How to Combo

[trans]

Easiest implementation of "some_method" in Ruby?

     a = %w|a b|

     b = %w|a x|

     c = %w|x y|

  some_method(a,b,c)

  #=>

   [ ["a", "a", "x"]

     ["a", "a", "y"]

     ["a", "x", "x"]

     ["a", "x", "y"]

     ["b", "a", "x"]

     ["b", "a", "y"]

     ["b", "x", "x"]

     ["b", "x", "y"] ]

  

Order doesn't really matter.

[Harry Kakueki]

On Sun, Dec 25, 2011 at 10:27 PM, Intransition <[hidden email]> wrote:

> Easiest implementation of "some_method" in Ruby?
>
>      a = %w|a b|
>      b = %w|a x|
>      c = %w|x y|
>
>   some_method(a,b,c)
>
>   #=>
>
>    [ ["a", "a", "x"]
>      ["a", "a", "y"]
>      ["a", "x", "x"]
>      ["a", "x", "y"]
>      ["b", "a", "x"]
>      ["b", "a", "y"]
>      ["b", "x", "x"]
>      ["b", "x", "y"] ]
>
> Order doesn't really matter.
>

This seems to do it.
I don't have time now to try something better.

Hope it helps.

def some_method(a,b,c)
  [].tap{|w| a.each{|x| b.each{|y| c.each{|z| w << [x,y,z]}}}}
end


Harry

[Bartosz Dziewoński]

def some_method(a,b,c)
  a.product(b, c)
end

I think it only works on 1.9.

-- Matma Rex

[trans]

Ah, that's what I had over looked... the product! 

Thank you.

[Brian Candler]

Thomas Sawyer wrote in post #1038150:

> Easiest implementation of "some_method" in Ruby?
>
>      a = %w|a b|
>      b = %w|a x|
>      c = %w|x y|
>
>   some_method(a,b,c)
>
>   #=>
>
>    [ ["a", "a", "x"]
>      ["a", "a", "y"]
>      ["a", "x", "x"]
>      ["a", "x", "y"]
>      ["b", "a", "x"]
>      ["b", "a", "y"]
>      ["b", "x", "x"]
>      ["b", "x", "y"] ]
>
> Order doesn't really matter.

Does some_method only accept exactly three arguments?
Is each argument an array of exactly two elements?

--
Posted via http://www.ruby-forum.com/.

[trans]

On Monday, December 26, 2011 4:36:26 AM UTC-5, Brian Candler wrote:

Does some_method only accept exactly three arguments?
Is each argument an array of exactly two elements?

Yes, Good questions. I should have made it clear this was an arbitrary example and any number of arguments, each with any number of elements ought to work too.

Thankfully, the simple solution, which I was pretty sure was there but couldn't recall, was presented: Ruby has Array#product.