   (encode o 772 op)
-   (check-equal? (get-output-bytes op) (bytes 1 2 3 4))))
-
-
-(test-module
- (check-equal? (send (+Integer 'uint8) size) 1)
- (check-equal? (send (+Integer) size) 2)
- (check-equal? (send (+Integer 'uint32) size) 4)
- (check-equal? (send (+Integer 'double) size) 8)
-
- (check-equal? (send (+Number 'uint8) size) 1)
- (check-equal? (send (+Number) size) 2)
- (check-equal? (send (+Number 'uint32) size) 4)
- (check-equal? (send (+Number 'double) size) 8))
-
-;; use keys of type-sizes hash to generate corresponding number definitions
-(define-syntax (make-int-types stx)
-  (syntax-case stx ()
-    [(_) (with-syntax* ([((ID BASE ENDIAN) ...) (for*/list ([k (in-hash-keys type-sizes)]
-                                                            [kstr (in-value (format "~a" k))]
-                                                            #:unless (regexp-match #rx"^(float|double)" kstr))
-                                                           (match-define (list* prefix suffix _)
-                                                             (regexp-split #rx"(?=[bl]e|$)" kstr))
-                                                           (map string->symbol
-                                                                (list (string-downcase kstr)
-                                                                      prefix
-                                                                      (if (positive? (string-length suffix))
-                                                                          suffix
-                                                                          (if (system-big-endian?) "be" "le")))))]
-                        [(ID ...) (map (λ (s) (datum->syntax stx (syntax->datum s))) (syntax->list #'(ID ...)))])
-           #'(begin (define-instance ID (make-object Integer 'BASE 'ENDIAN)) ...))]))
-                                                            
-(make-int-types)
-
-(test-module
- (check-equal? (size uint8) 1)
- (check-equal? (size uint16) 2)
- (check-equal? (size uint32) 4)
- (check-equal? (size double) 8)
-
- (define bs (encode fixed16be 123.45 #f))
- (check-equal? bs #"{s")
- (check-equal? (ceiling (* (decode fixed16be  bs) 100)) 12345.0)
-
- (check-equal? (decode int8  (bytes 127)) 127)
- (check-equal? (decode int8 (bytes 255)) -1)
-
- (check-equal? (encode int8 -1 #f) (bytes 255))
- (check-equal? (encode int8 127 #f) (bytes 127)))
diff --git a/xenomorph/xenomorph/undo/optional.rkt b/xenomorph/xenomorph/undo/optional.rkt
deleted file mode 100644
index 80b2cf6d..00000000
--- a/xenomorph/xenomorph/undo/optional.rkt
+++ /dev/null
@@ -1,30 +0,0 @@
-#lang racket/base
-(require racket/class
-         sugar/unstable/class
-         "private/helper.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Optional.coffee
-|#
-
-(define-subclass xenomorph-base% (Optional type [condition #t])
-
-  (define (resolve-condition parent)
-    (if (procedure? condition)
-        (condition parent)
-        condition))
-  
-  (define/augment (decode stream parent)
-    (when (resolve-condition parent)
-      (send type decode stream parent)))
-
-  (define/augment (size val parent)
-    (when (resolve-condition parent)
-      (send type size val parent)))
-
-  (define/augment (encode stream val parent)
-    (when (resolve-condition parent)
-      (send type encode stream val parent))))
-
diff --git a/xenomorph/xenomorph/undo/pointer.rkt b/xenomorph/xenomorph/undo/pointer.rkt
deleted file mode 100644
index ddb41362..00000000
--- a/xenomorph/xenomorph/undo/pointer.rkt
+++ /dev/null
@@ -1,107 +0,0 @@
-#lang racket/base
-(require racket/class
-         sugar/unstable/class
-         sugar/unstable/case
-         sugar/unstable/dict
-         sugar/unstable/js
-         "private/generic.rkt"
-         "private/helper.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
-|#
-
-(define (resolve-void-pointer type val)
-  (cond
-    [type (values type val)]
-    [(VoidPointer? val) (values (· val type) (· val value))]
-    [else (raise-argument-error 'Pointer:size "VoidPointer" val)]))
-
-(define (find-top-ctx ctx)
-  (cond
-    [(· ctx parent) => find-top-ctx]
-    [else ctx]))
-
-(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)) 
-  (define null-value (or (· options nullValue) 0))
-  (define lazy (· options lazy))
-  (define relative-getter-or-0 (or (· options relativeTo) (λ (ctx) 0))) ; changed this to a simple lambda
-
-  (define/augment (decode port [ctx #f])
-    (define offset (send offset-type decode port ctx))
-    (cond
-      [(and allow-null (= offset null-value)) #f] ; handle null pointers
-      [else
-       (define relative (+ (caseq pointer-style
-                                  [(local) (· ctx _startOffset)]
-                                  [(immediate) (- (pos port) (send offset-type size))]
-                                  [(parent) (· ctx parent _startOffset)]
-                                  [(global) (or (· (find-top-ctx ctx) _startOffset) 0)]
-                                  [else (error 'unknown-pointer-style)])
-                           (relative-getter-or-0 ctx)))
-       (define ptr (+ offset relative))
-       (cond
-         [type (define val (void))
-               (define (decode-value)
-                 (cond
-                   [(not (void? val)) val]
-                   [else
-                    (define orig-pos (pos port))
-                    (pos port ptr)
-                    (set! val (send type decode port ctx))
-                    (pos port orig-pos)
-                    val]))
-               (if lazy
-                   (LazyThunk decode-value)
-                   (decode-value))]
-         [else ptr])]))
-
-  
-  (define/augment (size [val #f] [ctx #f])
-    (let*-values ([(parent) ctx]
-                  [(ctx) (caseq pointer-style
-                                [(local immediate) ctx]
-                                [(parent) (· ctx parent)]
-                                [(global) (find-top-ctx ctx)]
-                                [else (error 'unknown-pointer-style)])]
-                  [(type val) (resolve-void-pointer type val)])
-      (when (and val ctx)
-        (ref-set! ctx 'pointerSize (and (· ctx pointerSize)
-                                        (+ (· ctx pointerSize) (send type size val parent)))))
-      (send offset-type size)))
-                 
-
-  (define/augment (encode port val [ctx #f])
-    (unless ctx
-      ;; todo: furnish default pointer context? adapt from Struct?
-      (raise-argument-error 'Pointer:encode "valid pointer context" ctx))
-    (if (not val)
-        (send offset-type encode port null-value)
-        (let* ([parent ctx]
-               [ctx (caseq pointer-style
-                           [(local immediate) ctx]
-                           [(parent) (· ctx parent)]
-                           [(global) (find-top-ctx ctx)]
-                           [else (error 'unknown-pointer-style)])]
-               [relative (+ (caseq pointer-style
-                                   [(local parent) (· ctx startOffset)]
-                                   [(immediate) (+ (pos port) (send offset-type size val parent))]
-                                   [(global) 0])
-                            (relative-getter-or-0 (· parent val)))])
-
-          (send offset-type encode port (- (· ctx pointerOffset) relative))
-         
-          (let-values ([(type val) (resolve-void-pointer type val)])
-            (ref-set! ctx 'pointers (append (· ctx pointers) (list (mhasheq 'type type
-                                                                            'val val
-                                                                            'parent parent))))
-            (ref-set! ctx 'pointerOffset (+ (· ctx pointerOffset) (send type size val parent))))))))
-
-
-;; A pointer whose type is determined at decode time
-(define-subclass object% (VoidPointer type value))
diff --git a/xenomorph/xenomorph/undo/private/generic.rkt b/xenomorph/xenomorph/undo/private/generic.rkt
deleted file mode 100644
index 04387488..00000000
--- a/xenomorph/xenomorph/undo/private/generic.rkt
+++ /dev/null
@@ -1,110 +0,0 @@
-#lang racket/base
-
-(require racket/generic
-         (prefix-in b: racket/base)
-         racket/dict
-         racket/class
-         racket/match)
-
-(provide (all-defined-out))
-
-(define-generics indexable
-  (ref indexable i [thunk])
-  (ref! indexable i [thunk])
-  (ref-set! indexable i v)
-  (ref-keys indexable)
-  #:defaults
-  ([hash? (define (ref o i [thunk #f]) (hash-ref o i thunk))
-          (define (ref! o i [thunk #f]) (hash-ref! o i thunk))
-          (define ref-set! hash-set!)
-          (define ref-keys hash-keys)]
-   [dict? (define (ref o i [thunk #f]) (dict-ref o i thunk))
-          (define (ref! o i [thunk #f]) (dict-ref o i thunk))
-          (define ref-set! dict-set!)
