diff --git a/.dir-locals.el b/.dir-locals.el
new file mode 100644
index 0000000..5923705
--- /dev/null
+++ b/.dir-locals.el
@@ -0,0 +1,4 @@
+((scheme-mode
+  (indent-tabs-mode . nil)
+  (lisp-local-indent
+   unpack-case 1)))
diff --git a/.gitignore b/.gitignore
index 52735aa..55b86bd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
-distfiles
+*.log
+*.tar
+*.tgz
diff --git a/lassik/dockerfile.scm b/lassik/dockerfile.scm
deleted file mode 100644
index 62d0fb3..0000000
--- a/lassik/dockerfile.scm
+++ /dev/null
@@ -1,124 +0,0 @@
-;; Emacs: this is -*- Scheme -*- code, not a Dockerfile.
-
-;; Copyright 2019 Lassi Kortela
-;; SPDX-License-Identifier: ISC
-
-(define-syntax only-when
-  (syntax-rules ()
-    ((_ condition body ...)
-     (if condition (begin body ...) #f))))
-
-(define (delimit delimiter strings)
-  (if (null? strings) ""
-      (let loop ((strings (cdr strings)) (acc (car strings)))
-        (if (null? strings) acc
-            (loop (cdr strings)
-                  (string-append acc delimiter (car strings)))))))
-
-(define (stringify s)
-  (cond ((string? s) s)
-        ((number? s) (number->string s))
-        (else (error "Don't know how to stringify that"))))
-
-(define (tight . ss) (delimit "" (map stringify ss)))
-
-(define (words . ss) (delimit " " (delete #f ss)))
-
-(define (name=value name value)
-  (string-append name "=" value))
-
-(define (string-list->json strings)
-  (call-with-port (open-output-string)
-                  (lambda (out)
-                    (parameterize ((current-output-port out))
-                      (write-char #\[)
-                      (unless (null? strings)
-                        (write (car strings))
-                        (for-each (lambda (s) (write-string ", ") (write s))
-                                  (cdr strings)))
-                      (write-char #\]))
-                    (get-output-string out))))
-
-(define (quote-string-with-vars s)
-  s)
-
-(define string-or-glob? string?)
-(define string-with-vars string?)
-(define name? string?)
-(define shellcmd list?)
-(define (any? x) #t)
-(define (nat x) (and (integer? x) (exact? x) (>= x 0)))
-
-;;
-
-(define (quote-dockerfile-instruction instruction)
-  (unpack-case instruction
-               ((blank-line)
-                "")
-               ((comment (text string?))
-                ;; TODO: Multi-line string should produce multi-line comment.
-                (string-append "# " text))
-               ((from (image name?) (as name? ?))
-                (words "FROM" image (only-when as (words "AS" as))))
-               ((run (shell shellcmd ?) (exec string? *))
-                (exactly-one-of shell exec)
-                (words "RUN" (cond (shell (shell-quote shell))
-                                   (exec  (string-list->json exec)))))
-               ((cmd (shell shellcmd ?) (exec string? *))
-                (exactly-one-of shell exec)
-                (words "CMD" (cond (shell (shell-quote shell))
-                                   (exec  (string-list->json exec)))))
-               ((label (name string?) (value string?))
-                (words "LABEL" (name=value name value)))
-               ((expose (port nat) (protocol string? ?))
-                (words "EXPOSE" (if protocol (tight port "/" protocol) port)))
-               ((env (name string?) (value string?))
-                (words "ENV" (name=value name value)))
-               ((add (user name? ?) (group name? ?) (dst string?) (src string-or-glob? +))
-                (words "ADD"
-                       (only-when (or user group) (tight "--chown=" user ":" group))
-                       (string-list->json (append src (list dst)))))
-               ((copy (from string? ?) (user string? ?) (group string? ?)
-                      (dst string?) (src string-or-glob? +))
-                (words "COPY"
-                       (only-when from (tight "--from=" from))
-                       (only-when (or user group) (tight "--chown=" user ":" group))
-                       (string-list->json (append src (list dst)))))
-               ((entrypoint (shell shellcmd ?) (exec string? *))
-                (exactly-one-of shell exec)
-                (words "ENTRYPOINT" (cond (shell (shell-quote shell))
-                                          (exec  (string-list->json exec)))))
-               ((volume (mountpoint string?))
-                (words "VOLUME" (string-list->json (list mountpoint))))
-               ((user (user string? ?) (group string? ?) (uid nat ?) (gid nat ?))
-                (exactly-one-of uid user)
-                (at-most-one-of gid group)
-                (at-most-one-of uid group)
-                (at-most-one-of gid user)
-                (words "USER" (tight (or user uid)
-                                     (only-when (or group gid)
-                                                (tight ":" (or group gid))))))
-               ((workdir (path string-with-vars))
-                (words "WORKDIR" (quote-string-with-vars path)))
-               ((arg (name string?) (value string?))
