From: Tom Sawyer <transami@...>
Date: 2003-02-15T07:01:21+09:00
Subject: Re: Lexical scope and closures

On Friday 14 February 2003 12:20 am, Tom Sawyer wrote:
> On Thursday 13 February 2003 08:03 pm, Yukihiro Matsumoto wrote:

> >   arr.each {|i|
> >     let a = ..
> >     let b = ..
> >     c = ..
> >     ...
> >   }

i'm concerned about using 'let' as it would not be clear why we wouldn't use 
it across the board. why would blocks be special? for example:

>   class A
>     def inititalize
>       c = "instead of @c"
>       let a = "instead of just a"
>     end
>   end

so, i'd be more comfortable specifying locals as one does with private, 
public, etc.:

  arr.each { |i|
    local :a, :b
    a = ..
    b = ..
    ...
  }

***

on another note:

this matter has become tricky to deal with because of the way in which ruby 
deals with scoping instance variables, vs. instance methods, vs. local 
variables, etc. point blank: it is not symmetrical. i wish it could be made 
so, but that would of course break code. :-( 

just the same i'll put the idea out here:

  class A
    def initialize
      # local variables
      initialize.a ="instead of just a"
      %b = "as sugar for above (used in blocks)"      
      # instance variables
      self.c = "instead of @c"
      d = "as above but where self is implied"
      # class variables
      A.e = "instead of @@e"
      @f = "this then could be class variable sugar"
      # globals
      toplevel.g = "or global.g"
      $h = "global sugar"
    end
  end


-- 
tom sawyer, aka transami
transami@transami.net