From: Caleb Clausen <vikkous@...>
Date: 2010-05-30T20:14:15+09:00
Subject: Re: Inject Loop Syntax

On 5/29/10, Intransition <transfire@gmail.com> wrote:
> I wonder if any other languages have any sort of "multiplicative
> operation" operator. I was thinking about this today b/c sometimes one
> has to use a block where it would read better if it could be avoided.
> For example:
>
>   [:a, :b, :c].each do |x|
>     define_method("#{x}?") do
>       instance_variable_get("@#{x}")
>     end
>   end
>
> I completely made this up off the top of my head, so ignore what it
> actually does. The point is rather it would be cool if the loop could
> described without encasing the code, something like:
>
>   define_method("#{x}?") do <-(x)[:a, :b, :c]
>     instance_variable_get("@#{x}")
>   end

Maybe you want something like python's array comprehensions? This is
one of the few areas where python really shines in comparison to ruby.

  define_method("#{x}?")
    instance_variable_get("@#{x}")
  end for x in [:a, :b, :c]

The problem I see with this is that x is a local variable, but that
fact won't be apparent to the parser/lexer until it gets to the end of
the expression and sees the for keyword. Not sure how that could be
solved in a way that's at all elegant.