-                (words "ARG" (name=value name value)))
-               ((stopsignal (signal name?))
-                (words "STOPSIGNAL" signal))
-               ((healthcheck (shell shellcmd ?) (exec string? *) (none any? *) #;option*)
-                #;(at-most-one-of none option*)
-                (exactly-one-of shell exec none)
-                (words "HEALTHCHECK"
-                       (cond (shell (words "CMD" (shell-quote shell)))
-                             (exec  (words "CMD" (string-list->json exec)))
-                             (none  "NONE"))))
-               (else (error "Unknown Dockerfile instruction" instruction))))
-
-(define (quote-dockerfile instructions)
-  (call-with-port
-   (open-output-string)
-   (lambda (out)
-     (for-each (lambda (x)
-                 (write-string (quote-dockerfile-instruction x) out)
-                 (newline out))
-               instructions)
-     (get-output-string out))))
diff --git a/lassik/dockerfile.sld b/lassik/dockerfile.sld
index c4304ef..fd49613 100644
--- a/lassik/dockerfile.sld
+++ b/lassik/dockerfile.sld
@@ -12,4 +12,124 @@
           (chibi match)
           (lassik unpack-assoc)
           (lassik shell-quote))
-  (include "dockerfile.scm"))
+  (begin
+
+    (define-syntax only-when
+      (syntax-rules ()
+        ((_ condition body ...)
+         (if condition (begin body ...) #f))))
+
+    (define (delimit delimiter strings)
+      (if (null? strings) ""
+          (let loop ((strings (cdr strings)) (acc (car strings)))
+            (if (null? strings) acc
+                (loop (cdr strings)
+                      (string-append acc delimiter (car strings)))))))
+
+    (define (stringify s)
+      (cond ((string? s) s)
+            ((number? s) (number->string s))
+            (else (error "Don't know how to stringify that"))))
+
+    (define (tight . ss) (delimit "" (map stringify ss)))
+
+    (define (words . ss) (delimit " " (delete #f ss)))
+
+    (define (name=value name value)
+      (string-append name "=" value))
+
+    (define (string-list->json strings)
+      (call-with-port (open-output-string)
+        (lambda (out)
+          (parameterize ((current-output-port out))
+            (write-char #\[)
+            (unless (null? strings)
+              (write (car strings))
+              (for-each (lambda (s) (write-string ", ") (write s))
+                        (cdr strings)))
+            (write-char #\]))
+          (get-output-string out))))
+
+    (define (quote-string-with-vars s)
+      s)
+
+    (define string-or-glob? string?)
+    (define string-with-vars string?)
+    (define name? string?)
+    (define shellcmd list?)
+    (define (any? x) #t)
+    (define (nat x) (and (integer? x) (exact? x) (>= x 0)))
+
+    ;;
+
+    (define (quote-dockerfile-instruction instruction)
+      (unpack-case instruction
+        ((blank-line)
+         "")
+        ((comment (text string?))
+         ;; TODO: Multi-line string should produce multi-line comment.
+         (string-append "# " text))
+        ((from (image name?) (as name? ?))
+         (words "FROM" image (only-when as (words "AS" as))))
+        ((run (shell shellcmd ?) (exec string? *))
+         (exactly-one-of shell exec)
+         (words "RUN" (cond (shell (shell-quote shell))
+                            (exec  (string-list->json exec)))))
+        ((cmd (shell shellcmd ?) (exec string? *))
+         (exactly-one-of shell exec)
+         (words "CMD" (cond (shell (shell-quote shell))
+                            (exec  (string-list->json exec)))))
+        ((label (name string?) (value string?))
+         (words "LABEL" (name=value name value)))
+        ((expose (port nat) (protocol string? ?))
+         (words "EXPOSE" (if protocol (tight port "/" protocol) port)))
+        ((env (name string?) (value string?))
+         (words "ENV" (name=value name value)))
+        ((add (user name? ?) (group name? ?) (dst string?) (src string-or-glob? +))
+         (words "ADD"
+                (only-when (or user group) (tight "--chown=" user ":" group))
+                (string-list->json (append src (list dst)))))
+        ((copy (from string? ?) (user string? ?) (group string? ?)
+               (dst string?) (src string-or-glob? +))
+         (words "COPY"
+                (only-when from (tight "--from=" from))
+                (only-when (or user group) (tight "--chown=" user ":" group))
+                (string-list->json (append src (list dst)))))
+        ((entrypoint (shell shellcmd ?) (exec string? *))
+         (exactly-one-of shell exec)
+         (words "ENTRYPOINT" (cond (shell (shell-quote shell))
+                                   (exec  (string-list->json exec)))))
+        ((volume (mountpoint string?))
+         (words "VOLUME" (string-list->json (list mountpoint))))
+        ((user (user string? ?) (group string? ?) (uid nat ?) (gid nat ?))