-          (define ref-keys dict-keys)]
-   [object? (define (ref o i [thunk #f]) (with-handlers ([exn:fail:object? (λ (exn) (hash-ref (get-field _hash o) i thunk))]) (dynamic-get-field i o)))
-            (define (ref-set! o i v) (with-handlers ([exn:fail:object? (λ (exn) (hash-set! (get-field _hash o) i v))]) (dynamic-set-field! i o v)))
-            (define (ref-keys o) (append (remove '_hash (field-names o)) (hash-keys (get-field _hash o))))]))
-
-(module+ test
-  (require rackunit racket/set)
-  (define h (make-hash '((foo . 42))))
-  (check-equal? (ref h 'foo) 42)
-  (ref-set! h 'foo 85)
-  (check-equal? (ref h 'foo) 85)
-  (ref-set! h 'bar 121)
-  (check-equal? (ref h 'bar) 121)
-  (check-equal? (apply set (ref-keys h)) (apply set '(foo bar)))
-  (define o (make-object (class object% (super-new) (field [_hash (make-hash)][foo 42]))))
-  (check-equal? (ref o 'foo) 42)
-  (ref-set! o 'foo 100)
-  (check-equal? (ref o 'foo) 100)
-  (ref-set! o 'bar 121)
-  (check-equal? (ref o 'bar) 121)
-  (check-equal? (apply set (ref-keys o)) (apply set '(foo bar))))
-
-(define (ref* c . is)
-  (for/fold ([c c])
-            ([i (in-list is)])
-    (ref c i)))
-
-(define (ref*-set! c . is+val)
-  (match-define (list is ... i val) is+val)
-  (ref-set! (apply ref* c is) i val))
-
-(require sugar/debug)
-(define (ref-set*! c . kvs)
-  (for ([k (in-list kvs)]
-        [v (in-list (cdr kvs))]
-        [i (in-naturals)]
-        #:when (even? i))
-    (ref-set! c k v)))
-
-(module+ test
-  (define h2 (make-hash (list (cons 'foo (make-hash (list (cons 'bar (make-hash '((zam . 42))))))))))
-  (check-equal? (ref* h2 'foo 'bar 'zam) 42)
-  (ref*-set! h2 'foo 'bar 'zam 89)
-  (check-equal? (ref* h2 'foo 'bar 'zam) 89)
-  (ref-set*! h2 'hi 1 'there 2)
-  (check-equal? (ref h2 'hi) 1)
-  (check-equal? (ref h2 'there) 2))
-
-(define-generics countable
-  (length countable)
-  (countable->list countable)
-  #:defaults
-  ([list? (define length b:length)
-          (define countable->list (λ (x) x))]
-   [vector? (define length vector-length)
-            (define countable->list vector->list)]
-   [string? (define length string-length)
-            (define countable->list string->list)]
-   [bytes? (define length bytes-length)
-           (define countable->list bytes->list)]
-   [dict? (define length dict-count)
-          (define countable->list (λ (x) x))]
-   [object? (define (length o) (b:length (get-field _list o)))
-            (define (countable->list o) (get-field _list o))]))
-
-(module+ test
-  (require racket/list)
-  (check-equal? (length (make-list 42 #f)) 42)
-  (check-equal? (length (make-vector 42 #f)) 42)
-  (check-equal? (length (make-string 42 #\x)) 42)
-  (check-equal? (length (make-bytes 42 0)) 42)
-  (check-equal? (length (map cons (range 42) (range 42))) 42)
-  (check-equal? (length (make-object (class object% (super-new) (field [_list (make-list 42 #f)])))) 42))
-
-(define-generics pushable
-  (push-end pushable xs)
-  #:defaults
-  ([list? (define push-end b:append)]
-   [object? (define (push-end o xs)
-              (append (get-field _list o) xs))]))
-
-(module+ test
-  (check-equal? (push-end (range 3) '(3 4 5)) (range 6))
-  (define o2 (make-object (class object% (super-new) (field [_list (range 3)]))))
-  (ref-set! o2 '_list (push-end o2 '(3 4 5)))
-  (check-equal? (ref o2 '_list) (range 6)))
-
diff --git a/xenomorph/xenomorph/undo/private/helper.rkt b/xenomorph/xenomorph/undo/private/helper.rkt
deleted file mode 100644
index eb9e01ae..00000000
--- a/xenomorph/xenomorph/undo/private/helper.rkt
+++ /dev/null
@@ -1,23 +0,0 @@
-#lang racket/base
-(require (for-syntax racket/base br/syntax) racket/class br/define "../base.rkt")
-(provide (all-defined-out) (all-from-out "../base.rkt"))
-
-
-(define-macro (test-module . EXPRS)
-  #`(module+ test
-      (require #,(datum->syntax caller-stx 'rackunit) #,(datum->syntax caller-stx 'racket/serialize))
-      . EXPRS))
-
-(define index? (λ (x) (and (number? x) (integer? x) (not (negative? x)))))
-
-(define key? symbol?)
-(define (keys? x) (and (pair? x) (andmap key? x)))
-
-(define (unsigned->signed uint bits)
-  (define most-significant-bit-mask (arithmetic-shift 1 (sub1 bits)))
-  (- (bitwise-xor uint most-significant-bit-mask) most-significant-bit-mask))
-
-(define (signed->unsigned sint bits)
-  (bitwise-and sint (arithmetic-shift 1 bits)))
-
-(struct LazyThunk (proc) #:transparent)
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/reserved.rkt b/xenomorph/xenomorph/undo/reserved.rkt
deleted file mode 100644
index b0649366..00000000
--- a/xenomorph/xenomorph/undo/reserved.rkt
+++ /dev/null
@@ -1,24 +0,0 @@
-#lang racket/base
-(require racket/class
-         sugar/unstable/class
-         "private/helper.rkt"
-         "utils.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Reserved.coffee
-|#
-
-(define-subclass xenomorph-base% (Reserved type [count 1])
-
-  (define/augment (decode port parent)
-    (pos port (+ (pos port) (size #f parent)))
-    (void))
-
-  (define/augment (size [val #f] [parent #f])
-    (* (send type size) (resolve-length count #f parent)))
-
-  (define/augment (encode port val [parent #f])
-    (make-bytes (size val parent) 0)))
-
diff --git a/xenomorph/xenomorph/undo/sizes.rkt b/xenomorph/xenomorph/undo/sizes.rkt
deleted file mode 100644
index 9502af2e..00000000
--- a/xenomorph/xenomorph/undo/sizes.rkt
+++ /dev/null
@@ -1,36 +0,0 @@
-#lang racket/base
-(require "private/helper.rkt")
-(provide type-sizes get-type-size)
-
-(define-values (int-keys byte-values) (for*/lists (int-keys byte-values)
-                                        ([signed (in-list '("u" ""))]
-                                         [bit-size (in-list '(8 16 24 32))])
-                                        (values (format "~aint~a" signed bit-size) (/ bit-size 8))))
-
-(define type-sizes (for/hash ([type-key (in-list (append '("float" "double") int-keys))]
-                              [byte-value (in-list (append '(4 8) byte-values))]
-                              #:when #t
-                              [endian (in-list '("" "be" "le"))])
-                     (values (string->symbol (string-append type-key endian)) byte-value)))
-
-(define (get-type-size key)
-  (hash-ref type-sizes key (λ () (raise-argument-error 'DecodeStream:get-type-size "valid type" key))))
-
-(test-module
- (check-equal? (get-type-size 'int8) 1)
- (check-equal? (get-type-size 'uint8) 1)
- (check-equal? (get-type-size 'uint8be) 1)
- (check-equal? (get-type-size 'int16) 2)
- (check-equal? (get-type-size 'uint16) 2)
- (check-equal? (get-type-size 'uint16be) 2)
- (check-equal? (get-type-size 'uint16le) 2)
- (check-equal? (get-type-size 'uint32) 4)
- (check-equal? (get-type-size 'uint32le) 4)
- (check-equal? (get-type-size 'int32be) 4)
- (check-equal? (get-type-size 'float) 4)
- (check-equal? (get-type-size 'floatle) 4)
- (check-equal? (get-type-size 'floatbe) 4)
- (check-equal? (get-type-size 'double) 8)
- (check-equal? (get-type-size 'doublele) 8)
- (check-equal? (get-type-size 'doublebe) 8)
- (check-exn exn:fail:contract? (λ () (get-type-size 'not-a-type))))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/string.rkt b/xenomorph/xenomorph/undo/string.rkt
deleted file mode 100644
index cecabfee..00000000
--- a/xenomorph/xenomorph/undo/string.rkt
+++ /dev/null
@@ -1,112 +0,0 @@
-#lang racket/base
-(require racket/class
-         sugar/unstable/class
-         sugar/unstable/case
-         sugar/unstable/js
-         "private/generic.rkt"
-         "private/helper.rkt"
-         "number.rkt"
-         "utils.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/String.coffee
-|#
-
-(define (read-encoded-string port len [encoding 'ascii])
-  (define proc (caseq encoding
-                      [(utf16le) (error 'bah)]
-                      [(ucs2) (error 'bleh)]
-                      [(utf8) bytes->string/utf-8]
-                      [(ascii) bytes->string/latin-1]
-                      [else values]))
-  (proc (read-bytes len port)))
-
-(define (write-encoded-string port string [encoding 'ascii])
-  ;; todo: handle encodings correctly.
