From: Ed Howland <ed.howland@...>
Date: 2010-04-26T05:47:17+09:00
Subject: Re: Metaprogramming - Array initialization

Had a small issue w/1.9.1.

Here is mine (inspired by Vicente's code):

def multi_array(*input)
  instabce_eval input.map {|i| "Array.new(#{i}"}.join(",") + ')' * input.length
end

Definitely a cool way to make arrays.



Cheers,
Ed

Ed Howland
http://greenprogrammer.wordpress.com
http://twitter.com/ed_howland



On Sun, Apr 25, 2010 at 2:08 PM, Vicente Bosch <vbosch@gmail.com> wrote:
> Hi Joel,
>
> You could construct the string that represents the command that would
> generate the multidimensional array creation and lauch it with
> instance_eval.
>
> def make_array(input)
>
> result = ""
>
> for i in input
>     result = result + "Array.new(#{i},"
> end
>
> for i in input
>     result = result + ")"
> end
>
> instance_eval(result)
>
> end
>
> The code is not very bright (and also a lot of checks on the input values
> should be made before executing instance eval) but I hope you get an idea.
>
> Regards,
> Vicente
>
> On 24 April 2010 23:13, Paul A. <cyril.staff@gmail.com> wrote:
>
>> Hi,
>>
>> In Ruby, we can declare array as explain in the doc:
>> http://ruby-doc.org/core/classes/Array.html#M002150
>>
>> That makes possible many kind of use, such as:
>> >> Array.new(1, Array.new(3, Array.new(2, Array.new(1))))
>> => [[[[nil], [nil]], [[nil], [nil]], [[nil], [nil]]]]
>>
>> For my needs, I would like to use a code that declare an array of any
>> arrays that we want. I don't know if it is possible.
>>
>> If the previous example can be generated using a function like:
>> my_array = make_array(1, 3, 2, 1)
>>
>> ...this could be awesome!
>>
>> Thank you for any comments and help.
>>
>> Regards.
>>  --
>> Posted via http://www.ruby-forum.com/.
>>
>>
>