+         (exactly-one-of uid user)
+         (at-most-one-of gid group)
+         (at-most-one-of uid group)
+         (at-most-one-of gid user)
+         (words "USER" (tight (or user uid)
+                              (only-when (or group gid)
+                                         (tight ":" (or group gid))))))
+        ((workdir (path string-with-vars))
+         (words "WORKDIR" (quote-string-with-vars path)))
+        ((arg (name string?) (value string?))
+         (words "ARG" (name=value name value)))
+        ((stopsignal (signal name?))
+         (words "STOPSIGNAL" signal))
+        ((healthcheck (shell shellcmd ?) (exec string? *) (none any? *) #;option*)
+         #;(at-most-one-of none option*)
+         (exactly-one-of shell exec none)
+         (words "HEALTHCHECK"
+                (cond (shell (words "CMD" (shell-quote shell)))
+                      (exec  (words "CMD" (string-list->json exec)))
+                      (none  "NONE"))))
+        (else (error "Unknown Dockerfile instruction" instruction))))
+
+    (define (quote-dockerfile instructions)
+      (call-with-port
+          (open-output-string)
+        (lambda (out)
+          (for-each (lambda (x)
+                      (write-string (quote-dockerfile-instruction x) out)
+                      (newline out))
+                    instructions)
+          (get-output-string out))))))
diff --git a/lassik/shell-quote.scm b/lassik/shell-quote.scm
deleted file mode 100644
index 5117285..0000000
--- a/lassik/shell-quote.scm
+++ /dev/null
@@ -1,103 +0,0 @@
-;; Copyright 2019 Lassi Kortela
-;; SPDX-License-Identifier: ISC
-
-(define (delimit delimiter strings)
-  (if (null? strings) ""
-      (let loop ((strings (cdr strings)) (acc (car strings)))
-        (if (null? strings) acc
-            (loop (cdr strings)
-                  (string-append acc delimiter (car strings)))))))
-
-(define (error* . strings) (error (delimit " " strings)))
-
-(define (natural? x) (and (integer? x) (exact? x) (>= x 0)))
-
-(define (the-natural x what)
-  (if (natural? x) (number->string x) (error* what "must be an integer")))
-
-(define (the-string x what)
-  (if (string? x) x (error* what "must be a string")))
-
-(define (the-natural-or-string x what)
-  (cond ((string? x) x)
-        ((natural? x) (number->string x))
-        (else (error* what "must be an integer or string"))))
-
-(define (bare-char? char)
-  (case char ((#\- #\. #\/ #\_) #t) (else (ascii-alphanumeric? char))))
-
-(define (bare-argument? string)
-  (and (not (string=? "" string))
-       (call-with-port (open-input-string string)
-                       (lambda (in)
-                         (let loop ()
-                           (let ((char (read-char in)))
-                             (or (eof-object? char)
-                                 (and (bare-char? char) (loop)))))))))
-
-(define (quote-string string)
-  (if (bare-argument? string) string
-      (call-with-port
-       (open-input-string string)
-       (lambda (in)
-         (call-with-port
-          (open-output-string)
-          (lambda (out)
-            (write-char #\" out)
-            (let loop ()
-              (let ((char (read-char in)))
-                (unless (eof-object? char)
-                  (case char ((#\$ #\` #\" #\\) (write-char #\\ out)))
-                  (write-char char out)
-                  (loop))))
-            (write-char #\" out)
-            (get-output-string out)))))))
-
-(define (quote-arg arg)
-  (cond ((string? arg) (quote-string arg))
-        ((and (pair? arg) (eq? 'arg (car arg)))
-         (let loop ((parts (cdr arg)) (acc ""))
-           (if (null? parts) acc
-               (let ((part (car parts)))
-                 (cond ((and (pair? part) (eq? 'verbatim (car part)))
-                        (unless (= 2 (length part))
-                          (error "Bad (verbatim ...) argument"))
-                        (loop (cdr parts) (string-append acc (cadr part))))
-                       (else
-                        (loop (cdr parts) (string-append acc part))))))))
-        (else (error "command line argument not a string or glob" arg))))
-
-(define (redir1 operator path)
-  (string-append operator (quote-string (the-string path "redirect path"))))
-
-(define (redir2 operator fd path-or-fd)
-  (string-append
-   (the-natural fd "file descriptor")
-   operator
-   (the-natural-or-string path-or-fd "redirect path or file descriptor")))
-
-(define (cmdgroup group)
-  (match group
-    (('redirect group . fd-map)
-     (let loop ((fd-map fd-map) (acc (cmdgroup group)))
-       (if (null? fd-map) acc
-           (loop (cdr fd-map)
-                 (string-append
-                  acc " "
-                  (match (car fd-map)
-                    (('in path)       (redir1 "<"  path))