-  ;; right now just utf8 and ascii are correct
-  (define proc (caseq encoding
-                      [(ucs2 utf8 ascii) string->bytes/utf-8]
-                      [(utf16le) (error 'swap-bytes-unimplemented)]
-                      [else (error 'unsupported-string-encoding)]))
-  (write-bytes (proc string) port))
-
-(define (count-nonzero-chars port)
-  ;; helper function for String
-  ;; counts nonzero chars from current position
-  (length (car (regexp-match-peek "[^\u0]*" port))))
-
-(define (byte-length val encoding)
-  (define encoder
-    (caseq encoding
-           [(ascii utf8) string->bytes/utf-8]))
-  (bytes-length (encoder (format "~a" val))))
-
-(define (bytes-left-in-port? port)
-  (not (eof-object? (peek-byte port))))
-
-(define-subclass xenomorph-base% (StringT [len #f] [encoding 'ascii])
-         
-  (define/augment (decode port [parent #f])
-    (let ([len (or (resolve-length len port parent) (count-nonzero-chars port))]
-          [encoding (if (procedure? encoding)
-                        (or (encoding parent) 'ascii)
-                        encoding)]
-          [adjustment (if (and (not len) (bytes-left-in-port? port)) 1 0)])
-      (define string (read-encoded-string port len encoding))
-      (pos port (+ (pos port) adjustment))
-      string))
-    
-
-  (define/augment (encode port val [parent #f])
-    (let* ([val (format "~a" val)]
-           [encoding (if (procedure? encoding)
-                         (or (encoding (and parent (· parent val)) 'ascii))
-                         encoding)])
-      (define encoded-length (byte-length val encoding))
-      (when (and (exact-nonnegative-integer? len) (> encoded-length len))
-        (raise-argument-error 'String:encode (format "string no longer than ~a" len) val)) 
-      (when (NumberT? len)
-        (send len encode port encoded-length))
-      (write-encoded-string port val encoding)
-      (when (not len) (write-byte #x00 port)))) ; null terminated when no len
-
-  
-  (define/augment (size [val #f] [parent #f])
-    (if (not val)
-        (resolve-length len #f parent)
-        (let* ([encoding (if (procedure? encoding)
-                             (or (encoding (and parent (· parent val)) 'ascii))
-                             encoding)]
-               [encoding (if (eq? encoding 'utf16be) 'utf16le encoding)])
-          (+ (byte-length val encoding) (cond
-                                          [(not len) 1]
-                                          [(NumberT? len) (send len size)]
-                                          [else 0]))))))
-
-
-(define-values (String? +String) (values StringT? +StringT))
-
-(define-subclass StringT (Symbol)
-  (define/override (post-decode string-val . _)
-    (string->symbol string-val))
-
-  (define/override (pre-encode sym-val . _)
-    (unless (or (string? sym-val) (symbol? sym-val))
-      (raise-argument-error 'Symbol "symbol or string" sym-val))
-    (if (symbol? sym-val) sym-val (string->symbol sym-val))))
-
-
-(test-module
- (define S-fixed (+String 4 'utf8))
- (check-equal? (encode S-fixed "Mike" #f) #"Mike")
- (check-exn exn:fail? (λ () (encode S-fixed "Mikes" #f))) ; too long for fixed string 
- (define S (+String uint8 'utf8))
- (check-equal? (decode S #"\2BCDEF") "BC")
- (check-equal? (encode S "Mike" #f) #"\4Mike")
- (check-equal? (size (+String) "foobar") 7) ; null terminated when no len
- (check-equal? (decode (+Symbol 4) #"Mike") 'Mike)
- (check-equal? (encode (+Symbol 4) 'Mike #f) #"Mike")
- (check-equal? (encode (+Symbol 4) "Mike" #f) #"Mike")
- (check-exn exn:fail:contract? (λ () (encode (+Symbol 4) 42 #f))))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/struct.rkt b/xenomorph/xenomorph/undo/struct.rkt
deleted file mode 100644
index a7efdcba..00000000
--- a/xenomorph/xenomorph/undo/struct.rkt
+++ /dev/null
@@ -1,161 +0,0 @@
-#lang racket/base
-(require racket/list
-         sugar/unstable/class
-         sugar/unstable/dict
-         sugar/unstable/js
-         racket/class
-         "private/helper.rkt"
-         "private/generic.rkt"
-         racket/dict
-         racket/private/generic-methods)
-(provide (all-defined-out) ref* ref*-set! (all-from-out racket/dict))
-(require (prefix-in d: racket/dict))
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
-|#
-
-
-(define private-keys '(parent _startOffset _currentOffset _length))
-
-(define (choose-dict d k)
-  (if (memq k private-keys)
-      (get-field _pvt d)
-      (get-field _kv d)))
-
-(define dictable<%>
-  (interface* ()
-              ([(generic-property gen:dict)
-                (generic-method-table gen:dict
-                                      (define (dict-set! d k v) (d:dict-set! (choose-dict d k) k v))
-                                      (define (dict-ref d k [thunk #f])
-                                        (define res (d:dict-ref (choose-dict d k) k thunk))
-                                        (if (LazyThunk? res) ((LazyThunk-proc res)) res))
-                                      (define (dict-remove! d k) (d:dict-remove! (choose-dict d k) k))
-                                      ;; public keys only
-                                      (define (dict-keys d) (d:dict-keys (get-field _kv d)))
-                                      (define (dict-iterate-first d) (and (pair? (dict-keys d)) 0))
-                                      (define (dict-iterate-next d i) (and (< (add1 i) (length (dict-keys d))) (add1 i)))
-                                      (define (dict-iterate-key d i) (list-ref (dict-keys d) i))
-                                      (define (dict-iterate-value d i) (dict-ref d (dict-iterate-key d i))))]
-               [(generic-property gen:custom-write)
-                (generic-method-table gen:custom-write
-                                      (define (write-proc o port mode)
-                                        (define proc (case mode
-                                                       [(#t) write]
-                                                       [(#f) display]
-                                                       [else (λ (p port) (print p port mode))]))
-                                        (proc (dump o) port)))])))
-
-(define-subclass*/interfaces xenomorph-base% (dictable<%>)
-  (StructDictRes)
-  (super-make-object)
-  (field [_kv (mhasheq)]
-         [_pvt (mhasheq)])
-                        
-  (define/override (dump)
-    ;; convert to immutable for display & debug
-    (for/hasheq ([(k v) (in-hash _kv)])
-                                      (values k v)))
-
-  (define/public (to-hash) _kv))
-
-
-(define-subclass xenomorph-base% (Struct [fields (dictify)])
-  (field [[_post-decode post-decode] (λ (val port ctx) val)]
-         [[_pre-encode pre-encode] (λ (val port) val)]) ; store as field so it can be mutated from outside
-  
-  (define/overment (post-decode res . args)
-    (let* ([res (apply _post-decode res args)]
-           [res (inner res post-decode res . args)])
-      (unless (dict? res) (raise-result-error 'Struct:post-decode "dict" res))
-      res))
-  
-  (define/overment (pre-encode res . args)
-    (let* ([res (apply _pre-encode res args)]
-           [res (inner res pre-encode res . args)])
-      (unless (dict? res) (raise-result-error 'Struct:pre-encode "dict" res))
-      res))
-  
-  (unless (or (assocs? fields) (Struct? fields)) ; should be Versioned Struct but whatever
-    (raise-argument-error 'Struct "assocs or Versioned Struct" fields))
-
-  (define/augride (decode stream [parent #f] [len 0])
-    ;; _setup and _parse-fields are separate to cooperate with VersionedStruct
-    (let* ([sdr (_setup stream parent len)] ; returns StructDictRes
-           [sdr (_parse-fields stream sdr fields)])
-      sdr))
-
-  (define/public-final (_setup port parent len)
-    (define sdr (make-object StructDictRes)) ; not mere hash
-    (dict-set*! sdr 'parent parent
-                '_startOffset (pos port)
-                '_currentOffset 0
-                '_length len)
-    sdr)
-
-  (define/public-final (_parse-fields port sdr fields)
-    (unless (assocs? fields)
-      (raise-argument-error '_parse-fields "assocs" fields))
-    (for/fold ([sdr sdr])
-              ([(key type) (in-dict fields)])
-      (define val (if (procedure? type)
-                      (type sdr)
-                      (send type decode port sdr)))
-      (unless (void? val)
-        (dict-set! sdr key val))
-      (dict-set! sdr '_currentOffset (- (pos port) (· sdr _startOffset)))
-      sdr))
-  
-
-  (define/augride (size [val #f] [parent #f] [include-pointers #t])
-    (define ctx (mhasheq 'parent parent
-                         'val val
-                         'pointerSize 0))
-    (+ (for/sum ([(key type) (in-dict fields)]
-                 #:when (object? type))
-                (send type size (and val (ref val key)) ctx))
-       (if include-pointers (· ctx pointerSize) 0)))
-
-  (define/augride (encode port val [parent #f])
-    (unless (dict? val)
-      (raise-argument-error 'Struct:encode "dict" val))
-
-    ;; check keys first, since `size` also relies on keys being valid
-    (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)))
-
-    (define ctx (mhash 'pointers empty
-                       'startOffset (pos port)
-                       'parent parent
-                       'val val
-                       'pointerSize 0))
-    (ref-set! ctx 'pointerOffset (+ (pos port) (size val ctx #f)))
-
-    (for ([(key type) (in-dict fields)])
-         (send type encode port (ref val key) ctx))
-    (for ([ptr (in-list (· ctx pointers))])
-         (send (· ptr type) encode port (· ptr val) (· ptr parent)))))
-
-
-(test-module
- (require "number.rkt")
- (define (random-pick xs) (list-ref xs (random (length xs))))
- (check-exn exn:fail:contract? (λ () (+Struct 42)))
-
- ;; make random structs and make sure we can round trip
- (for ([i (in-range 20)])
-      (define field-types (for/list ([i (in-range 40)])
-                                    (random-pick (list uint8 uint16be uint16le uint32be uint32le double))))
-      (define size-num-types (for/sum ([num-type (in-list field-types)])
-                                      (send num-type size)))
-      (define s (+Struct (for/list ([num-type (in-list field-types)])
-                                   (cons (gensym) num-type))))
-      (define bs (apply bytes (for/list ([i (in-range size-num-types)])
-                                        (random 256))))
-      (check-equal? (send s encode #f (send s decode bs)) bs)))
-                   
- 
-
diff --git a/xenomorph/xenomorph/undo/test/array-test.rkt b/xenomorph/xenomorph/undo/test/array-test.rkt
deleted file mode 100644
index 9907499f..00000000
--- a/xenomorph/xenomorph/undo/test/array-test.rkt
+++ /dev/null
