2:0

numformat-old: Number Formatting🔗ℹ

Neil Van Dyke

License: LGPLv3 Web: http://www.neilvandyke.org/racket/numformat-old/

1 Introduction🔗ℹ

The numformat-old package contains some old and highly-questionable Scheme number-formatting code, which happens to still be used. Do not use this for anything important. A better modern Racket implementation of this functionality should be done.

2 Interface🔗ℹ

procedure
(make-number-displayer specs)
→ (-> number? (output-port? (current-output-port)) void?)
specs : (listof (cons/c symbol? any/c))

Make a procedure that displays numbers to output ports using formatting that is customized by the alist in specs.

> (define display-dollars-and-cents
    (make-number-displayer
     '((sign                   parens)
       (prefix                 "$")
       (pad-whole-char         #f)
       (pad-whole-length       #f)
       (whole-spacers-char     #\,)
       (whole-spacers-interval 3)
       (decimal-point          #\.)
       (max-fractional-length  2)
       (pad-fractional-char    #\0)
       (pad-fractional-length  2)
       (suffix                 #f))))

> (display-dollars-and-cents 69.1)

Outputs:

$69.10

> (display-dollars-and-cents -987654321.6969697)

Outputs:

($987,654,321.69)

procedure
(display-number/us-style num out) → void?
  num : number?
  out : (current-output-port)
(display-number/european-style num out) → void?
  num : number?
  out : (current-output-port)

Write number num to output port out, using some formatting conventions of a particular locale. If out is not given, defaults to the value of (current-output-port).

For example:

> (define x -987654321.6969697)

> (display-number/us-style x)

Outputs:

-987,654,321.6969697

> (display-number/european-style x)

Outputs:

-987 654 321,6969697

3 History🔗ℹ

Version 2:0 — 2016-02-29
- Moving from PLaneT to new package system.
- Renaming package from numformat to numformat-old, to avoid grabbing better package name for this old code.
- Changed “European-style” to use spaces instead of apostrophes.
Version 1:0 — 2011-08-23
- Initial release of some old, buggy code.

4 Legal🔗ℹ

Copyright 2011, 2016 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, 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.