-                    (('in fd from)    (redir2 "<"  fd from))
-                    (('out path)      (redir1 ">"  path))
-                    (('out fd to)     (redir2 ">"  fd to))
-                    (('append path)   (redir1 ">>" path))
-                    (('append fd to)  (redir2 ">>" fd to))))))))
-    (('subshell group) (string-append "(" (cmdgroup group) ")"))
-    (('begin . groups)
-     (string-append "{ " (delimit "; " (append (map cmdgroup groups)
-                                               '("}")))))
-    (('and   . groups) (delimit " && " (map cmdgroup groups)))
-    (('or    . groups) (delimit " || " (map cmdgroup groups)))
-    (('pipe  . groups) (delimit " | "  (map cmdgroup groups)))
-    (('cmd c . args)   (delimit " "    (map quote-arg (cons c args))))))
-
-(define shell-quote cmdgroup)
diff --git a/lassik/shell-quote.sld b/lassik/shell-quote.sld
index b86b2e7..8199ebf 100644
--- a/lassik/shell-quote.sld
+++ b/lassik/shell-quote.sld
@@ -5,8 +5,109 @@
   (export shell-quote)
   (import (scheme base) (scheme write) (chibi match))
   (cond-expand
-    ((library (srfi 175)) (import (srfi 175)))
-    (else (import (scheme char))
-          (begin (define (ascii-alphanumeric? char)
-                   (or (char-alphabetic? char) (char-numeric? char))))))
-  (include "shell-quote.scm"))
+   ((library (srfi 175)) (import (srfi 175)))
+   (else (import (scheme char))
+         (begin (define (ascii-alphanumeric? char)
+                  (or (char-alphabetic? char) (char-numeric? char))))))
+  (begin
+
+    (define (delimit delimiter strings)
+      (if (null? strings) ""
+          (let loop ((strings (cdr strings)) (acc (car strings)))
+            (if (null? strings) acc
+                (loop (cdr strings)
+                      (string-append acc delimiter (car strings)))))))
+
+    (define (error* . strings) (error (delimit " " strings)))
+
+    (define (natural? x) (and (integer? x) (exact? x) (>= x 0)))
+
+    (define (the-natural x what)
+      (if (natural? x) (number->string x) (error* what "must be an integer")))
+
+    (define (the-string x what)
+      (if (string? x) x (error* what "must be a string")))
+
+    (define (the-natural-or-string x what)
+      (cond ((string? x) x)
+            ((natural? x) (number->string x))
+            (else (error* what "must be an integer or string"))))
+
+    (define (bare-char? char)
+      (case char ((#\- #\. #\/ #\_) #t) (else (ascii-alphanumeric? char))))
+
+    (define (bare-argument? string)
+      (and (not (string=? "" string))
+           (call-with-port (open-input-string string)
+             (lambda (in)
+               (let loop ()
+                 (let ((char (read-char in)))
+                   (or (eof-object? char)
+                       (and (bare-char? char) (loop)))))))))
+
+    (define (quote-string string)
+      (if (bare-argument? string) string
+          (call-with-port
+              (open-input-string string)
+            (lambda (in)
+              (call-with-port
+                  (open-output-string)
+                (lambda (out)
+                  (write-char #\" out)
+                  (let loop ()
+                    (let ((char (read-char in)))
+                      (unless (eof-object? char)
+                        (case char ((#\$ #\` #\" #\\) (write-char #\\ out)))
+                        (write-char char out)
+                        (loop))))
+                  (write-char #\" out)
+                  (get-output-string out)))))))
+
+    (define (quote-arg arg)
+      (cond ((string? arg) (quote-string arg))
+            ((and (pair? arg) (eq? 'arg (car arg)))
+             (let loop ((parts (cdr arg)) (acc ""))
+               (if (null? parts) acc
+                   (let ((part (car parts)))
+                     (cond ((and (pair? part) (eq? 'verbatim (car part)))
+                            (unless (= 2 (length part))
+                              (error "Bad (verbatim ...) argument"))
+                            (loop (cdr parts) (string-append acc (cadr part))))
+                           (else
+                            (loop (cdr parts) (string-append acc part))))))))
+            (else (error "command line argument not a string or glob" arg))))
+
+    (define (redir1 operator path)
+      (string-append operator (quote-string (the-string path "redirect path"))))
+
+    (define (redir2 operator fd path-or-fd)
+      (string-append
+       (the-natural fd "file descriptor")
+       operator
+       (the-natural-or-string path-or-fd "redirect path or file descriptor")))
+
+    (define (cmdgroup group)
+      (match group
+        (('redirect group . fd-map)
+         (let loop ((fd-map fd-map) (acc (cmdgroup group)))
+           (if (null? fd-map) acc
