From: ssmoot@...
Date: 2005-09-20T06:06:39+09:00
Subject: Re: Units for Ruby

Small caching problem:

The xmethods.net method seems to provide realtime data. Which is cool,
but the data is being cached by symbol names, so:

10.usd.to_yen returns 10*x

and 10.usd.to_jpy returns 10*y

Even though they should technically return the same value.

I doubt it'd affect anyone's actual code since you're likely to use one
or the other, not both, but still... modifying the code to use country
names instead looks like this:

  def lookup_currency(from, to)
  	from = @@currency_countries[from]
  	to = @@currency_countries[to]
    cache_key = :"#{from}_to_#{to}"
    @@currency_rates[cache_key] ||= @@currency_converter.getRate(from,
to)
    return @@currency_rates[cache_key]
  end

Problem solved.

Thanks for the code btw. :)