@@ -1,91 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict)
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Array.coffee
-|#
-
-;describe 'Array', ->
-;  describe 'decode', ->
-;    it 'should decode fixed length', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint8 4)) '(1 2 3 4)))
-
-
-;    it 'should decode fixed amount of bytes', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint16be 4 'bytes)) '(258 772)))
-
-
-;    it 'should decode length from parent key', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint8 'len) #:parent (mhash 'len 4)) '(1 2 3 4)))
-
-
-;    it 'should decode amount of bytes from parent key', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint16be 'len 'bytes) #:parent (mhash 'len 4)) '(258 772)))
-
-
-;    it 'should decode length as number before array', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 4 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint8 uint8)) '(1 2 3 4)))
-
-
-;    it 'should decode amount of bytes as number before array', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 4 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint16be uint8 'bytes)) '(258 772)))
-
-
-;    it 'should decode length from function', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint8 (λ _ 4))) '(1 2 3 4)))
-
-
-;    it 'should decode amount of bytes from function', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint16be (λ _ 4) 'bytes)) '(258 772)))
-
-
-;    it 'should decode to the end of the parent if no length is given', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint8) #:parent (mhash '_length 4 '_startOffset 0)) '(1 2 3 4)))
-
-
-; decode to the end of the stream if parent exists, but its length is 0
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4 5))])
-  (check-equal? (decode (+ArrayT uint8) #:parent (mhash '_length 0 '_startOffset 0)) '(1 2 3 4 5)))
-
-
-;    it 'should decode to the end of the stream if no parent and length is given', ->
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 3 4))])
-  (check-equal? (decode (+ArrayT uint8)) '(1 2 3 4 )))
-
-
-;  describe 'size', ->
-;    it 'should use array length', ->
-(check-equal? (size (+ArrayT uint8 10) '(1 2 3 4)) 4)
-
-
-;    it 'should add size of length field before string', ->
-(check-equal? (size (+ArrayT uint8 uint8) '(1 2 3 4)) 5)
-
-
-;    it 'should use defined length if no value given', ->
-(check-equal? (size (+ArrayT uint8 10)) 10)
-
-
-;  describe 'encode', ->
-;    it 'should encode using array length', (done) ->
-(check-equal? (encode (+ArrayT uint8 10) '(1 2 3 4) #f) (bytes 1 2 3 4))
-
-
-;    it 'should encode length as number before array', (done) ->
-(check-equal? (encode (+ArrayT uint8 uint8) '(1 2 3 4) #f) (bytes 4 1 2 3 4))
-
-
-;    it 'should add pointers after array if length is encoded at start', (done) ->
-(check-equal? (encode (+ArrayT (+Pointer uint8 uint8) uint8) '(1 2 3 4) #f) (bytes 4 5 6 7 8 1 2 3 4))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/test/bitfield-test.rkt b/xenomorph/xenomorph/undo/test/bitfield-test.rkt
deleted file mode 100644
index 8dba2c75..00000000
--- a/xenomorph/xenomorph/undo/test/bitfield-test.rkt
+++ /dev/null
@@ -1,51 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict
-         racket/list
-         racket/match)
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Bitfield.coffee
-|#
-
-;describe 'Bitfield', ->
-;  bitfield = new Bitfield uint8, ['Jack', 'Kack', 'Lack', 'Mack', 'Nack', 'Oack', 'Pack', 'Quack']
-;  JACK  = 1 << 0
-;  KACK  = 1 << 1
-;  LACK  = 1 << 2
-;  MACK  = 1 << 3
-;  NACK  = 1 << 4
-;  OACK  = 1 << 5
-;  PACK  = 1 << 6
-;  QUACK = 1 << 7
-
-(define bitfield (+Bitfield uint8 '(Jack Kack Lack Mack Nack Oack Pack Quack)))
-(match-define (list JACK KACK LACK MACK NACK OACK PACK QUACK)
-  (map (λ (x) (arithmetic-shift 1 x)) (range 8)))
-
-;  it 'should have the right size', ->
-(check-equal? (size bitfield) 1)
-
-;  it 'should decode', ->
-(parameterize ([current-input-port (open-input-bytes (bytes (bitwise-ior JACK MACK PACK NACK QUACK)))])
-  (check-equal? (decode bitfield) (mhasheq 'Quack #t
-                                           'Nack #t
-                                           'Lack #f
-                                           'Oack #f
-                                           'Pack #t
-                                           'Mack #t
-                                           'Jack #t
-                                           'Kack #f)))
-
-;  it 'should encode', (done) ->
-(check-equal? (encode bitfield (mhasheq 'Quack #t
-                                        'Nack #t
-                                        'Lack #f
-                                        'Oack #f
-                                        'Pack #t
-                                        'Mack #t
-                                        'Jack #t
-                                        'Kack #f) #f)
-              (bytes (bitwise-ior JACK MACK PACK NACK QUACK)))
diff --git a/xenomorph/xenomorph/undo/test/buffer-test.rkt b/xenomorph/xenomorph/undo/test/buffer-test.rkt
deleted file mode 100644
index f3d19d68..00000000
--- a/xenomorph/xenomorph/undo/test/buffer-test.rkt
+++ /dev/null
@@ -1,46 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict)
-
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Buffer.coffee
-|#
-
-;describe 'Buffer', ->
-;  describe 'decode', ->
-;    it 'should decode', ->
-(parameterize ([current-input-port (open-input-bytes (bytes #xab #xff #x1f #xb6))])
-  (define buf (+BufferT 2))
-  (check-equal? (decode buf) (bytes #xab #xff))
-  (check-equal? (decode buf) (bytes #x1f #xb6)))
-
-
-;    it 'should decode with parent key length', ->
-(parameterize ([current-input-port (open-input-bytes (bytes #xab #xff #x1f #xb6))])
-  (define buf (+BufferT 'len))
-  (check-equal? (decode buf #:parent (hash 'len 3)) (bytes #xab #xff #x1f))
-  (check-equal? (decode buf #:parent (hash 'len 1)) (bytes #xb6)))
-
-
-;  describe 'size', ->
-;    it 'should return size', ->
-(check-equal? (size (+BufferT 2) (bytes #xab #xff)) 2)
-
-
-;    it 'should use defined length if no value given', ->x
-(check-equal? (size (+BufferT 10)) 10)
-
-
-;  describe 'encode', ->
-;    it 'should encode', (done) ->
-(let ([buf (+BufferT 2)])
-  (check-equal? (bytes-append
-                 (encode buf (bytes #xab #xff) #f)
-                 (encode buf (bytes #x1f #xb6) #f)) (bytes #xab #xff #x1f #xb6)))
-
-
-;    it 'should encode length before buffer', (done) ->
-(check-equal? (encode (+BufferT uint8) (bytes #xab #xff) #f) (bytes 2 #xab #xff))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/test/enum-test.rkt b/xenomorph/xenomorph/undo/test/enum-test.rkt
deleted file mode 100644
index 5ca766c6..00000000
--- a/xenomorph/xenomorph/undo/test/enum-test.rkt
+++ /dev/null
@@ -1,37 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict)
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Enum.coffee
-|#
-
-;describe 'Enum', ->
-;  e = new Enum uint8, ['foo', 'bar', 'baz']
-;  it 'should have the right size', ->
-;    e.size().should.equal 1
-
-(define e (+Enum uint8 '("foo" "bar" "baz")))
-(check-equal? (size e) 1)
-
-
-;  it 'should decode', ->
-(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"))
-
-
-;  it 'should encode', (done) ->
-(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', ->
-
-(check-exn exn:fail:contract? (λ () (encode e "unknown" (open-output-bytes))))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/test/lazy-array-test.rkt b/xenomorph/xenomorph/undo/test/lazy-array-test.rkt
deleted file mode 100644
index 73eeb6a9..00000000
--- a/xenomorph/xenomorph/undo/test/lazy-array-test.rkt
+++ /dev/null
@@ -1,62 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict
-         "../private/generic.rkt")
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/LazyArray.coffee
-|#
-
-;describe 'LazyArray', ->
-;  describe 'decode', ->
-;    it 'should decode items lazily', ->
-
-(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 (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', ->
-
-(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', ->
-;    [skipped]
-
-
-;    it 'should decode length as number before array', ->
-
-(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', ->
-
-(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) ->
-
-(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/xenomorph/xenomorph/undo/test/main.rkt b/xenomorph/xenomorph/undo/test/main.rkt
deleted file mode 100644
index 87f862af..00000000
--- a/xenomorph/xenomorph/undo/test/main.rkt
+++ /dev/null
@@ -1,14 +0,0 @@
-#lang racket/base
-
-(require "array-test.rkt"
-         "bitfield-test.rkt"
-         "buffer-test.rkt"
-         "enum-test.rkt"
-         "lazy-array-test.rkt"
-         "number-test.rkt"
-         "optional-test.rkt"
-         "pointer-test.rkt"
-         "reserved-test.rkt"
-         "string-test.rkt"
-         "struct-test.rkt"
-         "versioned-struct-test.rkt")
diff --git a/xenomorph/xenomorph/undo/test/number-test.rkt b/xenomorph/xenomorph/undo/test/number-test.rkt
deleted file mode 100644
index 0ac7eb4c..00000000
--- a/xenomorph/xenomorph/undo/test/number-test.rkt
+++ /dev/null
@@ -1,339 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         racket/class
-         sugar/unstable/dict)
-
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Number.coffee
-|#
-
-;describe 'Number', ->
-;  describe 'uint8', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-(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 ([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', ->
-; 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)))
-
-;  describe 'uint16be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode uint16be (open-input-bytes (bytes #xab #xff))) #xabff)
-(check-equal? (size uint16be) 2)
-(check-equal? (encode uint16be #xabff #f) (bytes #xab #xff))
-
-;
-;  describe 'uint16le', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode uint16le (open-input-bytes (bytes #xff #xab))) #xabff)
-(check-equal? (size uint16le) 2)
-(check-equal? (encode uint16le #xabff #f) (bytes #xff #xab))
-
-;
-;  describe 'uint24', ->
-;    it 'is an alias for 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)))
-
-;
-;  describe 'uint24be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode uint24be (open-input-bytes (bytes #xff #xab #x24))) #xffab24)
-(check-equal? (size uint24be) 3)
-(check-equal? (encode uint24be #xffab24 #f) (bytes #xff #xab #x24))
-
-;
-;  describe 'uint24le', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode uint24le (open-input-bytes (bytes #x24 #xab #xff))) #xffab24)
-(check-equal? (size uint24le) 3)
-(check-equal? (encode uint24le #xffab24 #f) (bytes #x24 #xab #xff))
-
-;
-;  describe 'uint32', ->
-;    it 'is an alias for 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)))
