Index: main/binary-class.lisp
===================================================================
--- main/binary-class.lisp	(revision main,1)
+++ main/binary-class.lisp	(revision main,1)
@@ -0,0 +1,79 @@
+(defpackage #:binary-class
+  (:use #:cl #:cl-ppcre)
+  (:export #:lisp-type-for #:default-for #:read-binary #:define-file-struct))
+
+(in-package #:binary-class)
+
+
+
+(defstruct member-def
+  name
+  type
+  format)
+
+(defun parse-member-def (def)
+  (destructuring-bind (name type format) def
+    (make-member-def :name name :type type :format format)))
+
+(defgeneric lisp-type-for (binary-type)
+  (:method ((type (eql :unsigned)))
+    '(integer 0))
+  (:method ((type (eql :string)))
+    'string)
+  (:method ((type (eql :date)))
+    't))
+
+(defgeneric default-for (binary-type)
+  (:method ((type (eql :unsigned)))
+    0)
+  (:method ((type (eql :string)))
+    "")
+  (:method ((type (eql :date)))
+    (encode-universal-time 0 0 0 01 01 1970)))
+
+(defgeneric read-binary (type stream &optional format)
+  (:method ((type (eql :unsigned)) stream &optional (format 1))
+    (let ((r 0))
+      (dotimes (i format r)
+        (setf (ldb (byte 8 (* i 8)) r) (read-byte stream)))))
+  (:method ((type (eql :string)) stream &optional format)
+    (let ((v (make-sequence '(vector (unsigned-byte 8)) format
+                            :initial-element 0)))
+      (read-sequence v stream)
+      (string-trim '(#\Nul #\Space) (map 'string #'code-char v))))
+  (:method ((type (eql :date)) stream &optional format)
+    (assert (stringp format))
+    (cond
+      ((string= format "YYMMDD")
+       (let* ((year (read-binary 'unsigned stream))
+              (month (read-binary 'unsigned stream))
+              (day (read-binary 'unsigned stream)))
+         (encode-universal-time 0 0 0 day month year)))
+      ((string= format "YYYYMMDD")
+       (let* ((year (read-binary 'unsigned stream 2))
+              (month (read-binary 'unsigned stream))
+              (day (read-binary 'unsigned stream)))
+         (encode-universal-time 0 0 0 day month year)))
+      (t
+       (error "Date-format must be either \"YYMMDD\" or \"YYYYMMDD\".")))))
+
+(defmacro define-file-struct (name &body defs)
+  (let ((defs (mapcar #'parse-member-def defs)))
+    `(progn
+       (defstruct ,name
+         ,@(mapcar (lambda (def)
+                     (with-slots (name type) def
+                       `(,name ,(default-for type)
+                               :type ,(lisp-type-for type))))
+                   (remove-if #'null defs :key #'member-def-type)))
+       (defmethod read-binary ((type (eql ',name)) stream &optional format)
+         (declare (ignore format))
+         (let ((rec (make-instance ',name)))
+           ,@(mapcar (lambda (def)
+                       (with-slots (name type format) def
+                         (if name
+                             `(setf (slot-value rec ',name)
+                                    (read-binary ',type stream ,format))
+                             `(read-binary 'unsigned stream ,format))))
+                     defs)
+           rec)))))
Index: main/dso-binary-class.asd
===================================================================
--- main/dso-binary-class.asd	(revision main,1)
+++ main/dso-binary-class.asd	(revision main,1)
@@ -0,0 +1,5 @@
+;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp -*-
+
+(asdf:defsystem #:dso-binary-class
+  :depends-on (#:cl-ppcre)
+  :components ((:file "binary-class")))