+               (loop (cdr fd-map)
+                     (string-append
+                      acc " "
+                      (match (car fd-map)
+                        (('in path)       (redir1 "<"  path))
+                        (('in fd from)    (redir2 "<"  fd from))
+                        (('out path)      (redir1 ">"  path))
+                        (('out fd to)     (redir2 ">"  fd to))
+                        (('append path)   (redir1 ">>" path))
+                        (('append fd to)  (redir2 ">>" fd to))))))))
+        (('subshell group) (string-append "(" (cmdgroup group) ")"))
+        (('begin . groups)
+         (string-append "{ " (delimit "; " (append (map cmdgroup groups)
+                                                   '("}")))))
+        (('and   . groups) (delimit " && " (map cmdgroup groups)))
+        (('or    . groups) (delimit " || " (map cmdgroup groups)))
+        (('pipe  . groups) (delimit " | "  (map cmdgroup groups)))
+        (('cmd c . args)   (delimit " "    (map quote-arg (cons c args))))))
+
+    (define shell-quote cmdgroup)))
diff --git a/lassik/trivial-tar-writer-test.sh b/lassik/trivial-tar-writer-test.sh
index b4c4156..d6272d6 100755
--- a/lassik/trivial-tar-writer-test.sh
+++ b/lassik/trivial-tar-writer-test.sh
@@ -2,15 +2,16 @@
 set -eu
 cd "$(dirname "$0")"
 echo "Entering directory '$PWD'"
-payload="trivial-tar-writer.scm trivial-tar-writer-test.sh"
+payload="trivial-tar-writer.sld trivial-tar-writer-test.sh"
 set -x
-chibi-scheme -A . trivial-tar-writer-test.scm $payload \
+chibi-scheme -A .. trivial-tar-writer-test.scm $payload \
     >trivial-tar-writer-test-chibi.tar
-gsi-script . trivial-tar-writer-test.scm $payload \
+gsi-script .. trivial-tar-writer-test.scm $payload \
     >trivial-tar-writer-test-gambit.tar
-gosh -A . trivial-tar-writer-test.scm $payload \
+gosh -A .. trivial-tar-writer-test.scm $payload \
     >trivial-tar-writer-test-gauche.tar
-kawa -Dkawa.import.path="$PWD/*.sld" trivial-tar-writer-test.scm $payload \
+kawa -Dkawa.import.path="$(cd .. && echo "$PWD/*.sld")" \
+    trivial-tar-writer-test.scm $payload \
     >trivial-tar-writer-test-kawa.tar
 bsdtar -cf trivial-tar-writer-test-bsd.tar $payload
 gtar -cf trivial-tar-writer-test-gnu.tar $payload
diff --git a/lassik/trivial-tar-writer.scm b/lassik/trivial-tar-writer.scm
deleted file mode 100644
index 33974fe..0000000
--- a/lassik/trivial-tar-writer.scm
+++ /dev/null
@@ -1,64 +0,0 @@
-;; Copyright 2019 Lassi Kortela
-;; SPDX-License-Identifier: ISC
-
-(define tar-owner (make-parameter (cons 0 "root")))
-(define tar-group (make-parameter (cons 0 "root")))
-(define tar-unix-mode (make-parameter #o644))
-(define tar-unix-time (make-parameter 0))
-
-(define nulls (make-bytevector 512 0))
-(define blank-checksum (make-bytevector 7 (char->integer #\space)))
-
-(define (bytevector-sum bv)
-  (let loop ((i (- (bytevector-length bv) 1)) (sum 0))
-    (if (< i 0) sum (loop (- i 1) (+ sum (bytevector-u8-ref bv i))))))
-
-(define (tar-string nbyte string)
-  (let* ((bytes (string->utf8 string))
-         (nnull (- nbyte (bytevector-length bytes))))
-    (when (< nnull 1) (error "tar: string too long"))
-    (bytevector-append bytes (make-bytevector nnull 0))))
-
-(define (tar-octal nbyte number)
-  (unless (integer? number) (error "tar: not an integer"))
-  (when (< number 0) (error "tar: negative integer"))
-  (let* ((bytes (string->utf8 (number->string number 8)))
-         (nzero (- nbyte 1 (bytevector-length bytes))))
-    (when (< nzero 0) (error "tar: number too big"))
-    (bytevector-append (make-bytevector nzero (char->integer #\0))
-                       bytes (bytevector 0))))
-
-(define (tar-write-file fake-path bytes)
-  (let* ((nbyte (bytevector-length bytes))
-         (nnull (- 512 (truncate-remainder nbyte 512)))
-         (header-before-checksum
-          (bytevector-append
-           (tar-string 100 fake-path)
-           (tar-octal 8 (tar-unix-mode))
-           (tar-octal 8 (car (tar-owner)))
-           (tar-octal 8 (car (tar-group)))
-           (tar-octal 12 nbyte)
-           (tar-octal 12 (tar-unix-time))))
-         (header-after-checksum
-          (bytevector-append
-           (bytevector (char->integer #\space))
-           (bytevector (char->integer #\0))
-           (tar-string 100 "")
-           (tar-string 8 "ustar  ")
-           (tar-string 32 (cdr (tar-owner)))
-           (tar-string 32 (cdr (tar-group)))
-           (make-bytevector 183 0)))
-         (checksum
-          (let ((sum (+ (bytevector-sum header-before-checksum)
-                        (bytevector-sum blank-checksum)
-                        (bytevector-sum header-after-checksum))))
-            (tar-octal 7 (truncate-remainder sum (expt 8 6))))))
-    (write-bytevector header-before-checksum)
