Defining an object constructor that look like [] or {} ...?

ruby-talk
1

Hey Guys,

Ruby has built in object constuctors for Array and Hash via [] and {}..
ie:

an_array = [1, 2, 3, 6]
a_hash = {1=>3, 2=>5, 'a'=>'green'}

I would like to do the same for one of my classes.. i.e.

my_object = |2, 3, 5, 7|

should yield the same result as if I had done the following:

my_object = MyClass.new([2, 3, 5, 7])

Is this possible?

Sonny.

···

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2

my_object = MyClass.new([2, 3, 5, 7])

You should be able to use

as class method:

    my_object = MyClass[2, 3, 5, 7]

a method in Kernel or similar:

    my_object = MyClass(2, 3, 5, 7)

tom.

3

Hey Guys,

Ruby has built in object constuctors for Array and Hash via and {}..
ie:

an_array = [1, 2, 3, 6]
a_hash = {1=>3, 2=>5, 'a'=>'green'}

I would like to do the same for one of my classes.. i.e.

my_object = |2, 3, 5, 7|

should yield the same result as if I had done the following:

my_object = MyClass.new([2, 3, 5, 7])

Is this possible?

Offhand, I doubt you can use || for this task, but you can use .

     class MyClass
       def MyClass.(*arr)
         MyClass.new(arr)
       end

       def initialize(arr)
         @arr = arr
       end
     end

     > x = MyClass[2, 3, 5, 7]
     => #<MyClass:0x7a3b4 @arr=[2, 3, 5, 7]>

···

On Jan 16, 2009, at 1:15 PM, Sonny Chee wrote:

4

No, because you would have to change Ruby's syntax. See the other postings for alternatives.

Kind regards

  robert

···

On 16.01.2009 20:15, Sonny Chee wrote:

Ruby has built in object constuctors for Array and Hash via and {}..
ie:

an_array = [1, 2, 3, 6]
a_hash = {1=>3, 2=>5, 'a'=>'green'}

I would like to do the same for one of my classes.. i.e.

my_object = |2, 3, 5, 7|

should yield the same result as if I had done the following:

my_object = MyClass.new([2, 3, 5, 7])

Is this possible?

--
remember.guy do |as, often| as.you_can - without end

5

A method in Array :

class Array
  def to_my_class
    MyClass.new(self)
  end
end

my_object = [2, 3, 5, 7].to_my_class

Fred

···

Le 16 janvier 2009 à 20:26, Tom Link a écrit :

my_object = MyClass.new([2, 3, 5, 7])

You should be able to use

as class method:

    my_object = MyClass[2, 3, 5, 7]

a method in Kernel or similar:

    my_object = MyClass(2, 3, 5, 7)

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