From: Tom Sawyer <transami@...>
Date: 2003-01-08T03:08:06+09:00
Subject: Re: attr_cast, one a small step for interface techniques

On Tuesday 07 January 2003 10:39 am, Austin Ziegler wrote:
> Actually, I don't think I would ever want a reader that casts.
>
> -a

attr_reader :avar still works the same. no casting. having the option though  
helps with automatic typing of "internally" assigned instance variables when 
read out "externally":

attr_reader :c => :to_f

@a = 1
@b = 2
@c = @a + @b

puts @c.type --> Fixnum
puts c.type  #--> Float

thus if an attribute is to be accessable externally as a particular type, in 
this case a Float, this insures that it will be so even if you are 
manipulating the instance variable internally. its not static typing, but it 
dose nudge things in that direction when useful. 

of course, then there's the odder things you can do:

attr_writer :a => to_f
attr_reader :a => to_s

:-}

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


                                   .''.
       .''.      .        *''*    :_\/_:     .
      :_\/_:   _\(/_  .:.*_\/_*   : /\ :  .'.:.'.
  .''.: /\ :   ./)\   ':'* /\ * :  '..'.  -=:o:=-
 :_\/_:'.:::.  | ' *''*    * '.\'/.' _\(/_'.':'.'
 : /\ : :::::  =  *_\/_*     -= o =-  /)\    '  *
  '..'  ':::' === * /\ *     .'/.\'.   '._____
      *        |   *..*         :       |.   |' .---"|
        *      |     _           .--'|  ||   | _|    |
        *      |  .-'|       __  |   |  |    ||      |
     .-----.   |  |' |  ||  |  | |   |  |    ||      |
 ___'       ' /"\ |  '-."".    '-'   '-.'    '`      |_.
------------------------------------------------------------