-    (write-bytevector checksum)
-    (write-bytevector header-after-checksum)
-    (write-bytevector bytes)
-    (write-bytevector nulls (current-output-port) 0 nnull)))
-
-(define (tar-write-end)
-  (write-bytevector nulls)
-  (write-bytevector nulls))
diff --git a/lassik/trivial-tar-writer.sld b/lassik/trivial-tar-writer.sld
index 9018702..469eb63 100644
--- a/lassik/trivial-tar-writer.sld
+++ b/lassik/trivial-tar-writer.sld
@@ -1,3 +1,6 @@
+;; Copyright 2019 Lassi Kortela
+;; SPDX-License-Identifier: ISC
+
 (define-library (lassik trivial-tar-writer)
   (export tar-owner
           tar-group
@@ -6,4 +9,66 @@
           tar-write-file
           tar-write-end)
   (import (scheme base))
-  (include "trivial-tar-writer.scm"))
+  (begin
+
+    (define tar-owner (make-parameter (cons 0 "root")))
+    (define tar-group (make-parameter (cons 0 "root")))
+    (define tar-unix-mode (make-parameter #o644))
+    (define tar-unix-time (make-parameter 0))
+
+    (define nulls (make-bytevector 512 0))
+    (define blank-checksum (make-bytevector 7 (char->integer #\space)))
+
+    (define (bytevector-sum bv)
+      (let loop ((i (- (bytevector-length bv) 1)) (sum 0))
+        (if (< i 0) sum (loop (- i 1) (+ sum (bytevector-u8-ref bv i))))))
+
+    (define (tar-string nbyte string)
+      (let* ((bytes (string->utf8 string))
+             (nnull (- nbyte (bytevector-length bytes))))
+        (when (< nnull 1) (error "tar: string too long"))
+        (bytevector-append bytes (make-bytevector nnull 0))))
+
+    (define (tar-octal nbyte number)
+      (unless (integer? number) (error "tar: not an integer"))
+      (when (< number 0) (error "tar: negative integer"))
+      (let* ((bytes (string->utf8 (number->string number 8)))
+             (nzero (- nbyte 1 (bytevector-length bytes))))
+        (when (< nzero 0) (error "tar: number too big"))
+        (bytevector-append (make-bytevector nzero (char->integer #\0))
+                           bytes (bytevector 0))))
+
+    (define (tar-write-file fake-path bytes)
+      (let* ((nbyte (bytevector-length bytes))
+             (nnull (- 512 (truncate-remainder nbyte 512)))
+             (header-before-checksum
+              (bytevector-append
+               (tar-string 100 fake-path)
+               (tar-octal 8 (tar-unix-mode))
+               (tar-octal 8 (car (tar-owner)))
+               (tar-octal 8 (car (tar-group)))
+               (tar-octal 12 nbyte)
+               (tar-octal 12 (tar-unix-time))))
+             (header-after-checksum
+              (bytevector-append
+               (bytevector (char->integer #\space))
+               (bytevector (char->integer #\0))
+               (tar-string 100 "")
+               (tar-string 8 "ustar  ")
+               (tar-string 32 (cdr (tar-owner)))
+               (tar-string 32 (cdr (tar-group)))
+               (make-bytevector 183 0)))
+             (checksum
+              (let ((sum (+ (bytevector-sum header-before-checksum)
+                            (bytevector-sum blank-checksum)
+                            (bytevector-sum header-after-checksum))))
+                (tar-octal 7 (truncate-remainder sum (expt 8 6))))))
+        (write-bytevector header-before-checksum)
+        (write-bytevector checksum)
+        (write-bytevector header-after-checksum)
+        (write-bytevector bytes)
+        (write-bytevector nulls (current-output-port) 0 nnull)))
+
+    (define (tar-write-end)
+      (write-bytevector nulls)
+      (write-bytevector nulls))))
diff --git a/lassik/unpack-assoc.scm b/lassik/unpack-assoc.scm
deleted file mode 100644
index 16256c6..0000000
--- a/lassik/unpack-assoc.scm
+++ /dev/null
@@ -1,123 +0,0 @@
-;; Copyright 2019 Lassi Kortela
-;; SPDX-License-Identifier: ISC
-
-(define (unpack-using/many need? type key entry)
-  (if (not entry)
-      (and need? (error "Required key missing" key))
-      (let check ((tail (cdr entry)))
-        (cond ((null? tail)
-               (cdr entry))
-              ((not (pair? tail))
-               (error "Values do not form a proper list" key (cdr entry)))
-              ((not (type (car tail)))
-               (error "Key has value of the wrong type" key (car tail)))
-              (else (check (cdr tail)))))))
-
-(define (unpack-using/one need? type key entry)
-  (cond ((not entry)
-         (and need? (error "Required key missing" key)))
-        ((not (pair? (cdr entry)))
-         (error "Key is present but has no value" key))
-        ((not (null? (cddr entry)))
-         (error "Key has more than one value" key (cdr entry)))
-        ((not (type (cadr entry)))
-         (error "Key has value of the wrong type" key (cadr entry)))
-        (else (cadr entry))))
-
-(define-syntax unpack-using/let
-  (syntax-rules ()
-    ((_ (lets ...) () body ...)