-
-;
-;  describe 'uint32be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode uint32be (open-input-bytes (bytes #xff #xab #x24 #xbf))) #xffab24bf)
-(check-equal? (size uint32be) 4)
-(check-equal? (encode uint32be #xffab24bf #f) (bytes #xff #xab #x24 #xbf))
-
-;
-;  describe 'uint32le', ->
-;    it 'should decode', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode uint32le (open-input-bytes (bytes #xbf #x24 #xab #xff))) #xffab24bf)
-(check-equal? (size uint32le) 4)
-(check-equal? (encode uint32le #xffab24bf #f) (bytes #xbf #x24 #xab #xff))
-
-
-;
-;  describe 'int8', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(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 ([port (open-output-bytes)])
-  (encode int8 127 port)
-  (encode int8 -1 port)
-  (check-equal? (dump port) (bytes #x7f #xff)))
-
-
-;
-;  describe 'int16', ->
-;    it 'is an alias for int16be', ->
-;      int16.should.equal int16be
-
-;; 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)))
-
-
-;
-;  describe 'int16be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(let ([port (open-input-bytes (bytes #xff #xab))])
-  (check-equal? (decode int16be port) -85))
-
-(check-equal? (size int16be) 2)
-
-(let ([port (open-output-bytes)])
-  (encode int16be -85 port)
-  (check-equal? (dump port) (bytes #xff #xab)))
-
-
-;  describe 'int16le', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode int16le (open-input-bytes (bytes #xab #xff))) -85)
-(check-equal? (size int16le) 2)
-(check-equal? (encode int16le -85 #f) (bytes #xab #xff))
-
-
-;
-;  describe 'int24', ->
-;    it 'is an alias for int24be', ->
-;      int24.should.equal int24be
-
-;; 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)))
-
-
-;
-;  describe 'int24be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode int24be (open-input-bytes (bytes #xff #xab #x24))) -21724)
-(check-equal? (size int24be) 3)
-(check-equal? (encode int24be -21724 #f) (bytes #xff #xab #x24))
-
-;
-;  describe 'int24le', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode int24le (open-input-bytes (bytes #x24 #xab #xff))) -21724)
-(check-equal? (size int24le) 3)
-(check-equal? (encode int24le -21724 #f) (bytes #x24 #xab #xff))
-
-
-
-;  describe 'int32', ->
-;    it 'is an alias for int32be', ->
-; 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)))
-
-
-
-;
-;  describe 'int32be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode int32be (open-input-bytes (bytes #xff #xab #x24 #xbf))) -5561153)
-(check-equal? (size int32be) 4)
-(check-equal? (encode int32be -5561153 #f) (bytes #xff #xab #x24 #xbf))
-
-;
-;  describe 'int32le', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-equal? (decode int32le (open-input-bytes (bytes #xbf #x24 #xab #xff))) -5561153)
-(check-equal? (size int32le) 4)
-(check-equal? (encode int32le -5561153 #f) (bytes #xbf #x24 #xab #xff))
-
-;
-;  describe 'float', ->
-;    it 'is an alias for floatbe', ->
-; 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)))
-
-;
-;  describe 'floatbe', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-= (decode floatbe (open-input-bytes (bytes #x43 #x7a #x8c #xcd))) 250.55 0.01)
-(check-equal? (size floatbe) 4)
-(check-equal? (encode floatbe 250.55 #f) (bytes #x43 #x7a #x8c #xcd))
-
-;
-;  describe 'floatle', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-= (decode floatle (open-input-bytes (bytes #xcd #x8c #x7a #x43))) 250.55 0.01)
-(check-equal? (size floatle) 4)
-(check-equal? (encode floatle 250.55 #f) (bytes #xcd #x8c #x7a #x43))
-
-;
-;  describe 'double', ->
-;    it 'is an alias for doublebe', ->
-; 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)))
-
-;
-;  describe 'doublebe', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(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 1234.56 #f) (bytes #x40 #x93 #x4a #x3d #x70 #xa3 #xd7 #x0a))
-
-;
-;  describe 'doublele', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(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 1234.56 #f) (bytes #x0a #xd7 #xa3 #x70 #x3d #x4a #x93 #x40))
-
-;
-;  describe 'fixed16', ->
-;    it 'is an alias for fixed16be', ->
-; 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)))
-
-;
-;  describe 'fixed16be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-= (decode fixed16be (open-input-bytes (bytes #x19 #x57))) 25.34 0.01)
-(check-equal? (size fixed16be) 2)
-(check-equal? (encode fixed16be 25.34 #f) (bytes #x19 #x57))
-
-;
-;  describe 'fixed16le', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-= (decode fixed16le (open-input-bytes (bytes #x57 #x19))) 25.34 0.01)
-(check-equal? (size fixed16le) 2)
-(check-equal? (encode fixed16le 25.34 #f) (bytes #x57 #x19))
-
-;
-;  describe 'fixed32', ->
-;    it 'is an alias for fixed32be', ->
-; 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)))
-
-;
-;  describe 'fixed32be', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-(check-= (decode fixed32be (open-input-bytes (bytes #x00 #xfa #x8c #xcc))) 250.55 0.01)
-(check-equal? (size fixed32be) 4)
-(check-equal? (encode fixed32be 250.55 #f) (bytes #x00 #xfa #x8c #xcc))
-
-;
-;  describe 'fixed32le', ->
-;    it 'should decode', ->
-;    it 'should have a size', ->
-;    it 'should encode', (done) ->
-
-(check-= (decode fixed32le (open-input-bytes (bytes #xcc #x8c #xfa #x00))) 250.55 0.01)
-(check-equal? (size fixed32le) 4)
-(check-equal? (encode fixed32le 250.55 #f) (bytes #xcc #x8c #xfa #x00))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/test/optional-test.rkt b/xenomorph/xenomorph/undo/test/optional-test.rkt
deleted file mode 100644
index d5e87301..00000000
--- a/xenomorph/xenomorph/undo/test/optional-test.rkt
+++ /dev/null
@@ -1,116 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict)
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Optional.coffee
-|#
-
-;describe 'Optional', ->
-;  describe 'decode', ->
-;    it 'should not decode when condition is falsy', ->
-
-(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', ->
-
-(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', ->
-
-(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', ->
-
-(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', ->
-
-(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))
-
-
-;  describe 'size', ->
-
-(check-equal? (size (+Optional uint8 #f)) 0)
-
-;
-;    it 'should return 0 when condition is a function and falsy', ->
-
-(check-equal? (size (+Optional uint8 (λ _ #f))) 0)
-
-
-;    it 'should return given type size when condition is omitted', ->
-
-(check-equal? (size (+Optional uint8)) 1)
-
-
-;    it 'should return given type size when condition is truthy', ->
-
-(check-equal? (size (+Optional uint8 #t)) 1)
-
-
-;    it 'should return given type size when condition is a function and truthy', ->
-
-(check-equal? (size (+Optional uint8 (λ _ #t))) 1)
-
-
-;  describe 'encode', ->
-;    it 'should not encode when condition is falsy', (done) ->
-
-(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) ->
-
-(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) ->
-
-(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) ->
-
-(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) ->
-
-(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
diff --git a/xenomorph/xenomorph/undo/test/pointer-test.rkt b/xenomorph/xenomorph/undo/test/pointer-test.rkt
deleted file mode 100644
index 71093e08..00000000
--- a/xenomorph/xenomorph/undo/test/pointer-test.rkt
+++ /dev/null
@@ -1,239 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/js
-         sugar/unstable/dict
-         racket/class
-         "../private/helper.rkt")
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Pointer.coffee
-|#
-
-
-;describe 'Pointer', ->
-;  describe 'decode', ->
-;    it 'should handle null pointers', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 0))])
-  (check-false (decode (+Pointer uint8 uint8) #:parent (mhash '_startOffset 50))))
-
-
-;    it 'should use local offsets from start of parent by default', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 1 53))])
-  (check-equal? (decode (+Pointer uint8 uint8) #:parent (mhash '_startOffset 0)) 53))
-
-
-;    it 'should support immediate offsets', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 1 53))])
-  (check-equal? (decode (+Pointer uint8 uint8 (mhash 'type 'immediate))) 53))
-
-
-;    it 'should support offsets relative to the parent', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 0 0 1 53))])
-  (pos (current-input-port) 2)
-  (check-equal? (decode (+Pointer uint8 uint8 (mhash 'type 'parent))
-                        #:parent (mhash 'parent (mhash '_startOffset 2))) 53))
-
-
-;    it 'should support global offsets', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 1 2 4 0 0 0 53))])
-  (pos (current-input-port) 2)
-  (check-equal? (decode (+Pointer uint8 uint8 (mhash 'type 'global))
-                        #:parent (mhash 'parent (mhash 'parent (mhash '_startOffset 2))))
-                53))
-
-
-;    it 'should support offsets relative to a property on the parent', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 1 0 0 0 0 53))])
-  (check-equal? (decode (+Pointer uint8 uint8 (mhash 'relativeTo (λ (ctx) (· ctx parent ptr))))
-                        #:parent (mhash '_startOffset 0 'parent (mhash 'ptr 4)))
-                53))
-
-
-;    it 'should support returning pointer if there is no decode type', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 4))])
-  (check-equal? (decode (+Pointer uint8 'void)
-                        #:parent (mhash '_startOffset 0)) 4))
-
-
-;    it 'should support decoding pointers lazily', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 1 53))])
-  (define res (decode (+Struct (dictify 'ptr (+Pointer uint8 uint8 (mhasheq 'lazy #t))))))
-  (check-true (LazyThunk? (hash-ref (get-field _kv res) 'ptr)))
-  (check-equal? (· res ptr) 53))
-
-
-
-;  describe 'size', ->
-
-(let ([ctx (mhash 'pointerSize 0)])
-  (check-equal? (size (+Pointer uint8 uint8) 10 ctx) 1)
-  (check-equal? (· ctx pointerSize) 1))
-
-
-
-;    it 'should add to immediate pointerSize', ->
-
-(let ([ctx (mhash 'pointerSize 0)])
-  (check-equal? (size (+Pointer uint8 uint8 (mhash 'type 'immediate)) 10 ctx) 1)
-  (check-equal? (· ctx pointerSize) 1))
-
-
-;    it 'should add to parent pointerSize', ->
-
-(let ([ctx (mhash 'parent (mhash 'pointerSize 0))])
-  (check-equal? (size (+Pointer uint8 uint8 (mhash 'type 'parent)) 10 ctx) 1)
-  (check-equal? (· ctx parent pointerSize) 1))
-
-
-
-;    it 'should add to global pointerSize', ->
-
-(let ([ctx (mhash 'parent (mhash 'parent (mhash 'parent (mhash 'pointerSize 0))))])
-  (check-equal? (size (+Pointer uint8 uint8 (mhash 'type 'global)) 10 ctx) 1)
-  (check-equal? (· ctx parent parent parent pointerSize) 1))
-
-
-
-;    it 'should handle void pointers', ->
