From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2002-11-23T03:58:35+09:00
Subject: Re: Allow *array expansion anywhere in list

In article <20021122163518.GA9460@pelikan>,
Carlos  <angus@quovadis.com.ar> wrote:
>> |The findings of fact (well, OK, my opinion) are these:
>> |
>> |*array is only allowed at the end of arrays because it's implemented
>as a hack.
>> 
>> This is a false assumption.  The reason is it's not encouraged.  If
>> you need array expansion in the middle of arguments, there must be
>> something wrong, perhaps in method argument design.
>
>Yes, but sometimes you don't design the method, and expansion is useful to
>encapsulate arguments. For example, this is what I tried to do some weeks
>ago, and seemed very natural:
>
>==
>class Point
>	attr_accessor :x, :y
>
>	def initialize x=0,y=0
>		@x=x; @y=y
>	end
>
>	def to_a
>		[@x, @y]
>	end
>end
>
>p1=Point.new(5,4)
>p2=Point.new(10,10)
>
># now I have a 'line' method, from an external library, defined as:
># def line x1, y1, x2, y2, attrs
>
>line(*p1, *p2, attrs)  # parse error
>==
>
>Isn't this more clear and natural and mantainable and easy than
>
>line(p1.x, p1.y, p2.x, p2.y, attrs)
>
>?

Ummmm... I'd have to answer no.

Is the external library written in Ruby?  If so, then it would be better 
to do add another method:

line_from_points(p1,p2,attrs)

Phil