From: Damjan Rems <d_rems@...>
Date: 2008-03-04T07:11:22+09:00
Subject: Re: Why is this not implemented in Ruby

Jason Roelofs wrote:
> Show me a language that does allow you to do this, I've never seen it.
> Even then, Ruby doesn't deal with method overloads via parameter
> lists, so there's a fundamental reason why it won't work:
Clipper,Alaska xBase++. Omitted parameter is treated as nil. They can be 
tested as nil on the called site. If the value is nil some default value 
is set.

> 
> def foo(a)
> end
> 
> def foo(a, b)
> end
> 
> def foo(a, b, c)
> end
> 
> foo(1) # => ArgumentError: wrong number of arguments (1 for 3)
This is absolutly correct. All these parameters are required. But if I 
write
def foo(a,b=2,c=3)
end
First parameter is requested others are optional. It would be nice if I 
could call foo(1,,4). b would have got default value of 2.

> 
> 
> Ruby 1.9 has keyword arguments, so you'll be able to get past that
> easily then. You can fake it in 1.8 with a hash:
> 
> def aProc(options = {})
>   a = options[:a] || 5
>   b = options[:b] || 6
>   c = options[:c] || 7
>   print a, b, c
> end

I know this and hashes are great. Problem is of course libraries that 
are not written by me.

For example. I am using FPDF library which has method Cell.
Cell(w,h=0,txt='',border=0,ln=0,align='',fill=0,link='')

I would like to align to right and I don't care about border or ln 
parameter.
Cell(1,,'100.000,00',,,'R') would be my preferred solution.

And I know FPDF is ugly written library. But it supports using Eastern 
European characters unlike some other libraries.

by
TheR
-- 
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