-
-(let ([ctx (mhash 'pointerSize 0)])
-  (check-equal? (size (+Pointer uint8 'void) (+VoidPointer uint8 50) ctx) 1)
-  (check-equal? (· ctx pointerSize) 1))
-
-
-;    it 'should throw if no type and not a void pointer', ->
-
-(let ([ctx (mhash 'pointerSize 0)])
-  (check-exn exn:fail:contract? (λ () (size (+Pointer uint8 'void) 30 ctx))))
-
-
-;    it 'should return a fixed size without a value', ->
-
-(check-equal? (size (+Pointer uint8 uint8)) 1)
-
-
-;  describe 'encode', ->
-;    it 'should handle null pointers', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'pointerSize 0
-                     'startOffset 0
-                     'pointerOffset 0
-                     'pointers null))
-  (encode (+Pointer uint8 uint8) #f #:parent ctx)
-  (check-equal? (· ctx pointerSize) 0)
-  (check-equal? (dump (current-output-port)) (bytes 0)))
-
-
-;    it 'should handle local offsets', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'pointerSize 0
-                     'startOffset 0
-                     'pointerOffset 1
-                     'pointers null))
-  (encode (+Pointer uint8 uint8) 10 #:parent ctx)
-  (check-equal? (· ctx pointerOffset) 2)
-  (check-equal? (· ctx pointers) (list (mhasheq 'type uint8
-                                                'val 10
-                                                'parent ctx)))
-  (check-equal? (dump (current-output-port)) (bytes 1)))
-
-
-;    it 'should handle immediate offsets', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'pointerSize 0
-                     'startOffset 0
-                     'pointerOffset 1
-                     'pointers null))
-  (encode (+Pointer uint8 uint8 (mhash 'type 'immediate)) 10 #:parent ctx)
-  (check-equal? (· ctx pointerOffset) 2)
-  (check-equal? (· ctx pointers) (list (mhasheq 'type uint8
-                                                'val 10
-                                                'parent ctx)))
-  (check-equal? (dump (current-output-port)) (bytes 0)))
-
-
-;    it 'should handle offsets relative to parent', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'parent (mhash 'pointerSize 0
-                                    'startOffset 3
-                                    'pointerOffset 5
-                                    'pointers null)))
-  (encode (+Pointer uint8 uint8 (mhash 'type 'parent)) 10 #:parent ctx)
-  (check-equal? (· ctx parent pointerOffset) 6)
-  (check-equal? (· ctx parent pointers) (list (mhasheq 'type uint8
-                                                       'val 10
-                                                       'parent ctx)))
-  (check-equal? (dump (current-output-port)) (bytes 2)))
-
-
-
-;    it 'should handle global offsets', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'parent
-                     (mhash 'parent
-                            (mhash 'parent (mhash 'pointerSize 0
-                                                  'startOffset 3
-                                                  'pointerOffset 5
-                                                  'pointers null)))))
-  (encode (+Pointer uint8 uint8 (mhash 'type 'global)) 10 #:parent ctx)
-  (check-equal? (· ctx parent parent parent pointerOffset) 6)
-  (check-equal? (· ctx parent parent parent pointers) (list (mhasheq 'type uint8
-                                                                     'val 10
-                                                                     'parent ctx)))
-  (check-equal? (dump (current-output-port)) (bytes 5)))
-
-
-;    it 'should support offsets relative to a property on the parent', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'pointerSize 0
-                     'startOffset 0
-                     'pointerOffset 10
-                     'pointers null
-                     'val (mhash 'ptr 4)))
-  (encode (+Pointer uint8 uint8 (mhash 'relativeTo (λ (ctx) (· ctx ptr)))) 10 #:parent ctx)
-  (check-equal? (· ctx pointerOffset) 11)
-  (check-equal? (· ctx pointers) (list (mhasheq 'type uint8
-                                                'val 10
-                                                'parent ctx)))
-  (check-equal? (dump (current-output-port)) (bytes 6)))
-
-
-;    it 'should support void pointers', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'pointerSize 0
-                     'startOffset 0
-                     'pointerOffset 1
-                     'pointers null))
-  (encode (+Pointer uint8 'void) (+VoidPointer uint8 55) #:parent  ctx)
-  (check-equal? (· ctx pointerOffset) 2)
-  (check-equal? (· ctx pointers) (list (mhasheq 'type uint8
-                                                'val 55
-                                                'parent ctx)))
-  (check-equal? (dump (current-output-port)) (bytes 1)))
-
-
-;    it 'should throw if not a void pointer instance', ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define ctx (mhash 'pointerSize 0
-                     'startOffset 0
-                     'pointerOffset 1
-                     'pointers null))
-  (check-exn exn:fail:contract? (λ () (encode (+Pointer uint8 'void) 44 #:parent ctx))))
diff --git a/xenomorph/xenomorph/undo/test/reserved-test.rkt b/xenomorph/xenomorph/undo/test/reserved-test.rkt
deleted file mode 100644
index 40dbead8..00000000
--- a/xenomorph/xenomorph/undo/test/reserved-test.rkt
+++ /dev/null
@@ -1,35 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict)
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Reserved.coffee
-|#
-
-;describe 'Reserved', ->
-;  it 'should have a default count of 1', ->
-
-(check-equal? (size (+Reserved uint8)) 1)
-
-
-;  it 'should allow custom counts and types', ->
-
-(check-equal? (size (+Reserved uint16be 10)) 20)
-
-
-;  it 'should decode', ->
-
-(parameterize ([current-input-port (open-input-bytes (bytes 0 0))])
-  (define reserved (+Reserved uint16be))
-  (check-equal? (decode reserved) (void))
-  (check-equal? (pos (current-input-port)) 2))
-
-
-;  it 'should encode', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define reserved (+Reserved uint16be))
-  (encode reserved #f)
-  (check-equal? (dump (current-output-port)) (bytes 0 0)))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/test/string-test.rkt b/xenomorph/xenomorph/undo/test/string-test.rkt
deleted file mode 100644
index 786e594e..00000000
--- a/xenomorph/xenomorph/undo/test/string-test.rkt
+++ /dev/null
@@ -1,131 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         sugar/unstable/dict)
-
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/String.coffee
-|#
-
-;describe 'String', ->
-;  describe 'decode', ->
-;    it 'should decode fixed length', ->
-
-(parameterize ([current-input-port (open-input-bytes #"testing")])
-  (check-equal? (decode (+StringT 7)) "testing"))
-
-
-;    it 'should decode length from parent key', ->
-
-(parameterize ([current-input-port (open-input-bytes #"testing")])
-  (check-equal? (decode (+StringT 'len) #:parent (mhash 'len 7)) "testing"))
-
-
-;    it 'should decode length as number before string', ->
-
-(parameterize ([current-input-port (open-input-bytes #"\x07testing")])
-  (check-equal? (decode (+StringT uint8) #:parent (mhash 'len 7)) "testing"))
-
-
-;;    it 'should decode utf8', ->
-
-(parameterize ([current-input-port (open-input-bytes (string->bytes/utf-8 "🍻"))])
-  (check-equal? (decode (+StringT 4 'utf8)) "🍻"))
-
-;;    it 'should decode encoding computed from function', ->
-
-(parameterize ([current-input-port (open-input-bytes (string->bytes/utf-8 "🍻"))])
-  (check-equal? (decode (+StringT 4 (λ _ 'utf8))) "🍻"))
-
-
-;    it 'should decode null-terminated string and read past terminator', ->
-
-(parameterize ([current-input-port (open-input-bytes (string->bytes/utf-8 "🍻\x00"))])
-  (check-equal? (decode (+StringT #f 'utf8)) "🍻")
-  (check-equal? (pos (current-input-port)) 5))
-
-
-;    it 'should decode remainder of buffer when null-byte missing', ->
-
-(parameterize ([current-input-port (open-input-bytes (string->bytes/utf-8 "🍻"))])
-  (check-equal? (decode (+StringT #f 'utf8)) "🍻"))
-
-
-;  describe 'size', ->
-;    it 'should use string length', ->
-
-(check-equal? (size (+StringT 7) "testing") 7)
-
-
-;    it 'should use correct encoding', ->
-
-(check-equal? (size (+StringT 10 'utf8) "🍻") 4)
-
-
-;    it 'should use encoding from function', ->
-
-(check-equal? (size (+StringT 10 (λ _ 'utf8)) "🍻") 4)
-
-
-;    it 'should add size of length field before string', ->
-
-(check-equal? (size (+StringT uint8 'utf8) "🍻") 5)
-
-
-; todo
-;    it 'should work with utf16be encoding', ->
-
-
-;    it 'should take null-byte into account', ->
-
-(check-equal? (size (+StringT #f 'utf8) "🍻") 5)
-
-      
-;    it 'should use defined length if no value given', ->
-
-(check-equal? (size (+StringT 10)) 10)
-
-;      
-;  describe 'encode', ->
-;    it 'should encode using string length', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (encode (+StringT 7) "testing")
-  (check-equal? (dump (current-output-port)) #"testing"))
-
-
-;    it 'should encode length as number before string', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (encode (+StringT uint8) "testing")
-  (check-equal? (dump (current-output-port)) #"\x07testing"))
-
-
-;    it 'should encode length as number before string utf8', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (encode (+StringT uint8 'utf8) "testing 😜")
-  (check-equal? (dump (current-output-port)) (string->bytes/utf-8 "\x0ctesting 😜")))
-
-
-;    it 'should encode utf8', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (encode (+StringT 4 'utf8) "🍻" )
-  (check-equal? (dump (current-output-port)) (string->bytes/utf-8 "🍻")))
-
-
-;    it 'should encode encoding computed from function', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (encode (+StringT 4 (λ _ 'utf8)) "🍻")
-  (check-equal? (dump (current-output-port)) (string->bytes/utf-8 "🍻")))
-
-
-;    it 'should encode null-terminated string', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (encode (+StringT #f 'utf8) "🍻"  )
-  (check-equal? (dump (current-output-port)) (string->bytes/utf-8 "🍻\x00")))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/test/struct-test.rkt b/xenomorph/xenomorph/undo/test/struct-test.rkt
deleted file mode 100644
index 587428b9..00000000
--- a/xenomorph/xenomorph/undo/test/struct-test.rkt
+++ /dev/null
@@ -1,126 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         racket/class
-         sugar/unstable/dict
-         sugar/unstable/js
-         "../private/generic.rkt")
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/Struct.coffee
-|#
-
-
-;describe 'Struct', ->
-;  describe 'decode', ->
-;    it 'should decode into an object', ->
-
-(parameterize ([current-input-port (open-input-bytes #"\x05roxyb\x15")])
-  (check-equal?
