From: ts <decoux@...>
Date: 2003-12-31T23:50:04+09:00
Subject: Re: Overriding to_s

>>>>> "B" == Brad  <BCoish@Dymaxion.com> writes:

B> Is there a way to override the to_s method such that it takes a
B> parameter?  For example, if I wanted to provide a format specifier 
B> for a number:

 well, you have several problems

B>     class Numeric

 #to_s is defined in Integer, Float, Bignum, ... not in Numeric

 If you define it in Numeric, ruby will use the old definition in 
 Integer, ...

B>         def to_s(optFormat)

 you are saying that #to_s must have a parameter, this mean that you can't 
 call it 12.to_s

 Perhaps best to write it

           def to_s(optFormat = nil)

 now Integer#to_s can take an optional argument, this mean that your new
 method #to_s is not really adapted for Integer (except if format_number
 take this in count)

B>             if !optFormat.nil?
B>                 # format a string based on the optFormat format  
B>                 # specifier.
B>                 retVal = format_number(self,optFormat)
B>             else
B>                 retVal = self.to_s

 here, you call recursively #to_s.

 Perhaps best to alias #to_s before redefining it, and call the alias

B>             end
B>             retVal
B>         end
B>     end


Guy Decoux