-     (let (lets ...) body ...))
-    ((_ (lets ...) ((key more-stuff ...) more-rules ...) body ...)
-     (unpack-using/let (lets ... (key #f)) (more-rules ...) body ...))))
-
-(define-syntax unpack-using/case
-  (syntax-rules ()
-    ((_ (cases ...) this-key val)
-     (case this-key
-       cases ...
-       (else (error "Unknown key" this-key))))
-    ((_ (cases ...) this-key val (key more-stuff ...) more-rules ...)
-     (unpack-using/case (cases ... ((key)
-                                    (when key (error "Duplicate key" 'key))
-                                    (set! key (cons 'key val))))
-                        this-key val more-rules ...))))
-
-(define-syntax unpack-using/rule
-  (syntax-rules (* + ?)
-    ((_ (key type *)) (set! key (unpack-using/many #f type 'key key)))
-    ((_ (key type +)) (set! key (unpack-using/many #t type 'key key)))
-    ((_ (key type ?)) (set! key (unpack-using/one  #f type 'key key)))
-    ((_ (key type))   (set! key (unpack-using/one  #t type 'key key)))))
-
-(define-syntax unpack-using/set
-  (syntax-rules ()
-    ((_ (sets ...))
-     (begin sets ... #f))
-    ((_ (sets ...) rule rules ...)
-     (unpack-using/set (sets ... (unpack-using/rule rule)) rules ...))))
-
-(define-syntax unpack-using
-  (syntax-rules (key val)
-    ((_ for-each-pair pairs (rules ...) body ...)
-     (unpack-using/let () (rules ...)
-                       (for-each-pair
-                        (lambda (key val) (unpack-using/case () key val rules ...))
-                        pairs)
-                       (unpack-using/set () rules ...)
-                       body ...))))
-
-;;
-
-(define (alist-for-each proc alist)
-  (cond ((null? alist) #f)
-        ((not (pair? alist)) (error "Not a proper list" alist))
-        ((not (pair? (car alist))) (error "Alist entry is not a pair" alist))
-        (else (proc (caar alist) (cdar alist))
-              (alist-for-each proc (cdr alist)))))
-
-(define-syntax unpack
-  (syntax-rules ()
-    ((_ alist (rules ...) body ...)
-     (unpack-using alist-for-each alist (rules ...) body ...))))
-
-(define-syntax unpack-case/aux
-  (syntax-rules ()
-    ((_ (cases ...) entry)
-     (case (car entry) cases ...))
-    ((_ (cases ...) entry (else body ...))
-     (unpack-case/aux
-      (cases ... (else body ...))
-      entry))
-    ((_ (cases ...) entry ((head rules ...) body ...))
-     (unpack-case/aux
-      (cases ... ((head) (unpack (cdr entry) (rules ...) body ...)))
-      entry))
-    ((_ (cases ...) entry ((head rules ...) body ...) more-cases ...)
-     (unpack-case/aux
-      (cases ... ((head) (unpack (cdr entry) (rules ...) body ...)))
-      entry more-cases ...))))
-
-(define-syntax unpack-case
-  (syntax-rules (entry)
-    ((_ entry-expr cases ...)
-     (let ((entry entry-expr))
-       (unpack-case/aux () entry cases ...)))))
-
-;;
-
-(define (count-truthy . lis)
-  (let loop ((lis lis) (n 0))
-    (if (null? lis) n (loop (cdr lis) (if (car lis) (+ n 1) n)))))
-
-(define-syntax at-most-one-of
-  (syntax-rules ()
-    ((_ identifiers ...)
-     (unless (<= (count-truthy identifiers ...) 1)
-       (error "At most one of these must be given" '(identifiers ...))))))
-
-(define-syntax exactly-one-of
-  (syntax-rules ()
-    ((_ identifiers ...)