-   (dump (decode (+Struct (dictify 'name (+StringT uint8)
-                                   'age uint8))))
-   (hasheq 'name "roxyb" 'age 21)))
-
-
-
-;    it 'should support process hook', ->
-
-(parameterize ([current-input-port (open-input-bytes #"\x05roxyb\x20")])
-  (define struct (+Struct (dictify 'name (+StringT uint8)
-                                   'age uint8)))
-  (set-field! post-decode struct (λ (o . _) (ref-set! o 'canDrink (>= (· o age) 21)) o))
-  (check-equal? (dump (decode struct))
-                (hasheq 'name "roxyb" 'age 32 'canDrink #t)))
-
-
-
-;    it 'should support function keys', ->
-
-(parameterize ([current-input-port (open-input-bytes #"\x05roxyb\x20")])
-  (define struct (+Struct (dictify 'name (+StringT uint8)
-                                   'age uint8
-                                   'canDrink (λ (o) (>= (ref o 'age) 21)))))
-  (check-equal? (dump (decode struct))
-                (hasheq 'name "roxyb" 'age 32 'canDrink #t)))
-
-
-
-
-;
-;  describe 'size', ->
-;    it 'should compute the correct size', ->
-
-(check-equal? (size (+Struct (dictify
-                              'name (+StringT uint8)
-                              'age uint8))
-                    (hasheq 'name "roxyb" 'age 32)) 7)
-
-
-
-;    it 'should compute the correct size with pointers', ->
-
-(check-equal? (size (+Struct (dictify
-                              'name (+StringT uint8)
-                              'age uint8
-                              'ptr (+Pointer uint8 (+StringT uint8))))
-                    (mhash 'name "roxyb" 'age 21 'ptr "hello")) 14)
-
-
-;    it 'should get the correct size when no value is given', ->
-
-(check-equal? (size (+Struct (dictify
-                              'name (+StringT 4)
-                              'age uint8))) 5)
-      
-;    it 'should throw when getting non-fixed length size and no value is given', ->
-
-(check-exn exn:fail:contract? (λ () (size (+Struct (dictify 'name (+StringT uint8)
-                                                            'age uint8)))))
-
-
-
-;      
-;  describe 'encode', ->
-;    it 'should encode objects to buffers', (done) ->
-;      stream = new EncodeStream
-;      stream.pipe concat (buf) ->
-;        buf.should.deep.equal new Buffer '\x05roxyb\x15'
-;        done()
-;
-;      struct = new Struct
-;        name: new StringT uint8
-;        age: uint8
-;
-;      struct.encode stream,
-;        name: 'roxyb'
-;        age: 21
-;
-;      stream.end()
-
-(parameterize ([current-input-port (open-input-bytes #"\x05roxyb\x15")])
-  (check-equal? (dump (decode (+Struct (dictify 'name (+StringT uint8)
-                                                'age uint8))))
-                (hasheq 'name "roxyb" 'age 21)))
-
-
-;    it 'should support preEncode hook', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define struct (+Struct (dictify 'nameLength uint8
-                                   'name (+StringT 'nameLength)
-                                   'age uint8)))
-  (set-field! pre-encode struct (λ (val port) (ref-set! val 'nameLength (length (ref val 'name))) val))
-  (encode struct (mhasheq 'name "roxyb" 'age 21))
-  (check-equal? (dump (current-output-port)) #"\x05roxyb\x15"))
-
-
-;    it 'should encode pointer data after structure', (done) ->
-
-(parameterize ([current-output-port (open-output-bytes)])
-  (define struct (+Struct (dictify 'name (+StringT uint8)
-                                   'age uint8
-                                   'ptr (+Pointer uint8 (+StringT uint8)))))
-  (encode struct (hasheq 'name "roxyb" 'age 21 'ptr "hello"))
-  (check-equal? (dump (current-output-port)) #"\x05roxyb\x15\x08\x05hello"))
-
diff --git a/xenomorph/xenomorph/undo/test/test.rkt b/xenomorph/xenomorph/undo/test/test.rkt
deleted file mode 100644
index 9d1a6c05..00000000
--- a/xenomorph/xenomorph/undo/test/test.rkt
+++ /dev/null
@@ -1,21 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         racket/class)
-
-(define Person
-  (make-object Struct
-    (list (cons 'name (make-object StringT uint8 'utf8))
-          (cons 'age uint8))))
-
-;; decode a person from a port
-(define ip (open-input-bytes #"\4MikeA"))
-(define x (send Person decode ip))
-
-(module+ test
- (check-equal? (dict-ref x 'name) "Mike")
- (check-equal? (dict-ref x 'age) 65))
-
-;; encode a person from a hash
-(module+ test
- (check-equal? (send Person encode #f (hasheq 'name "Mike" 'age 65)) #"\4MikeA"))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/test/versioned-struct-test.rkt b/xenomorph/xenomorph/undo/test/versioned-struct-test.rkt
deleted file mode 100644
index f8e13351..00000000
--- a/xenomorph/xenomorph/undo/test/versioned-struct-test.rkt
+++ /dev/null
@@ -1,344 +0,0 @@
-#lang racket/base
-(require rackunit
-         xenomorph
-         racket/class
-         "../private/generic.rkt"
-         sugar/unstable/dict)
-
-#|
-approximates
-https://github.com/mbutterick/restructure/blob/master/test/VersionedStruct.coffee
-|#
-
-;describe 'VersionedStruct', ->
-;  describe 'decode', ->
-;    it 'should get version from number type', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))])
-
-  (parameterize ([current-input-port (open-input-bytes #"\x00\x05roxyb\x15")])
-    (check-equal? (dump (decode struct)) (hasheq 'name "roxyb"
-                                                 'age 21
-                                                 'version 0)))
-
-  (parameterize ([current-input-port (open-input-bytes (string->bytes/utf-8 "\x01\x0aroxyb 🤘\x15\x00"))])
-    (check-equal? (dump (decode struct)) (hasheq 'name "roxyb 🤘"
-                                                 'age 21
-                                                 'version 1
-                                                 'gender 0))))
-
-
-;    it 'should throw for unknown version', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))])
-
-  (parameterize ([current-input-port (open-input-bytes #"\x05\x05roxyb\x15")])
-    (check-exn exn:fail:contract? (λ () (decode struct)))))
-
-
-;
-;    it 'should support common header block', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 'header (dictify 'age uint8
-                                                  'alive uint8)
-                                 0 (dictify 'name (+StringT uint8 'ascii))
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'gender uint8)))])
-
-  (parameterize ([current-input-port (open-input-bytes #"\x00\x15\x01\x05roxyb")])
-    (check-equal? (dump (decode struct)) (hasheq 'name "roxyb"
-                                                 'age 21
-                                                 'alive 1
-                                                 'version 0)))
-
-  (parameterize ([current-input-port (open-input-bytes (string->bytes/utf-8 "\x01\x15\x01\x0aroxyb 🤘\x00"))])
-    (check-equal? (dump (decode struct)) (hasheq 'name "roxyb 🤘"
-                                                 'age 21
-                                                 'version 1
-                                                 'alive 1
-                                                 'gender 0))))
-
-
-;    it 'should support parent version key', ->
-
-(let ([struct (+VersionedStruct 'version
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))])
-
-  (parameterize ([current-input-port (open-input-bytes #"\x05roxyb\x15")])
-    (check-equal? (dump (decode struct #:parent (mhash 'version 0))) (hasheq 'name "roxyb"
-                                                                             'age 21
-                                                                             'version 0)))
-
-  (parameterize ([current-input-port (open-input-bytes (string->bytes/utf-8 "\x0aroxyb 🤘\x15\x00"))])
-    (check-equal? (dump (decode struct #:parent (mhash 'version 1))) (hasheq 'name "roxyb 🤘"
-                                                                             'age 21
-                                                                             'version 1
-                                                                             'gender 0))))
-
-
-
-;
-;    it 'should support sub versioned structs', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (+VersionedStruct uint8
-                                                     (dictify
-                                                      0 (dictify 'name (+StringT uint8))
-                                                      1 (dictify 'name (+StringT uint8)
-                                                                 'isDessert uint8)))))])
-
-  (parameterize ([current-input-port (open-input-bytes #"\x00\x05roxyb\x15")])
-    (check-equal? (dump (decode struct #:parent (mhash 'version 0))) (hasheq 'name "roxyb"
-                                                                             'age 21
-                                                                             'version 0)))
-
-  (parameterize ([current-input-port (open-input-bytes #"\x01\x00\x05pasta")])
-    (check-equal? (dump (decode struct #:parent (mhash 'version 0))) (hasheq 'name "pasta"
-                                                                             'version 0)))
-
-  (parameterize ([current-input-port (open-input-bytes #"\x01\x01\x09ice cream\x01")])
-    (check-equal? (dump (decode struct #:parent (mhash 'version 0))) (hasheq 'name "ice cream"
-                                                                             'isDessert 1
-                                                                             'version 1))))
-
-
-;
-;    it 'should support process hook', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))])
-  (set-field! post-decode struct (λ (o stream ctx) (ref-set! o 'processed "true") o))
-  (parameterize ([current-input-port (open-input-bytes #"\x00\x05roxyb\x15")])
-    (check-equal? (dump (decode struct)) (hasheq 'name "roxyb"
-                                                 'processed "true"
-                                                 'age 21
-                                                 'version 0))))
-
-
-;
-;  describe 'size', ->
-;    it 'should compute the correct size', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))])
-  
-  (check-equal? (size struct (mhasheq 'name "roxyb"
-                                      'age 21
-                                      'version 0)) 8)
-  
-  (check-equal? (size struct (mhasheq 'name "roxyb 🤘"
-                                      'gender 0
-                                      'age 21
-                                      'version 1)) 14))
-
-
-
-
-;
-;    it 'should throw for unknown version', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))])
-  
-  (check-exn exn:fail:contract? (λ () (size struct (mhasheq 'name "roxyb"
-                                                            'age 21
-                                                            'version 5)))))
-
-
-;
-;    it 'should support common header block', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 'header (dictify 'age uint8
-                                                  'alive uint8)
-                                 0 (dictify 'name (+StringT uint8 'ascii))
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'gender uint8)))])
-  
-  (check-equal? (size struct (mhasheq 'name "roxyb"
-                                      'age 21
-                                      'alive 1
