From: Austin Ziegler <austin@...>
Date: 2004-01-01T04:29:37+09:00
Subject: Re: Overriding to_s

You probably don't want to override #to_s to take a parameter.

I recommend looking at http://rubyforge.org/projects/extensions/;
specifically #format_s as defined in
extensions/lib/extensions/numeric.rb.

I have submitted a replacement for
extensions/lib/extensions/numeric.rb that handles (simple
before/after) currency formatting. If anything more complex is
necessary, please let me know and I'll look into it.

There are three possible further extensions to this method from my
perspective. First, this method does not ensure precision, but
instead formats exactly what is given. The :usd style provided will
format 1234.1234 as $1,234.1234. If you only want $1,234.12, it is
up to you to ensure that only the proper number of decimal places is
provided. It may be useful to provide for precision (both decimal
and general).

Second, it may be desirable to show the "+" sign in some instances.
This is not yet possible.

Finally, it may be desirable to have a parallel method, #format_a,
that returns the formatted constituent parts of the number as an
array [sign, integer-part, decimal-point, decimal-part] so that you
can format them as you wish. The simplest formatting of #format_a
would be #join, but you could do: ($1.20) instead of $(1.20). (The
currency formatting takes place after all other formatting.)
(Alternatively, one could specify a template, but that is overkill
in my opinion.)

-austin
--
austin ziegler    * austin@halostatue.ca * Toronto, ON, Canada
software designer * pragmatic programmer * 2003.12.31
                                         * 12.22.28