-     (unless (= (count-truthy identifiers ...) 1)
-       (error "Exactly one of these must be given" '(identifiers ...))))))
diff --git a/lassik/unpack-assoc.sld b/lassik/unpack-assoc.sld
index 4dcf591..910d643 100644
--- a/lassik/unpack-assoc.sld
+++ b/lassik/unpack-assoc.sld
@@ -17,4 +17,125 @@
 
           unpack-case/aux)
   (import (scheme base))
-  (include "unpack-assoc.scm"))
+  (begin
+
+    (define (unpack-using/many need? type key entry)
+      (if (not entry)
+        (and need? (error "Required key missing" key))
+        (let check ((tail (cdr entry)))
+          (cond ((null? tail)
+                 (cdr entry))
+                ((not (pair? tail))
+                 (error "Values do not form a proper list" key (cdr entry)))
+                ((not (type (car tail)))
+                 (error "Key has value of the wrong type" key (car tail)))
+                (else (check (cdr tail)))))))
+
+    (define (unpack-using/one need? type key entry)
+      (cond ((not entry)
+             (and need? (error "Required key missing" key)))
+            ((not (pair? (cdr entry)))
+             (error "Key is present but has no value" key))
+            ((not (null? (cddr entry)))
+             (error "Key has more than one value" key (cdr entry)))
+            ((not (type (cadr entry)))
+             (error "Key has value of the wrong type" key (cadr entry)))
+            (else (cadr entry))))
+
+    (define-syntax unpack-using/let
+      (syntax-rules ()
+        ((_ (lets ...) () body ...)
+         (let (lets ...) body ...))
+        ((_ (lets ...) ((key more-stuff ...) more-rules ...) body ...)
+         (unpack-using/let (lets ... (key #f)) (more-rules ...) body ...))))
+
+    (define-syntax unpack-using/case
+      (syntax-rules ()
+        ((_ (cases ...) this-key val)
+         (case this-key
+           cases ...
+           (else (error "Unknown key" this-key))))
+        ((_ (cases ...) this-key val (key more-stuff ...) more-rules ...)
+         (unpack-using/case (cases ... ((key)
+                                        (when key (error "Duplicate key" 'key))
+                                        (set! key (cons 'key val))))
+                            this-key val more-rules ...))))
+
+    (define-syntax unpack-using/rule
+      (syntax-rules (* + ?)
+        ((_ (key type *)) (set! key (unpack-using/many #f type 'key key)))
+        ((_ (key type +)) (set! key (unpack-using/many #t type 'key key)))
+        ((_ (key type ?)) (set! key (unpack-using/one  #f type 'key key)))
+        ((_ (key type))   (set! key (unpack-using/one  #t type 'key key)))))
+
+    (define-syntax unpack-using/set
+      (syntax-rules ()
+        ((_ (sets ...))
+         (begin sets ... #f))
+        ((_ (sets ...) rule rules ...)
+         (unpack-using/set (sets ... (unpack-using/rule rule)) rules ...))))
+
+    (define-syntax unpack-using
+      (syntax-rules (key val)
+        ((_ for-each-pair pairs (rules ...) body ...)
+         (unpack-using/let () (rules ...)
+                           (for-each-pair
+                            (lambda (key val) (unpack-using/case () key val rules ...))
+                            pairs)
+                           (unpack-using/set () rules ...)
+                           body ...))))
+
+    ;;
+
+    (define (alist-for-each proc alist)
+      (cond ((null? alist) #f)
+            ((not (pair? alist)) (error "Not a proper list" alist))
+            ((not (pair? (car alist))) (error "Alist entry is not a pair" alist))
+            (else (proc (caar alist) (cdar alist))
+                  (alist-for-each proc (cdr alist)))))
+
+    (define-syntax unpack
+      (syntax-rules ()
+        ((_ alist (rules ...) body ...)
+         (unpack-using alist-for-each alist (rules ...) body ...))))
+
+    (define-syntax unpack-case/aux
+      (syntax-rules ()
+        ((_ (cases ...) entry)
+         (case (car entry) cases ...))
+        ((_ (cases ...) entry (else body ...))
+         (unpack-case/aux
+          (cases ... (else body ...))
+          entry))
+        ((_ (cases ...) entry ((head rules ...) body ...))
+         (unpack-case/aux
+          (cases ... ((head) (unpack (cdr entry) (rules ...) body ...)))
+          entry))
+        ((_ (cases ...) entry ((head rules ...) body ...) more-cases ...)
+         (unpack-case/aux
+          (cases ... ((head) (unpack (cdr entry) (rules ...) body ...)))
+          entry more-cases ...))))
+
+    (define-syntax unpack-case
+      (syntax-rules (entry)
+        ((_ entry-expr cases ...)
+         (let ((entry entry-expr))
+           (unpack-case/aux () entry cases ...)))))
+
+    ;;
+
+    (define (count-truthy . lis)
+      (let loop ((lis lis) (n 0))
+        (if (null? lis) n (loop (cdr lis) (if (car lis) (+ n 1) n)))))
+
+    (define-syntax at-most-one-of
+      (syntax-rules ()
+        ((_ identifiers ...)
+         (unless (<= (count-truthy identifiers ...) 1)
+           (error "At most one of these must be given" '(identifiers ...))))))
+
+    (define-syntax exactly-one-of
+      (syntax-rules ()
+        ((_ identifiers ...)
+         (unless (= (count-truthy identifiers ...) 1)
+           (error "Exactly one of these must be given" '(identifiers ...))))))))