-                                      'version 0)) 9)
-  
-  (check-equal? (size struct (mhasheq 'name "roxyb 🤘"
-                                      'gender 0
-                                      'age 21
-                                      'alive 1
-                                      'version 1)) 15))
-
-
-
-;    it 'should compute the correct size with pointers', ->
-
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'ptr (+Pointer uint8 (+StringT uint8)))))])
-  
-  (check-equal? (size struct (mhasheq 'name "roxyb"
-                                      'age 21
-                                      'version 1
-                                      'ptr "hello")) 15))
-
-
-;    
-;    it 'should throw if no value is given', ->
-
-
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))])
-  
-  (check-exn exn:fail:contract? (λ () (size struct))))
-
-
-
-;  describe 'encode', ->
-;    it 'should encode objects to buffers', (done) ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))]
-      [port (open-output-bytes)])
-  (encode struct (mhasheq 'name "roxyb"
-                          'age 21
-                          'version 0) port)
-  (encode struct (mhasheq 'name "roxyb 🤘"
-                          'age 21
-                          'gender 0
-                          'version 1) port)
-  (check-equal? (dump port) (string->bytes/utf-8 "\x00\x05roxyb\x15\x01\x0aroxyb 🤘\x15\x00")))
-
-
-;
-;    it 'should throw for unknown version', ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))]
-      [port (open-output-bytes)])
-  (check-exn exn:fail:contract? (λ () (encode struct port (mhasheq 'name "roxyb"
-                                                                   'age 21
-                                                                   'version 5)))))
-
-
-
-;    it 'should support common header block', (done) ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 'header (dictify 'age uint8
-                                                  'alive uint8)
-                                 0 (dictify 'name (+StringT uint8 'ascii))
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'gender uint8)))]
-      [stream (open-output-bytes)])
-  
-  (encode struct (mhasheq 'name "roxyb"
-                          'age 21
-                          'alive 1
-                          'version 0) stream)
-  
-  (encode struct (mhasheq 'name "roxyb 🤘"
-                          'gender 0
-                          'age 21
-                          'alive 1
-                          'version 1) stream)
-  
-  (check-equal? (dump stream) (string->bytes/utf-8 "\x00\x15\x01\x05roxyb\x01\x15\x01\x0aroxyb 🤘\x00")))
-
-
-
-;    it 'should encode pointer data after structure', (done) ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify 
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'ptr (+Pointer uint8 (+StringT uint8)))))]
-      [stream (open-output-bytes)])
-  (encode struct (mhasheq 'version 1
-                          'name "roxyb"
-                          'age 21
-                          'ptr "hello") stream)
-
-  (check-equal? (dump stream) (string->bytes/utf-8 "\x01\x05roxyb\x15\x09\x05hello")))
-
-
-
-
-;    it 'should support preEncode hook', (done) ->
-
-(let ([struct (+VersionedStruct uint8
-                                (dictify
-                                 0 (dictify 'name (+StringT uint8 'ascii)
-                                            'age uint8)
-                                 1 (dictify 'name (+StringT uint8 'utf8)
-                                            'age uint8
-                                            'gender uint8)))]
-      [stream (open-output-bytes)])
-  (set-field! pre-encode struct (λ (val port) (ref-set! val 'version (if (ref val 'gender) 1 0)) val))
-  (encode struct (mhasheq 'name "roxyb"
-                          'age 21
-                          'version 0) stream)
-  (encode struct (mhasheq 'name "roxyb 🤘"
-                          'age 21
-                          'gender 0) stream)
-  (check-equal? (dump stream) (string->bytes/utf-8 "\x00\x05roxyb\x15\x01\x0aroxyb 🤘\x15\x00")))
diff --git a/xenomorph/xenomorph/undo/utils.rkt b/xenomorph/xenomorph/undo/utils.rkt
deleted file mode 100644
index 4d806221..00000000
--- a/xenomorph/xenomorph/undo/utils.rkt
+++ /dev/null
@@ -1,15 +0,0 @@
-#lang racket/base
-(require racket/class
-         "number.rkt"
-         "private/generic.rkt"
-         "private/helper.rkt")
-(provide (all-defined-out))
-
-(define (resolve-length len-arg [stream #f] [parent #f])
-  (cond
-    [(not len-arg) #f]
-    [(number? len-arg) len-arg]
-    [(procedure? len-arg) (len-arg parent)]
-    [(and parent (key? len-arg)) (ref parent len-arg)] ; treat as key into RStruct parent
-    [(and stream (NumberT? len-arg)) (send len-arg decode stream)]
-    [else (raise-argument-error 'resolveLength "fixed-size argument" len-arg)]))
\ No newline at end of file
diff --git a/xenomorph/xenomorph/undo/versioned-struct.rkt b/xenomorph/xenomorph/undo/versioned-struct.rkt
deleted file mode 100644
index e36924d6..00000000
--- a/xenomorph/xenomorph/undo/versioned-struct.rkt
+++ /dev/null
@@ -1,155 +0,0 @@
-#lang racket/base
-(require racket/class
-         racket/list
-         sugar/unstable/class
-         sugar/unstable/dict
-         sugar/unstable/js
-         racket/dict
-         "struct.rkt"
-         "private/generic.rkt"
-         "private/helper.rkt")
-(provide (all-defined-out))
-
-#|
-approximates
-https://github.com/mbuttrackerick/restructure/blob/master/src/VersionedStruct.coffee
-|#
-
-
-(define-subclass Struct (VersionedStruct type [versions (dictify)])
-  
-  (unless (for/or ([proc (list integer? procedure? xenomorph-base%? symbol?)])
-            (proc type))
-    (raise-argument-error 'VersionedStruct "integer, function, symbol, or Restructure object" type))
-  (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 post-decode)
-  (inherit-field fields)
-  (field [forced-version #f]
-         [versionGetter void]
-         [versionSetter void])
-
-  (when (or (key? type) (procedure? type))
-    (set-field! versionGetter this (if (procedure? type)
-                                       type
-                                       (λ (parent) (ref parent type))))
-    (set-field! versionSetter this (if (procedure? type)
-                                       type
-                                       (λ (parent version) (ref-set! parent type version)))))
-
-  (define/override (decode stream [parent #f] [length 0])
-    (define res (_setup stream parent length))
-
-    (ref-set! res 'version
-              (cond
-                [forced-version] ; for testing purposes: pass an explicit version
-                [(or (key? type) (procedure? type))
-                 (unless parent
-                   (raise-argument-error 'VersionedStruct:decode "valid parent" parent))
-                 (versionGetter parent)]
-                [else (send type decode stream)]))
-
-    (when (ref versions 'header)
-      (_parse-fields stream res (ref versions 'header)))
-    
-    (define fields (or (ref versions (ref res 'version)) (raise-argument-error 'VersionedStruct:decode "valid version key" (cons version (· this versions)))))
-
-    
-    (cond
-      [(VersionedStruct? fields) (send fields decode stream parent)]
-      [else
-       (_parse-fields stream res fields)
-       res]))
-  
-  (define/public-final (force-version! version)
-    (set! forced-version version))  
-
-  (define/override (encode stream val [parent #f])
-    (unless (hash? val)
-      (raise-argument-error 'VersionedStruct:encode "hash" val))
-
-    (define ctx (mhash 'pointers empty
-                       'startOffset (pos stream)
-                       'parent parent
-                       'val val
-                       'pointerSize 0))
-
-    (ref-set! ctx 'pointerOffset (+ (pos stream) (size val ctx #f)))
-
-    (when (not (or (key? type) (procedure? type)))
-      (send type encode stream (or forced-version (· val version))))
-
-    (when (ref versions 'header)
-      (for ([(key type) (in-dict (ref versions 'header))])
-           (send type encode stream (ref val key) ctx)))
-
-    (define fields (or (ref versions (or forced-version (· val version))) (raise-argument-error 'VersionedStruct:encode "valid version key" version)))
-
-    (unless (andmap (λ (key) (member key (ref-keys val))) (ref-keys fields))
-      (raise-argument-error 'VersionedStruct:encode (format "hash that contains superset of Struct keys: ~a" (dict-keys fields)) (hash-keys val)))
-
-    (for ([(key type) (in-dict fields)])
-         (send type encode stream (ref val key) ctx))
-
-    (for ([ptr (in-list (ref ctx 'pointers))])
-         (send (ref ptr 'type) encode stream (ref ptr 'val) (ref ptr 'parent))))
-
-  
-  (define/override (size [val #f] [parent #f] [includePointers #t])
-    (unless (or val forced-version)
-      (raise-argument-error 'VersionedStruct:size "value" val))
-
-    (define ctx (mhash 'parent parent
-                       'val val
-                       'pointerSize 0))
-
-    (+ (if (not (or (key? type) (procedure? type)))
-           (send type size (or forced-version (ref val 'version)) ctx)
-           0)
-       
-       (for/sum ([(key type) (in-dict (or (ref versions 'header) empty))])
-                (send type size (and val (ref val key)) ctx))
-
-       (let ([fields (or (ref versions (or forced-version (ref val 'version)))
-                         (raise-argument-error 'VersionedStruct:encode "valid version key" version))])
-         (for/sum ([(key type) (in-dict fields)])
-                  (send type size (and val (ref val key)) ctx)))
-
-       (if includePointers (ref ctx 'pointerSize) 0))))
-
-#;(test-module
-   (require "number.rkt")
-   (define (random-pick xs) (list-ref xs (random (length xs))))
-   (check-exn exn:fail:contract? (λ () (+VersionedStruct 42 42)))
-
-   ;; make random versioned structs and make sure we can round trip
-   #;(for ([i (in-range 1)])
-          (define field-types (for/list ([i (in-range 1)])
-                                        (random-pick (list uint8 uint16be uint16le uint32be uint32le double))))
-          (define num-versions 20)
-          (define which-struct (random num-versions))
-          (define struct-versions (for/list ([v (in-range num-versions)])
-                                            (cons v (for/list ([num-type (in-list field-types)])
-                                                              (cons (gensym) num-type)))))
-          (define vs (+VersionedStruct which-struct struct-versions))
-          (define struct-size (for/sum ([num-type (in-list (map cdr (ref struct-versions which-struct)))])
-                                       (send num-type size)))
-          (define bs (apply bytes (for/list ([i (in-range struct-size)])
-                                            (random 256))))
-          (check-equal? (send vs encode #f (send vs decode bs)) bs))
-
-   (define s (+Struct (dictify 'a uint8 'b uint8 'c uint8)))
-   (check-equal? (send s size) 3)
-   (define vs (+VersionedStruct uint8 (dictify 1 (dictify 'd s) 2 (dictify 'e s 'f s))))
-   (send vs force-version! 1)
-   (check-equal? (send vs size) 6)
-   #|
-   (define s2 (+Struct (dictify 'a vs)))
-   (check-equal? (send s2 size) 6)
-   (define vs2 (+VersionedStruct (λ (p) 2) (dictify 1 vs 2 vs)))
-   (check-equal? (send vs2 size) 6)
-|#
-   )
-
-