1 Introduction
2 Encoding
digit-list->postnet
char-list->postnet
string->postnet
3 Debugging
postnet->debug-string
4 History
5 Legal
Version: 0.4

postnet: USPS POSTNET Barcode Encoding in Racket

Neil Van Dyke

License: LGPL 3   Web: http://www.neilvandyke.org/racket-postnet/

 (require (planet neil/postnet:1:=1))

1 Introduction

This postnet Racket library can be used to generate the United States Postal Service POSTNET barcode binary pattern, as described in Chapter 4 of USPS Publication 25, “Designing Letter and Reply Mail,” dated 2003-06. This library supports ZIP, ZIP+4, and DBPC codes.

The generated binary representation is a Racket list of boolean values. Separate code must be written to render this representation to a particular printing devices.

2 Encoding

There are several procedures for encoding POSTNET from various input representations. It is suspected that most applications will encode from a string representation, using string->postnet.

(digit-list->postnet digits)  any/c
  digits : any/c

Yields a POSTNET encoding of a list of digit numbers. For example:

(digit-list->postnet '(1 2 3 4 5))
==>
(#t #f #f #f #t #t #f #f #t #f #t #f #f #t #t #f
 #f #t #f #f #t #f #t #f #t #f #f #t #f #t #f #t)

(char-list->postnet chars)  any/c
  chars : any/c

Yields a POSTNET encoding of a list of characters. For example:

(char-list->postnet '(#\1 #\2 #\3 #\4 #\5))
==>
(#t #f #f #f #t #t #f #f #t #f #t #f #f #t #t #f
 #f #t #f #f #t #f #t #f #t #f #f #t #f #t #f #t)

(string->postnet str)  any/c
  str : any/c

Yields a POSTNET encoding of a string. For example:

(string->postnet "12345-6789 01")
==>
(#t #f #f #f #t #t #f #f #t #f #t #f #f #t #t #f
 #f #t #f #f #t #f #t #f #t #f #f #t #t #f #f #t
 #f #f #f #t #t #f #f #t #f #t #f #t #f #f #t #t
 #f #f #f #f #f #f #t #t #f #t #f #f #t #t)

3 Debugging

Although this package does not render POSTNET for OCR use, for debugging purposes, the postnet->debug-string procedure can be used to approximate the barcode visually, using ASCII characters.

(postnet->debug-string postnet)  any/c
  postnet : any/c

Yields a string visual approximation of a POSTNET encoding. For example:

(postnet->debug-string (string->postnet "12345"))
==> "|...||..|.|..||..|..|.|.|..|.|.|"

4 History

5 Legal

Copyright (c) 2004–2011 Neil Van Dyke. This program is Free Software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License (LGPL 3), or (at your option) any later version. This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. See http://www.gnu.org/licenses/ for details. For other licenses and consulting, please contact the author.

Standard Documentation Format Note: The API signatures in this documentation are likely incorrect in some regards, such as indicating type any/c for things that are not, and not indicating when arguments are optional. This is due to a transitioning from the Texinfo documentation format to Scribble, which the author intends to finish someday.