Note: This is taken from the Chicken Wiki, where a more recent version could be available.
Perform currency convertion, using data from the XML feeds of the European Central Bank.
1.0.0 (initial release)
Procedure: (currency-convert FROM TO AMOUNT [#:table TABLE] [#:format? FORMAT?])
FROM and TO are symbols, AMOUNT is either a string or a number. TABLE is an alternate conversion to use, an alist of (SYMBOL . EURO-VALUE) FORMAT?, if #f, will not format the result as money (and thus return a string)
When #f (the default) the XML is retrieved and parsed from the bank at every call to currenncy-convert. When set, it's value is used as the conversion table.
Retrieve and parse current values from the bank and set currency-converter-table.
Chinese yuan renminbi
Hong Kong dollar
South Korean won
New Zealand dollar
New Romanian leu
New Turkish lira
South African rand
(currency-convert 'USD 'EUR 45.34) => "32.03" (currency-convert 'USD 'EUR 45.34 #:format? #f) => 32.3003490774382 (currency-convert 'USD 'EUR 45.34 #:table '((EUR . 1)(USD . 34))) => "1.33"
Copyright 2007 Jean-Philippe Theberge
This program is free software: you can redistribute it and/or modify it under the terms of the GNU 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 the GNU General Public License for more details.
A full copy of the GPL license can be found at http://www.gnu.org/licenses/.