From: Jean-Hugues ROBERT <jean_hugues_robert@...>
Date: 2004-05-03T20:23:39+09:00
Subject: Re: The code I forgot to include

Hi,

Thanks to reading your code I learned that new syntax to create an array:
x = Array[1,2,3].
So far I used to do:
x = [1,2,3]

But using Array.[]() is cool if I want to create a subclass of Array.

So I tried:
class MyArray < Array
   def self.[](*a); super[*a] end
end
x = MyArray[1,2,3] # => NoMethodError: super: no superclass method '[]'

I don't understand what is happening because obviously Array.[]()
exists. In fact it is the only class method defined by Array:
Array.methods( false)   # nota: false to avoid inherited methods, not in my 
Pickaxe
MyArray.methods( false) # => ["[]"] in both cases.

BTW: In your code you redefine [](a), the instance method, whereas in mine
I redefined self.[](*), the class method. I don't think that [](a) gets
called at all in your example, only your to_s() is called.

???

Yours,

Jean-Hugues

At 02:58 03/05/2004 +0900, you wrote:
># My idea of how to convert an array of strings to a string with a specified
>delimiter
>class MyArrayType1 < Array
>     def [](a)
>         puts "Entering MyArrayType1#[](a) -- calling parent"
>         super a
>     end
>     def to_s
>         s = ""
>         self.each { |x|
>             s += ";  " if s.length>0
>             s += x.to_s
>         }
>         s
>     end
>end
>
>myA1 = MyArrayType1['x1', 'y1'] # uses the Array#[](a) method with an Array
>argument and sets
>                                 # myA1 to a reference to a new object of
>type MyArrayType1
>                                 # which is an Array of two strings,  'x1'
>and 'y1'
>                                 # with an over-ridden 'to_s' method
>puts "myA1 = MyArrayType1['x1', 'y1'];  puts myA1.to_s ==> " + myA1.to_s #
>==>   x1;  y1
>
>
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